2011-07-13

Teensy-weensy, itsy-bitsy



I want to put a few things in perspective. Strings, for instance.
As I mentioned last time, I’m working my way through George Musser’s The Complete Idiot’s Guide to String Theory. I want to get a handle on what subatomic level we are dealing with when we talk about strings.

Deconstruction of matter:
1. Macroscopic, e.g., diamonds
2. Molecular, diamond allotrope
3. Atomic, carbon
4. Subatomic - Electron
5. Subatomic - Quarks
6. Strings (Image**)
First, let’s take another look at the diagram I used in my last entry, showing the progressively smaller and more basic parts of matter.

Now, try to wrap your mind around this concept: the most common estimate of the size of strings is that a string compares to an atom in roughly the same proportion that a human being compares to the entire observable universe. And we know that atoms are so small that it is only in recent years that we’ve been able to scan to the level of individual atoms with advanced electron microscopes. So I find it hard to imagine how infinitely smaller strings must be.

Beyond that basic fact lies the practical problem of ever even being able to observe a string—assuming they do exist. It would be tantamount to looking from earth to some very, very distant planet in a galaxy far, far away with the intention of being able to read the scoreboard at a Buckyball stadium there (Buckyball being the sporting pastime of the residents of that very, very distant planet). It’s likely to be a long time, if ever, that we have instruments able to directly observe either strings or Buckyball scoreboards on distant planets.

Of course, even when I was in school, no one had ever seen an atom. Technically, just a few short decades ago, atoms were just a theory, sort of like strings are now—or global warming or evolution, for that matter. But, even then, there was evidence that atoms existed. Their effects could be predicted and tested so that, even if we couldn’t see them, we knew the little devils were there.

We’re not quite at that point with string theory, though. There are competing theories which still have legitimate physicist adherents. Among the major contenders is loop quantum gravity theory. Among other things, the loop gravity theory proposes that space itself is actually composed of something, “space atoms” if you will, that act as the means for the transference of gravity—gravity being the main problem between defining the macro-universe (planets, stars, galaxies) and the micro-universe (atoms, protons, neutrons, electrons quarks and strings).

While the effects of gravity were well established by folks like Isaac Newton and Albert Einstein, their theories don’t hold up on that micro-universe, subatomic level. Hence, as I’ve mentioned, quantum theory was developed.

As Musser notes, for most practical purposes, those discrepancies don’t matter. Both astronomers and particle physicists can each explore their respective fields without regard to the theoretical offsets regarding gravity. But, eventually, when the ultimate questions of black holes or the Big Bang must be answered, then it will matter a great deal.
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