Strange

So, if having mass is a requirement, then this takes us to the end of the electroweak era, when symmetry breaking caused the Higgs mechanism to give particles mass: https://en.wikipedia.org/wiki/Chronology_of_the_universe#Electroweak_symmetry_breaking

It depends, to some extent, on what is meant by "matter". If you define "matter" as fermions (as opposed to bosons, the force carriers) then as far back as our physics can take us, there was always "matter". But if you think of matter as atoms, then they didn't appear until much later when the universe has cooled enough for atoms to form. There may be intermediate definitions and stages. Edit: cross-posted with Beecee's much more detailed answer!

By the "length" of the set, do you mean the cardinality? If so, why do you think it is a natural number? Do you think the cardinality of all sets is a natural number? The ordinal numbers are. But what about the cardinality?

! Moderator Note The discussion of "white supremacy" is totally off topic. No more discussion of that comment, please.

There is no conflict there. Both statements are true (in as much as they are analogies, and therefore not true at all) and both are consistent. Diamond is very hard, but it still deforms. Here is a paper that analyses the "stiffness" of space and confirms that it is, indeed, very stiff (about 1020 times stiffer than steel): http://physics.princeton.edu/~mcdonald/examples/stiffness.pdf These are visualisations, just that. They are intended to help those who don't understand the science get a vague idea of that it is about. The fact that they are not terribly realistic doesn't invalidate the science. I don't think your confusion and lack of understanding has any impact on the validity of the discovery. Sorry.

I have a few friends who insist they don't follow fashion and just wear what is comfortable and practical. They all wear cargo pants, trainers and faded heavy-metal T-shirts. Looks like a fashion statement to me!

This is an interesting paper: http://physics.princeton.edu/~mcdonald/examples/stiffness.pdf It is mainly about calculating the "stiffness" of space that gravitational waves experience. It derives a value for the Young's modulus of space. He then goes on to consider light and derive an "Young's modulus, YQED, of elasticity of (quantum) electromagnetism" Expansion is less in the presence of concentrations of mass; because they are held together by gravity.

Probably worth keeping an eye on the CERN ALPHA project which will probably falsify this hypothesis before too long: http://alpha.web.cern.ch/node/248 So far, preliminary results are slightly more favour of antimatter behaving just like matter. Also, from the introduction to the paper:

It isn't really possible to represent the curvature of a 4D thing, especially not in 2 dimensions! Here is an attempt to give a slightly more 3D view: From: https://scienceatyourdoorstep.com/2017/09/28/einstein-space-time-curvature/ But we also need to say: From: https://xkcd.com/895/

There is not free speech because we have rules about what people can say. If you don't like the rules, move on. There isn't much, if any, advancement of science here as it is a discussion forum not a research lab. People presenting the latest science, or even controversial science, are not labelled or banned. At least not for that. Some people who do that will persistently break the rules though. You know the sort of thing: hijacking other threads with their idea, preaching (either literally or metaphorically; both of which are against the rules), etc. You have run into problems with the rules because nearly eery thread you participate in gets dragged off into a discussion of your beliefs.

I don't understand what you mean. Obviously, all scientific theories and observations are treated as more or less provisional. But why is having serious doubts wrong? Why does having serious doubts mean it is taken too seriously? In completely baffled by your comment.

No. That movement changes gravity, which causes the Doppler effect. If that were the case, surely a passing cyclist who hears a sound with a different pitch would also affect your perception of the sound? We are not allowed to moderate threads we take part in. While there is some truth in that, it has nothing to do with gravity. The gravitational effect of a car (moving or stationary) would be hard to measure with precision instruments. It certainly isn't going to compress air enough to change sound.

Citation needed. Or should I ask a moderator to move this to Speculations so you are required to defend this nonsense?

It is incomprehensible, why you can't understand something so simple and obvious. You move towards the source and therefore you see more peaks and troughs per unit tine = higher frequency. You move away and you see fewer wavefronts per unit time = lower frequency. This has nothing to do with gravity or particle interactions or any other nonsense like that. It is purely about how frequently you encounter the wavefronts. I cannot believe there is anyone on the planet who is not able to understand that trivially obvious fact. Let's try this analogy. When you were little did you ever hold a stick and run it along a fence made up of lots of metal posts close together: dink dink dink dink ... Think of those posts as the wavefront. As you move faster the frequency of the links increases. If you move slower, it decreases. Your movement is not creating gravity to distort the fence. You are just encountering the "wavefront" more or less slowly. Sheesh. I'm sure I could explain this to primary school children more easily. If you and the police car/radar gun or whatever are on the same stretch of road then the gravity is the same, yes. Moving at a constant speed won't change that. Gravitational redshift has nothing to do with the relative motion between the source and the observer. It happens even if they are both stationary. I just cannot understand your confusion. Citation needed.

! Moderator Note This doesn't make much sense. Unless you can make your point more clearly, we will close this thread.

This link (to here: http://www.cut-the-knot.org/pythagoras/CalculusProof.shtml) is a proof of the Pythagorean theorem using calculus, not the other way round. It does NOT say that calculus is based on the Pythagorean theorem, it says that you can use calculus to prove the Pythagorean theorem. That is obvious, just from the title.

No. Have you studied calculus? it is up to you to support your claims. So provide a link to it.

! Moderator Note @just_wondering Stop posting your conspiracy theories here. It is off topic.

! Moderator Note More off-topic lunacy hidden

! Moderator Note Conspiracy theory nonsense moved to Trash

No. The reason it is called "Newton's Law of Universal Gravitation" us because it isn't local and works for everything from apples to planets. Please provide a reference for this claim.

The full paper is here https://arxiv.org/abs/1802.00832

! Moderator Note New post merged with existing thread on this "theory"

The speed of light in a vacuum is constant. More importantly it is invariant: the same for all observers. It isn't a medium. It is a set of measurements of distance (space) and time. Do we? What is this "golden rule"?

As we know that energy conservation doesn't apply, this is not evidence against the big bang model