Infinite regression in the physical world?

Question

Can space be subject to infinite regression? Can there always be something smaller? Does a zero dimension really exist in space, or just time?

I thought of this question by thinking about an object between two perfectly parallel mirrors. Does an infinite series of images appear? Is this the same as the above question?

Answer 1

1. Not really. There's a certain length, the Planck Length, shorter than which the universe becomes fuzzy; there's a real sense in which you can't have anything shorter that a Planck Length. Or happen more quickly that a Planck Time, for that matter. Time is also granular on those scales.

2. This would never work, because light travels at a finite speed, c. It would take an infinite amount of time for an infinite series of reflections to appear.

Answer 2

I have been reading recently in Scientific American (Feb. 20, 2006) where it is suggested by Serious People that Space & Time are Quantized! The articles propose that there are discrete units of Volume and Time. These units are within "Planck" measurements. Part of the search is for Quantum Gravity, which is hopefully a Link between Quantum Mechanics and Relativity! (A Huge Goal in Physics!)

In addition, S. Hawkings has revised his oppinion about Blackholes as Singularities. He and Others think that Quantum fluctuations neccessitate the volume of a Blackhole to be atleast that of Planck Distances & Times. (Heisenberg Uncertainties)

So, given the success of Quantum Mechanics in general and the support of Quantum Space/Time by "Thoughtful" Others,
I, for one, am willing to entertain these Ideas.

p.s. Scratch a little silver off the back of one of your Mirrors, and you'll have yourself a Laser! But that's another story!:-)

Answer 3

Hi. Quite a difference between regression and reflection. A better idea may be what happens in a super-conducting loop of material.