Back in 1968. when I saw Stanley Kubrick’s 2001: A Space Odyssey on the gigantic curved screen at the Ambassador Theater in St. Louis, I thought that the timing was a bit optimistic. December of that year would see the first trip around the Moon, a startling and expansive moment, but even with Apollo in the air, I thought a human mission to the moons of Jupiter would take longer than 2001. 2025 seemed more like it. Now, of course, we see that 2025 is out of the question for manned missions, and the best attitude for space futurists is caution.

It’s easy to see how tricky the future is to predict by looking at the past. If you extrapolated from the technology of the Hellenistic Greeks, you would have wound up with a space-going civilization somewhere around 1300, as Carl Sagan once speculated. Bumps happen along the way, civilizations topple, technologies are shelved. Even so, the allure of prognosis keeps us looking ahead, and the truly optimistic among us can easily go over the top. As witness a fascinating study performed by Tom Murphy that is now up on his Do the Math blog. Thanks to Philip Bagust for passing this along.

Attitudes About the Future

Murphy is a physicist at UC-San Diego, now working on General Relativity by bouncing laser pulses off the reflectors the Apollo astronauts left on the Moon. Prompted by an unwise comment by a student (“If it can be imagined, it can be done,”) Murphy created a survey to see what people thought was likely in the future by way of technology. He sought comments from academics about ideas ranging from futuristic jet-packs to wormholes, asking physics faculty at a variety of top-20 schools across the US, as based on graduate program rankings drawn from US News and World Report.

But to keep things in perspective, Murphy presented the same survey questions to physics grad students and physics undergraduates, as a way of tracking attitudes according to age, expertise and selected path in life. So, for instance, the survey asked what is the likelihood that humans can carry out the bulk of transportation in personal flying machines rather than being tied to the ground in cars. Respondents could choose from the following:

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

The answers to 20 questions like these are all laid out graphically on Murphy’s blog. It turns out that professors don’t think personal flying cars are likely — in fact, more of them chose ‘unlikely to happen for humans’ than any other answer. Grad and undergrad students, however, opted for choice 2, ‘likely within 500 years,’ perhaps reflecting an optimism divide or simply a lack of knowledge of the problems involved. Murphy, a licensed pilot, says he is with the faculty on that one. After all, flying and driving are two different things: “Unleash the population into 3D space and watch the mayhem!” As a former flyer myself, I can’t help but agree.

Technologies and Skepticism

So you see the method. The range of questions goes from flying cars and jetpacks to up-close study of black holes, permanent Moon colonies, fusion power, terraforming, robots and more. Have a look at Murphy’s site for the complete list. For now, I want to focus on the items most pertinent to the interstellar community. The fusion issue seems timely since early starship designs like Daedalus rely on a form of fusion, and so does the ongoing Project Icarus. Murphy frames the issue this way: “Power our society with fusion, opening up practically inexhaustible supplies of deuterium on the planet (forget about tritium here—imagine D–D reactions)?”

We’re not talking about fusion engines for spacecraft, but it seems clear enough that a breakthrough in fusion on the ground would help us develop options for space travel. The old saw is that fusion is always 50 years in the future, so you might have expected that to be reflected in the survey. But while almost no one said it would never be accomplished, few thought it would be available within decades. In fact, faculty, grad students and undergrads all cluster around choice 2, ‘likely within 500 years.’ Fusion, it seems, may take a while.

Clearly a survey like this has no predictive value of its own, but let’s think about what it does mean. When you’re talking about futuristic ideas, as we so often do in these pages, it’s obviously helpful to get a range of opinion, and that includes especially people who specialize in issues related to the subject at hand. I doubt many of Murphy’s faculty are fusion engineers, but they do work in the discipline of physics and thus understand the issues involved. It’s also useful to see where popular opinion on such matters is, and here we see that while many undergrads think fusion is a long way off, a much larger group of them than faculty think it might happen within 50 years.

A Star Trek Future?

You can see what we’re coming around to. Murphy now asks survey responders what they think of the Star Trek universe, quizzing them on things like warp drive, wormholes and teleportation. The question on warp drive is posed this way:

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)?

Choice 6, ‘less than 1% likely to ever happen, or impossible,’ is the overwhelming choice of faculty, with 91 percent finding it essentially impossible. Both grad students and undergrads chose choice 6 more than any other, but a wider range of answers show up among them, including a few who opt for warp drive within 500 years or less. As to wormholes, faculty opinion is almost unanimously in the ‘not likely’ to ‘impossible’ range, while teleportation shows the same faculty skepticism but much broader support for the idea among the undergrad community.

I won’t go through all the items in this survey other than to note that a lunar colony within 500 years is widely accepted — few think it will happen within 50 years. 80 percent of the respondents in each group think it will happen someday, but few peg it within the next five decades. Murphy comments:

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.

Two other quick things to note. First, on the question of whether humans will ever open a line of communication with aliens, the answer from the survey seems to be, across the board, ‘someday’ but not within the immediate future. The other interesting point is that Murphy does not ask about interstellar travel using slower methods that do not violate Einsteinian relativity. It would be helpful to see the breakdown there, though I suspect we would see an answer somewhat like the SETI question, with most respondents putting it in the ‘someday’ camp.

Exponential Growth vs. Outlandish Ideas

But among the professional physicists, out of the 20 ideas Murphy covers, only one (auto-pilot cars) is deemed likely to happen within 50 years, and only two (true robots and fusion power) make the 500 year cut. Murphy comments that although we’ve been living in an era when progress felt like an exponential rush, physicists still 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.

Murphy’s survey gives us a sense where professional and popular opinion is on a range of ideas that weave through today’s science fiction. And that’s worth keeping in mind: Science fiction wouldn’t carry the imaginative charge it does unless its ideas pushed us beyond the conventionally expected. How realistically should we take the futures it shows us? When it comes to space, the weight of opinion in this survey is that a future interplanetary, much less interstellar, culture is a long way off if it arrives at all.

Some would find this pessimistic, but I think it’s simple realism based on experience. On the other hand, optimists will say that realism is sometimes overtaken by unexpected events. My own axiom: It is the business of the future to surprise us. There’s historical precedent for that one, too.