Strange

It is reversible here on Earth, as well. GR treats mass and energy as equivalent so the idea of "equilibrium" doesn't seem particularly helpful. As the conditions within the event horizon are causally disconnected from (can have no effect on) the universe outside, I don't see how this can make any difference to the expansion of the universe. How does your model explain the red-shifts of galaxies and, much more importantly, the CMB? Oh dear.

Well, it probably wasn't a very accurate statement. Except that SR only deals with local, inertial frames of reference - so no curvature, no change in scale factor (expansion), etc.between the two frames. For those cases you need GR where, as we can see, it is possible for apparent speeds to be greater than c. (But still, locally, the speed limit applies.)

That is correct. If you multiply the distance between things by a constant scaling factor, then the speed of separation is proportional to distance. Consider a number of galaxies separated by the same distance (far enough apart that the expansion of space is significant and the same between all of them). At time 0, they are 1 unit apart: A.B.C.D.E.F After some time they are 2 units apart: A..B..C..D..E..F After the same time again, they are 3 units apart: A...B...C...D...E...F And so on: A....B....C....D....E....F Now, if we look at the distance between B and C, for example, it increases by 1 at every time step. But the distance between B and D increases by 2 at every step. So the distance between B and D is increasing twice as fast as the distance between B and C; i.e. the speed of separation is twice as great. Choose any pairs of galaxies and you will see that apparent the speed of separation is proportional to the distance between them. Take two objects far enough apart and the speed of separation will be greater than the sped of light. We can see galaxies that are receding faster than the speed of light. This isn't a problem because the "speed limit" only applies locally (or you can think of it as being a limit within special relativity but not general relativity). We are not in the same (inertial) frame of reference as those distant galaxies. We are connected causally to galaxies in the observable universe (because we can see them). Some of these are receding faster than c. But we are not causally connected to things beyond the cosmological horizon (outside the observable universe - actually, that isn't exactly the same thing, but near enough for now!) I'm not familiar enough with inflation to comment on that. My understanding is that, unlike expansion, it would have been driven by some sort of force/field in order to achieve the massive expansion rates hypothesised.

Are you sure? Everything I have read suggests that dark matter has been around as long as matter. One of the lines of evidence for dark matter is the cosmic microwave background (CMB) and that is a lot more than 10 billion years old. The Big Bang model is not an explosion, and certainly not an explosion of matter from some central point. Well, it has. And it is space that has expanded (not matter exploding into space). Space is not made of anything. It is just the distance between things. Which is affected the presence of mass - the effects of this include the thing we call gravity. I don't know if that is true. Everyone agrees we can't know. I don't know what proportion think it is infinite. People pop up on science forums insisting it is impossible for it to be infinite and impossible for it to be finite with about equal frequency. I have never seen a survey of physicists, though. It wasn't an explosion into anything. The universe was once entirely full of hot, dense matter (plasma). The universe expanded and, as a result, the matter cooled and gravity caused the gas to clump into stars and galaxies. There is no "outside". Note that a singularity means that the theory no longer applies at that point - a bit like dividing by zero. There are many variations of the basic Big Bang model. Some of these suggest multiple Big Bang "events" (inflation and expansion) producing multiple universes. These ideas are not really testable but are a natural consequence of the mathematics. For example: https://en.wikipedia.org/wiki/Eternal_inflation However, the universe we can see came from a single Big Bang event. That doesn't work. If there is an even distribution of matter around the universe (and it would have to be evenly distributed because expansion is the same in all directions) then it will have no net effect - the matter pulling to the left will be exactly counterbalanced by the matter to the right (and so on for all directions). Newton proved this a long time ago! That almost certainly won't happen. Nearly all of the matter in the galaxy will continue to orbit without being affected by the black hole (which only makes ups tiny amount of the matter in the galaxy). The gravity of black holes behaves just like any object of similar mass. One the gas and stars around the black hole have been absorbed then there will be nothing else for it to absorb. Actually, you can treat gravity as space falling into a body like a black hole: http://jila.colorado.edu/~ajsh/insidebh/waterfall.html But that's OK because space is not made of anything so it isn't really disappearing or being used up. Not only suggested, but it has now been observed several times. Exciting stuff. This can only happen if the black holes are in orbit around each other. It is a pretty rare event.

Certainly, if you leave Earth at near the speed of light, you will see their clocks running slow. And they will see yours running slow. It doesn't really make sense to ask what will happen at the speed of light because it is non-physical: if you try and apply the theory, you end up dividing by zero and similar meaningless things. Not sure what you mean by "true" but it does tell us that time (and distance) are not fixed measurements, they depend on who does the measuring.

In physics, "light" usually refers to all electromagnetic radiation. Because of expansion, there is a distance beyond which light is able to reach us - it would take longer than the age of the universe to arrive. As a result, there are a finite number of stars in the observable universe.

This is a really good question! This is called Olber's Paradox. And the reason the sky is dark is because the universe is expanding so at some distance there are no more galaxies to see. https://en.wikipedia.org/wiki/Olbers'_paradox

That is the only bit that makes any sense. What is the point of all those random equations.

It works very well. You need to explain how it does that despite having (according to you) a serious flaw. Not for calculating gravity we don't. How is that relevant? You keep bringing in irrelevant distractions. Unless you can focus on the specific argument you are trying to make, you will confuse everyone (including yourself). You need to stop going off at tangents. They are attracted towards the galaxy. Just much, much less. The same reason the moon orbits the Earth and is (barely) affected by the Sun's gravity. I don't think anyone has said you are stupid. Ignorant, maybe. But we all are to differing extents. And it is a good thing because it is an opportunity to learn.

If you were correct, then Newton's equation for gravity, which doesn't include density, would give wrong (or consistent) results. As it works for the moons of all the different planets (with their varying densities) this implies that the density factor is not needed. Can you explain why that is? You seem to be substituting "common sense" for scientific rigour. The scientific method is designed to stop thinks like intuition and common sense getting in the way of results. You are also confusing things by introducing things like stopping a bullet/beachball or firing a projectile into the Earth, where shape, surface area, friction, rigidity, air resistance and all sorts of other factors come into play. Most of these have nothing to do with your central hypothesis.

A spring balance. But you will need to be careful about friction. (Taking care of confounding factors like that is an important part of experimental design.) Nope. If that were true, you could use a 4D sheet ... They did think about it. Newton has a very famous proof that you are wrong. https://en.wikipedia.org/wiki/Shell_theorem Basically, it makes no difference if the mass is spread out every throughout a sphere, forms a then shell at the surface or is concentrated at the centre. You know this from Newton's law of gravitation, right? And this, of course. No? You have never seen people in coal mines? There seems to be gravity there, just like on the surface.

I'm going to blame autocorrect (and bad typing). I don't think my knowledge of geography is that bad! But you wouldn't be getting closer to mass. The mass is distributed (roughly) uniformly throughout the universe and that remains true as you go back earlier in the universe. If anything it becomes more evenly distributed (no stars and galaxies, just a uniform plasma) and so there is less possible variation in gravitational time dilation.

Well, its an interesting question: could it be that the equations describing how things work would need to have been different in the past? Possibly. But only if the end result looked just the same as that predicted by our current equations! The earliest evidence we can see appears to be consistent with current models.

There have been a number of measurements made to see if various physical constants have changed. Some come from astronomy: when we look at distant galaxies, we are effectively looking back in time (because of the time taken for light to get here). If the speed of light or other physical constants were different then we would expect to see the some changes (such as different spectral lens of elements). Another source of information is the natural nuclear reactor that existed at Oslo in Gabon about 2 billion years ago. As far as I know, none of these studies have produced any evidence that physical constants have changed. Although we can never prove that they haven't changed, just that any change must be smaller than the experimental error.

I think this is an example of a sort of blind patriotism that thinks one's own country is best, even when it isn't. Similar to the old (and equally foolish) "my country, right or wrong" attitude.

CQ has some quite strict anti-spam measures - that might be the reason. Anyway, glad you found some good answers. And thanks for updating us! BTW:you might be interested in the article I linked in this thread:

The bizarre thing about this is, from what I have seen, not only do the insurance companies spend far more (per capita) than, say, the NHS but the US government also spends far more than the NHS per capita. So it is a double failure. The NHS is struggling but it works pretty well - and provides universal health care. So why does the supposedly more efficient capitalist/competitive system in the USA work so badly? I think because there are so many people opposed on principle to the idea of helping everyone, whatever their circumstances. It is the cult of individuality gone mad.

Excellent answer, as always! So the confusion seen so often (and which I just fell into) comes from only thinking of the simple "special relativistic" case (which only applies at one moment) and not taking into account the accelerations. Thanks.

Are you suggesting that humans are able to play without being told the rules? If not, what are you suggesting? Note that go is notoriously difficult because knowing the rules (which are extremely simple: you take turns to place stones on empty positions and capture an opponent's stone by surrounding it) doesn't tell you how to win. I'm not convinced that the Turing test, in itself, is that good a test. But some refinement of it could be. There are a number of systems that are claimed to have passed it. For example: http://www.bbc.com/news/technology-27762088 and http://www.zdnet.com/article/mits-artificial-intelligence-passes-key-turing-test/ Of course one can argue about whether they really passed, was the test carried out correctly, etc. But that is one of the problems with this asa test. It is subjective and so any conclusion can be rejected for some reason.

I like that. The methods used support those goals. Science is based on quantitative evidence that is used to test hypotheses based on a mode of how things work. (Ideally the model is mathematical or, at least, quantitative so that it can be tested objectively.) Philosophy uses logic (n the formal sense, not the "common sense" model) and rational analysis of causes and effects to try and get deeper than science does.

Indeed. That is what I asked in my first post in the thread. Only the OP can explain what he had in mind. The most obvious answer would be the classical luminiferous aether. It is hard to imagine what evidence there could be for that, which didn't violate Lorentz invariance. The word ether could be, and has been, used for many other things. You could consider the medium of light to be the electromagnetic field, in which case there is copious evidence for it. Or it could be Einstein's ether, i.e. space-time. In which case there is, again, copious, evidence for it. Most other uses of the word I have seen apply it to things that we know exist (and hence we have evidence for). The only usage I am aware of for an aether that lacks evidence (which could therefore prompt the original question) is the classical luminiferous aether. But if it is applied to other things for which there is no evidence, then we need a model in order to define the evidence that would be required.

If they said "had a lower velocity [than the other plane] relative to the one on the ground" then I would certainly agree. But they seem to be saying that the westbound plane was moving slower than the clock on the ground (relative to a frame of reference that is not rotating, I assume). I have just realised that this is a version of the Twin's Paradox: we are not comparing time dilation (which would, I assume, be symmetrical for the two planes relative to the ground), but the total elapsed time experienced by each clock. This depends on the accelerations each makes to get up to speed and then come back together again. And that will presumably be different in each direction because all three clocks are in an accelerating (rotating) frame of reference. Is that it?

That's why I added the "prevailing wind" comment. Planes fly at a speed relative to the Earth (the air moves with the Earth - but you know that!) so I don't think that is the answer.

And, unlike many "personal theories" presented on science forums, they are based on pre-existing theories and evidence. I think this is a key point that is often missed. The current "dogma" had to earn its place. And continuously fight to maintain it (your point [4]). Also worth noting, that the big prizes and fame go to those who challenge and change currently accepted physics. And, many young students have the same desire to overthrow the status quo as those who present their ideas on science forums. The students are better equipped to do that. Which means they are also better equipped to destroy 99.99% of their own ideas with a little thought and back-of-the-envelope calculation. I am not a scientist, but I get the impression that this can be just as brutal as the critiques of personal theories on forums like this. If not more so, because they take place with a level of rigour and detail analysis we rarely see here. Don't believe it. They might get a hard time. But then they did from their peers. (See comment above.)

The [luminiferous] was a proposed medium for the transmission of light. It was later found to be (1) not necessary, (2) physically implausible and (3) undetectable. Nothing to do with wacky ideas about "direction".