Strange

But you need to be precise about what is "zero". So you can say the mass of beans is 0g (or the mass of the universe 0kg). But that doesn't mean you can say that "the can = zero" (or that spacetime = zero). The latter makes no sense.

They may be gravitationally bound now (because they collapsed due to gravity) but that doesn't mean they always were - any more than anywhere else: after all the universe was more homogeneous early on - the large scales structures are thought to have been seeded by quantum (i.e. very small) fluctuations. And anyway, gravity might stop them expanding but it wouldn't stop them collapsing.

It was a reply to this: "I use an equals sign...is this not math?" I'm not quite sure what the error/fallacy here is, but saying that the can (or spacetime) equals zero because it is empty is just meaningless. (Even if it contains an equals sign.)

That is just repeating the same point, not explaining why you think it. What makes you think those regions have never expanded?

So how are these reflections different from those occurring in an optical fibre? The REFRACTIVE index is a ration of velocities, not an average. So can you tell us what it is? I haven't been able to find anything (meaningful). What does it mean for time and space to be "trivial"? How does quantum mechanics show this? Yes.

That doesn't change the fact that dividing by infinity is undefined. And weren't you trying so argue that your ideas was based on logic, earlier? Infinity is not an irrational number. And the value is not indeterminate. Any irrational number (any number, come to that) divided by itself equals 1.

The red shift is predicted by the model which is based on the universe being homogeneous. I have no idea why you would think that. Huh?

Which is exactly what I said. The voids and the denser regions (stars and galaxies and large scale structures) were created by gravity causing matter to collapse together. This has been pretty accurately modelled.

Science follow the evidence. The big rewards: fame, Nobel Prize, etc. (driven by youthful ambition and dissatisfaction with current explanation) comes from showing that existing theories are wrong (or incomplete). This idea that scientists were happy to overthrow theories of the past with revolutionary ideas but have now given up is just silly. As this is a science forum, perhaps you could provide some evidence for this - like show that all the research and published papers looking at alternative theories don't actually exist. They want to know the science is sound (i.e. the particle accelerator will work, the detectors will detect, etc. and that it isn't been proposed by some Internet crank) But they don't know what the results will be. Many physicists were disappointed when the LHC found the Higgs boson because all it did was provide yet more confirmation of the Standard Model. It would have been much more exciting if it had found something else, or shown that the Higgs didn't exist. Experiments may be described in the popular press as "proving Einstein" or whatever, but what the researchers are really hoping for is to find a crack in the theory that leads to new physics.

Except that gas can be compressed more than stars and planets can. The universe was more homgeneous then. The current "clumpiness" was magnified by areas of fractionally higher density collapsing under gravity.

Do you expect us to reverse-engineer your code, or are you going to explain it?

It wasn't resolved by the observation of red-shift. There were other possible explanations for that. Even the steady state model could be extended to account for that.

You are right. of course. And I suppose this relates to the fact that, currently, the kilogram is the only base unit defined by an object. But it is still different from, speed, say where we cannot define zero velocity, just zero relative to something else. And something with a mass of 1kg will have the same mass everywhere and at all speeds, etc. That is not quite true: the prediction of expansion came first. Red-shift was just the first bit of evidence (and not the most convincing). If you mean reinterpreting expansion as shrinking matter, it has been thought about a lot: both by physicists who have worked out the implications and by people who post their theories on science forums! I don't see why: you still have to account for "something" that caused the rate of contract to start accelerating at some point. (But this is what every one who claims to have invented this idea says.)

That doesn't explain why you think mass is relative or what you think it is relative to. I'm not even sure what it means. We know we can measure the speed of object B relative to object A. But we can measure the mass of A independently of anything else. That is what I am trying to get at: relative to what? If there is one thing we learn from science (the methodology, not any particular subjects) it is that what we think should be true, what we want to be true, or what seems sensible is often irrelevant. So study philosophy or theology, not physics. That is where the answers to those questions lie. There is nothing wrong with wanting those answers, you are just looking in the wrong place.

That would be true if the galaxies had always existed. But we know (even if we don't understand all the details) that they formed from clouds of gas. And that gas was once denser and hotter. So the "coins" analogy only works for the universe as it s now.

I'm not really asking you to prove it, just for some reason or evidence why you think it is so. Otherwise, why say it? Do you have any reason for saying that mass is relative other than you just like the idea?

Er, ... that's what I meant ...

And you can quantify that uncertainty and dertermine if it is significant or not. Apparently not.

OK. You have said that. Now can you justify it? Currently, mass (*) does not appear to be relative; it is independent of location, state of motion, etc. So in what sense are you saying it is relative? (*) i.e. rest mass, the "real" mass of an object

It isn't clear how they define efficiency from that news story. My guess is that it is the number of times you get a pair rather than just one of the electrons.

In the first case, there is only one photon in the latter there are two. At the detectors or, in the case of this Cooper pair thing, at the two single-electron transistors. (In some cases, you might only detect one of the entangled pair, but in that case, for all practiocal purposes you just had one photon/electron which might as well have been unentangled.)

True. But in everyday life, that is rarely significant. Not necessarily. There are plenty of things we can understand equally well whether they are near or far. We understand a lot about the lifecycle of stars. We know that they don't just disappear, so no.

Sorry, but I think the concept of "significance" is a very important one to grasp. It is completely unconnected to magnitude or to whether something is relative or not. That is all I am trying to explain. A value may be very large or very small in absolute terms. It may be very large or very small relative to you. It may be an absolute value or may only be defined relative to something else. It may be significant or not significant. Any given measurement could be any combination of the above.

You are not doing it precisely because you are doing it in words and by way of analogy. There is no way that can be precise. I think they have very different meanings. For example, velocity is always relative. But it may or may not be significant; for example, when calculating the speed at which your car is moving relative to the Earth, then tectonic movements are probably insignificant. In other contexts (the famous CERN OPERA neutrino experiemtn, for example) those movements might be significant. Mass, on the other hand is not relative, but a given mass may be significant or not (independent of whether it is large or small).

That is more a matter of significance. For example, you don't need to worry about the moon's gravity when weighing ingredients for a cake, but you do when calculating tides. The relative effects are the same in both cases but in one they are insignificant. So when you slam your finger in the car door, it doesn't hurt because it isn't physical? Does it? Where do you get that from? It doesn't seem to be. Do you have any evidence for that claim? (I assume we are talking about real mass, i.e. rest mass.)