Good Math, Bad Math

Via the Bad Astronomer comes one of the most pathetic abuses of
probability that I’ve ever seen. I’m simply amazed that this idiot was willing
to go on television and say this.

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The crank in question is Walter Wagner, the moron who tried to use a lawsuit
to stop the LHC from being activated. (Just that much, already, is amazingly silly;
he sued in Hawaii, but the LHC is in Geneva, Switzerland. How does a Hawaiian court
have any jurisdiction?)

Anyway… Wagner claims that the LHC could destroy the earth. See, there’s a tiny theoretical chance that the right collision in the LHC could create a microscopic black hole. According to Wagner, if that happens, the black hole will swallow the entire earth.

That claim is, itself, based on some pretty bad math. The only theory that predicts
that it’s possible to create a microscopic black hole also predicts that such a black
hole would evaporate – that is, would completely disappear in a burst of energy – immediately. The
exact same math that predicts that you could create a black hole in a high-energy collision also
predicts that the hole would be destroyed before it had time to do any damage. If you tweak it so that the black hole lasts longer, the energy requirements change so that it’s no longer possible to create it in the LHC. To make the black hole last a microsecond is absolutely beyond the
energy of any collider that we could ever build on the earth.

But let’s skip that – demonstrating that is pretty complicated. To get an idea of
the level of understanding of the guy who claims that there’s a real danger, let’s just
take a look at what he says.

When asked what the probability of the LHC destroying the earth is, he says 50%. Why?
Because either it could happen, or it couldn’t – therefore, there’s a 50% chance of it happening.

You could argue that that’s naive Bayesian reasoning – but if you did, you’d be an idiot. Classic Bayesian arguments about stuff like this would say that you use 50/50 as an initial prior in the absence of any other information; then you adjust that based on whatever
other information you have available. For Mr. Wagner’s stupid argument, it’s based on
a complex physical theory – a complex physical theory which provides lots of information
which you can use to update your probability estimate.

Mr. Wagner’s 50/50 claim is based on the fact that he’s absolutely clueless about how any of
this stuff works. He clearly doesn’t understand probability, and he clearly doesn’t understand
physics.

But he’s awfully funny.

Comments

  1. #1 Dan J
    May 3, 2009

    It seems that the court in Hawaii dismissed the suit on the grounds that the named US defendants weren’t able to be sued because the statute of limitations had run out (funding was provided years before the project was started) for them, and that the court had no jurisdiction over the project in Switzerland.

    Dr. (and I use that term loosely) Wagner is truly not playing with a full deck.

  2. #2 John Fouhy
    May 3, 2009

    There’s a 50% chance that I will win lotto this week: either I will win, or I will not. That practically guarantees I will win this year! Riches are a’coming my way!

    …I wonder if I should buy a ticket? I would, but the model doesn’t seem to require it.

  3. #3 CRM-114
    May 3, 2009

    I wanted to ask Walter Wagner how he would figure the odds in a horse race. Horse number N will either win the race or it won’t, so the best estimate for N to win is 0.5? If there are eight horses in the race, then the win probabilities add up to 4.0, and there’s where he’ll need to help me. I thought probability was constrained to the interval [0,1].

  4. #4 dreikin
    May 3, 2009

    Hm, I wonder what the minimum mass & energy input would be for a black hole to last, say, 60 seconds..

  5. #5 Courtney
    May 3, 2009

    From a comment over on Cosmic Variance:

    [Bayesian Joke]

    With the prior information that Walter Wagner has, 50/50 is probably a fair estimate.
    [/Bayesian Joke]

  6. #6 mj
    May 3, 2009

    Oh, but that last bit is so redeeming. John Oliver suggest that he and Wagner try to breed, as the last two humans on Earth, because hey the chances are 50/50 that it will work right?

  7. #7 Skemono
    May 3, 2009

    I seem to recall hearing someone trying to make an argument for the existence of God with a similar basis: the two options are “God exists” or “God does not exist”, and therefore each has a 50% chance of being true.

  8. #8 jeff
    May 3, 2009

    Skemomo, that’s basically the reasoning of every agnostic.

  9. #9 rpenner
    May 3, 2009

    The Daily Show clip is good at many issues, but it wasn’t a Hawaiian court so much as the US Federal court in Honolulu.

    Dan J, while the US Government argued that the case should be thrown out due to statue of limitations. But Judge Helen Gillmor did not rule on that argument or Article III standing or mootness. The September 26 decision was based on the finding that at less than 10% the US was not the main funding source for the construction of the LHC, and has no authority over it’s operation so the relevant statue invoked by Wagner and Sancho did not apply.
    http://sciforums.com/showthread.php?p=2029021#post2029021

    Wagner (alone, apparently) filed an appeal of this dismissal, and in February I mocked his arguments and suggested if he continued to disagree we could approach The Daily Show.

    In the past two weeks, three physicists (including two Nobel Laureates) asked and were granted approval to join the case as friends of the court, Wagner’s suggestion that the US be ordered to halt any funding of LHC was rejected, Wagner’s website went dark, a deadline for Wagner’s promised response to the Government’s side of the appeal came and went, the appeal was marked as ready to be scheduled for a hearing _and_ John Oliver’s piece was aired.

  10. #10 Anonymous
    May 3, 2009

    did he really say the 50/50 chance fact? i thought it was just media B.S.ing the LHC. that’s hilarious i’m an eleventh grader and i know its not a 50/50 chance that’s pretty funny stuff.

  11. #11 John Armstrong
    May 3, 2009

    jeff, stop setting up straw men, especially since this isn’t a post in any way about religion.

    Mark: good to see I can finally comment again without signing up and giving information and/or money to yet another service.

  12. #12 jeff
    May 4, 2009

    I was responding to another poster who brought up “god”, so it wasn’t me that changed the subject. But I happened to find the relation striking, actually, which is why I made the comment. If it’s a straw man, it’s inadvertent, so enlighten me.

  13. #13 Vishal
    May 4, 2009

    I discovered that video, yesterday, via another blog and when I watched Wagner argue that there was a “1 in 2″ chance of a blackhole being created by the LHC, I was at a loss for words, really! He is a high school science teacher, isn’t it?

    Of course, the most fitting reply to his “theory of probability” is provided at the end of the video!

  14. #14 ascendingPig
    May 4, 2009

    An agnostic would point out that we really don’t have all that much information about the origins of the Universe. It could have started at one point from a “Big Bang”, it could be a cyclic universe repeatedly contract and “Bang”-ing again, and it could be a simulation or creation be some extraterrestrial (extra-cosmic, really) or external being. There’s no point in arguing passionately against faith-based assumptions when mysteries abound anyway.

    … But I’m just helping derail the comments. I don’t feel SO guilty, since I feel we’ve said pretty much all that had to be said about Bayesian probability here.

  15. #15 featheredfrog
    May 4, 2009

    Gee, I guess I gotta read more newspapers (you know, those dead tree things?)

    I really thought the Wagner thing was setup with an actor. If he is real, and understands physics and probability so well, it’s kind of frightening that he’s a high school teacher.

    Anyone know where? I must NEVER move there.

  16. #16 Mu
    May 4, 2009

    Since it was brought up – how does probability deal with untestable points, like the probability of a big bang, be it from nothing or cyclic or god made?

  17. #17 Brett Hall
    May 4, 2009

    Is it just me or is anyone else conerned that this guy is a high school “science” teacher?

  18. #18 Brian
    May 4, 2009

    “one of the most pathetic abuses of probability that I’ve ever seen.”

    Mr. Chu-Carroll what worse abuses of probability have you seen?

    What could be worse?

    Would the old canard of getting 5 heads in a row from tossing a fair coin making it more likely that tails comes up be any worse?

    Brian

  19. #19 Mark C. Chu-Carroll
    May 4, 2009

    Re #11:

    John: glad to hear that it’s finally fixed. I had nothing to do with it; Seeds wonderful scienceblogs goddess, Arikia, updated our blog templates, and that seems to have fixed the problem.

  20. #20 Andrew
    May 4, 2009

    My physics professor always said the same exact thing, weird. He gave me a detention when I asked him if there was a 50 percent chance of him getting hit by a meteorite and killed and the next five seconds for “being belligerent”.

  21. #21 Seth Manapio
    May 4, 2009

    Actually, the worst thing about this clip is that of every news agency in the entire world, only the guys who follow puppets making prank phone calls were willing to say that Walter is a nut job. Everyone else just fed on the controversy.

    Sad.

  22. #22 Cerandor
    May 5, 2009

    Actually, Wagner’s argument is almost a direct quotation of Terry Pratchett. I can’t remember the exact quote, but this is somewhat similar.

    “Every million-to-one event comes down to a 50-50 chance: either it will happen or it won’t.”

    Of course, Pratchett was funny. Wagner was a joke.

  23. #23 Cerandor
    May 5, 2009

    Actually, Wagner’s argument is almost a direct quotation of Terry Pratchett. I can’t remember the exact quote, but this is somewhat similar.

    “Every million-to-one event comes down to a 50-50 chance: either it will happen or it won’t.”

    Of course, Pratchett was funny. Wagner was a joke.

  24. #24 john
    May 5, 2009

    @ dreikin “Hm, I wonder what the minimum mass & energy input would be for a black hole to last, say, 60 seconds..”
    Using the value given at http://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/hawking.html
    I get about 17,000,000kg, or approximately 10^43 eV. (Assuming that I haven’t made a careless conversion error)
    That’s a few nonillion times the energy of the LHC.

  25. #25 rpsms
    May 5, 2009

    For many years I have used this as a joke setup, mostly by way of explaining that probabilities are arrived at by adding up everyone’s 50% chance.

    Its ridiculous on its face, but most people hesitate…

  26. #26 Grant
    May 5, 2009

    While watching I found myself wondering if he was trying to sound bayesian, or just making things up. Glad to hear good priors getting some airtime.

  27. #27 Bayesian Bouffant, FCD
    May 6, 2009

    An agnostic would point out that we really don’t have all that much information about the origins of the Universe…

    A philosophically well-rounded atheist, say Bertrand Russell, might say something like this:

    It is curious that not only the physicists, but even the theologians, seem to find something new in the arguments from modern physics. Physicists, perhaps, can scarcely be expected to know the history of theology, but the theologians ought to be aware that the modern arguments have all had their counterparts at earlier times. Eddington’s argument about free will and the brain is, as we saw, closely parallel to Descartes’s. Jeans’s argument is a compound of Plato and Berkeley, and has no more warrant in physics than it had at the time of either of these philosophers. The argument that the world must have had a beginning in time is set forth with great clearness by Kant, who, however, supplements it by an equally powerful argument to prove that the world had no beginning in time. Our age is rendered conceited by the multitude of new discoveries and interventions, but in the realm of philosophy it is much less in advance of the past that it imagines itself to be.

    from The Scientific Outlook (1931) as included in Bertrand Russell on God and Religion (ed. Al Seckel, (1986)

  28. #28 Mark C. Chu-Carroll
    May 6, 2009

    Re #16:

    Since it was brought up – how does probability deal with untestable points, like the probability of a big bang, be it from nothing or cyclic or god made?

    That’s an interesting question, which naturally doesn’t have a simple answer.

    It depends on your interpretation of probability theory.

    To a frequentist, probability isn’t applicable to untestable points. The frequentist interpretation says (roughly) that probability is applicable to domains where you’ve got something which can be done repeatedly by a controlled experiment. Then the probability of an event X occurring is the percentage of times that controlled trials will produce X as a result. So a frequentist would just say that talking about the probability of something like the big bang or the existence of God is just rubbish.

    To a Bayesian, probability is pretty much always applicable. Probability is a measure of certainty about the state of your knowledge. Ultimately, everything has either a probability of 100% (it happened), or 0% (it didn’t). A measure of probability is a way of measuring how certain you can be that an event will (or will not) happen, based on your current knowledge.

    So – for an uncontrolled, untestable hypothesis, the Bayesian approach allows you to attach a probability to it. That probability is based on your knowledge. But Bayesians believe that you must always factor in all of the knowledge that you have in order to produce a meaningful measure of certainty.

    Given an event that could or could not happen, with absolutely no other knowledge other than the fact that it could happen or not, the initial starting point is 50/50.

    But in the case of something like the supposed possibility of a black-hole event at the LHC, we know a lot – we’ve got lots of knowledge about how things work. We’re not sure about any of it. But we’ve got a pretty high degree of certainty about
    some facts. To omit that from a Bayesian computation of probability of such an event is simply incorrect. If you have that information, and you omit it from your probability calculation, you’re doing it wrong, and your answer will be wrong.

  29. #29 Shadow Caster
    May 7, 2009

    LMAO! That was one hilarious video. Thanks for sharing.

  30. #30 Jake
    May 7, 2009

    When asked what the probability of the LHC destroying the earth is, he says 50%. Why? Because either it could happen, or it couldn’t – therefore, there’s a 50% chance of it happening.

    But by that reasoning, there’s a 50% chance that the LHC will destroy the Earth even if you don’t turn it on, so what does his lawsuit accomplish, exactly?

  31. #31 John
    May 7, 2009

    Wow, yea its all just hilarious. Right up to the point where everyone finally realizes they’ve made a horrible mistake. Unfortunately by then, it will be too late. I take it none of you “supporters” have children. If you did, you wouldn’t even fathom going through with this experiment that puts billions of lives in danger. I’m not a religious nut or anything, I just believe there is just way too much uncertainty to do this. Many reputable scientists have agreed that this thing could create black holes that would destroy the Earth. Hawking radiation has yet to be proven……if it turns out to be false, we’re dead. Its funny how people laugh all this off and say the risk is 0 percent. I’m sure if you asked scientists in the 1800′s what is the probability for theories like quantum physics, special relativity, and general relativity to be true, they would unanimously said 0% ! And they would all have been dead wrong.

  32. #32 Michael Ralston
    May 7, 2009

    Actually, John, even if you ignore Hawking Radiation and ignore minimum-size issues, you can work out that the largest-possible black hole (purely off of conservation of energy), isn’t big enough to eat more than a few thousand atoms before the sun goes nova.
    So you know what? I really don’t see anything to fear.

  33. #33 Michael Noonan
    May 9, 2009

    Actually the odds of 1 in 50 million were calculated by Martin Rees for RHIC in 1994. At those odds there is a half a chance of destruction by the year 2100. Since no time frame was given then half a chance of destruction is 50/50.

    The LHC will be 25 to 30 times more powerful so presumably the 50/50 scenario will be arrived at a whole lot sooner.

  34. #34 Stark
    May 10, 2009

    Sorry to butt in, but I call Poe’s Law on John.

  35. #35 paul mann
    May 15, 2009

    Chucho stick to your job, computer programming, dont make a fool of yourself, obviously you know nothing about black hole physics, the dispute is between Einstein, whose concept of black hole is a frozen star of dense matter (in this case top quarks) and will eat the earth, and Hawking, which says Einstein is wrong and black holes have no substance (no quaks) and evaporate. So it is 50 vs 50, hawking vs Einstein, and that seems conservative, as Einstein has beenproved right most times and hawking lost all his bets, apart from that your insults disqualify you

  36. #36 Phil
    June 24, 2009

    The screen at 2:25 is one of the windows boot error screens. Lol.

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