Strange

That supposes there is a "root" to be reached. I assume we will just keep creating better models.

I didn't mention Planck time. I have a vague recollection of an experiment that measured (an upper limit on) the time for an electron to absorb the photon's energy. I doubt I could find it again, though... But the important point is that photons are indivisible quanta. If the photon has less energy than required to "kick" the electron up to the next energy level, then it will have no effect; you can't do it with one photon after another, for example. This is basically what Einstein got his Nobel Prize for.

It is actually quite important. Some people seem to think that the job of science is to find "truth" or how the universe "really" is. But those things are inaccessible and are the subject of philosophy, not science. Asking that science should tell us "absolutes" is equally hopeless. There are few absolutes in science, and certainly not when it comes to relative motion. And all scientific knowledge is provisional until new evidence or better theories are found.

I think some very serious scientists have proposed exactly what you suggest. They suggest we perceive time moving forwards because of increasing entropy, which may be related to the expanding universe. http://en.wikipedia.org/wiki/Arrow_of_time http://preposterousuniverse.com/eternitytohere/faq.html

I think it does: at one time there is no photon, later there is. There are many factors that affect the time taken for an excited atom to emit a photn, but it can be calculated. http://en.wikipedia.org/wiki/Spontaneous_emission

Exactly, the photon is created when the system loses energy as electromagnetic radiation.

Does that mean that if it started to contract that backwards run would time?

It doesn't exist.

e is "the zero point energy due to the Heisenburg uncertainty principle"; i.e. the lowest energy state of the vacuum.

And (apparently - it is way over my head) Poplawski's "universe from a black hole" theory is able to create the energy needed to create a new universe when a black hole forms.

Although a lot of them depend on GPS working correctly.

We don't know it came from nothing. I suppose it may have done, but it seems implausible.

It is important to note that scientists are continually coming up with new experiments and observations to test the theory. The important point here is that "test" means, try and find something that shows it doesn't work. (After all, that is the way to Nobel Prizes, etc.) So far, every test has been consistent with the theory within experimental error. And some of those experiments are just ludicrously precise (like 1 part in 10-36 if memory serves).

The only points of disagreement are on things like what will happen when we are able to come up with a theory of quantum gravity, what the implications are for the history and fate of the universe, and other speculative ideas.

It obviously doesn't know any such thing. One person makes a measurement and gets one result; another person makes a measurement and gets another result. If these two observers measured the speed of the object (relative to them), they would both get different results but that doesn't seem surprising. Who knows. That just seems to be the way the universe is built. Maybe it is impossible for a universe to behave otherwise. I'm not sure that makes sense. It is just about measurements made from different frames of reference.

It hasn't been disregarded. Your misunderstanding has been explained to you. Writing this in CAPS does not make it true. As has been explained, this is not instant. The force is propagated at the speed of sound (even slower than the speed of light).

You are absolutely right. I should have said "points out that spelt a word wrong" or something (and I was definitely not thinking in terms of using that as an excuse to attack someone's argument, more in the context of reviewing a piece of writing).

It is similar to, say, perspective in that it is caused by geometry. But I think it is misleading to call it an illusion; the different measurements made by each frame of reference are both equally real (without getting into a philosophical discussion of what "real" means).

After all it was once thought that Earth was round ... and it still is!

Length contraction is a function of speed. Same speed, same length contraction.

I don't think anyone would claim that chess computers, for example, are examples of, or evidence for, AI. If they do, then I would agree with you that they are hopelessly naive. What is it allows the brain to do that but not another computing machine?

It isn't buoyancy, because that is a reduction in weight caused by displacing a fluid. Are you confusing mass and weight? If you were to stand on bathroom scales underwater, you would weight less. But your mass would be unchanged. The question assumes that the objects are rotating at the same speed. It isn't meant to be physically realistic. You may be overthinking it.

One answer is that it is at the scale where the universe starts to appear approximately homogeneous; at which point the FLRW metric (which describes the expansion) becomes a reasonable description. Below that level, the model is more complex and is dominated by the gravitational and other forces holding matter together.

That would be me, then. Which still leaves the question, in what way is the brain not deterministic? (Just to be clear, I am not convinced that strong AI is possible. And definitely not arguing that it is. But I have heard several good arguments why it might be. The only arguments against, basically come down to: "I don't believe it. Minds are like, you know, special.")