Is Mr Velev a String Theory proponent and simply says GR is just plain wrong since String Theory is based on the idea that QM is correct and it's GR that needs tweaking? Find a real String Theorist and see if they'll say GR is just wrong.

It appears that there are at least two things that attract people to a denial to relativity theory.

First, it’s about space and time which people think they perceive directly. And even though everything they deal with moves only a minuscule speed compared to light, they suppose that their experience must also apply to things moving a million or a hundred million times faster.

Second, relativity theory is essentially the work of a single man, Albert Einstein. So people suppose all they have to do is find where Einstein was wrong.

Any talented student of theoretical physics can, and indeed must, master the skill of being able to describe a generally covariant field theory in curved spacetime, of which Einstein’s theory is the simplest example.

The concepts and the mathematical apparatus of general relativity are fundamental to quantum field theory. And quantum field theory is a much harder subject to study than the simple classical field theory of gravitation.

But there are many, tens, perhaps even hundreds of thousands of physicists and physics students out there in the world (it’s a big world) who know how to derive Einstein’s field equations from the Einstein—Hilbert Lagrangian, how to solve those field equations in the simpler cases (e.g., spherical symmetry, axisymmetry, homogeneous and isotropic spacetime), or how to deduce the weak field, slow motion approximation and relate it to the Poisson equation for gravitation and thus, Newtonian gravity.

Quantum mechanics, which is much more counter-intuitive, was developed by a whole community of physicists Heisenberg, Born, Jordan, Schroedinger, Dirac, Pauli, Feynman… Einstein did not develop his theory in the total isolation of a cramped garret room. He was in communication, in person and by means of letters, with the physics community in Europe. Other smart people contributed to his theory: Poincare’, Lorentz, Fitzgerald, Hilbert, Minkowski, Dirac, Mach…

Today the theory is presented in a simpler and clearer fashion than Einstein’s own formulation. So people look back at Einstein’s papers and pick on some unfortunate or haphazard phrasing or assumption and beat it to death. Einstein did make some mistakes. He originally thought there would be gravitational waves and then he wrote a paper with Rosen concluding there couldn’t be gravitational waves, however they have been found today…but it was in error and he wrote a third paper about gravitational waves. He, like most people up to Roger Penrose in the ‘60s, thought black holes could not form and wrote a paper about it.

Third, people don’t know the details of the experimental proofs of relativity theory because they don’t know the Newtonian physics very well. They want to rely on thought experiments where, in their own thoughts, contradictions of relativity arise. Because it is counter-intuitive, it is hard to conceive a contrary relativistic thought experiment without deceiving yourself.

If you have a problem then destroy Einstein's arguments with logic and mathematics. But mainstream Physics does not do that. Instead it attributes ridiculous properties to some obscure virtual particle, justifies it by inventing another hypotheical field, then claims victory. It then labels dissenters as Fruit Cakes and the moves ever onward to the Great Unification which is totally inplausible.

Imagine that you are moving at 70mph on the motorway, and a police car overtakes you.

From where you are sitting — the police car seems to be moving at 10mph.

How fast is the police car going relative to the road?

Hopefully, you should instinctively say that the police car is going at 70+10=8070+10=80mph.

This is — to humans — instinctively obvious, and the way the world works.

Mathematically, speaking, what you have done in this case is called a Galilean Transform. You have “transformed” between two frames, the frame which is moving at 70mph along the road (you in the car), and the frame which is stationary on the road.

Thus, since you have worked out the relative speed, using a Galilean transform, we call this kind of physics Galilean Relativity.

Galilean Relativity is simply defined by just adding (or taking away) the frame velocity. All observers measure the same amount of time passing.

Therefore, if person A measures an object at position 𝑥𝐴 at time 𝑡𝐴t, then person B (who is in a car moving at velocity 𝑣) measures the same object to be at:

Position: 𝑥𝐵=𝑥𝐴−𝑣𝑡xB=xA−vt

Time: 𝑡𝐵=𝑡𝐴tB=tA

This is all exactly what you would think intuitively — and how physics modelled the world before the 20th century.

However, in 1905, a really clever bloke by the name of Albert Einstein realised that something was fishy.

Our best theory of electromagnetism predicted some weird stuff. See — when you try and use electromagnetism to predict the speed of light, it quite simply tells you that:

𝑣𝑙𝑖𝑔ℎ𝑡=1𝜇0𝜖0√≈3×108vlight=1μ0ϵ0≈3×108ms−1−1

Which is nice….except that it doesn’t tell you who is measuring it.

That’s like saying “how fast is the car going?” and the answer being “10mph”, but not telling you if that’s with respect to the road, another car or even the centre of our galaxy.

A lot of people assumed that this implied that there was some sort of fixed reference frame, which the laws of physics referred to by default — much like if I said I was travelling at 50mph you would assume I was talking about relative to the road.

If I measure light as travelling at 𝑐c, and my buddy is on a car on the motorway, then he obviously measures the same beam of light to be travelling at 𝑐′=𝑐−70c′=c−70mph

Right? Nope.

If you assume this “light-speed postulate” to be true, then you find out that Galilean relativity is wrong.

For starters — time enters into the equation. Not everyone measures time to be the same! Me and my buddy on the motorway are actually measuring time to be ever so slightly different! Space, too, is affected — my buddy on the motorway and I cannot agree on how long a road is, for example.

Now — the speed of light is fantastically large, so these discrepancies in time and space for travelling observers is tiny almost all of the time — WolframAlpha* just gives up trying to calculate the difference for 70mph because it’s so small!

If you do the maths, then you find out that with the addition of this extra postulate, our new “relativity” is given by the following transforms — which we call Special Relativity.

𝑡𝐵=𝛾(𝑡𝐴−𝑣𝑥𝐴𝑐2)tB=γ(tA−vxAc2)

𝑥𝐵=𝛾(𝑥𝐴−𝑣𝑡)xB=γ(xA−vt)

Where 𝛾=11−𝑣2𝑐2√γ=11−v2c2

Now — that second equation is really similar to the Galilean version, isn’t it? There’s just the added constant 𝛾γ multiplying everything. At ‘normal’ speeds, 𝛾≈1γ≈1, which is why Galilean Relativity looks right!

The only really weird bit is that time transforms here. If my friend is moving at 60% the speed of light, for a year (his time), then whilst he measures a year, I measure 𝑡𝑚𝑒=11−0.62√∗1yr=1.25yrtme=11−0.62∗1yr=1.25yr

Weird, right?

Well — not so much.

The only reason we think it is weird is because in 99.99% of our lives, this effect is totally ignorable — it doesn’t affect us in the slightest. It is only for stuff going really fast that it matters!

There’s a load more mathematical formalism in Special Relativity — this is obviously only an incredibly brief overview.

Stuff gets even more complicated when you try and factor in Gravity.

In fact, it gets so complicated that you realise special relativity doesn’t work at all! You need another kind of relativity — which we call General Relativity.

General Relativity is really involved, so I won’t go into it here, but this is where all the “curved space” stuff you hear about comes from.

So ultimately, what is relativity?

All theories of relativity (Galilean, Special & General) give you rules about how to tell what the universe looks like to different people.

Different people measure the universe to be different, depending on their position, velocity and acceleration. A theory of relativity allows you to “transform” between these different people, and see what they each measure.

Fundamentally, that is all they tell you — but as you can see from the fact that my answer isn’t one paragraph long, it’s somewhat more complicated than that!

This stationary reference frame was called the “aether”. But nobody could find it.

So Einstein came at the problem from a different direction. He supposed that rather than the equations telling you that light travelled at 𝑐 in some “default” frame — he supposed that the equations told us that light is measured to have the same speed by everyone, no matter how fast they are travelling.

Hartmann352

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See: https://groups.google.com/g/alt.philosophy/c/C_p9X9pOICU

See: https://www.quora.com/Why-does-Pent...e-seem-to-hate-Einstein-Is-he-a-troll?share=1