Messier 82

Messier 82
Beautiful Hubble shot of a starburst galaxy, M82

Friday, November 28, 2008

Bad Science and Bad Logic

I wrote an entry a few days ago praising the science reporting in the New York Times. But it seems that for every good pop-science article, there are a dozen bad ones. Take this latest from Discover Magazine as an example.

Science's Alternative to an Intelligent Creator: The Multiverse Theory

Now, I can't speak with authority on whether the scientists quoted in the article are doing bad science (improbable), or whether they're just terrible at communicating their good science (entirely possible), or whether the person who wrote the article simply misrepresented them horribly (most likely in my opinion). But I do know that the article is woefully misleading in both science and logic.

The article discusses the idea of the "multiverse," which is actually an interesting idea to contemplate. It proposes that there are many (possibly an infinite number of) other universes, which may have different physical laws than our own. Some variations of this theory include the proposition that other universes are continually spawning (possibly even from our own, through black holes or other oddities). Now, there are significant and legitimate arguments for the possible existence of a multiverse. The ones described in the article are not among them.

The authors try to tie the multiverse concept to another legitimate scientific idea: that the existence of the universe as we know it is highly improbable. It turns out that if you tweak certain parameters of our fundamental physical laws, life as we know it - along with other elements of the universe as we know it, such as stars, planets, etcetera - could not exist.

In the process, they commit at least two grievous logical errors which not only undermine their argument but could serve to discredit in the minds of the public the real, legitimate scientific theories which they are claiming to promote.

The first sin against logic is basing their argument on a highly-flawed understanding of probability. In essence, the argument is based on the idea that our universe's laws are highly improbable, but would be more probable if there were a bunch more universes out there. This argument is perhaps emotionally compelling, but it is in fact ridiculous.

It is true that when you play a game of chance a lot of times, it is in fact more likely that you will get a specific desired outcome one of the times. If I play the lottery ten million times, it is more likely that I will win one of those times than if I only play it once. This is basic probability, and most people have an intuitive understanding of it.

However (this is a big however), our intuition frequently leads us astray. The fact is that playing the game many times does not increase the odds of getting the specified outcome on any one specific play. Most of us intuitively believe that it does. It's normal, when playing at a slot machine, to think "I've lost so many times, I'm due to win any minute now!" Casinos base their profits on this intuitive misunderstanding. In reality (and casinos' profit margins operate in reality) the odds of winning the next time you play are completely unaltered by the fact that you lost the last 50 times you played.

This seems contradictory - doesn't playing more increase my chances of winning? Yes. But it doesn't increase my chances of winning at any one particular time. The converse is that knowing I've won on one particular play does not increase the probability that I've played a bunch of other times and lost. If I went out tomorrow, bought a lottery ticket, and won, you would not be able to reason from that outcome that I'd probably played the lottery hundreds or thousands or millions of other times.

How does this relate to the Discover article? The fact is that (assuming the laws of the universe arose by chance and not by some mechanism of necessity that we have yet to discover) all we know is that we've played the game at least once and won. We won this one specific time, and this specific universe has stars and planets and galaxies and life in it. If we had not won, we would not be here to argue about it, so it's guaranteed that in any universe where we exist to talk about it, we won. We can not deduce from that outcome how many times the game was played. It could have been played once, ten times, a thousand times, a million times, an infinite number of times, and none of those would alter the probability of this particular specific universe being the winning ticket. The probability of us being here, in this universe, right now, would be completely unchanged and would remain (again, assuming the laws we're talking about are a matter of chance) statistically infinitesmally small.

The second is invoking a false dichotomy. Here's the claim in the article:
Call it a fluke, a mystery, a miracle. Or call it the biggest problem in physics. Short of invoking a benevolent creator, many physicists see only one possible explanation: Our universe may be but one of perhaps infinitely many universes in an inconceivably vast multi­verse. Most of those universes are barren, but some, like ours, have conditions suitable for life.
Now, I don't know if they got this from the physicists. I certainly hope not. It lends credibility to two horrible anti-science arguments: first, that scientists are out to disprove the existence of a deity (and will go to any number of ridiculously absurd and illogical lengths to do so); second, that observations about the universe as we know it can be used as scientific evidence to point to the existence of a deity. Both of these arguments are patently false. Scientists in general are not hostile to religion and are not out to disprove it, and the fact that our universe is improbable is not an argument for the existence of an even more improbable entity.

Even barring the argument I made above from the discussion and assuming that the multiverse is actually a legitimate solution to the problem of the improbability of our universe (if it is a problem), this argument is still a false dichotomy.

First of all, for the same reason that intelligent design is not a solution to the problem of complexity, a divine or intelligent creator is not a solution to the problem of improbability. The creator/designer itself would have to be complex, and is certainly improbable - it would have to exist in the first place (how? we'll never know unless we can detect and measure it) and have a very specific set of characteristics in order to have created this specific universe as we know it.

Secondly, there are other possible solutions to the problem of improbability. Maybe there's something inherent to the process by which our universe formed that made its characteristics inevitable. Maybe there's something inherent to the stuff that comprises it. We don't know, and we're trying to find out. There are many potential solutions to this problem, and it is horribly disingenuous to point to two of them (neither of which is actually a solution) and claim that they're the only two.

Discover, I'm extremely disappointed in you.


  1. I'd back up the mistake(s) further. How do we know that the universe as it is is improbable? To define probability you divide the number of times the experiment (tossing a coin, whatever) came out the way that you wanted by the total number of trials. For the universe, we have 1 trial and it came out with us. Insofar as you can talk about probability, which you can't really about a singular event, the probability of a universe like ours is 1.

    Slightly more generally, there's nothing that says that, say, the fine structure constant really could be very different from what it is. The apparent 'fine tuning' is that we've chosen a particular set of units and assume that the variable can range from zero to infinity. Yet we've never observed a universe where it's different. Until we do, it's ... er, premature to talk of the present universe being improbable.

    For now, we're in the situation of Douglas Adams' puddle -- surprised that the hole we're in matches our size so well.

  2. I was giving them the benefit of the doubt on that particular assumption, which, I agree, is not a great one to make. The puddle is an excellent analogy.

    But I am aware of legitimate scientists outside the pop-science-writing universe who make actual arguments about the essential arbitrariness of the fine structure constant, and while I'm not 100% sure I agree with them, I'm also not 100% equipped to argue with them, not knowing everything they used to come to that conclusion.

    On the other hand, if there are any scientists actually trying to make the argument that the article outlined...I don't know what to say. Even granting the possibility that they're right about the fine-tuning being a matter of chance, which I'm prepared to concede for the sake of debate, their argument still falls apart.

  3. come on, aren't you being a little bit too critical, quasar? If you take it, in and of itself, the article isn't very strong, but the post in it's entirety is quite good. Many comments offer the same criticisms that you point out. I am talking of course about the EvolutionBlog post, not the article, or meta-article. That article only made some claims, nothing doncrete. "The hypothesis of a multiverse explains a lot of data"- flat out wrong, the multiverse is something which comes from the information, and makes no predictions as of yet.

    Additionally, i am confused: multiverse- yes or no?

  4. I think you may be misunderstanding - I liked the EvolutionBlog post (which I only found some days after I wrote this one - I'm not responding to it or any of the comments in it). I just think the Discover article was a disaster.

    I'm not sure where you got the quote "The hypothesis of a multiverse explains a lot of data" but as far as I can tell, it's not from me - with whom are you arguing?

    Re: multiverse, I'm not yet qualified to have an opinion.

  5. i was agreeing with you. It is from the evolutionblog article, which paraphrased the other. The original stated that the facts fit the theory, but it is quite ther reverse, as the multiverse hypothoses has made no predictions other than 'anything and everything.' I think that there is a multiverse, simply from a eternal inflation perspective. The "fine tuning" line of reasoning is a red herring, and should be recognized as such.
    Now honestly, i don't care about your qualifications quasar, i just want to know where you stand. I have no qualifications either. In particular, what are your thoughts on my comments and those of cwfong? they are great fodder for discussion, after all.

  6. Ah :)

    Seriously, I honestly don't know. I have been working on developing a level of understanding of the math behind the theories. From a purely conceptual point of view, I find the multiverse quite compelling, but without understanding the math I'm not really able to take a position and stand behind it.

    As far as the comment thread there, I think I agree pretty solidly with you on this point:
    "i have to agree that the only life we know of is us, so the universe being "primed for life" seems excruciatingly ad hoc. We don't even know if the paramenters can be changed in the first place, like jim harrison said."

    However, I had a little trouble following the rest of the thread, which seemed to get bogged down with a bit too much metaphysics.

    (for anyone else reading, we're talking about this post/thread:)

  7. you mean the CTC's and such (you can ignore the God/gods discussion)? Those aren't metaphysical entitites, but interesting manefestations of the "wild side" of general relativity. There was a paper, like i said, on this verey topic, by J. Richard Gott, III and Li-Xin Li (Can the Universe create itself?):

    After that discussion, cwfong gets into the whole "time is only a metaphor" argument, and i think it is important to note this beforehand:

    Posted by: John Morales- #211-

    RickrOll, I suppose cwfong seems to be saying that, if the Universe is but one of many embedded in some Metaverse, and if the Metaverse is eternal, it "says little" to investigate any given universe's origin or end.

    I don't see how it follows, even granting the premises, and the light beams example doesn't seem relevant.

    cwfong seems to be poo-pooing the very concept of time's arrow as relevant.

  8. um, are you there?i guess this thread is done. what a shame