05 February 2006

2-D Time

This presentation (by Alexander Franklin Mayer) was apparently slashdotted, but I heard of it through other means. It is arguing a new cosmology, in which rather than there being a Big Bang, inflation, Dark Matter, and Dark Energy, there's "simply" some six dimensions (or more) to spacetime. The old model says that there's four dimensions - 3 dimensions of space (x, y, z) and time (t). This radical model says that instead time itself is orthogonal (perpendicular) to space wherever it's located, and since space is warped, time takes up more than one dimension. This has a few interesting results.

  1. Dark matter is not required.

  2. Dark energy is not required.

  3. The CMB (cosmic microwave background), which traditionally is a result of the reionization period, is now explained by gravity.

  4. The universe is eternal, and has eternally been in dynamic equilibrium, with only local changes.


Item #4 is fishy to me. I don't see how galaxies, once evolved, can be recycled into the rest of the universe. Mayer also mentions the concept of not being able to see time orthogonal to your own. I would speculate that you can only see the projection of somewhere else's time onto your own time axis. Somewhere with their time vector going 180ยบ to ours would appear to be evolving backwards. I think the point of this talk is that it's not well understood, and he claims to have another self-consistent model, and more data is required to determine whether his or the traditional one works better with the observations.

Mayer then gets into some theoretical geometry - such as how you can explain why we see fewer galaxies in the past if we assume either non-Euclidian geometry or assuming accelerating expansion. He kinda glosses over how it could be instead a measurement bias (it's harder to see further, fainter galaxies), or just that there were fewer galaxies. So basically, his talk is just a little too complex for a layperson, and some parts are a little too simple for someone who knows his stuff. I don't blame him really, it's damned hard to present complex material at the appropriate level!

I made it to around slide 24 (of 90) before it started overwhelming me. It's tough for me to wrap my head around this stuff. I understand some of cosmology in general just enough to follow it, but not enough to explain it well yet. If you, gentle reader, have specific questions, I would enjoy answering them, as I find that trying to explain to others often helps me further my own understanding. I won't guarantee I'll be right, or even comprehensible, but I shall try my best. :)

4 comments:

utenzi said...

I prefer to only deal with the first 3 dimensions. The 4th, time, is confusing enough, heading off to 5th plus dimensions is too frustrating to even think about for me. More power to you, ZP, for trying.

zandperl said...

So you know how Tic-Tac-Toe is usually two dimensions? Draw three of them next to each other and you'll get 3-D Tic-Tac-Toe. I've seen games (both computer and physical) of this. It's really intriguing trying to determine all the ways of winning.

Now, when that game gets boring, make a 3x3 grid of Tic-Tac-Toe grids, so that there's 9 Tic-Tac-Toes in all. That's a 4-D game. Add two more sets of 9 grids and you get 5-D...

Also look up Flatland sometime to help understand 4 physical dimensions (time is not considered a dimension for those purposes). It won't get you up to understanding the 26+ dimensions that some cosmology models require, but it's a step in the right direction.

zandperl said...

danteclc:
Well, it's a website through Stanford University (though it appears to be down now), so I don't think he's a crackpot but a real scientist. I suspect he's a grad student rather than a prof, since his name doesn't really come up on a google search, but he is in the Stanford directory, and I doubt it'd be just an undergrad.

Arthur said...

I've read both the intro presentation and the two follow-ons. I won't claim to follow all the math, but it does seem to hang together. I would agree that this approaches being as big as E=mc², too.

zandperl, you said you didn't see how galactic matter was being recycled? I think he touches this briefly in the second set of slides. Among lots of other things, he takes issue with the tuning-fork model of galactic classification. If I read that part correctly, in his view, there's a single chain of galactic evolution:

1. A Quasar develops at some point when a black hole at some other point on the surface of the hypersphere opens up a wormhole exiting there.

2. Eventually, a Seifert Galaxy with long ejection bands forms

3. Which becomes a barred spiral galaxy and

4. Settles down to being a stable spiral.

5. Eventually, galaxies attract each other and collide. The more this happens, the sooner...

6. The galaxy becomes elliptical.

Somewhere in the last three stages, the galaxy develops its own black hole which becomes bigger and bigger compared to the mass of the rest of the galaxy, and...

7. Its matter pours through another black hole to spawn the birth of a new galaxy somewhere else.

Insofar as I have misunderstood and distorted Mayer's model, I apologize. I came here because I, too, was looking around for corroborating/refuting arguments -- or at least substantive critical discussion -- regarding the model Mayer has developed. I will say, fwiw (which ain't much), that it seems intuitively more satisfying than theories that require such large quantities of "things" we've never been able to observe.