Strange

I am told (by people I trust understand these things) that it is quite possible to change the coordinate system used to describe the universe so that there is no expansion but a change in time: thus red-shifted photons are not "stretched" (or lower energy, if you prefer) but were ticking at a slower rate. No one uses this coordinate system because it has no advantages and is more complex (the speed of light is not constant, for example). And, for most people, it is less intuitive than the normal coordinate choice.

If clocks don't measure time, then what do they measure!? (And what use are they? ) And if time is not measured by clocks, how can we measure it?

Pigeon Chess? http://rationalwiki.org/wiki/Pigeon_chess

That doesn't make much sense (when compared with observation): when you increase your speed, their clock slows down (and they will say your clock slowed); when they increase their speed, their clock slows down (and they will say your clock slowed). How can that be a result of something happening to your clock (which was the point of the thread)?

If you are so sure, then perhaps you can present the math or evidence that convinced you. Maybe we will be convinced as well.

But you (and your clock) are always stationary in your own frame of reference. Your own clock always runs at the same rate (proper time). It is only someone else's clock you will see running slow - because you "made" them move. The point is, it is just about observations / measurements made between frames of reference. Nothing "happens" to anyone's clock.

Getting close enough to feel the shapes of individual molecules. Because the probe is being repelled by the atoms. Errr, that is what "touching" is. I would like some to explain what touching means that excludes this case, but allows for the identical process when we can touch something. It makes no sense.

It is important to realise that Schroedinger proposed the cat thought experiment (you talk about it as if it were a real thing!) to show how ridiculous the Copenhagen interpretation of quantum mechanics is. It was not really supposed to make sense and probably isn't physically realistic. So, yes, I'm sure there are better examples. Ones taken from real life, perhaps, where we have shown quantum superposition in the lab. And note that wave-particle duality is a completely different thing. It is just a (rather misleading) way of describing the properties of quantum particles.

You are correct. And even proton interactions are not purely electromagnetic. I would like to know what they think "touch" means. Or maybe what "atom" means. If the atoms of two surfaces are not touching each other, then what is happening? An atomic force microscope works by "feeling" or "touching" individual atoms: https://en.wikipedia.org/wiki/Atomic-force_microscopy

I lik to think I am like a Zen master. But the point I was trying make is that the questions you are asking really depend on what you mean by touching. The interaction of two surfaces is purely electromagnetic in nature (*). That is true whether you talk about a ball hitting wall or two atoms. You can throw a ball and watch it bounce off a wall. We can fire atoms (or even subatomic particles) at other atoms, and watch them bounce off. The effect is the same in both cases. So, I suspect that whoever said that atoms can't really touch was trying to sound clever (and failing). (*) Actually, the Pauli exclusion principle may play a role as well ...

What do "touching in macro level" and "touching in micro level" mean? And how are they different?

And that was exactly my point. Therefore, time dilation cannot be a "mechanical" effect on the clock.

I guess it depends partly on the definition of "touch". Also, if the atoms aren't touching one another but the electromagnetic fields are, then that implies that the fields are not part of the atom. But it is clear tat the fields are part of the atom; arguably they are the atom.

The wave functions describe how the atoms interact (in other words, touch each other).

I think you should be more worried about the CMB, than red shifts. People came up with all sorts of alternative theories when Hubble's law was the main evidence for expansion. All those ideas died when the CMB was confirmed to exist.

It may be related to the idea of a false vacuum. But that is a bit vague...

No it doesn't. There are several models that allow for multiple inflationary events. (Just to be picky, the "big bang" model describes the current expanding and cooling of the universe from an early hot, dense state.)

He has posted his nutty ideas on a number of forums. I am glad he has found one (i.e. his own) where he can post whatever he wants. I hadn't realised quite how crazy he is, though. I wonder how people like that manage in real life.

Welcome to the forum. Nice to see that you are interested in science and have a good imagination. Perhaps you could show, in mathematical detail, that your idea matches or improves on the predictions of general relativity. How exactly would it explain the rotation curves of galaxies? Please show calculations that match the observed data. How exactly would it explain the apparent acceleration of expansion? Please show calculations that match the observed data. How exactly would it explain the red shifts of distant galaxies? And why would the red-shift be proportional to distance? Please show calculations that match the observed data. And how does this explain the cosmic microwave background?

The only way the balloon analogy makes sense is if: 1) You remember that it is a 2D analogy for 3D space (so there is no thickness) 2) The only things it illustrates are: 2.1) There is no centre of the surface 2.2) All dots on the surface move away from each other and the speed of separation is proportional to how far apart they are.

This is the great challenge of our age. The mathematics of general relativity requires that manifolds are continuous and differentiable. Attempting to deal with the possibility of quantised time and space is the reason for things like string theory, loop quantum gravity, etc.

Which, given the number that would be required, would be a lot of the time. Unless you can produce some calculations and/or evidence to show that the scientists who looked into this got it wrong? Again, the amount that is required to account for the missing mass would be visible either by its own emissions or by blocking the light from other sources. Unless you can produce some data or other evidence to show that the scientists who looked into this possibility got it wrong? Here is a link to the NASA article, rather than some new-age dick: https://www.nasa.gov/mission_pages/chandra/news/H-12-331.html And this, of course, has nothing to do with dark matter. 1. Yes, all these have been included in calculations. (The clue is in the name "missing baryon problem" - in other words, scientists had a good idea how much "normal" matter there should be in the galaxy. This research fills in some of the gaps.) 2. Satellite galaxies cannot affect the orbital speeds of stars and gas inside the galaxy. And, given the enormous numbers of black holes that would be required, this would be very visible. Unless, of course, you can produce some calculations and/or evidence to show that the scientists who looked into this got it wrong? Excellent! So are you now going to address some of the questions / objections to your idea?

If the explosion is throwing things towards you then that will be blue-shifted. We do not see that.

I believe he was referring to the surface of a torus (as a 2D analogy). As far as I know, there are no modern cosmological models that describe the universe with a boundary.

And that raises a good question: how could changing your own velocity (or gravitational potential) affect someone else's clock!?