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Physicist Kip Thorne On the Physics of "Interstellar" 289

A review of Interstellar at Scientific American that was not entirely flattering of the film's scientific aspects caught the eye of Cal Tech physicist Kip Thorne, who served as a consultant on the movie, and has actually written a book on the physics depicted. He and SciAm writer Lee Billings ended up having a conversation about how the film deals with time travel, black holes, and more. A slice: I think the laws of physics very probably forbid warp drives and traversable wormholes. The research that has gone on over the past 25 years trying to determine whether its possible all point in negative directions, but it’s not a firmly closed door. So there are two issues here. One is that the laws of physics probably forbid it, but, gee, if they don’t, it would be great to have! The other is that the technology required to make a warp drive or a traversable wormhole is so far, far, far beyond the technology needed for a laser sail or a nuclear-pulse rocket that I would not be in favor of putting any significant resources into trying to develop it. Now, you may have small amounts of money—tens or hundreds of thousands of dollars—spent on this, but nothing is wrong with that. Peer-review, at least in the United States and in Europe, is too strong for there to be any danger of millions or billions of dollars being spent on these things. The technology required for wormholes is so far removed from our current and plausible near-future capabilities that to throw lots of money at it would almost certainly be a total boondoggle.
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Physicist Kip Thorne On the Physics of "Interstellar"

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  • by XxtraLarGe ( 551297 ) on Sunday November 30, 2014 @02:23PM (#48491707) Journal

    The technology required for wormholes is so far removed from our current and plausible near-future capabilities that to throw lots of money at it would almost certainly be a total boondoggle.

    So basically what he's saying is we might as well dump the money into a black hole. Sounds like most government programs.

    • by Feral Nerd ( 3929873 ) on Sunday November 30, 2014 @02:47PM (#48491915)

      The technology required for wormholes is so far removed from our current and plausible near-future capabilities that to throw lots of money at it would almost certainly be a total boondoggle.

      So basically what he's saying is we might as well dump the money into a black hole. Sounds like most government programs.

      Does that cover the government projects where they bail to private companies that are to big to fail?

      • Re:Total Boondoggle (Score:4, Interesting)

        by XxtraLarGe ( 551297 ) on Sunday November 30, 2014 @02:56PM (#48492029) Journal

        Does that cover the government projects where they bail to private companies that are to big to fail?

        Yes. They should have let them fail, but then they wouldn't have gotten the golden parachutes.

      • yes, too big to fail.. infinite mass, wormhole.. singularity.. and we're right back where we started with this discussion.

    • by joh ( 27088 )

      Just be happy to get not all the government you pay for.

    • by sphealey ( 2855 )

      So basically what he's saying is we might as well dump the money into a black hole. Sounds like most government programs.

      Such as the government program that created the Internet, thus making it possible to post the quoted comment on Slashdot.

    • by plopez ( 54068 )

      Well just merge it under the f-35 program

  • breakthroughs and follow-on tech arising in decades (example of invention of SR and GR and their use in present everyday life) means such cautions about "boondongles" might be nonsense.

    We already know the "Standard Model" and "General Relativity" both are incomplete and have mutual contradiction where their realms overlap; something better is needed

    • He's talking needing energies that would make Doctor Who's Tardis, powered by an exploding supernova, gasp in disbelief.

      I'm all for breakthroughs, but geeze.

      • those are estimations based on current models that may be *wrong*

        • ... but have huge amounts of evidence that indicae they're not THAT wrong.

          • we have no working quantum gravity theory to explain what would really happen; so no real or theorectical evidence that wormholes could either be created or sustained. introducing a basic part of quantum mechanics into wormholes leads to out-of-control creation and flow of virtual particles without limit

          • Beware of breakthroughs... [that] have huge amounts of evidence that indicate they're not THAT wrong.

            Well, they are good enough for everyday work. Today's everyday work. We'll be looking for something better tomorrow, since what we got now will not get us the flying cars we want.

            But remember kids, it all starts with imagination. Which is not at all scientific. Which most definitely is not "real", even though all our technology and all the things good and bad that we do with that technology could never have come into existence without someone first imagining a thing.

            To use the language of grandparent post

  • by microcars ( 708223 ) on Sunday November 30, 2014 @02:35PM (#48491771) Homepage

    I am so disappointed.

    • by nine-times ( 778537 ) <nine.times@gmail.com> on Sunday November 30, 2014 @03:20PM (#48492305) Homepage

      Yeah, the blog post seems a little insane to me. I get it when Neil deGrasse Tyson complains about things like, in some movie the Earth spins the wrong way, or if the constellations are wrong for the time that the movie takes place. He's nit-picking and he knows it. He's pointing out interesting scientific inconsistencies. It might possibly be educational, and he's showing off his knowledge and attention to detail, and whatever, that's fine.

      But this guy is actually complaining that the movie depicts a stable wormhole that we can travel through. His problem with it is, scientifically, we have no reason to think that it's possible, though we don't strictly know. Did he think that either Christopher Nolan or the audience was not aware that we can't create wormholes?

      Even in the movie, it's not depicted as something that's easy to create. But that's beside the point, really, since it's a science fiction movie that is just positing that such a thing is possible for the sake of building a plot around that supposition. It's like complaining about Jurassic Park on the grounds that, "It's unlikely that we'll ever be able to clone dinosaurs from ancient mosquitoes formed in amber." Or complaining about the movie E.T. because, "We've never been visited by extra-terrestrial life forms-- at least not so far, not as far as we know..."

      • by sconeu ( 64226 )

        OBDISCLAIMER: I'm a nitpicker. I'm even a member of a movie nitpicking site.

        That said, I'm with nine-times. There is a thing in fiction, particularly in film, called "willing suspension of disbelief". Yes, the wormhole may not be possible, but it's plausible, and it moves the plot. You suspend your disbelief and go along for the ride.

        • Thats how I approach movies/tv. I'll allow one giant off the wall liberty (i.e. zombies, warp drive, super powers, senator all of a sudden turns evil and becomes a murderer because he wasn't given majority leader, etc) but everything else has to follow along somewhat logically. Moderate wiggle room is sometimes allowed if I remain entertained cause thats the whole point of course. But if too many plot devices are required to keep the story going I'll give up on it pretty quick.

      • I get it when Neil deGrasse Tyson complains about things like, in some movie the Earth spins the wrong way,

        It spins the wrong way in the opening sequence of The Daily Show and he has previously remarked about this to Jon Stewart.

    • [SPOILERS]

      It's the wild inconsistency that was really a drag on the story. It was cool when they lost seven years by wasting a few minutes' time on a rescue attempt by getting a little bit close to a supermassive black hole.

      But then later, we have a man in a ship skimming the event horizon and the person up in a much higher orbit is talking to him in realtime by radio.

      It's like, why even bother with the pretext of being scientific if the whole damn thing is going to be thrown out when the plot holes demand

  • by SuricouRaven ( 1897204 ) on Sunday November 30, 2014 @02:39PM (#48491805)

    It's all theory work. Money isn't the limiting factor there, it's just that very few people have the required intellect and level of education to advance the field. There's nothing to spend money on until some of them propose an experiment to test their latest theory. Even the particle physics people can ask for new accelerators, and cosmologists always have some new instrument on their wish-list.

    The only hope for fundamentally new space travel tech right now is the quantum vacuum thruster, and that only because the experimental evidence so far has too many flaws to say anything more than 'something funny going on here.'

    • A quantum vacuum thruster has never been tested in a vacuum, or anywhere else it couldn't produce its micronewton thrust by plain old fashioned electromagnetism.

    • I would not call it theory work, if the question is which 'machine' might be able to create a worm hole.
      But well, thinking about machines not built yet, might be considered theoretical work.
      However we are so far away from stuff like worm holes that thinking about technologies regarding them is IMHO more a 'philosophical work' than a theoretical one.
      I mean you can theoretice about a new type of transistor ... because we know how they work and that they exist.

    • physicist have to eat. And raise families and live like civilized people who have actual lives. This of course is incomprehensible to some US TV viewers who suspect that Big Bang Theory is just slightly not a documentary. People are as amazed watching Tyson and Hawking hold their own on Colbert or Oliver a if they had just seen a talking squirrel. So it'll be an uphill slog for a while here. It takes money for faculty positions and the time to do the work. Einstein's work was pure theory until it was
    • by Illserve ( 56215 )

      It's all theory work. Money isn't the limiting factor there...

      Exactly! Theory is essentially free. You just sit down and stare at a wall and maybe write some damn equations on it. There's no need to test those theories, or to even pay the utility bills for the scientists who create them. The best scientists work on a pro-bono basis because they have transcended the need to eat, sleep, or pay their staff a living wage.

  • by Anonymous Coward on Sunday November 30, 2014 @02:47PM (#48491917)

    Why is Scientific American even running such an article?

    What's next? Supposedly-serious newspapers "fact-checking" a comedy sketch?

    • Re: (Score:2, Informative)

      by Anonymous Coward

      It's an ad. There's a movie out, and you know how it is with the movie industry: They're starving.

    • by Anonymous Coward on Sunday November 30, 2014 @03:06PM (#48492139)

      Why is Scientific American even running such an article?

      What's next? Supposedly-serious newspapers "fact-checking" a comedy sketch?

      Scientific American stopped being about Science at least 15 years ago. If you want to see how much it has gone downhill compare the scientific quality of the articles of the 1950/60/70/80s and those of the 90/00/10s. And weep in dispair.

  • by RichMan ( 8097 ) on Sunday November 30, 2014 @02:55PM (#48492019)

    Tidal forces. This is the biggy, If you are in orbit deep in a gravity well with a steep gradient then the orbital velocities of things 1m up/down from each other are significantly different. The material stength of any object extending over that 1m has to resist that force.
    Those forces will rip materials to shreds.

    Think of your hands being pulled up, while your feet are pulled down. The further into the gravity well you get the more up and the more down the two pulls get.

    The only way to avoid the tidal forces are a straight in drop. But you can't do that as all around the well is a swirling gas field that will push you into an orbit.

    • Re: (Score:2, Interesting)

      by Anonymous Coward

      "Shreds?" The correct term, which was developed by Italian physicists but what it describes is actually of ancient Chinese origin, is 'spaghetti;' i.e. If you get anywhere within proximity of a Black Hole, you and your crew and craft will become spaghetti.

    • Of you go straight to the center of a gravitational body, you still have the problem that the force closer thr the center is higher than at the opposite site. I have no idea where you got your wrecked idea about phisics from, and what exactly is a 'gas field' that is pishing you outwards? And atmosphere that is 'breaking' your decent?

      • by sconeu ( 64226 )

        Gargantua was a Kerr object. I seem to recall [DISCLAIMER: I may be wrong] that in that case the event horizon is stretched into a disk, and if you approach it perpendicular to the disk, it's possible to survive the tidal forces.

      • My intepretation of their comment is that you point directly towards the center of mass and then ACCELERATE (not "drop") "down". Then there is the two-fold assumption that #1 there is an accretion disk and #2 for some odd reason you've decided to go through it. The idea is that it would be rather difficult to maintain your orientation with the accretion disk material pressing against you laterally (not "outwards"... but "sideways" - the gas is orbiting and you're trying not to).

        First, I'm curious about th

        • by Immerman ( 2627577 ) on Sunday November 30, 2014 @05:32PM (#48493053)

          > Even if this works, ...
          Absolutely. As you travel deeper into a gravity well the difference between the acceleration of your head and feet is increasing super-linearly - gravity falls off with 1/r^2 after all, and the difference would be:

          difference in acceleration (using h as height and r as your average distance for the center of the gravity well)
          = 1/(r-h/2) - 1/(r+h/2)
          = [(r+h/2) - (r-h/2)] / (r-h/2)(r+h/2)
          = h/(r^2 + h^2/4)
          ~= h/r^2 -- since h will be a negligible component of the denominator

          So anyway, yes, to avoid being pulled apart you will have to accelerate at an ever greater speed as you plunge headfirst into an intense gravity well. And it doesn't actually improve things much: where before your head was being ripped off as it accelerated 100g's faster than your feet, now your feet are being crushed into pulp as they try to transfer 100g's of acceleration to your legs.

          You wouldn't need infinite acceleration though, just enough to carry you to the event horizon, at which point in a black hole physics as we know it can no longer connect your head and feet and all bets are off. Or, in the case of a classic SF wormhole, once you reach the edge of the "tube" at the center things probably stabilize and you're good to go, and you still haven't reached zero radius or infinite acceleration.

          So, depending on the size of the "boundary sphere" at the center, and the tricks you play to minimize your acceleration delta, it just might be possible to reach it alive.

    • by Trogre ( 513942 )

      The movie explained that away by making it a supermassive black hole, where tidal forces are (supposedly!) much less.

  • "Physics" (Score:2, Insightful)

    by Dereck1701 ( 1922824 )

    "physics very probably forbid warp drives and traversable wormholes."

    I would imagine that the human understanding of physics 50 years ago would have forbid the creation of the kind of microelectronics/transmitters/battery technology that are commonplace in most of our pockets today. Admittedly the physics of FTL (or any interstellar travel method) are far more difficult than what we have done in the electronics field over the past few decades, but believing that our pre infantile understanding of the unive

    • Re:"Physics" (Score:5, Informative)

      by rogoshen1 ( 2922505 ) on Sunday November 30, 2014 @03:16PM (#48492283)

      Well, think of it like this.. with limiting factors such as the speed of light, or planck length, those tend to be rather concrete 'limits' to technology. So unless our understanding of those limits is 'wrong', it's not like they can just be removed by some handwaving and dilithium crystals.

      Your comparison to electronics 50 years ago was purely a lack of understanding of materials science. To create a transistor there's nothing in the fundamental physical laws that preclude its construction, thus requiring a workaround to construct.

      • by Kjella ( 173770 )

        Of course the universe is impossible given our current understand of physics. Big bang created energy. Big bang created an imbalance between normal matter and anti-matter. Big bang created a singularity with zero entropy and it's been growing ever since. None of those things are possible with physics as we know it, yet it all apparently happened. The only thing we can be quite sure of is that we don't know everything.

      • Re:"Physics" (Score:5, Interesting)

        by Immerman ( 2627577 ) on Sunday November 30, 2014 @05:55PM (#48493187)

        Actually the whole point is that we have several theoretical constructs that should allow travel from A to B at speeds greater than lightspeed. All rely on the fact that special relativity only imposes a local speed limit: i.e. you can't travel faster than light *through space*. Nothing in it forbids the existence of short cuts (wormholes) that connect distant parts of the universe with drastically shorter paths. Nor does it forbid things like an Alcubierre warp drive, where you don't move at all through the space you're in, but instead move an isolated bubble of flat space through the surrounding space at arbitrary speeds, while leaving the contents of that bubble of space in free fall (Relativity imposes no speed limit on space itself.)

        Both constructs have their weak spots, but so far every time someone comes up with something showing them to be "impossible" somoeone else comes up with a modified construct that removes the impossibility. And of course there's the little issue that if Special Relativity is correct then any method of getting between A and B faster than light can also be used to send information into your own past, which would wreak havoc with our understanding of causality. But then the whole "time passes in only one direction" thing is a serious weak spot in our current understanding of the universe as well, so it may be that it's only us that would have an objection to causality loops, and not the universe itself.

        Where every construct falls flat on it's face is that we have absolutely no idea how to actually create such a thing - we're mathematically modeling the things we might be able to do if we had nuclear reactors while still living in the stone age. But then that's what our species does, we tell ourselves stories of things that have never existed, and then try to figure out how to make them exist. We did it when our ancestors imagined how useful a killing-stone with a long, light handle would be, and we do it today on a million different fronts. Only difference is today we do our imaginings with a level of mathematical precision that guarantees that, if our starting assumptions are true, then the thing we imagine can in principle be built, even if we don't know how to do so at present.

    • Re: (Score:2, Interesting)

      by Anonymous Coward

      No, 50 years ago the primary limitations blocking cell phones were in the engineering, not so much in the theoretical physics.

      You will have to reach back a few hundred years before cell phones were a theoretical impossibility.

      Which means, unless you expect to live another several hundred years, there is no way you will see warp drive in your lifetime.

    • "I would imagine that the human understanding of physics 50 years ago would have forbid the creation of the kind of microelectronics/transmitters/battery technology that are commonplace in most of our pockets today."

      There have been very few advancements in basic physics in the past 50 years that have made their way into products and most of the cutting edge stuff we have today was foreseen decades ago.

      • Few advancements? Dark mater/energy (assuming that it even exists) wasn't even theoretical 50 years ago, the presiding theories of the day said that the universe was slowing (current theories say it is accelerating), the Higgs Boson (still not proven) was just beginning to be theorized and I don't know if it qualifies as physics but it was assumed that the solar system was swept clean of asteroids millions of years ago, then Shoemaker-Levy Nine slammed into Jupiter, the resulting search eventually led to t

        • 'Few advancements? Dark mater/energy (assuming that it even exists) wasn't even theoretical 50 years ago, the presiding theories of the day said that the universe was slowing (current theories say it is accelerating), the Higgs Boson (still not proven) was just beginning to be theorized'

          and neither of those resulted in any technology at all. And you're wrong about dark matter. It was hypothesized 80 years ago to explain orbital velocities of stars in the galaxy and confirmed by more recent and precise mea

    • 50 years ago? The diode was invented in 1906, bro. Binary logic was well established by the 60's and Li-Ion batteries weren't far behind in the 70's. Most everything we're using today was floating around in some form in the 60's, just a hell of a lot bigger. Even the discovery of the Higgs was a minor disappointment to physicists because it turned out to behave almost exactly as predicted.

      I agree there is a long long way to go but to say we're still pre-infantile is shitting on all the great achievements hu

  • by GreatDrok ( 684119 ) on Sunday November 30, 2014 @03:11PM (#48492213) Journal

    I can't be alone in not liking this film. It wasn't the science (there was obviously a lot of work done there) that bothered me, and besides which with Sci Fi you always get a 'gimme' or two (warp drive, transporters, technobabble etc) but I really didn't feel anything with the story. It didn't draw me in, it just dragged. This wasn't what I was expecting as I had been looking forward to this film since I saw the first teaser. I see so many people going on about who great this film was but I can't help but wonder what it was that I missed?

    • by microcars ( 708223 ) on Sunday November 30, 2014 @03:35PM (#48492431) Homepage

      I see so many people going on about who great this film was but I can't help but wonder what it was that I missed?

      The film is about Love. Everything else is window dressing.

      If you try and make the film to be about something else, you will be disappointed.

    • by brxndxn ( 461473 ) on Sunday November 30, 2014 @06:14PM (#48493331)
      I loved this movie.. It wasn't perfect - but no science-based sci-fi movie is. It's up to us to figure out how to make the impossible possible. No one needs another engineer or scientist telling us what we cannot do. We need more people like Elon Musk saying what we can do - and going out and proving it. The laws of physics are there to be broken. Defy them. Prove them wrong. Einstein broke Newton's laws.. Someone needs to break Einstein's laws.

      I'll take Interstellar over any one of the normal Hollywood we get fed to us.. (ie.. XMen, Random war movies, save-the-world CIA shit). So please tell me you think this movie was at least better than the typical Hollywood movie.

      If engineers and scientists tended to be optimistic rather than pessimistic, engineers and scientists would be running the world. Obama didn't get elected by telling us what mankind cannot do.
  • by Frans Faase ( 648933 ) on Sunday November 30, 2014 @03:14PM (#48492269) Homepage

    Spoiler alert for the movie Interstellar

    It seems he did not get the main idea of the movie. The whole movie rests on the idea that it is possible to manipulate gravity in the past. The traversable wormhole was created by some humans in the far future and allowed the main character to communicate with the past, causing himself to join a space program, which would lead him to the place to communicate with the past, and by this save human kind from some disaster and in the far future allow to develop the technology to create the wormhole and a black hole with strange properties. So, it also involves a form of bootstrapping. Which makes even less sense, if indead traversable wormholes could be made at all.

    • Re: (Score:2, Interesting)

      by Anonymous Coward

      Yeah. In philosophical circles the term is "reverse causality." It means that something you do today causes something to have happened several days ago.

      Though our mathematical models of subatomic particles suggest that something like this can happen, there hasn't been any demonstration that such a visualization of microscopic behavior can result in the logical equivalent in macroscopic scales (meaning, even if electrons seem to do this, humans still can't and never will).

      Few things excite me as much as th

      • Well, as the saying goes: "Special Relativity, FTL, and causality: pick any two". If SR is correct then any ability to transfer information between two points faster than light automatically implies the ability to send information into your own past. And honestly, as weak as our theory is as to why we *can't* send information back in time, I think causality is a little shaky.

        So, at least in the context of an science geek watching science fiction: if you're suspending your disbelief to allow FTL travel, yo

      • I had just entered an extended period of relative calm in dealing with the concept of regular old blame, and then you have to plant the mindworm of "It means that something you do today causes something to have happened several days ago." Great. All hands - brace for therapy bills.
    • Dr. Thorne was the primary scientific consultant on the movie. For this article he's stepping away from the movie and talking about how possible or plausible some of the ideas presented in it actually are.

  • The Newtonian Physics was far more compelling than the Einsteinian Physics in that film. For example the space station link up scene and of course the part where Matt Damon punches Matthew McConaughey in the face. I only wish they could have had it that Matt Damon was punching Matthew McConaugheyin the face near the Event Horizon so it could last forever to an outside observer.

  • So just because you can't figure it out, the rest of humanity should wait? On you?
  • by PPH ( 736903 )

    A workable robot with a humor setting anywhere near 75%? Not going to happen IRL. That was investigated with the Bender character in Futurama and look at the mess that turned out to be.

  • Inconsistent fuel? (Score:4, Interesting)

    by pmontra ( 738736 ) on Sunday November 30, 2014 @06:29PM (#48493423) Homepage

    *Warming: (mild) spoilers follow*

    They leave Earth with a Saturn V like rocket and they take 2 years to go to Saturn. That contrasts Cassini's and Pioneer 11's 6.5 years to get there and the 3 years for the two Voyager probes. Let's say that 2 years is within the bounds of what we could achieve with our technology if we really have to hurry up.

    On the other side of the wormhole they do all sort of manouvres landing on (easy) and leaving planets (difficult) with only a small craft (the Ranger). One would expect you need at least a large rocket to lift off from a planet with 80% of Earth's gravity (the ice world).

    It seems they burnt normal fuel in the Solar system and used some very energetic fuel later on. Anyway, who cares, it's only fiction :-)

    By the way, does anybody know what kind of rocket would be required to leave Mars and fly back to Earth?

  • by russotto ( 537200 ) on Sunday November 30, 2014 @07:42PM (#48493823) Journal

    The worst physics didn't involve strong gravity fields or high velocities or accelerations. Just Newton's Third Law and an energy argument. The second-worst bit of science was biological, but also involved an energy argument.

    Spoilers:
    1) Matt Damon's spaceship just would have been gently pushed away when he opened the airlock. Maybe gently pushed to one side or another depending on the partial seal. It certainly would NOT have set the entire Endurance vehicle spinning like mad.

    2) The blight was better adapted because it utilized nitrogen from the air instead of oxygen? Yeah I don't think so; what do you combine with N2 that yields energy instead of spending it?

    • Totally agree with both points. The part I HATED was when our intrepid astronauts were doing much hand-wringing over which two of three planets they should be looking at. The dialog goes on for a painfully long time, and then the big reveal that one of the astronauts in the discussion is voting in favor of one of the planets specifically because she's in love with the guy on the probe ship. At this point, she makes an impassioned argument that "love" must play some role in the physics of how things work.
  • by PPH ( 736903 )

    So we can enginer our way out into space and through wormholes. But we can't cure* a crop blight?

    *OK. So the resulting food would probably lose its organic certification. And hipsters would rather die than eat GMO.

    • So we can enginer our way out into space and through wormholes. But we can't cure* a crop blight?

      Of course we could. But we didn't, so we won't. Typical SF causality loop.

  • There are much bigger problems [google.com] with the physics in Interstellar, which Kip Thorne is not willing to address now that he has his name on a book claiming that the movie is unusually scientifically grounded. He should have run the plot past some colleagues.
  • The "science" in Interstellar is all invented for the film. It has much more in common with Calvinball than astrophysics.

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