Futuristic Physicists?


One day, sitting around with a group of undergraduate physics students, I listened as one made the bold statement: “If it can be imagined, it can be done.” The others nodded in agreement. It sounded like wisdom. It took me all of two seconds to violate this dictum as I imagined myself jumping straight up to the Moon. I may have asked if the student really thought what he said was true, but resisted the impulse to turn it into an impromptu teaching moment. Instead, I wondered how pervasive this attitude was among physics students and faculty. So I put together a survey and in this post report what I found. The overriding theme: experts say don’t count on a Star Trek future. Ever.

The Survey

First, we’ll take a look at the questions in the survey. If you want to try it for yourself before being tainted with results, I have set up a separate survey at SurveyMonkey that you are welcome to try. If you’re reading this post on Do the Math (the original source), please identify yourself as a Do the Math reader when you fill out the survey here.

Let me clarify that I do not design surveys for a living, and may have made some rookie mistakes. But hey: this is just for my own enlightenment, and to the extent that others learn from the experience: great.

Here is the introductory text that survey takers saw:

Each question has the same set of options for answers, corresponding to timescales in which you might imagine humans likely accomplish some feat. By “likely”, I mean better than 50% probability, in your mind. The “eventually” qualifier might fold in your projection on the lifespan of humans or their direct evolutionary descendants.


I am most interested in functional aspects of the phenomenon, rather than clever technicalities that many of us might proffer. For instance, teleportation may have been “shown” in quantum optics experiments, but teleporting a human from San Diego to Boston stands apart from this lab trick.

For each question, choices are (and the numbers will play a role):

  1. No Opinion
  2. likely within 50 years
  3. likely within 500 years
  4. likely within 5000 years
  5. likely to happen for humans eventually
  6. unlikely to happen for humans
  7. < 1% likely to ever happen, or impossible

Note that answers 5 and 6 qualify as pessimistic: probably not ever. Answer 4 is a non-committal “probably.” It is easy to remember answers 1, 2, and 3 as a sort of scientific notation: 5×10x years.

Okay; here is the set of twenty questions:

What do you think is the likelihood that humans can:

  1. Have widespread personal transport that can replace the task of driving with a fully-automated piloting system (auto-pilot)?
  2. See jet-packs as practical transportation devices on a daily basis?
  3. Carry out the bulk of transportation in personal flying machines, rather than being tied to the ground in cars (what are wheels, daddy?)?
  4. Routinely teleport live human bodies respectable distances—enough to revolutionize the way we travel?
  5. Come up with a means of interstellar travel that allows round-trips to locales tens of light-years away within years or decades, without having Earth (and its people) age substantially more than the traveler—thus operating outside the normal confines imposed by sub-luminal travel and special relativity (the equivalent of warp drive in Star Trek)?
  6. Use wormholes as tools to move across vast distances?
  7. Visit the vicinity of a black hole to study it up-close?
  8. Do astrophysics by traveling to sources (outside our solar system) rather than via telescopes?
  9. Be able to create local gravity (not just magnetic boots) in a spaceship by some means other than kinematically (e.g., rotation or acceleration of spacecraft)?
  10. Have a permanent colony on the Moon, where some might live their entire (normal-length) lives?
  11. Have a permanent colony on Mars, also with whole lives spent there?
  12. Terra-form a planet (like Mars) to make it human-habitable?
  13. Power our society with fusion, opening up practically inexhaustible supplies of deuterium on the planet (forget about tritium here—imagine D–D reactions)?
  14. Create our food without growing or raising it—like the Star Trek method of “replicating” food by patterning atoms/molecules appropriately, maybe straight from the source of energy?
  15. Have robots as common entities among us that can intelligently converse with us and perform sophisticated tasks (housework, transport repair, nanny for the kids)? I’m talking about C-3PO, nothing like today’s machines.
  16. Have cloaking devices that, at the flip of a switch, can render a macroscopic device like a car, plane, or spaceship impossible—or exceedingly difficult—to see from virtually any angle?
  17. Be able to travel back in time by an amount significant enough to change actions?
  18. Communicate with intelligent alien species (extra-terrestrial), sharing technology, history, etc.?
  19. Either physically visit or be visited by an intelligent alien species?
  20. Substantially eliminate disease and block aging so that we may routinely see lives exceeding 200 years?

Who’s the Expert?

I will be using the term “expert” to distinguish the level of knowledge/experience within the physics discipline. But don’t take the term too literally. There is no such thing as an expert on warp drive or teleportation—outside of geeky fan clubs, where one might find full blueprints of imaginary spaceships. But if you sought an opinion on the possibility or likelihood of these futuristic ideas having a chance of being realized (and on what timescale), what sort of expert might you seek?

Does somebody on your street or in your building know? Ask your neighbors and find out how relevant their knowledge base is to address these questions with any credibility. Somebody working in your community’s retail services might know something. No? The big-shots at big banks? Somebody in the government? Probably the NASA folks who aren’t busy actually doing a job in the here and now would have interesting insights. But in general, I think it is natural to seek the opinion of academics with a handle on fundamental limitations and possibilities. Academic researchers are among the only group whose job description is to explore the unknown and open new frontiers. These are the dreamers of the future, and the ones with the rigorous training to sort out the possible from fantasy.

And which academic department would you visit to query about teleportation, artificial gravity, or nuclear fusion? Theater? History? Psychology? Medicine? Chemistry? Physics? Yeah—that last one. So even though the questions are somewhat diverse and out of left field, let’s conclude that academic physicists at top research universities are as qualified a pool of experts as we’re likely to find for these topics.

I invited physics faculty at a handful of top-20 schools across the U.S. (using graduate program rankings from the US News and World Report) to participate in the anonymous survey. I promised that neither they nor their institutions would be revealed. I also invited physics graduate students and physics undergraduates to contribute, so that I could track attitudes as a function of age, expertise, or selected path in life.

Graphical Results

We’ll pick apart the results in a variety of ways. First, let’s get a look at all the questions in turn.

The answers are broken out in groups of three, with titles (and question numbers) relating to the above list. Each graphic has nine panels: three questions across, and three response groups down. This arrangement makes it easier to compare left-right shifts among the three populations surveyed. Each panel contains four numbers at left: median, mean, standard deviation, and percent pessimistic (answers 5 or 6). The first three statistics do not include the few “no opinion” answers, when they exist. The median and mean values are also marked on the distribution as dashed and dotted lines, respectively.

One note on the standard deviation: with only 6 numerical options (ignoring no opinion = 0), a completely uniform distribution (same number of responses for each answer) would score a standard deviation of 1.7. The most extreme possible standard deviation is 2.5, which would happen if responses were equally divided between the most extreme answers in a pathological bimodality.

So let’s dive in with the first three. I’ll offer some comments after each group. Then we’ll look at some aggregate characterizations and reflections.

Looking at the left-hand column, the grad students have a pretty strong consensus (low standard deviation) that autopilot cars will soon be commonplace. The median for all three groups says we might expect widespread autopilot cars within 50 years. Undergrads and faculty scored virtually the same mean, around 1.5. Loosely speaking, we could turn this into an expectation around 150 years using our 5×10x rule of thumb for numbers in the 1–3 range. No grads register as pessimistic on this count, and only 2% of undergrads and 4% of faculty think that autopilot cars are unlikely to ever happen. The results offer an important indication that the respondents are capable of rendering optimistic answers on futuristic ideas (i.e., ideas not implemented anywhere in the world now). It goes downhill from here.

I like the jetpack question, because jetpacks have come to symbolize angst in my generation for toys we were promised as kids that never materialized. On the whole, all three groups tilt pessimistic on jetpacks ever being a practical mode of transportation. The scores are pretty consistent across the board, with a median of 5 (likely never happen), a mean around 4.0, and identical standard deviations. Substantial bimodality appears in the undergrads, with the mode (tallest spike) actually putting jetpacks inside of 500 years. That same answer and bimodal tendency shows up in more expert opinions as well—just not as strongly.

Personal flying cars fare better than jetpacks, but a huge difference shows up in the pessimism score. Professors don’t buy it, on the whole (albeit with a bimodal split). The median response goes from 500 years among students to “probably never” among faculty. Our first dramatic difference. As a faculty member who is also a licensed pilot, I can say that flying is a gigantic departure from driving. Unleash the population into 3D space and watch the mayhem! (I would suggest erecting a strong shield over your house.)

Beam me up! Traveling to the other side of the world takes a whole day and is such a hassle! (Just wait until fossil fuels are scarce and see what you think then.) If we could just teleport ourselves as coded energy streams (or whatever) we’d finally be liberated—unless it turned out to cost $10 million a pop… What do physicists think? We see the usual gradient, with 85% of professors saying it’s not likely to ever happen (the bulk labeling it as impossible). The median marches from 4 to 6 among the three groups. The grad distribution resembles the faculty distribution, but the undergrad distribution is much more nearly uniform.

So what about faster-than-light interstellar travel (warp)? This looks pretty similar to teleportation, with a slightly higher fraction (91%) of faculty saying it’s essentially impossible. Student opinions are regressively softer.

When it comes to using wormholes to get around, majority opinion counts this as unlikely to ever happen. It’s almost a lock among faculty, except for one individual who thinks we’ll be doing this inside of 500 years! This same outlier registered identical answers for the previous two questions. We’ll see more of him/her later.

Will we ever be able to send a probe to visit a black hole and study it up close? Three-quarters of faculty say not likely. Grads are also skeptical on balance, but undergrads have a loud “someday” response. Note the steady march of median, mean, percent pessimistic, and tightening of standard deviation as we increase expertise. This pattern asserts itself often (e.g., the previous three questions as well), and we’ll call it the expert gradient.

This question is similar to the last, but expanded to cover any astrophysical object of interest outside our solar system (another star, nebula, cluster, pulsar, etc.). Not a single undergrad wants to claim this is <1% likely, and only 10% say it is unlikely to ever happen. Meanwhile, 62% of faculty members say don’t count on it ever happening. A small spike of physics professors think 500 years is reasonable. I’m betting against these folks being astro-familiar faculty, actually. Aside from the evolution of the standard deviation, the trends follow the expert gradient.

Switching gears a bit, if we do manage space travel beyond the Earth environs (obviously not guaranteed), will we be able to walk about in a simulated gravity environment by some means other than rotating or accelerating the spacecraft? I don’t count the cheap trick of magnetic boots either, which still leave your body weightless. I’m thinking the Star Trek non-gyrating ship with gravity pointing perfectly downward on all decks, ubiquitous crawl tubes, etc. We see the normal expert gradient on strong display. The undergrads are surprisingly bullish, many expecting results in 500 years. By contrast, the grad and faculty distributions share a similar character.

What about living a life off the Earth, in a lunar colony? The mode in all three says within 500 years, while the mean says somewhat longer. at least 80% of folks in each group think this will happen some day, although very few expect it to happen inside of 50 years. Pause for a second to reflect on the fact that 50 years after the space race began, we think it will be at least another 50 before we’re living on the Moon. I’m guessing this is a radical change in attitude compared to prevailing views in the 1960’s. An interesting departure from the expert gradient shows up here: undergrads are more skeptical than grads. This reversal may be due to the termination of the U.S. human spaceflight program during a stage in life (late high school, early college) when world views are forming and fluid. Perhaps this group has been more impacted by the shutdown than grad students whose noses are buried in research.

A somewhat similar pattern shows up on the subject of a colony on Mars. A comparable number think it will happen someday, and the undergrads are again a little more circumspect than grads. The mode shifts a bit, too. For the lunar colony, <500 years was a standout modal preference. It’s much less clear for Mars, becoming especially broad for faculty.

Speaking of living on Mars, what do physicists think about the likelihood of terraforming a planet like Mars? We get the expert gradient back, although no group trips over to a pessimistic balance. Let me just say that we have not identified a viable way to fix a 100 part-per-million CO2 problem in our own atmosphere, with all the resources of Earth available to us. Transforming another planet’s atmosphere is a one-million parts-per-million problem with virtually no available industrial resources at hand. What I’m telling you is that I’m in the skeptical camp.

Coming closer to a Do the Math topic, what is the physicists’ view of nuclear fusion? It is often jokingly said to be perpetually 50 years in the future. Did 50 years win? No! The mean, median, and mode all roughly pick out the <500 year choice: most strongly so among professors. Virtually no one said it was unlikely to ever be realized, but comparably few expect fusion to be a viable solution on the scale of decades—which I note is the relevant timescale for the great energy challenge as we seek to transition away from finite fossil fuels.

How about feeding the world with synthesized food akin to the replicated food in Star Trek? Sort of a 3-d printer for food. The expert gradient re-emerges for this one, save the standard deviation. The faculty are on the fence on the pessimism score, perched at 50%. Not much buy-in for the 50 year timeframe, when population pressures, agricultural limits, and climate-change-induced crop failure may collide to produce food shortages.

Robots, anyone? Maybe androids would be a more apt term: an intelligent “being” with whom we could converse and count on to do complex, adaptive tasks that humans today perform. A strong vote emerges for <500 years, although interestingly the undergrads are the most wary of the lot. Perhaps robots are the new jetpack: a target of angst for still being so lame.

We hit some turbulence over cloaking devices, which I find surprising. The faculty response, in particular, shows a strong bimodality, reflected also in the large standard deviation. The mode for all three says <500 years, although a 33% pessimism score among the faculty drag their median to 4 (“someday”). For me, it’s the “from virtually any angle” that’s the killer. Devices have been built that divert microwave “light” around a small object in only one direction, employing a bulky apparatus much larger then the hidden object itself to accomplish. It’s no good cloaking if the cloaking device itself is an even larger target that itself is not cloaked. A shrub moving across the lawn raises suspicion even if the motive force cannot be clearly seen. But whatever. The respondents have a soft spot that I don’t share. I’ll get back to reporting the actual responses, rather than what I think they should have said.

When it comes to time travel, it appears we all got the memo. Not gonna do it. All three groups have the mean, median, and mode pointing to “impossible.”

What about opening a line of communication with aliens. And I don’t mean dolphins. Means and medians are pretty uniform in saying “someday,” but hardly anyone appears to expect it to happen in their own lifetimes. Grads and faculty register similar levels of pessimism about it ever happening at all, but neither crossing the 50% mark.

What about an actual close encounter with an alien? First piece of advice: don’t accept any blankets. This looks like a virtual copy of the previous response about alien communications. The grad response is so similar that it’s hard to confirm any differences at all. Curiously, the undergrad mean says it’s more likely we’ll shake hands than be pen-pals: suggesting an unannounced visit. The faculty barely tip into the “unlikely ever” category on balance, with 52% expressing this sentiment.

Finally, what can we expect in terms of aging? Will we solve the problem and extend life to 200 years or more? Almost no one says “impossible.” Students are nearly identical in outlook, expecting this to be common within 500 years, but not in time for them personally. Faculty think it will be much longer than this, but 84% think it will ultimately happen. It is worth pointing out that this question is perhaps less in the domain of physics than most of the other questions.

Group Attitudes

Group-wise, a somewhat predictable trend emerges—reflected by the “expert gradient” seen in many of the individual answers.

The median answer goes from 3.4 to 3.7 to 4.0 for undergrads through faculty: a steady progression toward more guarded outlooks. Meanwhile, we see a less steady progression of the mean—more clearly separating faculty from students—but still conveying the same overall story. Note the optimistic outlier in the faculty ranks. We saw this individual stand out on the wormhole question. Examining this person’s responses, it’s all 1, 2, and 3 responses, save one 4 for time travel. Nothing is off limits to this professor, and most things deserve a timescale. This individual is clearly out of step with the cohort, and tying the most optimistic undergrad: forever young.

Expert Gradient and Biggest Dissimilarities

Most questions show the “expert trend,” wherein the median, mean, and percent pessimistic increase with level, often accompanied by decreasing standard deviation.

Notable exceptions are the autopilot, flying cars, lunar and Martian colonies, fusion, and robots. Also, the roving astrophysics, synthetic food, and cloaking show most of the characteristics of the expert gradient, while the standard deviation increases with level of expertise.

The biggest differences between faculty and grad students crop up on questions pertaining to flying cars, cloaking, and studying astrophysical objects up close. The largest graduate-undergraduate discrepancy appears for the question about artificial gravity. The largest end-to-end discrepancies (faculty to undergraduate) relate to flying cars, artificial gravity, and warp drive.

Meanwhile the jetpack and time travel questions have the most similar statistics.

Expert Opinion, Summarized

The table below is organized in rank order according to median opinion among physics faculty members. Within each group sharing the same median, the mean is used as the sorting metric. Columns are given for the mean and percentage of pessimistic responses, followed by a verbal characterization of what the median expert says in response to the question. In cases where the mean is between 1–3, a timescale conversion is offered for the mean opinion.

Topic Mean % pessim. median disposition
1. Autopilot Cars 1.4 (125 yr) 4 likely within 50 years
15. Real Robots 2.2 (800 yr) 10 likely within 500 years
13. Fusion Power 2.4 (1300 yr) 8 likely within 500 years
10. Lunar Colony 3.2 18 likely within 5000 years
16. Cloaking Devices 3.5 32 likely within 5000 years
20. 200 Year Lifetime 3.3 16 maybe within 5000 years
11. Martian Colony 3.4 22 probably eventually (>5000 yr)
12. Terraforming 4.1 40 probably eventually (> 5000 yr)
18. Alien Dialog 4.2 42 probably eventually (> 5000 yr)
19. Alien Visit 4.3 50 on the fence
2. Jetpack 4.1 64 unlikely ever
14. Synthesized Food 4.2 52 unlikely ever
8. Roving Astrophysics 4.6 64 unlikely ever
3. Flying “Cars” 3.9 60 unlikely ever
7. Visit Black Hole 5.1 74 forget about it
9. Artificial Gravity 5.3 84 forget about it
4. Teleportation 5.3 85 forget about it
5. Warp Drive 5.5 92 forget about it
6. Wormhole Travel 5.5 96 forget about it
17. Time Travel 5.7 92 forget about it

Note that ten out of twenty are in the trash bin, with an eleventh precariously perched on the rim. Meanwhile grad students put 7 ideas in the trash, and undergrads only managed to get two fully in the can, a third hung on the rim. Thus 3, 7, and 11 ideas are essentially written off in a steady progression of pessimism with level of experience.

Optimistically, one might say that we just need to wait until the young can-do generation moves into the upper ranks and then we’ll get our teleportation: kick the old fogies out. Keep this thought train going, and if we just wait for current 5-year olds to come into power, we can look forward to living in giant sand castles on the Sun (where it is never bedtime), eating ice cream for every meal, surrounded by talking animals. We only have to wait a generation or two!

But just as kittens turn into cats, starry-eyed youths get a dose of reality when they try to actually do things in life.

The other noteworthy characteristic of the table above is that only one idea out of 20 is deemed likely to happen in the next 50 years. Only two ideas make the 500 year cut, and two or three more within 5000 years. I think this is an astounding result. After all, physicists are people too, and subject to the same psychological tendencies to extrapolate as the rest of the population.

The rate of progress in the last few hundred years has felt like an exponential headlong rush into an ever-more-brilliant future. But the practitioners of physics appear not to have fallen victim to the commonly expressed notion that a person 200 years ago could never have dreamed of the technology and capabilities we would have today; therefore we ourselves cannot possibly dream of the mind-boggling advances to be made in the next 200 years.  Physicists appear to be willing to bet against the more outlandish notions.

A key element here is that we know a heck of a lot more about fundamental physics now than we did 200 years ago. Undoubtedly we have much yet to learn. But the frontiers 200 years ago pertained to everyday time, length, and energy scales. Today’s frontiers are at 10−18 m scales on one end, and at cosmological scales on the other. Ultra-high energy frontiers are increasingly hard to access, requiring monster machines like the LHC at CERN. The chances that new physics will intercede at human-familiar scales are increasingly slim as the boundaries of our knowledge push out. Most technological developments of the last 50 years have been based on incremental progress in manipulation of matter, rather than on fundamental breakthroughs in physics like electromagnetism, quantum mechanics, or general relativity from roughly a century ago.

So it appears to me that the respondents to the survey were doing more than extrapolating our recent joy ride into a shiny future. My guess is that they consulted their understanding of physics—combined with a sense of practicality—to address questions of time travel, warp drive, teleportation, etc. In other words, the responses cannot easily be written off as coming from a bunch of wet blankets.

Indeed, physicists get into the game motivated by the thrill of exploration and discovery in one of the few remaining frontiers. There is no selection effect for attracting pessimistic downers. Probably the opposite, in fact. Most are fans of science fiction at some level—at least to the point of having positive feelings toward classics like Star Trek and Star Wars. Despite this, their physics-informed opinions don’t paint those genres as likely future paths for us.

Escapism Won’t Help Us

A primary motivation for my performing this survey stemmed from a sense that un-allayed optimism (“If it can be imagined, it can be done”) is detrimental to our successful navigation of the challenges foisted upon us this century. I perceive that a pervasive attitude in our society is that “we’ll solve any big problem that comes our way: we’ve got brilliant scientists working on it.” I would bet that most members of our society would put us living on the Moon and Mars within a few hundred years. I think they would be shocked to learn that the experts largely disagree.

It matters. The belief that we can escape our Earthly bounds (and problems) impairs our commitment to take positive corrective action to address problems here on Earth. When I initially wrote the piece Why Not Space, I was blown away by the certainty expressed in many comments that we would of course break free of our evolutionary nursery. Fish crawls onto land; reptile takes flight; man jumps to the stars. A compelling storyline, yet likely completely wrong. Desolation and danger cut in the wrong direction to make space a natural leap. We don’t do so well away from our eggshell-thin biosphere. Even high mountains and ocean depths pose serious challenges to human survival.  If we’re destined for space, why don’t we live undersea today?. Space is orders of magnitude more difficult still, leaving aside the stiff energetic barrier to getting there in the first place.

What we have in this survey is a reality check that calls to question our most ambitious dreams, and puts a pretty distant timescale on even the more tractable problems. As we face unprecedented, parallel challenges this century (energy, growth limits, food, water, population, climate change), we should be careful to check our hubris at the door. It appears that the physicists have largely done this already.

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118 thoughts on “Futuristic Physicists?

    • I think context is key, here.

      If Grapms is telling you that you can’t build a supercomputer-class device with global telecommunications capabilities that’ll stylishly fit in your pocket, yeah, he’s probably worng.

      But if he’s telling you that you can’t draw a figure (in flat Euclidean space) with three straight sides and more than one right angle, you should pay attention.



    • I’d like to think that Clarke was alluding to basic comprehension of the scientific method – it is about falsification, not proof – which is not the only notion of “impossible”. If he wasn’t, it would illustrate that one should trust distinguished but elderly writers about as much as aspiring scientists of any age.

      Tom’s key argument is that we have models of the applicable physics that have withstood very expensive attempts at falsification over a century at scales and energies so far remote from anything relevant that it is extremely unlikely we will discover a new fundamental interaction, particle etc. that has observable impact on our lives, or those of our descendants. What we have mastered in applied science is the electromagnetic force. We have found very narrow applications of the strong nuclear force of yet-to-be-determined net benefit, if any, and might yet find ourselves ended by its “fallout”. We have no way of manipulating the weak force, and any attempt to manipulate gravity – even Robert Forward’s beloved non-Newtonian forces – requires the manipulation of impractical amounts of mass.

      Given the track record of these models – which I would expect informs faculty judgement even more than grad student judgement – impossible might not be a scientifically correct answer, but then, the probability here is with respect to our certainty, not with respect to the universe. Miracles, if any, are not exactly within the scope of science, and scientists do not have anything more meaningful to say about miracles than non-scientists, by definition.

      In second approximation, “impossible” might simply be “economically unaffordable”. Even if one could capture all the solar energy output and divert it into an extremely inefficient and wasteful production pipeline for anti-matter for occasional interstellar travel, the opportunity cost might well make it “impossible” in any human society that is not of the space cadets, by the space cadets, for the space cadets.

      Maybe Tom is at fault for mixing categories of certainty / possibility with notions of feasibility, with predictions of future history. I don’t see that this is a fatal flaw with respect to the point he continues to make: We better take seriously our predicament. Insufficient for survival, but necessary nonetheless.

  1. Some thoughts come to mind.

    First, I’m not entirely certain that humanity will make it through our looming energy crisis. I answered the questions with the assumption that we will and that we’ll do so magically and with ease, which I took as an unstated assumption you wanted us to make. But I think you’d agree that human civilization really is facing an existential crisis and that there might well not be any humans at all at some point in the timescales you use.

    Next, some of what you’re asking for is already here. Google has self-driving cars on the road today, and many high-end cars have driver assist features that aren’t all that far off from self-driving. Unless the economy totally tanks, I’d be astounded if we don’t see self-driving cars for sale to the public in the next five to ten years. The only way that won’t happen in fifty years is if we off ourselves before then.

    Something of the same is true of robots. Siri fits part of the bill, as do Roombas, and the Japanese love humanoid robots. They’re basically here, just not as polished as those in the movies.

    And, last, many of the “ain’t gonna happen” things will happen…but only in fully immersive virtual realities. James Hogan has some entertaining novels that start with a hybrid virtual reality, one that lets you virtually visit places on the other side of the globe and interact with others in virtual reality machines at other arbitrary places on the globe — like today’s multi-person video games but with virtual reality. We’ve come a long way from constructing virtual realities with words spoken around a campfire; it won’t be all that much longer before it starts to become difficult to tell the difference between virtual and real realities. When that day comes, who’s to say that the teleportation you experience in the virtual reality isn’t itself somehow real?



  2. It may be that, the survey coming from you, the respondents were already a little bit “conditioned”?
    Overall I was more pessimistic than all the physicists, and I am not into science at all (but still read quite a bit of science-fiction).

    • Invitations went out from individual departments, generally speaking, so it would not have been abundantly clear that the survey originated from me, in most cases. And even if it were clear, most would not know me or my views. A more likely bias may arise from which kinds of people are motivated to take a survey with these kinds of questions. But I could see that going either way.

      • Fair enough. Will you share with us also the result of the internet version of the survey? I would be interested in seeing both what the “non-experts” think and what difference, if any, there is between those that came from this blog and those that didn’t.

  3. To be fair, star trek had automatic sliding doors and cellphones.
    But as far as groundbreaking discoveries my (biased) money is on condensed matter: Fundamental physics has explained the hydrogen atom perfectly. You put two of them together and you can get very accurate models that still describe the system. Add an oxygen and it starts getting complicated. If your system has just 1000 atoms (1nm x 1nm x 1nm) it’s very hard to predict what will happen. Not to mention switching those atoms with other ones from the periodic table. There is still a lot to explore.

  4. > Substantially eliminate disease and block aging so that we may routinely see lives exceeding 200 years?

    Actually this one is much closer than 5000 years. The worst problem is money. My understanding is that the budget for such research is in the 10s of millions of dollars.

    • As Richard Dawkins stated in one of his books (and I’m pretty sure it’s not originally his idea), all it would take would be a total government that would forbid people having children before they are 40 years old. Because genetic “mistakes” cumulate over time, those that are able to “produce” healthy children at 40 years and older have better genes to pass. When their children are not allowed having children before 50, etc. etc. all it takes is a few generations and you have a real economical problem with all the people who live 200 years.

    • Well, if much longer life costs only millions of dollars, why are reach people who have billions of dollars still dying of old age? And why billions of dollars spent on life longevity research in universities and medical companies only improve life longevity very incrementally?

      • That’s the problem: billions of dollars aren’t being spent on this.
        You might want to check http://www.sens.org/ for more info about a promising approach. The basic idea is that early periodic interventions can be used to fix the metabolic “damage” before it becomes a problem. One doesn’t have to do it perfectly, just enough to add 10 – 20 years of life expectancy. The technologies and knowledge will evolve in time and better treatments will become available, thus at one point people will become virtually immortal.

    • Check out CDC’s life expectancy trends for the US for the past 30 years (http://www.cdc.gov/nchs/data/hus/hus11.pdf#fig33) and then just “do the math” to determine the most optimistically “possible” (not probable – due to diminishing returns) time to achieve life expectancy of 200 years.

      • First of all, the American system is way down there in the life expectancy charts. Think of the 50 mil or so people receiving the equivalent of medieval medicine due to the lack of insurance.
        Second, people couldn’t get to high up in the air until they invented flight (balloons or whatever) . It’s a similar situation here.

      • For what is possible re aging, you need to look at the extremes rather than the current median. Yes, many if not most Americans are effectively dooming themselves to premature death through their lifestyle choices. But there are many outliers who make different choices, and so are physically & mentally healthy at advanced ages.

        Now if we follow the breeding logic above, we might suspect that humanity will eventually split into two species, the jocks and the couch potatos. Indeed, from scattered observations taken at my local WalMart, this may have happened already, since there does not seem to be a lot of interbreeding between populations 🙂

  5. I agree with your skepticism regarding metamaterial cloaks, but when you were asking about cloaking devices, I was thinking more along the lines of the Mercedes that had LED screens all over it with cameras providing images from the other side (an image search of “invisible Mercedes” on google shows what I’m talking about). While that only worked for one side, I think it would be possible to get a pretty good coverage without the cameras taking up so much area that they would stand out. While it of course wouldn’t be a perfect cloak, I think it could get pretty close for slow moving objects at 20 or 30 meter distances, especially within the next 5000 years as it just requires improvements in camera and LED technology that seem quite feasible.

  6. I find it interesting what is predicted to be impossible based on physical laws vs economic and practical considerations. It is almost certainly possible to have the equivalent of Flying cars as a functional transportation tool at very high level of available energy and the worries about peoples ability to drive them are pretty much negated by the self driving prediction. Will they ever become a reality? Not with the our probable population and resource constraints.

    There are also several questions which are ambiguous in nature. The synthesized food for instance. Making food from energy or even molecule by molecule is never likely to be a reality. Making food from 3d printed soy protein, carbohydrates, fiber, gelatin, flavoring agents, colorings is within easy reach as a novalty item now but probably won’t ever be cheaper than a self assembling chicken.

    @b& “When that day comes, who’s to say that the teleportation you experience in the virtual reality isn’t itself somehow real?”
    It may certainly seem real to an inside observer but Percieved Reality is not Physical Reality and the Aliens who eventually visit and pull the plug will know the difference.

    • I have to agree that some of the items are doable in less than fifty, if cost does not matter. Google already built a self driving car, we can put a colony on the moon, daily supply ships would cost a lot. Flying cars are do able, just not practical. Jets packs are going to burn the back of your legs.

      • AFAIK Google has not built a self-driving car that’s a full substitute in uncertain traffic for a human driver.

        Getting 80% of human performance with ‘AI’ is often pretty simple, but that last 20% can be really important sometime,s especially when lives or lots of money are on the line.

  7. The timescales of the questions (50, 500, 5000) strike me as somewhat silly. For starters, while I certainly hope homo sapiens isn’t extinct or operating at a neolithic tech level in 5000 years, I wouldn’t bet on the possibility. My guess is if we have to wait more than 500 years for any technology to arrive, we’ll wait forever.

    There’s a major apples-to-oranges problem with the questions, in that in some cases you’re asking about whether a technological problem is capable of solution (faster-than-light travel, wormholes, teleportation, time travel, etc); in others you’re asking whether things that clearly can be done will ever be economical or practical enough to be in widespread use (flying cars, jet packs, fusion); in still others you’re basically asking a loosey-goosey question about whether a given technology will ever be as cool as it looks in science-fiction movies (talking humanoid robots); and in others you’re asking people to make unsupported guesses about the Drake equation. I don’t think you can draw meaningful conclusions about a person’s technological optimism when the responses are biased by political and economic realism — which in my experience is quite directly linked to age. I mean, I’m fairly sure nobody who said we won’t have a moon colony in fifty years was thinking that it’s impossible; they merely think it’s enormously expensive and has no clear economic benefit, so human nature being what it is, we probably won’t bother. But I’m equally sure everybody in your sample who thinks we won’t invent time travel does think it’s impossible.

    • You’re right: it’s a real mix, and requires simultaneous attention to physical possibility and practicality—just like the real world. It might have been interesting in some other sense to narrow the questions into a pure domain, but I was more interested in the combined, complex effect.

      • I did like your set of questions, in that they collectively throw the implausibility of a Star Trek future into amusingly sharp relief, but my point was that the split in responses between undergraduates, grad students and faculty may have had more to do with the increasingly sophisticated understanding of market forces that comes with age than it did with knowledge of physics.

        • But the ‘youth idealism’ effects was also registered on physical possibility questions like FTL travel, wormholes and artificial gravity, not just on economical feasibility questions.

    • I agree with a lot said here, especially about the timescales.

      I think 500 and 5000 years is a ridiculously long timescale in our current technology pace. Either we will overcome our current issues, in which case most of the 500 year timescales are more likely to occur in 100-200 years, or we will hit hard technology and resource walls that will prevent them from ever happening.

  8. I suspect the responses rest upon the assumption of continued societal investment in science and an ~exponential growth in knowledge. These in turn rest upon a foundation of cheap energy which has given us the luxury of pursuing knowledge. Noting this, and referring again to your fossil-energy-consumption-over-time stalagmite graph…

    [Tom: PLEASE PASTE your graph here: I tried, but the system wouldn’t accept it. THANKS!]

    …I’d suggest responders consider where on that graph we’ll be in 50 years? 500 years? 5000 years?

    And under those plateaued or post-peak conditions, what will we – scientists included – be doing then? Telepathing with aliens or burning journals to keep warm? There’s certainly a hint of the answer in the air right now in the presidential campaign’s scientifically-ignorant-to-absent discussion of climate, energy, population, growth, the real economy, and more. This suggests, tragically, we may have reached PEAK SCIENCE – as a politically viable tool for operating civilization, anyway.

    I hope we all accept it as our personal challenge – to which you have obviously dedicated unimaginable passion, intellect, time, and energy – to reverse this trend and bend the arc of history back toward – may I suggest – rationality and genuine sustainability.

    • I also fantasized about jet pack-ing around, but my real disappointment was the failure of scientists and engineers to deliver on the promise – and yes, it was a promise – of nuclear energy “too cheap to meter.” Thus my own reality check: there are limits.

      Your stalagmite graph (1) raises this point, (2) suggests the future won’t be an easy extrapolation of the past, and (3) should be screaming to anyone taking your quiz: think FIRST about the real world context in which scientists and engineers operate and THEN answer.

      For these reasons, it is one of the most thought-provoking graphs of our time. I hope you will insert it or at least link to it above.

  9. I wasn’t thrilled by the answer list; what’s the difference between “won’t happen for humans [or successor species]” and “<1% likely or impossible"? I guess it doesn't matter if you lump them in as pessimistic, except it kind of does when you're calculating means and standard deviations on this arbitrary ordinal scale.

    I'd link undergrad pessimism on intelligent robots partially to greater religious belief and thus skepticism of soulless automata.

    I note that many of the space questions become potentially a lot more likely if robots are included in the successor species. So the median physics prof is saying robots are likely in 500 years but unlikely to ever visit other astrophysical objects.

    I think I voted impossible for cloaking devices, but as I type I recall an idea of "photon rerouters", where the skin of the object routes photons around, or detects and re-emits them. E.g. http://www.engadget.com/2012/03/04/mercedes-f-cell-gets-led-camouflage/

    • Answer #5 is a 50/50 judgement call: thinking something is unlikely (heads vs. tails) is not the same as practically ruling it out as impossible or < 1% likely. So I appreciate seeing the difference in opinion between these options.

      • Hah! I’d particularly noted the 50% definition of likely while reading the instructions, then promptly forgot about it while taking the survey. Guess I can’t make fun of people for forgetting “or successor species” then.

  10. On the aging question, it’s worth pointing out that thus far we haven’t really extended the length that the human organism is capable of living. Increases in life expectancy are due almost entirely to decreased mortality. In other words, more people are making it to old age, they aren’t living longer than what their acestors were physiologically capable of.

  11. Tom,

    A few reasons to very skeptical about the skepticism of some these profs:

    1) Who the heck thinks we will have a martian colony *eventually*, but not within 5000 years? Profs, that’s who. They also (sensibly) think that we’ll have abundant fusion energy and intelligent robots will be doing lots of human tasks within 500 years. So what exactly will we *not* be doing for the following 4500 years, that we will suddenly start doing thereafter? In our own solar system! Jeez! This is evidence of total imagination failure. Note here the bimodal distribution showing evidence of intelligent life in the <500 year bucket.

    2) 200-year lifetimes not in the next 5000 (*5000*!) years, but most likely thereafter! See 1) above.  Again, the bimodal sign of intelligent life.

    3) "Synthesized food??? That's outrageous! Nobody will ever produce protein in a lab! Not even with unlimited fusion energy, or intelligent robots. Not in 5000 years. Not ever!" Seriously?

    These silly responses show two possible sources of bias:

    1) Knee-jerk bias in favor of killjoy conservatism.  Happens to old people.

    2) Total lack of creative thought. Haven't thought about it in 50 years. Can't remember what I used to think. I'll just say no. Also happens to old people.

    So what we get is a bimodal mix two competing effects: expertise vs curmudgeonhood and the onset of dementia. All the prof distributions are seriously contaminated by this subgroup.

    And here's to the undergrads who predict a higher probability of a Martian than a Lunar colony between now and 500 years. Good point. Why would you spend your whole life on the Moon? It's so close you can just use your fusion energy source rocket to go back to earth. The moon sucks! It's strictly for robots. If anybody's going to live permanently anywhere other than earth, it'll be somewhere far away. And the possibility of terraforming (even if small) is yet another plus in the Mars column. Try to put an atmosphere on the moon.

    Overall, I'd go with the profs, eliminating those whose responses indicate presence of the terminally debilitating psychological conditions noted above. Also, of course, throw out the wormhole/time-travel/warp-drive/general-violation-of-the-known-laws-of-physics people.

    • You’re making all kinds of assumptions about the demographics of the faculty group. I’m not sure how you can be so certain of their makeup. I’ll bet most respondents are on the younger end of the spectrum. I don’t know for sure, but I’m not about to assume they’re all geezers.

      [Added later]: It strikes me that just because the surveyed physicists don’t agree with your personal vision of the future, you conclude their logic is flawed: too conservative or lacking creativity. When some subgroup agrees with you, you think finally some are thinking “correctly.” How do you know what level of complex consideration went into the answers? Maybe there was a whole heck of a lot of creativity there that led down a path not considered likely by mainstream “thinkers?” It takes a sort of creative thought to recognize limitations as well, rather than apply blind extrapolation. In the end, these are all opinions—including yours. No one knows what the future will turn out to be, so your foundation for criticism is weak.

      • Tom,

        I am not assuming they are geezers. I’m saying they appear to *think* like geezers. The idea that a Martian colony is likely eventually, but not within 5000 years, (while fusion and intelligent robots apparently happen within 500) shows evidence of lack of careful consideration and conservative bias. Unless they think we have to terraform it first (I’d bet they are the same people who reject terraforming), what on earth could we possibly be doing for 4500 years? In a society with intelligent robots and unlimited energy, that is a *ridiculous* amount of time on the scale of any relevant physical process. Which makes me think they are biased in the direction of impossible.

        Saying that something is impossible is a way to signal authority. Some experts get joy from pointing out how other people are naive, which seems likely to produce a bias. And I think the data show evidence of such bias.

        • Oh, and giving the Moon an atmosphere is probably easier than Mars; it’s closer. It won’t *keep* the atmosphere for nearly as along, but hey, a million years is a long time for humans.

          “what on earth could we possibly be doing for 4500 years”

          Things other than colonizing Mars. It’s not like there’s some compelling imperative.

          • I did that problem in a kinetic theory assignment in my undergrad (long time ago – I’m a geezer). As I remember it, the moon can’t hold an atmosphere for any reasonable amount of time at anything remotely resembling room temperature. Mars can. Also, the question asked about living out *whole lives* on the moon. Being a few days from earth makes that less, not more, likely. I’m with the undergrads. 

            If you find no compelling reason to go to Mars within 4500 years of developing intelligent robots and unlimited energy, why would you think it *likely* that you would ever subsequently have a reason to go? 5000 years is a huge amount of time with that level of development. It’s the relative odds of going before vs after that are weird. 

            I agree, btw, that the profs have the basic physics more right than the undergrads (no #^%* Sherlock!).  But on creatively thinking through the logic of future development some of the profs look weak. There appears to me to be a subgroup that gives poorly considered knee-jerk conservative responses. At the very least, I think you you can make a well reasoned case for a high quantity of implausible responses at both ends of the educational spectrum. There is no closed and shut case that the rising conservatism is uniquely driven by rational accumulation of knowledge and not at least partly also by irrational  negativity (fueled by personal failures, dashed hopes and dreams, or God knows what). 

            The grad students, as a group, strikes me as overall the most reasonable. 


            I should have mentioned that it’s a fantastic study. The data are really remarkably clear and evocative (even if we can’t agree of what!) Thanks!

    • 1) Perhaps they imagine “life spreads if it can, so likely we’d eventually end up elsewhere” but can’t imagine any particular path that makes it likely or plausible on the time-scale of past human civilization.

      2) Ditto, even more so. An assumption of possibility but great difficulty.

      3) We can synthesize food, that doesn’t mean we ever will on a societal scale.

  12. I think one reason for quite big disagreements between technical and non-technical opinions is that non-techs cannot distinguish energy modest and energy hungry “wonders” each to other. “Wonders” that don’t require all planet’s energy for achieving are quite achievable (miniaturization, medicine etc.). Other “wonders” which require all planet’s energy could be achievable eventually, but outside this range any theoretical possibility is only possibility.

  13. I cannot help but consider something . . . if we go back 100 years, what would the leading men of science said?

    A 5 ton weapon capable of devastating anything in a 1-mile radius? Took less than 40 years.

    A handheld device capable of accessing a sizable percent of mankind’s stored knowledge, from anywhere in the world? I’m using one now. They thought it was improbable as late as 1966: it was considered one of the most unrealistic parts of Star Trek.

    Not only is matter made of tiny atoms, which they suspected, but that those atoms were themselves made of yet smaller things? Theory, it’s true, but inconceivable so short a time ago.

    Oh yes, we’ll get to the moon, and find out it’s boring.

    Btw, time isn’t a constant, and the universe has speed limits.

    Leaving flippancy aside, it is folly to assume that we can predict science. It is folly when people predict that science will certainly save us. And it is folly when we predict science cannot save us. We have no idea what the world will look like in 100 years, if our race even lives that long. Asking people to predict this, even highly schooled and knowledgeable people, is only amusing.

    I’m not saying science will advance, there may be no more fundamental realities to discover. But every scientific community in our history has thought they understood more than they did, we are apt proof of that. Assuming our science is the exception to this rule flies in the face of the math.

    • Technically, 100 years ago is 1912, and people already knew about electrons and alpha particles and radioactivity and special relativity. The lack of air and water on the Moon had been established in the 1830s.

      • For the record, I never said a thing about radioactivity, nor about our knowledge of an airless moon. I said that people 100 years ago would likely not expect the atomic bomb, nor that we would reach the moon within 60 years.

        J.J. Thomson did in fact discover the electron before 1900, I was referring more to the fact that electrons are themselves made up of smaller parts.

        Special relativity was already a published paper, but was scoffed at by the majority of scientists at the time, which is the point I am making.

        We understand that fusion is possible: we have weapons that exploit it. What they understood isn’t the point, but what they would predict. Science is a constant process of expanding what is considered ‘possible’.

        • “the fact that electrons are themselves made up of smaller parts.”

          This fact is not a fact. Nuclei are made of protons and neutrons, and those are models as being made of quarks. Electronss are fundamental, unless we get into string theory.

          And what you said was “Not only is matter made of tiny atoms, which they suspected, but that those atoms were themselves made of yet smaller things? Theory, it’s true, but inconceivable so short a time ago.”

          You said it’d be a surprise 100 years ago that we’d get to the moon and it’d be boring. Perhaps you meant something else by boring, but the probable absence of life was already known.

          http://en.wikipedia.org/wiki/History_of_special_relativity#Early_reception hardly sounds like physicists scoffing at special relativity; it describes several defending and extending it in the years before 1912. You did say ‘a majority’, but I’ve never heard that.

  14. Flying cars may become technically possible, but we will be unable to insure them against falling out of the sky and wrecking someone’s house.

    • As someone noted, if you have automated driving, they become a lot safer. Less ‘driver’ error, also they can be more confidently confined ot safe corridors. Also, planes very rarely simply fall out of the sky; most accidents are at take-off or landing. Sometimes an engine goes out but hey, there’s another engine.

      Someone noted elsewhere that it’s rather inconsistent to rate roving astrophysics as less likely than alien visitation, as the physics faculty do. If you can visit another alien species, you can visit astrophysical phenomena.

      • That may be due to slightly unfortunate wording in the question: I assumed that “visit” meant by humans or successor species and not non-conscious probes.

        • AI/intelligent robots aren’t non-conscious probes. Which gets us back to whether they count as a successor species. (Biological successors genetically engineered for longevity count too; stopping aging for baseline humans might look Really Hard compared to designing it in.)

  15. Very entertaining survey, thank you. And thanks for all the other articles here, they’re very good read as well.

    However, I still have to take issue with you and others who wish to attack what you call “escapism,” i.e. the belief that the humanity should eventually move beyond its cradle. I do understand that for those who believe off-world colonization is a matter of decades, such escapism may make them postpone or discount measures that are necessary to ease present-day problems. Nevertheless, discounting the possibility of off-world colonization also has a negative effect of its own.

    My personal motivation for spending several hours every day learning and arguing about looming environmental disaster (which, currently, isn’t what I’m supposed to be doing) has for a decade been intimately tied to the vision of Earth-derived life or its successors eventually spreading beyond this world. If we don’t do that, we and the biosphere are doomed anyway; it’s only a matter of when. And if so, what difference would a few hundred or a few thousand, or even a hundred thousand years do, in the long-term view? Would eking out a subsistence-level existence, even if for a million years, really be a “victory?” A mere wink of an eye in the galactic timescale.

    My personal judgment is that unless we simultaneously strive for the really long-term vision as well – of life and preferably intelligent life beyond the Earth, sustained possibly until the end of the Universe – what we do here on Earth to buy us, at best, some time is simply not worth it. No reason for me to worry about environmental degradation then; in fact, the sooner the end comes, the better, both for the humans and for the planet. (Perhaps evolution will try again, perhaps not.)

    I see the only real long-term sustainable vision being the one where intelligent life is not tied to one, vulnerable planet. The other visions, even though they are marketed as “long-term” or “sustainable” are in fact myopic: they barely look or care beyond the next thousand years. Worse, their underlying philosophies of low-energy life are often explicitly dead ends in the long term. However I try to look these, they do not fit my definition of “sustainable” or “long-term.” They are short-term solutions, not qualitatively any different from what the business as usual crowd is offering.

    If we really are the only intelligent species in the galaxy, or even in our immediate neighborhood, failing to protect intelligence would be the most heinous conservation crime ever. Even if there are others, failing to protect Earth-derived life would constitute a massive loss of biodiversity. Of course, your mileage may vary.

    • “If we don’t do that, we and the biosphere are doomed anyway; it’s only a matter of when”
      Even if we were somehow able to colonize the entire universe, it would still be only a matter of “when”. What difference would a few billions years more or less, once you reach that timescale you are essentially speaking of “eternity” in human-scale time anyway.

    • All our previous scientific discoveries and technological innovations, which I argue probably represent the vast majority of the whole spectrum of discoveries that will ultimately have any real relevance to our societies over the entire span of human civilization (in other words, as of today, we are basically finished with what scientific discovery is going to provide for us, for all practical purposes), have resulted in this energy transition:

      A hundred, or a thousand, or 10,000 years ago, we derived about 97% of our energy (my rough estimate) from burning dead things that used to be alive. The other approximately 3% came from drying things in the sun, floating down rivers, and blowing across oceans. We appropriated around 0.00001% to 1% of global ecological productivity.

      Today, in contrast, we derive about 97% of our energy from burning dead things that used to be alive (when you include all the factors required for food production). The other approximately 3% comes from drying things in the sun, floating down rivers, blowing across oceans, with the minor additions of nuclear reactors, wind turbines and solar panels that still only add up to about 3% overall. We now appropriate 25% of global ecological productivity. Total global ecological productivity has dropped 10%.

      Our escape from the bounds of our planet isn’t happening. But if we do not shift our energy sources away from burning dead things that used to be alive, I agree with you: we are certainly doomed to a planetary collapse, 100% guaranteed, and that it would be best to get it over with now.

      However, the potential does exist that we could transition to renewable energy sources in time and on a sufficient scale to prevent that die-off from occurring. The only other alternative besides alternative energy is leaving our planetary bounds in a future Noah’s Ark. Since the chances of us colonizing space on any meaningful scale are about 0.00000%, then our only option is to develop alternative energy systems as quickly as possible and to concurrently halt global economic growth as quickly as possible.

    • Here’s the deal about escapism: the energy costs are just huge. The energy cost of getting off the planet in the first place is huge, and the incremental cost of adding an additional person even when you have a ship already going is less huge but still huge. I suspect we’ll have colonies on the Moon and Mars, and can dream about colonies further away. But they’re not going to be a place for the Earth population to **get away**. First, it’s too costly to launch everybody, so we’re only going to launch small groups, at most, ever. But, even if we were able to send (say) half the population away, the rest of the population would refill the Earth in relatively short order and we’d be facing a full planet again.

      I mean, heck, Europe is hardly emptied even though they exported all kinds of people to the Americas in the 16th through 19th centuries. And, there, the energy costs of sending somebody away were trivial compared to the cost of getting somebody into orbit (even when you put the costs in the context of their times.)

      Sending small groups to establish colonies might be great for the survival of the *species* and our culture, but it’s not going to do squat for all the individuals on Earth. The energy cost of evacuating everybody is just unreasonable, and we grow back too fast.

      (Unless, that is, we manage to make perfect simulations of ourselves in software, at which point we can transmit ourselves as pure information, and the energy costs of sending ourselves away go way down. This does bring its own host of practical, as well as ethical and philosophical, problems.)

      • Energy costs to get off-planet are so high because our current technology for doing so is so mind-bogglingly inefficient. The energy content of a kg in geosynchronous orbit compared to earth’s surface is only a few tens of kWhr.

        • Yes, but there’s been a notable lack of progress in making our launches much more efficient. Not for lack of ideas.

          • Too true. I don’t think we are lacking ideas so much as economic imperative.

      • Rob Knop, I fully agree with what you’re saying. Precisely for the reasons you stated, and for other reasons such as the difficulty of sustaining humans even in low orbit, I tried hard to avoid using the term “humans” in my original response.

        I do hope and believe life and intelligent life will not be constrained to one vulnerable planet, but I doubt we today could recognize the intelligences that will/might spread beyond Earth and make intelligence invulnerable to a single cosmic “oops.” Not as humans, at any rate.

        It is of course desirable that we make this Earth as good as possible, for as many people and non-human species as possible, for as long as possible. But if the peddled alternative is to hunker down in a sort of subsistence-level, minimal energy society, just waiting for the next planetary-scale catastrophe to finish us off… then I do not see much point in spending my limited time and resources fighting what obviously will be a losing battle anyway. It’s a losing battle simply because no matter how many times the message is repeated, the vast majority of humans will not voluntarily reduce their consumption to the levels that would be sustainable in the long term. As anyone following e.g. your presidential elections can attest, it’s also highly unlikely anyone is going to make them do so in time.

        Luckily, I do not see that the goal of eventually becoming the (local) origin of intelligent life is in any significant manner in conflict with the goal of changing the system into a less unsustainable one. In fact, since we’re still at least decades and possibly centuries from creating intelligences (biological or otherwise) that could thrive beyond this world, sustaining the Earth-system is of highest priority.

        It is just with certain low-energy, back to the imagined simpler life scenarios – which, quite frankly, seem to be just escapist fantasies of another sort – I have issues with. Unfortunately, these fantasies seem to be popular with many critics of the current system.

        I’m far from cornucopian and actually believe that the coming century will be extremely trying one – to the extent that I have serious doubts about having children – but I still have faith that even as we try to stop the ecological disaster, we 1) can and 2) should simultaneously strive to spread intelligence throughout our stellar neighborhood at the least. And that if we do not, then what we do here on Earth will matter very little in the long run.

    • Frankly, if we’re not even capable of living in an existing ecosystem without constantly damaging it, what makes you think we’ll be able to spread life elsewhere and preserve it there?

  16. From the book “Project Orion: The True Story of the Atomic Spaceship” we know that technically it would not be that hard to send small colonies to some of the planets. Dyson and others had all the math worked out for sending a crew of 20 to Jupiter in less than a month, let them stay for a year, and return. All it takes is igniting focused tactical nukes at your backside.
    Our youthful dreams of Moon bases and interplanetary travel were cut short by test ban treaties and well placed fear of fallout. I could not rule out some of your questions because some of these slightly more mundane ideas have a greater than zero chance of happening. If the world order between nations begins to crumble, there is at least a possibility that someone who can build submarines, missiles and nukes could say screw the treaties, launch in T minus 10.
    On the other hand, in those same circumstances, it seams unlikely that someone will go through the effort just because it’s there. I’d expect there would need to be a return on the investment. It’s not clear to me what that would be. A purely political motivation doesn’t seem to cut it. If your international neighbors are already in a tail spin, what’s the point of throwing resources into space?
    If I have any fantasy wishes about the future, it is that we as a species can learn to be stewards of our own planetary environment, and stop treating it as a strip-mine.

  17. Looks like physics has run out of crazy dreams. It’s place as the origin for sci-fi ideas had been taken first by computer science, then by biology. Which is consistent with the economical efficiency considerations: software and genetics are not that bounded by fundamental limitations, and don’t require all the planet’s energy.

    The commonly accepted view in futurology is that biology will have the same sort of revolution in 21st century as one that happened in physics in 20th century and in computer science on the verge 20-21st. [Bruce Sterling. Envisioning the Next Fifty Years. Tomorrow Now]

    What if we feel bad for physics? Just come up with new crazy dreams! A decade ago such were nanobots, now it’s quantum computer, I think. Also, I’m surprised that question: Will we ever understand the fundamental theory of everything? is not on the list.

    • Understanding the fundamental theory of everything is a very different sort of thing from the questions that are on the list. The questions on the list are about things that affect everyday life.

      You can have (or can fail to have) the Star Trek future, in both cases, either with or without understanding of a fundamental theory of everything.

  18. I’m a cranky old man professor now — kind of sad, because back when Tom and I used to hang out together, we were the optimistic grad students… although we called ourselves Data Monkeys.

    I didn’t take the survey, but it most cases I’d be pretty close to the “professor” mean. I’m more optimistic about synthetic foods than most, in the relatively near timescale. (Maybe even the 50-year timescale.) Not Star-Trek-synthesizer stuff (i.e. via physics), which I’d like to think is on the “indefinite but possible” timescale, but vat grown biotech stuff, i.e. meat that doesn’t require the killing of something with a central nervous system.

    (I should say it’s not clear to me exactly how Star Trek synthesizers work. Are they doing E=mc^2 and building matter out of pure energy? I think that’s what transporters are supposed to do, and that’s improbable to me long term. But if we’re talking nanomachines doing molecular assembly, I suspect that’s possible on the >500 year timescale. Of course, you could say that a gamma ray laser plus pair production plus nanomachines gives you not only a source of antimatter, but the ability to take the excess matter as inputs for your nanomachines, but that’s going to be way more energy inefficient and impractical than just taking the matter that’s around, with atoms (and even mostly molecules) already in the form in which they’ll be used.)

    Jetpacks WILL happen, I predict, if they haven’t already, but will only be used by extreme sports wackos and will have a high fatality rate. They will never be common. I should go back and review the Darwin Awards; I wouldn’t be surprised if there were already evidence for jetpacks there.

    I do have to admit that I think of the 500-year threshold as the boundary for “arbitrarily far into the future”. The 5000-year threshold is not completely absurd, as that’s the threshold that is closest to a time corresponding to the history of human civilization, and thus I can see why it’s worth considering. We do have a historical baseline to allow us to think about that timescale. But, when it comes to technological advances, if I can’t predict that it’ll happen in the next 500 years (and there are definitely things that I think will happen in the next 500 years but not the next 50, including, sadly, nuclear fusion as an effective power source), I would say “sometime in the far-off future”. I can’t tell the difference, myself, between 1000 years from now and 100,000 years from now. To me, it’s in the next 500 years, “sometime”, or “just impossible or impractical”.

    Of course, if we DO manage to invent time travel, we can screw up all the time scales we want….

    • Rob! What’s a steege like you doing in a dump like this? Thanks for sharing good points and interesting perspective. I especially like your response to J. M. Korhonen.

    • Synthesizers: I’m no ST expert, but my impression is that TOS (The Original Series) ones were more ‘real’, making food from chemicals, while TNG (The Next Generation) introduced ‘replicators’ that are more like universal assemblers via lower-resolution (so no living tissue) transporter tech, interconverting enegy and matter. (Better than nanotech!)

      If you give a modern chemist an unlimited budget would she able to synthesize nutritious and somewhat flavorful stuff from raw elements, without resorting to bacteria or yeast? I wouldn’t be surprised if the answer is “yes” or “yes with exceptions”, along with “but the texture would be blah and many food experiences would be unreachable.”

      • I have seen it explained by the writers, ST (at least TNG on) Replicators were the second half of Transporters and converted energy into matter based on “blueprints” in the Computer. The first half of Transporters scanned matter into “patterns” and then transmitted that pattern thru space and time. If you needed a transporter pad on the ship, why did you not need a pad at the destination? Sorry, I digress.

        This is what I assumed from the question and why I was surprised that so many profs did not answer it the same way as they did Teleportation. I assume you all know about the Heisenberg uncertainty principle? This is what makes Teleportation impossible and would therefore make Replication impossible. We just cannot create an object that big, element by element, or particle by particle.

        I did not think that a physicist would ask a question about some bio-growth food stuff. Heck that is just cellular biology and chemistry in a beaker. What do you think Kraft does?

  19. Another fun essay with some data meat on its bones.

    I found myself extrapolating the trend of the “expert gradient” to those hypothetical 200-year-olds if they existed, as 150-year-old physicists in the prime of their lives. By whatever coincidence, that’s where my answers put me, and I suspect that the estimable Dr. Murphy might find his own answers clustering within that speculative demographic. Could be that any sufficiently experienced physicist is indistinguishable from a curmudgeon… at least to a layperson.

    But now that I’ve paraphrased Clarke, I’ll note that I see other references to him above. He was a neat guy, a friend, and a funder of some of my projects. A vigorous skepticism about probable real-world outcomes wasn’t his specialty, though.

    In all the data, even among these relative experts, one sees that serious systems discontinuities from the downslope of human overshoot seem not greatly incorporated into their narratives.

  20. It may well be that if we don’t accomplish incredible things within the next 50-500 years, we won’t have the volume of energy to tackle them after our fossil fuels run out. As I look out my 16th floor window at the skyscrapers around me and then all around my office, it seems that this is the world that “burning dead things” created. There’s no guarantee that we’ll be living a richer, more scientifically advanced life in 5,000 years, even if we don’t wipe ourselves out.

    • Agreed: no guarantees—especially when we have built our amazingness on a finite resource. We have no proven model that says we can truck along. This is a key point that I think we must absorb. Not the dismal prediction aspect so much as acknowledging the real possibility of a less lustrous future. There is a tendency to be utterly dismissive of this possibility, taking shelter behind extrapolation of a centuries-long spree (that is based, of course on the finite resource).

  21. We’ve been spoiled by the industrial revolution. For about 100 years, progress came quickly and easily, and people began to just expect constant revolution in science technology. Unfortunately, most of the technological progress has come from burning larger and larger amounts of fossil fuel. Meanwhile, the scientific progress has discovered some fundamental barriers on what we can’t do. For example:
    1) We can’t go infinitely fast (relativity)
    2) We can’t make things infinitely small (quantum mechanics)
    3) We can’t generate infinite amounts of energy (thermodynamics)
    4) Anything we make will eventually break (thermodynamics again)
    5) Some problems are impossible to solve, or would take longer than the lifetime of the universe to compute (mathematics and computer science)
    I expect that most progress from now on will be incrementally pushing towards limits, rather than the massive exponential progress of the industrial revolution.

    • Considering that most (guestimate, do not flame) of the population was born post WW2 and has lived in a world (western) unlike any before it, we have a hard time seeing how humans have lived since the time before the “Egyptians” up to the industrial revolution.

      Barring the lifestyle of the elite in Egypt, Greece and Rome, most toiled in the field to survive in a harsh world. I do not expect us to revert to that level, but a steady state with nature is going to have to be achieved.

  22. Thank you for doing this! I’ve run into this “all it takes is an idea and a will to make it happen!” nonsense so many times and it always irritates and worries me. The worst part of the story for me is not that this student said it but that the other students treated it like wisdom. In my experience when people express a sentiment like this it’s said with smug satisfaction, often as a put down to any knowledgeable person who has just pointed out a legitimate concern with whatever the topic is. It’s a very practical example of the Dunning-Kruger effect where the optimist has a one-answer-fits-all catchphrase that makes them feel vindicated in their dismissal of any criticism (however well argued and informed) of their vision.

    Similar lines of thinking include “but compare the last hundred years to now” which is just silly on the face of it; as though technological progress is guaranteed for the future because it happened in the past. Even though it’s one questionnaire with a small sample I’m heartened that some of the undergrads showed a more realistic attitude than the grads. Hopefully we are seeing a generation that doesn’t think the future will definitely provide the high-tech tools to solve their problems (perhaps compounded by the socioeconomic problems western nations have undergone in the past half decade) and will therefore be better equipped to tackle these problems in a practical manner.

    • “all it takes is an idea and a will to make it happen!”

      It has been referred to as the “Green Lantern Theory” in other contexts (originally referring to the refusal to end pointless war – all about the triumph of the will).

      Every time one actually does try to fight entropy and inertia to make something happen in the real world, one experiences an object lesson about the difficulty of getting something done.

      The “idea on demand” fallacy, in turn, is born from empty free-wheeling “creativity” that is all inspiration, no transpiration. A bit like the Foundation Trilogy rewritten for a McGyver re-run.

  23. Only one item on the list made the 50 year cut, and that was, of all things, Robo-cars. The issue of whether robo-cars are actually useful, or desirable wasn’t raised, but hey, at least its something we *can* look forward to, even if its a pointless and a colossal waste of resources to invest in. Flying cars! Actually we can make those already, or least something 9/10 people would agree qualifies as one. Again, just because we can make them, doesn’t mean they make much sense either. Of all the things on his list, including some which would be very very (cool) if they ever came about, the only two we can do, are also utterly useless in every sense of the word! 🙂

    The funny thing I noticed about Sci-fi, is when it deals with some scientist, usually set 20 mins into the future, is everyone you encounter is either A) a Roboticist, or B) A Genetic engineer. Bonus points if they are hot 20-somethings who are not seeing anyone at the moment. But when you look at both fields in the real world, the reality is a lot less shiney. Robotics seem to have largely fallen out of favor, as soon as our corporations discovered hiring the Chinese offered significant savings, even over machines. When I was in high school, no one worried about being replaced by the chinese or Indians on the other side of the world, but we all worried robots would make us redundant Didn’t see that future coming did we?

    And Genetic engineers? No Gattaca babies, or Roy Batty on the horizon. Instead, what we got was Monsanto, GMO ‘foods’, and terminator seeds. At this point, I have made my peace with the idea the world will probably look pretty much the same in 3 or 4 decades as it does today (barring a major energy shock that is). In which case, 2050 might look more like 1850. Time will tell!

    • Robo-cars “pointless and a colossal waste of resources”? I’d say the busywork of driving we do now is the waste of resources. Steering, braking and throttle are electrically operated on cars already, so only the sensors and computation need to be added. Pretty cheap, really. Robotic driving will be safer, too, most likely. In any event, the kids will insist upon it, as driving interferes with their texting.

      • Think of all the room in a taxi with no driver. You could have your mobile transmit the destination to the taxi and off you go.

        Tie this in with something like Uber and even better.

    • Robocars and flying cars would certainly be useful and desirable; whether they’d be sufficiently useful for the cost (including opportunity cost) is another matter. Cheaper taxis, cars that can take drunk people home, cars you can study in while it drives you to work; all improvements over a dedicated human driver. How many hours does America waste in autonomous driving? Or stuck in traffic jams?

      I think your view of the fields is too narrow. Globalization diverted US attention to cheap labor for a while, but the labor doesn’t stay cheap. China’s looking to Africa for even cheap labor; what happens when we run out of cheap Africans? Meanwhile, the technology *is* improving: Roomba, and robot cars, and drones… hell, we’re fighting wars with robots. And Japan’s looking to robots to save them from their demographic crisis, since they have a strong bias against importing cheap labor.

      Meanwhile our genetic knowledge is growing, though that includes awareness of how ignorant we are. But remember the guys predicting a need for no more than 6 computers in the world? Or 640K of RAM? Pessimism is also a mistake.

      • Why we would we construct such a society, that condemns humans to be mere sedentary sock puppets trapped in autonomous, expensive, machines? Present agricultural surplus, built environment, and will aside, how much energy would it take? What would be the downsides?

        • Are you still talking about self-driving cars? It’s hard to tell with your rhetoric being so bizzare. You make it sound like some Orwellian dystopia where all humans are trapped inside a suit of armour that will walk and talk for them from conception til birth. In reality what we’re talking about is only marginally different from autonomous transport that already exists like driverless trams and trains.

          If self driving cars can be demonstrated to be, en mass, safer than human drivers then what we gain is saving of lives, economic cost to repairing infrastructure damaged in crashes, quicker journey times and increased fuel efficiency due to the reduction of congestion via platooning*, removal of an attention demanding chore, increased free time for work and leisure during journeys and potentially a decrease in roads (originally not designed with cars in mind) cluttered with cars as well as larger homes due to the decreased need for garages/driveways as self-driving cars are pooled rather than personally owned. The latter makes a lot of sense given that cars spend upwards of 90% of their time stationary, it may even help with transport poverty in poorer areas.

          If that means giving up the freedom/chore to operate a potentially dangerous machine then I couldn’t give it up fast enough.


          • Americans are already largely trapped in their cars, having built an environment that virtually mandates their use. Walk around a suburb? How? There’s often no sidewalk, only a trash strewn gutter. And to where? There’s nothing for a carless human to do or see.

            So say in a decade America actually has self-driving cars (and tallied some 300,000 more roads deaths courtesy the existing car-mandating system, plus burning however many more scads of CO2 in the process), and the population is still quite sedentary, with back and health problems from all that sitting in the–amazing! efficient! etc!–self driving cars. Or we could instead build walkable communities where one need not ever use a car, except perhaps for trips out to the boonies, or other special events.

            Why can’t you give up your dangerous machine, today? Are you not free to live without one? Being thus trapped, is the obvious solution then to try to develop self-driving cars, instead of simpler solutions? As a lifetime walker, reading sites where self-driving vehicle proponents wax on about robots that will deliver exercise bicycles to residents so they can exercise… well, it’s something.

          • Firstly I’m not American, nor do I live there. Secondly I do walk all the time, I only take the car if I’m going out of town, need to be somewhere In a hurry or the weather is awful.

            I agree with you that people should be encouraged to walk more and if your nation has a problem with suburban sprawl well that sucks because it’s far harder to accomplish the former. But given your objections there’s nothing a self driving car would really change. Your problem seems to be with town planning that is anti-pedestrian and increasingly sedentary life styles. Whilst car use may be a part of that whether or not people or machines drive wont change much.

  24. Your question is bizarre. We already know what a car-oriented society looks like. One with robot cars instead of current cars wouldn’t be any more sedentary, and would probably use less energy (more efficient driving, maybe fewer cars due to easier sharing.)

  25. I’d like some clarifications on a couple of questions:

    14. Create our food without growing or raising it—like the Star Trek method of “replicating” food by patterning atoms/molecules appropriately, maybe straight from the source of energy?

    Does food derived from bacteria count, or you mean only food produced by a completely abiotic process?

    15. Have robots as common entities among us that can intelligently converse with us and perform sophisticated tasks (housework, transport repair, nanny for the kids)? I’m talking about C-3PO, nothing like today’s machines.

    Do you mean something like an enbodied Siri or an human-like artificial intelligence?

    • For the food question, I’m thinking a 3-D printer for food, at the least. I’m agnostic about whether this should be done abiotically or not, but the idea would be that you could “print” a steak or an ear of corn and think it was the real thing. Cut out the agricultural aspect.

      For robots, I don’t mean software. I mean the whole package. Look at C-3PO in Star Wars, Data in ST-TNG, etc. Not an iPhone app.

      • The robot one threw me a bit as well. I don’t think a fully conscious, strong-AI in an android body would happen but I also don’t think it’s needed to get at what a lot of those old films/books were suggesting (not to mention the huge ethical quagmire of creating what are essentially slaves).

        Whilst I don’t expect that I do think it’s reasonable to expect a continuation of what we have accomplished already: greater automation of tasks previously requiring a human or thought to be an AI-complete problem and an improvement in user interfaces making them more intuitive and easy to use. A house in the future may not have a Robby the Robot but it might have an energy efficient appliance for nearly every task (think better versions of dishwashers, microwave meals, roombas etc) that can be interacted with through aesthetically pleasing touch screen interfaces or even natural language interfaces.

        I realise that this isn’t the question you were asking however I feel that it’s a bit of a loaded question because one could draw from the answers that no one expects anything like that in the future.

      • Ok, so you are thinking of nanoscale assembly at least, I was thinking of something like tofu or cheese made in a vat without significant material input from a full grown soy plant or a live animal.

        I’m not an expert, but that seems to me at least technically feasible in the near future.

        I don’t know about economic feasibility, but AFAIK plants are inefficient at capturing solar energy with respect to our photovoltaic or thermal solar panels. We can’t eat electricity or heat, but if somebody finds an efficient way to use this energy to make food out of inedible stuff (sea water, organic waste, etc.) then, in a world where solar power production competes with agriculture for land, this synthetic food could even be cheaper than the naturally grown one.

        For robots, it seems to me that it should be “relatively simple” to put a personal assistant software like Apple Siri on a robotic body like BigDog or PETMAN (by “relatively simple” I mean that I expect it to be done in more than ten but less than fifty years). The result would be probably something resembling C3PO, which is arguably quite stupid.

        Artificial intelligences capable of autonomously inventing novel solutions to problems in broad domains, arguably like the fictional robots Data and R2D2, seem to be much more technically difficult.

  26. I’ve noticed that while almost all the physicists you surveyed think that time travel to the past is impossible, some of these believe that FTL travel, wormhole traversal and artificial gravity might be possible some day.

    That seems strange, since in my admittedly limited understanding of general relativity, these things are exactly what it would take to allow time travel to the past.

    Maybe the issue is that you mentioned changing past actions in the question, that is, a form of time travel that allows causality paradoxes, while general relativity allows causality loops but not causality paradoxes.

    Or maybe it’s an issue of intuition: Travel to distant stars without temporal distortions is intuitive, it’s just an extension of our familiar concept of travel on earth. Routine time travel, on the other hand, is highly counter-intuitive: it would require us to completely revolutionise our way of thinking about causality. Since we have no clear intuitions about how a world with time travel would be, we tend to it’s impossible.

  27. As stated: “But the practitioners of physics appear not to have fallen victim to the commonly expressed notion that a person 200 years ago could never have dreamed of the technology and capabilities we would have today … ”

    Accepted, but what questions would have appeared on the equivalent of this survey 200 years ago? Aside from the question: “Were there surveys 200 years ago?” is there any record of futuristic thought on physical/technological possibilities from that period?

    • What people thought before the fossil fuel revolution would certainly be amusing to know. The 200 years that followed was as unpredictable as the 200 years we now face. Only there is a glaring asymmetry. 200 years ago, people were on the verge of exploiting our energy inheritance. At this time, we’re peering at the depletion of that inheritance, so extrapolation is off the table. In 200 years, people might think it’s really funny that our surveys were about wormholes and synthesized food when the primary concerns of the day may revolve around worm bins and personally growing food in the sun. What a bunch of bozos we were: didn’t understand anything about the future…

      • tmurphy,I disagree with you on these points, as you know.

        “What people thought before the fossil fuel revolution would certainly be amusing to know.”

        Personally I dislike the term “fossil fuels” very much. It refers to different things which have very little in common. Fossil fuels are very different from each other, in how they are discovered, extracted, transported, and used. Take coal and natural gas as examples. Granted, they are both derived from dead things, but how similar are they otherwise? One of them (natural gas) is a totally different phase of matter (gas rather than solid), is used in a turbine (not a steam engine), is extracted in a totally different way, is transported by pipeline rather than rail, and so on. Natural gas does not have any of the same infrastructure as coal.

        This term “fossil fuels” only gained popularity recently. It’s used by the energy-decline community only after their doomsday scenarios surrounding specific fuels (coal and then oil) proved to be incorrect. Their response to the failure of their predictions, has been to change the terms, and place all of the prior different fuels into a single category called “fossil fuels”, and then to pretend that no transition has ever happened since we are all still using “fossil fuels”.

        Instead of collapse, we have gone through a series of energy transitions successfully: coal to oil, oil to gas, onshore oil to offshore oil, conventional oil to tar sands and shale, coal to nuclear (in some places, like France), and so on. In light of this, can you explain again why we cannot transition once more, to using mirrors and sunlight to boil water? Frankly, the transition to mirrors, seems easier than the transition to nuclear fission was. Why can’t we transition this time? Is it because solar thermal is not a fossil fuel? What difference does that make? It’s not the ORIGIN of the fuel which determines the difficulty of the transition, but the similarity of infrastructure. In that regard, the transition to solar thermal will be far easier and less eventful than the transitions to gas or nuclear were, both of which passed easily in the places that attempted them.

        -Tom S

        • I’m fine with the term “fossil fuels” owing to their common properties: finite being foremost. It’s an inheritance. That’s important. They also share the common feature that they are hydrocarbons, so chemically similar (reactions combust oxygen to produce CO2 and H2). So similar contributions to climate change, and similar use as a thermal source in heat engines. Calling them fossil fuels does not pretend that they’re the same thing, just that they can be placed into a sensible category, quite distinct from hydroelectricity, wind, solar, and to a lesser extent nuclear and biomass (these still tend to run heat engines).

          • Perhaps I should clarify. I’m not saying that fossil fuels aren’t a category. I’m saying that it’s not the relevant category here. There are lots of possible categorizations. For example, we could categorize power plants based upon whether they are heat engines, whether they are internal combustion engines or steam turbines, etc. If we did so, then solar thermal and coal burning plants would both be in the same category, and in a different category from natural gas or oil.

            We’re discussing energy transitions, and in that context, the fact that two sources of energy both have carbon, combust, and come from dead microbes doesn’t matter. The difficulty of the transition is determined by the similarity of infrastructure, technology, and so on, between various energy sources. In this context, solar thermal belongs in the same category as coal burning plants, because they are both large centralized steam turbines (heat engines) which distribute power through an AC grid. The difference is how we boil the water. This is less of a transition than going from one form of oil to another (e.g. onshore to offshore), to say nothing of different fossil fuels.

            The reason we haven’t transitioned to solar thermal yet, is because it’s too expensive. Although the transition to solar thermal is quite easy, compared to the transitions between fossil fuels, that’s not important. Most energy transitions are easy anyway, for a market economy, which is continuously undergoing a transition anyway. Since most transitions are easy, we are more than willing to go through comparatively complicated and difficult transitions (like fracking or nuclear) if the price is ultimately lower (nuclear was cheaper in the 1970s because of lower safety requirements). Transitions are not actually very difficult, and are overshadowed by other concerns, like long-term price.

            -Tom S

          • One missing ingredient in your analysis is energy storage. It’s a compelling reason for not lumping coal into the same category as solar thermal. Storage is another aspect of fossil fuels that binds them together. You use the word “easy” a lot. The world in which I operate (and build things that have to work) is rather harder than the armchair version.

            But we’ve gotten pretty far off topic for a post on sci-fi technologies, so I’ll stop the thread here (will run into its 10-day limit soon anyway).

        • As tmurphy said, they’re chemically similar, hydrocarbons (or for coal, mostly carbon). They’re fossil as in being buried fuels, probably originally biogenic (methane could be primordial); the really important bit is that burning them adds CO2 to the atmosphere. Your blaming an “energy-decline community” shows your own blind spot. They also share the attributes of being very convenient to transport and energy dense. Oil’s most convenient, but compared to the intermittency and low density of wind and solar even coal looks good.

      • tmurphy,

        “The 200 years that followed was as unpredictable as the 200 years we now face.”

        Some things were unpredictable, like WWI. Other things, however, are quite predictable, subject to recurring patterns (otherwise there would be no science). Here’s one recurring pattern: market economies transition easily and quickly from one energy source to another, when the need arises. Another recurring pattern: energy decline theory denies that market economies will ever transition between energy sources, predicting collapse instead. Another recurring pattern: energy decline theory is wrong 100% of the time. Another recurring pattern: energy decline theory keeps coming back anyway, despite its failed predictions. Every time it comes back, it’s totally unchanged from before. The methods, assumptions and conclusions are completely the same despite a 100% failure rate of prediction for more than a century. Thus, energy decline theory is taken verbatim from old, refuted sources like Frederick Soddy, M King Hubbert, ecologists from the late 1970s, and so on, whose predictions already failed decades ago. My favorite is the theory that market economies require growth or they will collapse, because of interest. This one was taken from MEDIEVAL sources who predicted the imminent collapse of civilization from usury.

        I can’t predict the future, but if I had to hazard a guess, it would be this: the world economy will have grown by 10x in a century. Furthermore, energy decline theorists will still be predicting imminent collapse. How could we POSSIBLY EVER transition away from breeder reactors as uranium depletes? Sadly, I won’t be there to comment, unless your colleagues are wrong about the 200-year lifespan thing.

        -Tom S

        • Market economies have done very well transitioning to superior forms of energy as we laid our hands on fossil fuels. Just because something has worked in an ascendent energy phase does not guarantee that this is an immutable feature of nature. Just because life is easy and always improving while inherited money is still in the bank doesn’t mean that troubles can’t arise. And the rise and fall of fossil fuels takes a few centuries to play out. Looking at recurring patterns on the timescale of decades does not predetermine their extrapolated constancy over longer stretches of time.

          • Market economies transition because they are like big brains, which calculate, optimize, determine the best options, evolve, backtrack, and so on. This is a consequence of decision-making at firms, of strategies succeeding or failing, and of firms communicating with each other via prices. None of this is dependent upon increasingly superior energy sources. It’s only dependent upon an energy source in which these decisions and transitions are _possible_.

            “Market economies have done very well transitioning to superior forms”

            But we haven’t transitioned to superior forms. Usually, we’ve transitioned to _inferior_ forms of energy. As peak oilists used to remind us, oil in texas used to gush out of the ground, with an EROEI of 100. Now we shovel tar sands, frack, use shale oil, drill offshore rigs, use crappy low-grade brown coal instead of anthracite, and do all kinds of things which are quite difficult and unpleasant. In fact, we’ve undergone a continuous energy degradation for at least 100 years. Nevertheless, the total amount of energy available to us has increased by an enormous amount. How? Because the market economy finds a good solution when transitions are still _possible_, despite degredation of energy sources.

            “Just because life is easy and always improving while inherited money is still in the bank doesn’t mean that troubles can’t arise.”

            That analogy is true in some senses, but false in others. In this case, the amount of energy in fossil fuels (our inheritance) is paltry compared to our potential income (solar thermal). It’s like having an inheritance of $1000, but an income of millions per year. It’s like money shooting out from the Sun and falling from the sky, in vast amounts, far more than our inheritance.

            “And the rise and fall of fossil fuels takes a few centuries to play out.”

            This is true, and it means that the transition to renewables is the easiest and surest yet. We replace our entire energy infrastructure every 30 years anyway, due to wear. We could transition ten times over without any special effort. In fact, a market economy with the benefit of science could rebuild industrial society entirely from scratch, using only renewable sources, in far less time than that.

            -Tom S

          • Again, we’re pretty far off topic, but I’ll put in a last word before putting this one to bed.

            The big brains of markets can be big stupid brains too. Market failures happen, and leave millions hurting. I’m one of the lucky folks who saw the housing market about to crash and cashed out, despite market-gaga experts saying this was the new normal, and that the fundamentals were strong.

            The transition to superior forms is pretty clear: wood to whale oil to kerosene/coal to oil, etc. Sure, we’re coping with a slow degradation in quality lately, but we face a gulf in all-round superiority when transitioning from fossil fuels to alternatives (see the alternative energy matrix).

            I am as impressed by the solar constant as the next guy. But just because it’s there doesn’t mean it’s easy to utilize (esp. compared to fossil fuels). The large flux means we can’t rule out a solar future on quantitative grounds, but that’s not the complete, complex story.

  28. Looking at the self-driving car, I see this one as a very near reality. However, the benefits of such are minor in the short-term, but much greater in the long run.

    Early on, it will be mainly about personal advantage. I can drink, I can text, I can sleep while driving.

    But as more and more people use auto-driving cars, group benefits emerge. Cars can talk to each other and reduce traffic and energy through collaborative networks. It won’t solve traffic problems entirely (obviously only less cars can do that) but it can certainly help.

    Beyond that, as the inevitable reality that personal cars can’t continue as they are, self driving cars make certain new models much more likely. We can create pools of cars that will drive to your home when you need them, and as such allow us to drive many more people with fewer cars. We can allow for people to own the new super slim cars for their work driving…but then schedule that big family car they still need for soccer games and family trips to be ready at their home when they need it.

    Also, culturally auto-driving cars are likely to devalue the personal nature of car ownership we have today. As the car becomes less about “my vehicle” and simply another tool in the box, it is easier to get people to accept smaller and more identical vehicles…..even the sharing of such cars with other people.

  29. Also, on the topic of synthesized food, to me this is less about instantaneous creation of food then it is freeing the components of food we need (vitamins, proteins, energy) from their traditional agricultural sources.

    Meat grown in the lab from cells instead of cows on the farm (already big research in progress here). Carbohydrates created from laboratory factories instead of wheat farms. These to me are the more important concepts when dealing with synthetic foods.

    And heck from a taste perspective we already well ahead of the game. One thing fast food marvels at is making highly processed food taste good. If someone can create cereals from factory carbohydrates, I am sure there are food scientists who could make it taste good.

  30. Why do physicists think flying cars are “unlikely ever?” It surprises me. Flying cars are the only things on your list which could plausibly be built now. I don’t see why flying cars are less plausible than (say) terraforming another planet.

    The technology for self-piloting aircraft is far simpler than self-driving cars, from an AI perspective. Image recognition of the sky is vastly easier than of a street. As a result, some aircraft can already self-pilot to an airport (avoiding other aircraft) and land, using a computer, should the pilot become incapacitated.

    Furthermore, there are already vertical takeoff and landing airplanes. In fact, they’ve been around since about 1965.

    What’s so difficult about this? Am I missing something here?

    -Tom S

    • What you’re missing is the judgement as to whether flying cars will ever be practical. The instructions explicitly encouraged broader thought, rather than confining thoughts to the narrow realm of demonstration. For that matter, jet packs have been demonstrated, but I don’t expect them to ever be a practical tool.

    • What you’re missing is energy and failure modes. The energy to constantly keep a car sized object suspended from the ground and then fly to the destination makes it economically far less attractive than ground based methods.

      But the second issue is greater IMO. If a car breaks down in the best case scenario it rolls to a safe stop. Worst case it crashes at high speed killing the passengers and perhaps those of other cars. If a flying car breaks at best it will plummet to Earth in an empty space killing or gravely wounding the passengers. Worst case it flies straight into a building at high speed and could kill dozens if not more. This has obvious security implications as well.

      At the end of the day whilst there are advantages to flying cars there don’t seem to be enough to outweigh their costs.

  31. Very interesting survey. It was pleasing to see the results were similar to my personal predictions.

    I too would like to see the results of the DTM Reader survey.

    What would be even more interesting would be to open the survey to a wider audience and see how the views of a wider cross section of the public varied.


  32. A couple of thoughts come to mind. Asimov thought we’d have contact lenses in about 5000+years but hyperdrive and robots about, well now. The Chinese have a saying, “Those who think something is impossible should not be allowed to interfere with those who are doing it anyway.” And finally, this shows the SF stereotype that physics departments stifle creativity and would reject radical innovation is sadly very close to the mark. Here’s to sand castles in the sky.

    • The SF authors are welcome to actually build something on their own, and show the physicists how it’s done. I don’t see the interference. Nor do I see the SF crowd “doing it anyway.”

      • *Ouch* 🙂

        I agree with the sentiment, as both a physicist and SF writer. Note that Arthur C. Clarke’s non-fiction accomplishments, as substantial as they are, are not those of a builder.

        On a side note, as far as actually building rockets goes – or simply being a passenger – the video game crowd has a much more substantial track record at this time than the SF writers, despite 70-odd years of lead time and much higher head count for the writers. Garriott made it into orbit, and Carmack is trying to build something that reliably goes up there. There are SF writers employed by builders, but I am not aware of comparable examples of “actually building something on their own”, or earning the money to be “doing it anyway”.

        On a related note, can we do away with the proverbs? Next, we’ll get Nostradamus and the Farmer’s Almanac as authorities on spaceflight – the latter has at least some Bayesian aspect to it, but it is still a stretch. I can’t decide whether uninformed optimism is better than ill-informed or ill-conceived optimism, but it is more endearing. Ignorance can be rectified, faith can not.

  33. And I’m also reminded of the Outer Limits where a man from the 20th century wakes up to a future that has no apparent technology. Says, “So little progress in 200 years?” Only to find out people communicate with animals, can levitate, do TK, etc. One *never* knows the future.

    • I am fully on board with the final statement. So can you accept a world in 200 years where we live an entirely more primitive lifestyle than we do today and have lost many of our present-day perks? If this notion chafes, remember: one never knows the future.

      This alternative perspective would have less sway with me if not for the untested nature of 7 billion people and growing on a finite planet with finite resources: especially in the fossil energy domain, which has played a central role in the current scale of technology and civilization.

      • I’d also like to point out that there are historical examples of climate change, extinction events, and cultural and societal collapse – to wit: the ongoing examination of Easter Island – that give us some indication of what is possible, and Tom’s projection is certainly backed by the record. One might never know the future, but one does have an obligation to endeavour to know the past.

        • I’ve been playing around with the idea that what we are facing now will be similar to what the Europeans faced towards the end of the high middle ages. They entered a period of prosperity due to the good climate of that time allowing abundance of crops (among other things) that resulted in a population boom, economic prosperity and other advances. Of course this is a simplification but the point seems made.

          Likewise our current prosperity could be that we entered a period of prosperity due to the easy abundance of fossil fuels and the scarcity imposed upon us by their end could play out similar to the scarcity imposed by the onset of colder weather at the end of the high middle ages (I think we descended into the little ice age after that).

          The result was scarcity and population decline but not collapse. Hopefully we can weather the storm better.

  34. It’s interesting to see that a lot of physicists are skeptical that we will make much technological headway in the near future. I expect that as time goes on a lot of these things will look further and further off as simply being not feasible. I’ve been thinking that depending on how well we transition to a post peak age that perhaps the desires to even do a lot of these things will not be imminent.

    One of the things I find strange about some of the commentators here is that they seem to fall into a false dichotomy. Either we face great difficulties in the near term and began an energy decline or that we continue the march of progress towards the stars. Why is the notion of progress being cyclical with periods of progress and regression but the sums of these periods tending towards progress not considered?

    Why was is that the Romans discovered steam power but did not use it? Because their energy needs were fulfilled by slaves. Why did us Westerners first explore space but halted our advances? Maybe there is a cultural and technical aspect that prevents us from going forth. We look at the history of medieval thinkers and they considered themselves as inferior when compared to the wisdom of classical thinkers… we seem to be a unique civilization in that we position ourselves as the center of history rather then being in history. I’d argue this is due to our strong belief in the notion of progress.. one that is rooted in the enlightenment worldview.

    My bets (hopeful they are) is that 50 years from now things will be roughly the same and we will likely have a few more gadgets. Life spans increases have hit the point of diminishing returns, modern medicine will also have hit points of diminishing returns and energy usage per capita will have declined sharply and then began to recover (or if not recover at least per capita energy usage will stagnate).

    • In the early 1950’s I was a HS freshman taking Ancient & Mediæval History. We read about the steam turbine of Heron. A student asked why they never put it to use back then. The teacher, a first-year novice (and φΒΚ graduate), replied that back then there was so much cheap slave labor that there was no need for labor-saving machinery.
      That evening I told all this to my Dad, an extremely well-read HS dropout. Smoke pouring out of his ears, he said ignorant, unthinking people like this teacher had no business teaching. He pointed out that slave labor is not so cheap, compared with hired workers. A steam engine is a power source, more than a labor-saving device (as is a lever, a steel knife vs an iron knife, etc. — fussy details), and besides, in 19th Century US and Brazil, there were slaves operating steam engines. Most importantly, he said, no engineer of today or days of yore could produce a practical, economic steam engine if what he had to work with was crude iron or copper-based alloys of uncertain composition.
      History must include material science, physics, mathematics, economics and much more, otherwise “History is bunk” (Henry Ford). Kinda hard to fit into a HS syllabus. And it is still true that those who fail history are doomed to repeat it.

      • Yeah, I looked into the information about it after and metallurgy was definitely a limiting factor of the time. Even if the desire for power was around they would still have encountered problems. Thanks for the history lesson!

    • There’s an unasked question to some of these: yes, you probably could do them, but why would you want to? With a good lab, you could probably synthesize edible proteins, fats, & carbohydrates now, but why would you want to when plants & animals are far cheaper & tastier?

      Likewise, it’d be technically possible to build a colony on the Moon or (an unterraformed) Mars where people could live out their lives, but why would people want to? It’d be worse than having to spend your life in Manhattan or LA. Sure, you might work there for a while, but then you take the money and leave.

      • Plants and Animals only are cheaper in today’s conditions, but perhaps not in the future.

        Plants require a lot of water and petroleum based fertilizer…both of which will start to run out in upcoming years.

        Grazing Animals also produce a large amount of methane, a far worse greenhouse gas than CO2.

        Both line is if want to keep feeding the planet we need better food, not just more of it.

  35. It would have been interesting to see this poll with a question drawn from McKibben’s math regarding available fossil fuel resources vs. remaining carbon “allowance”, and its implications for temperature. As in: what probability would your test subjects put on what temperature increase, and/or the amount of fossil fuels we will leave in the ground…. if any.

    I think that the “Prisoner’s Dilemma”/”Tragedy of the Commons” aspect of five times as much fossil fuel as we could conceivably “risk to use” should cast a really strong doubt on the viability of the “change @ home” approach. Do the math, game-theoretically speaking – the incentive structure is terrifying.

    The countdown from 565 gigatons over the next decade implies that our problem is not that we will run out of fossil fuel. Quite the opposite – we will not run out of oil etc. fast enough. It also implies that the energy issues we are facing are more pressing than “peak oil”. It would have been interesting to see if and how this reality is reflected in the undergrad and faculty guesstimates.

  36. It’s revealing to watch the 2001 Space Odyssey movie again, made in 1968, and compare what technology from that movie has come true and what hasn’t. That movie made a real attempt to stay true to science, not like Star Trek. The rotating gravity simulation of the space station was a nice touch.

    On that same space station there is a scene where he Skypes down to Earth to talk with his daughter, which seems to go on for a while, as if the producers were trying to make a point about how amazing future communications technology would be. Imagine that — video conferencing with your kids halfway around the world! Next we’ll be teleporting around the world!

    Well, that Skype prediction turned out wrong – it didn’t actually materialize until about 5 years later than they predicted – somewhere around 2006 I believe was when you could get a laptop that could Skype around the world. Secondly, they vastly overestimated the size of the contraption that could do this Skyping. In reality, in 2011, you could do that video communication with an iPhone that fits in your pocket. Plus it has a touch screen. And you can watch TV on it too, you can take a video with it, you can do pretty much anything with it.

    With that science fiction from 45 years ago being so accurate in its predictions about future technology, then surely we’ll conquer the universe some day!

    But when you analyze different predictions from the movie, then some glaring divergences appear. As of 2012 the US no longer has a manned space program, I believe. That prediction of space colonization couldn’t have been more wrong. We have millions of iPhones of course, but none are in space.

    The opening act of the movie ended with the pre-humans picking up the bone and using it to bash the capybara into submission, followed by the next act opening with the scene of the orbiting space station – suggesting that it was humanity’s use of tools, starting with the bone, which had enabled this amazing feat, that through our intelligence and ingenuity we had escaped the earthly bounds of our barbaric ecological origins.

    No mention of energy’s role, of course… An energy analysis reveals that nothing could be further from the truth. How were those rockets powered? Oil products, of course! Or at least, energy from fossil fuels. Ironically, while everyone was celebrating our space future, our actual dependence on ecological productivity (symbolized by the dead capybara they had beaten into submission) was actually increasing, exponentially. In fact, per capita US consumption of fossil fuels didn’t stop increasing until around 2001, ironically! Too bad we’re beating that ecology into submission; it seems we’re going to need it after all!

    I don’t recall if you’ve ever discussed this much – the difference between advances in information transformation (an iPhone) versus energy transfer (a car), and why one of those is advancing in leaps and bounds and why one has stagnated. I think there is a great deal of confusion about this, maybe that’s a suggestion for a future post, to get into the physics of entropy and information to explain why there is this difference.

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