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Cosmic Variance
« A Glimpse Into Boltzmann’s Actual Brain
Knowing How to Wear Clothes »

Anthropic Selection Illustrated

by Sean Carroll

From Saturday Morning Breakfast Cereal.

Sat Morn Breakfast Cereal

We go to war with the laws of physics we have, not the ones we wish we had.

Share

May 6th, 2007 11:06 AM
in Humor | 33 comments | RSS feed | Trackback >

33 Responses to “Anthropic Selection Illustrated”

  1. 1.   mollishka Says:
    May 6th, 2007 at 1:29 pm

    There’s a joke in here somewhere about H2 being a hydrogen atom with one too many protons, but I’m not exactly sure where it is …

  2. 2.   Carl Brannen Says:
    May 6th, 2007 at 4:20 pm

    This is hilarious for multiple reasons.

  3. 3.   Watch what you wish for! « Entertaining Research Says:
    May 6th, 2007 at 5:48 pm

    [...] Watch what you wish for! Tip from Sean at Cosmic Variance. [...]

  4. 4.   Quasar9 Says:
    May 6th, 2007 at 6:14 pm

    lol Sean, so did the Genie turn into Dark Matter
    and ‘disappear’ into Thin Air?

    PS – If thoughts (and imagination) are physical and chemical processes – does that mean what we think or dream off ‘physically’ exists even if it is not ‘real’

    Do Thoughts & Dreams evaporate – or – simply move between two phases: from the observable universe or ‘physical’ 3D+T dimension, into another ‘dimesion’

  5. 5.   Quasar9 Says:
    May 6th, 2007 at 6:55 pm

    Does that prove that the arrow of Time is not reversible
    Not even Genie’s can take you back in Time?
    Not even to the last written test or exam?

    Mind you a ‘bent’ teacher or a good ‘hacker’ could alter his school grades or test results – for a small bribe.

  6. 6.   V. Says:
    May 6th, 2007 at 9:05 pm

    Am I the only one he thinks that all of recent skepticism and cynicism over string theory, dark matter, and supersymmetry is to somehow related to the failure to find WMD in Iraq and belief that we were misled into the war? Am I just crazy?

  7. 7.   Paul Valletta Says:
    May 6th, 2007 at 11:37 pm

    If the Anthropic reasoning/selection is correct, then there’s is a definate choice for why things are the way they are?

    Hydrogen, in a specific form, may have multiple choice’s for placing Electrons into a certain Valence.

    Sometimes, it’s better to re-STATE the question?..and other times it’s better to let Nature remain correct!

  8. 8.   weichi Says:
    May 7th, 2007 at 12:32 am

    V,

    yes, you are crazy

  9. 9.   V. Says:
    May 7th, 2007 at 1:07 am

    Weichi,
    I may very well be crazy, but my theory is that a lot of people are deeply upset about being led into a war on the basis of claims which turned out to not be accurate. I think this has produced a mood of mistrust of ‘authorities’ and deep cynicism on the part of some people, which reflects their attitudes towards things we are told should exist, such as dark matter, susy, and extra dimensions. Perhaps my theory is just crazy enough to be right.

  10. 10.   crazee Says:
    May 7th, 2007 at 2:49 am

    or just crazy enough to be crazy. cf Godwin’s law

  11. 11.   Haludza Says:
    May 7th, 2007 at 3:17 am

    You know V, I think you may be onto something there.

    It would be interesting to see how, say, trust in the media over the decades might relate to attitudes to the more abstract ends of science. Mind you, surely just the mere existence of a Peter Woit or two has been a comparable factor?

  12. 12.   Neil B. Says:
    May 7th, 2007 at 11:34 am

    Hey, if those flaky smart-aleck theories are right somehow, where observers retroactively create the conditions for the self-contained universe in the past, then we do go to “war” with the laws of physics we wish we had (i.e., anthropically friendly ones.) Yet, I think such “explanations” are rubbish (mainly because what ultimately needs explaining is always the existential given, not due to origination in time anyway.)

    PS – I think the point of the cartoon is that if a genie made the valence statement true (not, the student having answered right given our world), then lots of things explode for some chemical reason. Is that so?

  13. 13.   Stephen Uitti Says:
    May 7th, 2007 at 12:04 pm

    We are all agreed that your theory is crazy. The question which divides us is whether it is crazy enough to have a chance of being correct. My own feeling is that it is not crazy enough.

    Niels Bohr

  14. 14.   Kea Says:
    May 7th, 2007 at 4:00 pm

    LOL!!!! I agree with Carl. Elephants all the way down.

  15. 15.   aquariid Says:
    May 7th, 2007 at 6:39 pm

    I think I get it. If things were different then they wouldn’t be the same, uh, I think.
    Could someone please explain to a non-physicist (though 50 yr sci-fi fan) why the so-called anthropic principle has any significance beyond being a classic tautology?

    I’ve lurked here for the past few months. I really appreciate the opportunity to have something of a behind the scenes view of the professional cosmologist. Thanks
    Aquariid (a frequently unnoticed meteor shower)

  16. 16.   confused Says:
    May 7th, 2007 at 8:22 pm

    Alright, someone help me because I don’t get it. It’s not as though there isn’t an element with two valence electrons; we just arbitrarily named it helium instead of hydrogen.

    So how does changing an arbitrary label blow up the universe?

    Or is the genie just being really obtuse and changing the laws of physics so that an atom with 1-proton and 2-electrons is stable (which presumably makes it impossible for anything to exist)?

  17. 17.   Jordan Says:
    May 8th, 2007 at 12:03 am

    The problem is that if every hydrogen atom in the universe suddenly has two valence electrons in is 1s orbital, you get lots of hydride anions. So. Many. Hydrides. And they will all react. Quickly. And probably explosively.

  18. 18.   Lab Lemming Says:
    May 8th, 2007 at 4:18 am

    In addition to Jordan’s issue, the universe would presumably suddenly find itself with a strong net negative charge.

    But speaking of boom, can any of you professional astronomers give us the lowdown on this super-duper nova reported in the New York Times? What was it, where was it, can we see it, what is the actual data, and where does it fit in the grand scheme of things?

  19. 19.   Jason Dick Says:
    May 8th, 2007 at 4:37 am

    Either that, Jordan, or all protons in the universe will suddenly have a charge of +2e, suddenly causing all matter to blow itself apart due to the incredible repulsive force of all that positive charge.

    And Lab Lemming, are you talking about this one?
    http://www.nytimes.com/2006/02/24/science/24star.html?ex=1298437200&en=5a1593907c7dfe1e&ei=5090&partner=rssuserland&emc=rss
    Or something else?

  20. 20.   Scott Says:
    May 8th, 2007 at 5:10 am

    Cool!

  21. 21.   Arun Says:
    May 8th, 2007 at 6:42 am

    A variation on “I wish I never see her/him again” and become blind.

  22. 22.   island Says:
    May 8th, 2007 at 11:06 am

    aquariid asked:
    why the so-called anthropic principle has any significance beyond being a classic tautology?

    Strong interpretations aren’t tautological, because they include a “fundamental dynamical principle” that defines the structure of the universe from first principles.

    Weak interpretaions are both, circular, and tautological, but there is no valid weak interpretation without the multiverse, because the weak features are not what is observed.

    “People”, (like David Gross), say that the (weak) fact of our existence can’t be falsified, so the selection principle can’t be falsified, but ANY valid cosmological principle necessarily falsifies any possibilty for selection effects.

    The fact that the ‘main failure in 20 years’ to produce a fundamental dynamical principle in lieu of “anthropic selection”, *most apparently* and only indicates that the anthropic constraint must be strongly linked to any realistically plausible cosmological structure principle, so he has disassociated the dynamical structure principle that is being indicated by the only two relevant facts, while complaining about the solution that is *most apparently* being offered.

    A Very Strong Anthropic Principle

  23. 23.   James Nightshade Says:
    May 8th, 2007 at 8:42 pm

    Suppose I was born in a particular small town in Illinois, population

  24. 24.   James Nightshade Says:
    May 8th, 2007 at 8:46 pm

    Suppose I was born in a particular small town in Illinois, population < 100.

    Isn’t it unlikely for me to be born there, rather than a large city like Los Angeles, Nanking, or Mexico City? Should I suppose that some cosmic selection principle has determined my unlikely birthplace?

    [This dumb comment revised to comply with the dumb comment parsing.]

  25. 25.   Robert O'Brien Says:
    May 9th, 2007 at 12:35 am

    Sean:

    Where were you when your fellow atheists were taking a dump on physics?

  26. 26.   island Says:
    May 9th, 2007 at 5:04 am

    A selection principle isn’t a physics principle when it is a selection effect.

    I think that I do no disservice to science when I say that the term “principle”, in context with Barrow and Tipler’s weak interpretation, is a careless misuse of terminology by a field that used to be so very careful about such wording.

    A “cosmic selection principle” that relies on random probabilities to rationalize improbabilty is a selection effect, not a physics principle.

    A physics principle says something fundamental about structure and dynamics, whereas, selection effects, do not. A cosmological principle says something fundamental about the structure and dynamics of the universe, but they also define theories of everything, because this explains the motivating physics for the observed constraints on the forces.

    I wonder what theory of everything that the theory of evolution might dictate if the anthropic constraint on the forces includes a mechanism or thermodynamic function for Darwinian-like evolution, which preserves the second law by conserving energy through evolutionary leaps to higher orders of the same basic structure?

    You know, kinda-following the hard-evidenced fact that we became more “entropically efficient” when we lept from apes to harness fire, and beyond…

    You know, hard empirical stuff like that…

    Too bad that science can’t even recognize the begged question.

  27. 27.   The Crossed Pond » When facts count Says:
    May 9th, 2007 at 4:52 pm

    [...] Shamelessly lifted from Cosmic Variance, who linked it from Saturday Morning Breakfast Cereal [...]

  28. 28.   Neil B. Says:
    May 9th, 2007 at 6:26 pm

    aquariid:

    Sorry, but I am more adept at philosophical analysis than physics and not a cosmologist (can reply re L. Wittgenstein better than Ed Witten…) However, to answer your question:
    …why the so-called anthropic principle has any significance beyond being a classic tautology?
    A well put anthropic principle is not the tautology, that of course outcomes must be consistent with starting conditions (i.e., our being here and the original laws.) That doesn’t explain why there wasn’t any number of possible lifeless universes, without observers existing (whether anyone would be there to say so being rather irrelevant to most astute thinkers.) Hence, the real point is, the “horizontal” question: why a universe like this (favorable laws AND outcome regarding life) or not, rather than the phony “vertical” question, of the outcome (life) being consistent with the starting conditions/laws, which of course it would be.

    The interesting thing is, as any reader of the Tippler and Barrow classic The Anthropic Cosmological Principleknows, that the range of suitable laws is very narrow indeed (like the required value of the fine structure constant.) Hence, why is “the universe” like that, if not “designed” for life? There are lots of avenues there, like multiple universes with different laws such that we find ourselves in one of the few that are suitable etc. However, once one can believe in multiple universes with “different laws”, then where does it end? The modal realists have made the cogent argument that “all logically possible” universes should “exist”, since no clear logical reason can be given for selection and reification of some and not others. Indeed, they make a cogent case that the idea of “existing” as some special material state other than the platonic mathematical world description is circular, indefinable, and not logically coherent — can you do it?

    If so, then the problem is actually even worse, because then all possible worlds really means all possible descriptions. If so, one has a vanishing Bayesian probability of finding oneself in a world that continues to be lawful instead of one of the infinitely more that were like this up to this point and then begin to diverge. Why? Because of all the change to different laws and variations and distortions of laws that can be described, and indeed the entirety of what behavior can be described after that point which certainly includes a gigantic set of chaotic futures, etc.

    Hence, I think there really needs to be a manager of some sort, to ensure placement in effect of observers like us in a world that really has laws, since logical possibility is just too inclusive. Think of that as you wish. (Not to mention, our having experiences etc., but that gets into consciousness issues and I am just making the argument relating to physical conditions and our being here.)

  29. 29.   Zach Says:
    May 10th, 2007 at 1:20 am

    Hey, I’m the guy who actually drew the comic above.

    This is probably the most flattering blog post about any of my work ever. It’s nice when people a lot smarter than you enjoy your work.

    thanks!

    Zach

  30. 30.   Lab Lemming Says:
    May 10th, 2007 at 5:43 am

    Jason,
    Actually I was talking about this one:
    http://www.berkeley.edu/news/media/releases/2007/05/07_supernova.shtml

  31. 31.   Sean Says:
    May 10th, 2007 at 10:58 am

    Zach, thanks, I’m a big fan of the comic.

  32. 32.   Cuidado com o que deseja at 100nexos Says:
    May 16th, 2007 at 8:36 am

    [...] “Quantos elétrons de valência tem um átomo de hidrogênio?” Dois Um Depois… “-Você pode ter o que desejar!” “- Eu queria ter acertado aquela questão”. “BOOOOM!” [via Cosmic Variance] Veja também:Monstro Espaguete Voador: o Jogo Ilumine o maior número possível de pessoas&nbsp…Jogo: administre o McDonald’s E não só uma franquia. Das vacas &a…Autostitch: Crie panoramas fantásticos com três cliques O Autostitch é um programa gratuito fenome…Gizmo — Imperdível “Gizmo” é uma compilação fa… [...]

  33. 33.   Ten cuidado con lo que deseas... « La Singularidad Desnuda Says:
    May 23rd, 2007 at 11:50 am

    [...] deseo del poco avezado estudiante. Alguna de estas ideas provienen de un hilo de discusión en Cosmic Variance, donde vi por primera vez esta tira cómica. En primer lugar habría que ver cómo decide el genio [...]





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