... we might say that we, its observers, are contracting? Is it that the math would be more complicated?

its all relative anyway . . . right?

What do you mean by contracting? That everything remains in the same place but is getting smaller?

The red shift we see is not consistent with objects contracting. Specifically, we observe the further away an object is the longer its red shift. That is something you would not observe if everything was just getting smaller. Longer red shifts for more distant objects point to an expanding universe not a contracting one.

Stu

Doesn't matter. The universe is ending in the next 14 trillion years. We're all doomed!

If we were contracting, but the light wasn't, then the light would appear redder due to the longer wavelength. But then we would observe the speed of light getting faster and faster.

We could correct for this by making C slow down over time, but then the red-shift would disappear. So yeah, I don't think it really works as a model.

Feynman elaborated on this in “Six Not so Easy Pieces,” p. 26-27, where he explained that physical laws are not symmetrical under a change of scale. “The wavelength of light emitted by the atoms in one box of sodium atoms and the wavelength of light emitted by a gas of sodium atoms 5 times in volume is not 5 times longer, but in fact is exactly the same as the other. So the ratio of the wavelength to the size of the emitter will change.”

He also talks about trying to build a cathedral to scale with matchsticks and how it doesn’t work.

Occam's Razor?

We are contracting, and the universe stays the same size.

The maths would be identical.

Piers,

Math is math. If we are contracting, the physical laws, and hence the math, would tell us that we are contracting. Simply because it is impossible for us to contract without being able to observe and measure such a phenomena. We can measure such a phenomena because the laws of physics aren’t symmetrical at different scales.

I'd like mathmatical proof of these statements

What do you mean by 'we'? Don't think the earth or solar system is contracting. Galaxies are moving further apart, thus the universe is expanding. Although they never explain what or where are we are expanding to.

I could be wrong here. I was just going off my interpretation of what I read in Feynman’s book. The wavelength of light emitted by a bundle of atoms stays the same regardless of expansion or contraction, so the ratio of the wavelength to the size of the emitter changes. So I assumed if we were contracting, we could measure it, which ( if I’m understanding it ) we can. However, Piers may be right. I was thinking we would know the difference between a contraction and expansion, but, as Piers said, the math would be identical.

Sorry, I think I over thought (or under thought ) this one.

Edit - the scale of individual atoms is not arbitrary, but quite definite. Would it not be impossible to contract past a certain level?

If we are contracting, why do I keep gaining weight?
lol

We live in an expanding universe. All of it is trying to get away from Chuck Norris

A mind boggling question to be sure. But even more so, is that not only is the universe expanding, it is accelerating! Or is light and everything in it slowing down?