Strange

Actually, the strings concept is the starting point, not a prediction. In otherwise it is a working assumption or hypothesis. It is basically quantum field theory but using one-dimensional objects instead of point objects. This might not be too surprising as particles are described as wavefunctions in quantum field theory and strings vibrate! As far as I understand it, it produces results that are compatible with quantum theory and GR but has not yet produced any testable results that could be used to show if it is a better model than either of those.

Argument for on incredulity. Shrug. Are you confusing the concept of an empty universe with one that has no size? So you can measure things even in an empty universe. Of what? We are talking with of a model of an empty universe so there is no light. (But, yes, obviously light can travel through empty space)

What is it then? Are you saying that metres and seconds are made of something? What are they made of? Wood, brass, sealing wax? I don't know what you base that on. But if you define a metric then that defines how distances are measured.

Well, it can't do. (After all protons are pretty large and yet they only contain three zero-sized marks.) For all sorts of reasons. For example, the Heisenberg uncertainty principle means that the momentum would be infinite if the distance was zero. (See the thread about why an electron doesn't fall into the nucleus for more info.) The weak interaction is not really a force and it doesn't hold things together. And it wouldn't be able to overcome the massive kinetic energy you would need to give things to get them that close together. And any such system wouldn't be stable (after allow don't see any of this around us). And gravitational singularities do not really exist. But apart from every single aspect of it being impossible . . .

You can't do that. There are some mesons (particles formed from a pair of quarks) with a positive charge. But in this case, only one quark can be up, the other would have to be strange or bottom (to end up with unit charge). A few other combinations can produce a net positive charge (of +1). But these are all highly unstable. I suppose it might be possible to form a very brief "pseudo atom" of an electron orbiting a meson (such a thing doesn't appear here: https://en.wikipedia.org/wiki/Exotic_atom) but it would have a very short lifetime. I don't see why that would be the case. This might be the closest to your concept: https://en.wikipedia.org/wiki/Degenerate_matter See also: https://en.wikipedia.org/wiki/Neutron_star

But the specific thing about the windy postman problem is that the edges have a different cost depending which way you traverse them. The OP's question may be related to the generalisation of that (route inspection) or the the travelling salesman problem. But I somehow suspect that someone who is working on multi-agent pathfinding is well aware of those problems and possible solutions.

Can you explain how that is relevant. The OP didn't mention anything about asymmetry in the costs of traversing edges.

Very succinct. Hopefully, that might help clarify what is meant. The "actual" dimensions are the just coordinate systems we use to measure time and distance. Whether "space-time" and the associated "dimensions" exist is a question for philosophy. (Or, to put it another way, one that can't be answered.) Obviously. As the dimensions are what define space-time. On the other hand, you can have "empty" space-time; dimensions defining space-time but with no matter or energy in it. (This can be useful to test some concepts; for example, certain such empty universes will still expand, and so on.)

I wouldn't bother trying! This is a common metaphor used in daily life. It has nothing to do with relativity. In some frames of reference, maybe. But expansion of space between objects is not the same as those objects moving relative to one another.

That is because your question is so poorly defined. You don't like the answers you get (they don't seem to fit with the model in your head) and yet you are unable to clarify the question. Don't be silly. It has nothing to do with "wanting" to answer. I am trying to understand what you are asking; and I am trying to answer based on what I can understand of your question. Then it isn't a dimension. It is not clear if you mean something non-standard by "dimension" or by "point". A dimension consists of an infinite number of points: roughly it is a measurement of "distance" (which can be spatial or temporal). If there is only one point, then there is no measurement possible. Why? And what does "in its own dimension" mean? Are you now referring to points in a single (spatial dimension)? Are you trying to say that every point along one dimension (e.g. every point along x) is at a different time? Why would that be the case? In this case, these don't seem to be "dimensions" in the usual meaning of the word; one of the defining characteristics of dimension is that they are independent. But if you are making the position in the time dimension dependent on the position on one of the time dimensions, then they are no longer independent. I'm not sure it does. You seem to back to thinking of time as some sort of universal thing independent of space. If by "point" you mean a location in 3D spatial coordinates, then you cannot talk about that as if it were independent of time. In relativity, things are defined in terms of 4D space-time coordinates ("events"). When you make measurements from different frames of reference, then both the time and the time coordinates change. So to take about "a point to exist at different times" doesn't really make sense. When viewed from another frame of reference, an event will be at a different time (as you put it) but it will also be at a different place. Basically, the coordinate system as seen from one frame of reference is rotated when seen from another frame of reference.

No

That list of impossible properties makes little sense. As you are apparently proposing a physically impossible thought experiment, then you can make up any results you want. It is pure science fiction. I think the most likely outcome is that dragons will fly out of your nose. Neither of those provide any support for your claims.

An atom always has the same number of protons and neutrons, because it has to be electrically neutral. However, there can be varying numbers of neutrons (within some range) in atoms (these are called isotopes). So, for example, hydrogen has 1 proton and 1 electron but can have 0 (hydrogen), 1 (deuterium) or 2 (tritium) neutrons. There are 118 elements in the periodic table. But only 94 occur in nature (the others are too unstable). https://en.wikipedia.org/wiki/Periodic_table There are 253 stable isotopes of all the different atoms: https://en.wikipedia.org/wiki/Isotope And atom can temporarily lose (or possibly gain) one or more electrons, to form an ion but, again, these are not stable and quickly gain (or lose) the electron(s) to revert to an atom.

I had to look it up to find out what this "obvious" reason was

IF you are using time as a dimension (as in relativity) then you no longer have just two points. IF you are using a different model of time, then you need to say what it is. You refer to relativity but then reject "the established spacetime model". So which is it: do you want to discuss relativity, or do you want to discuss another model that you have made up? As you are the one who has invented this "two pint mode" only you can answer these questions. If anyone else attempts to answer them (which can only be attempted based on known science) you say you don't want to talk about "the established spacetime model". Relativity doesn't say anything like that.

I guess you mean "hydroelectric" rather than hydrogen? Or are you thinking of that back-yard fusion reactor... What I don't understand is why some people will credulously accept fraudulent claims about "free energy" and then reject (on the basis of "reasonable scepticism") scientific explanations of why they won't work.

The fake perpetual motion machine isn't backed up by anything except a fake video. Magic. Or invisible pink unicorns.

http://lmgtfy.com/?q=coloured+rubber

As that page very clearly explains, that is because of the apparent separation that we see now. It also clearly says that they were denser then. The excellent article you linked to.

It is not clear what you mean. Are you defining a 2D "universe" which consists entirely of two points, for example (0,0) and (1,1). That isn't much of a universe and there are only spatial dimensions so there is no time to "flow". (There would actually be four points in such a universe: 0,0 0,1 1,0, 1,1) I suspect that is not what you are asking, but I don't know how else to interpret what you are saying. Do you mean two "points" or do you mean two objects (of insignificant size and mass)? OK. So you do mean a model that isn't described in terms of space-time. In which case, how are you modelling time in order to allow it to "flow" or not? This is your model. Only you can define what "time" means in this model.

That makes no sense, even if we remove the random punctuation. If it is orbiting then it is constantly accelerating and falling.

And another thing, if you are denying the Big Bang model then you need to come up with an alternative explanation for the CMB. How do you explain that? (Good luck with that; this was the final nail in the coffin of steady-state and pseudo-steady-state models.) Also, how do you explain the relative proportions of hydrogen and helium in the universe? (The Big Bang model predicts this.)

The wavelength of an electron depends on its energy. The link I referred to earlier will calculate it for you: http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/debrog2.html The separation of the slits needs to be several times larger than the wave length. For example: http://iopscience.iop.org/article/10.1088/1367-2630/15/3/033018/meta Not sure what the relevance of that picture is.

What do you mean by "stretching"? Depending what you mean, that might be an accurate analogy for the metric expansion of space. Or not... It isn't expanding "into" anything. Because the universe is all there is. It might be easier to think of it as getting less dense, instead.

Then why is there measurable red shift? No it doesn't. The recessional speed is proportional to distance away from us. This was generally assumed to be the case. But, surprisingly, it turns out that velocities started increasing a few billion years ago. Then you should learn a little bit about the theory your are criticising. Arguing from a position of near ignorance is not very convincing. For example, Davis and Lineweaver: "We show that we can observe galaxies that have, and always have had, recession velocities greater than the speed of light." https://arxiv.org/abs/astro-ph/0310808 The graph is wrong in that respect. Perlmutter, Schmidt and Riess got the Nobel Prize in physics for discovering that the rate of expansion is increasing: https://www.nobelprize.org/prizes/physics/2011/summary/ Actually, that raises another question: why are you using such old data, based on a very limited number of samples? Why don't you use more modern data? We can't see anything earlier than 13.8 billion years because the light hasn't had time to reach us yet. But that doesn't appear to answer the question. If we see galaxies moving away from us (which we do) then they must have been closer in the past. Which means that, at some point in the distant past, all the matter we can see must have been right here. If you don't agree with that, please explain why. The video shows that, at one time the universe was entirely full of hot, dense matter which then collapsed under the effects of gravity as the universe expanded and cooled. This is known as the "Big Bang model" - you might have heard of it. So if you accept what the video shows (even though it seems you may not understand it) then you accept the Big Bang model. I don't know what that means. Do you want to try again in English. Or maybe show us what you mean mathematically.