Natalie Wolchover, Life's Little Mysteries, Space.com (April 22, 2011)
(NASA, via Space.com, used w/o permission)
"Incomprehensible as it sound, inflation poses that the universe initially expanded far faster than the speed of light and grew from a subatomic size to a golf-ball size almost instantaneously. | CREDIT: NASA"
"A refreshingly simple new idea has emerged in the complicated world of high energy physics. It proposes that the early universe was a one-dimensional line. Not an exploding sphere, not a chaotic ball of fire. Just a simple line of pure energy.
"Over time, as that line grew, it crisscrossed and intersected itself more and more, gradually forming a tightly interwoven fabric, which, at large distances, appeared as a 2-D plane. More time passed and the 2-D universe expanded and twisted about, eventually creating a web — the 3-D universe we see today.
"This concept, called 'vanishing dimensions' to describe what happens the farther one looks back in time, has been gaining traction within the high energy physics community in recent months.
The Lemming's no theoretical physicist, but the simplicity of the 'vanishing dimensions' model is attractive - aesthetically, if nothing else.
Maybe another reason the 'vanishing dimensions' cosmological model looks good is that we've been through this sort of thing before, in a way.
The Ptolemaic model for the universe - with Earth in the middle, surrounded by concentric circles and spheres all moving at a steady pace - was simple enough. Problem was, it wasn't a particularly good match for what we actually saw in the sky - like planets apparently slowing down, stopping, backing up, and then going 'forward' again.
Folks who liked the Ptolemaic system had and answer: more circles. Lots and lots more circles. epicycles is what they called them - and by the time they were through, they had a wonderfully elaborate set of epicycles circling epicycles circling - - - but the thing still didn't match what we saw in the sky.
Then Copernicus came along, with a model that had our sun in the center. Turns out, the 'perfect circles' idea isn't the way the Solar system works - but even assuming that the orbits of planets were exactly circular - the comparatively simple Copernican model was a much better match to observations, that the Ptolemaic system.
Maybe this 'vanishing dimensions' thing is another case of 'simpler is better.'
Back to the Space.com article:
Vanishing Dimensions and Occam's Razor"...If correct, it promises to bridge the gap between quantum mechanics -- the physics of the very small -- and general relativity – the physics of space-time. It would also make sense of the properties of a hypothetical elementary particle called the Higgs boson. And best of all, it would do so with elegant simplicity.
" 'In the last 30 years, [physicists] were trying to make our theories more complicated by introducing more particles, more dimensions,' said Dejan Stojkovic, a physicist at the University of Buffalo who researches vanishing dimensions. 'We decided to go the other way and make theories less complicated in the high energy realm. At high energy [in the early universe], we are changing the background on which the standard model of particle physics is formulated. In 1-D, the problem greatly simplifies.'..."
Like the Lemming said before: sometimes the trick is to see which explanation is simpler. That principle's called Occam's Razor - named after William of Occam, a Franciscan friar. (Phil Gibbs, 1996; Sugihara Hiroshi, 1997; math.ucr.edu)
What's particularly attractive about the 'vanishing dimensions' model is that it can be tested. There's one experiment, mentioned in the article, that will/would 'look' at gravity waves. Just one problem with that: it seems that nobody's managed to detect a gravity wave yet.
There are other ways to test the 'vanishing dimensions' model, though: outlined in the article.
Whether it turns out to be a good match with reality or not: the 'vanishing dimensions' model for the early universe is a fascinating, elegant, idea. In the Lemming's opinion.
- "Looks Like a Cosmic Constant - Isn't"
(September 16, 2010)
- "Dark Matter Either Exists, or It Doesn't"
(June 14, 2010)
- "Dark Flow: This Universe on the Move?"
(March 18, 2010)
- "Dark Matter, Dark Energy, Galaxies, Mathematics and Observations"
(January 17, 2010)
- "Physics, Black Holes, and the Nature of Space: The More We Know, the More We Know that We Don't Know"
(May 15, 2008)