Tuesday, October 23, 2007

Brains and Branes

Yesterday I made the terrible mistake of purchasing a copy of Scientific American. Actually the purchase was all right (if expensive); the real mistake was to read an article titled, "The Great Cosmic Roller-Coaster Ride: Could Cosmic Inflation Be a Sign That Our Universe is Embedded in a Far Vaster Realm?" by Cliff Burgess and Fernando Quevedo (November 2007). This article is all about "string theory," a unified theory of . . . everything, really--the whole physical enchilada, from the universe(s) to particles--although I don't think they use that term, enchilada. Instead the use the following terms:

observable universe--self-explanatory

other universe--"an unobserved region of spacetime" [if you say so!]

calabi-yau--this sounds like the name of an interesting dessert, but it actually refers to a six-dimensional shape; because I am able to visualize only shapes that have a maximum of three dimensions, 6 might as well be 66, as far as I'm concerned. SA tries to illustrate a calabi-yau, but it just looks like a splash of milk: a highly confused three-dimensional space, although I'm sure they were doing their best.

brane--this is short for membrane. Why don't they just say (or write) "membrane"? What's so hard about that?

scalar field--"a field described by a single number at every position. Examples: temperature, inflation field." I guess this means heat as measured by temperature is one slice of the universe.

moduli--I think this would be a good name for a car. "What are you driving these days?" "Well, I'm leasing a Moduli." Instead it refers to "scalar fields that describe the size and shape of hidden space dimensions." Oh, I see. It describes something hidden. If it's really hidden, then how can it be described? Answer: by guessing, under the cover of mathematics. Sez me.

annihilate--no, this doesn't mean what you think it means. It means "to convert completely to radiation." I believe I have done this to dinner a few times, in the oven or on the stove-top.

So I talked with my computer-science/math colleague today in the coffee shop (ah, the perks of being a professor--you can find an expert on the premises), and I said, "I think physics is looping back to philosophy." He said, "It never left philosophy!" I said, "I think these guys are just making stuff up." He smiled. I said, "I can't visualize any of what they're talking about." He said, "You [he meant "one"] can with math. Math can visualize it." Math became very uncomfortable to me after basic algegra and geometry--Euclidean geometry, I should say. I loved that kind of geometry. It made sense, and it seemed to apply to my world, or my "scalar field."

From a philosophical point of view, I approve of the idea of multiple universes, because at least it stalls for time. Otherwise we have to confront the question of what's outside the boundary of this universe. "Nothing" is one answer. To which we respond, "What does nothing look like, and where does it begin, and why does it begin there?" From a theological point of view, heaven could be one of these additional universes. So could hell, but I prefer not to talk about that, and I refuse to make a joke about the "scalar field" of "temperature" with regard to hell. Anyway, with string-theory, we can say, "There's some other stuff on the outside of the universe, and we're going to have a look at it some day, but for now . . . look at the pretty bird!"

Of course, there's also something called an anti-brane. I think it's something that annihilates a brane, but my brain was annihilated by the article, which must be some kind of anti-brane in my case.

My colleague says that string theory is pure theory insofar as it cannot (at the moment) be observed, nor can it make predictions, whereas people were able to make accurate predictions based on Einstein's theories of relativity. One prediction was that the path of light from a distant star (I guess they're all distant, including the sun) would bend when it went past the sun and was observed from Earth. Apparently this was verified during a lunar eclipse of the sun. I don't know if they just eye-balled it or whether they used instruments. :-)

I said, "Well, if you can't observe phenomena, repeat experiments, or make verifiable predictions, then you're not doing science, are you?" My colleague said, "No, and there are books out there that call string theory 'not even wrong'--that is, not even worth trying to disprove." Wow. Beyond wrong. That's pretty bad. That's almost anti-brane.

He recommended a book by Brian Greene called The Fabric of the Universe, which tries to explain string theory, I guess.

Let's talk size for a minute. According to the SA article, the observable universe is this big: 10 to the 26th power meter(s). An ant is 10 to the minus 2 power meter. Presumably an aunt is somewhat larger than that. The minimum meaningful length in "nature" is 10 to the minus 35th. That's a lot smaller than an atom, but don't go by me, because I've never seen an atom all by itself. They seem to travel in packs.

As far as poetry goes (and it seems remarkably similar to physics these days), I can get only as far as Einstein, and really I can't even get that far, but here goes:

Whereabouts Unknown

If I understand Einstein
correctly, and I don’t,
my whereabouts are, strictly
speaking, unknown.

No one is the center of the
universe, but anywhere can be.
Therefore everyone’s coordinates are
contingent, just a song at twilight.

Don’t worry: If I say I’ll be
somewhere at a certain time,
I’ll be then there—unforeseen
whereabouts notwithstanding.

That you know where to find
me, and I you, exemplifies relative
dependability, a feature of our companionship—
love’s old sweet Newtonian song.

from The Coast Starlight: Collected Poems 1976-2006, by Hans Ostrom.
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