# Tag Info

12

If you say: According to me the electron is at rest. that means you have measured the electron momentum to be zero, in which case the electron position is completely uncertain. So you can't be sitting on the electron. If you say: Let us say I sit on an electron. that means you have measured its position precisely so you have no idea what its ...

4

velocities don't add up like A + B = C. This is only approximately true in the limit of every day perception. You have to consider your coordinate frames relative to each other if you approach relativistic (meaning a fraction of the speed of light) velocities. $s = \frac{u + v}{1 + \frac{u v}{c^2}}$ would be the added velocity s of two objects moving ...

3

Yes, all 4-vectors transform as you state under a Lorentz transform. For the case of $\vec E$ and $\vec B$, they are indeed not 4-vectors. There are two ways of transforming the $\vec E$ and $\vec B$ fields to different coordinate frames. You can define the $A$ 4-vector in terms of the potential functions $\phi$ and $\vec A$, letting A = ...

2

Yes. General Relativity is perfectly capable of showing how a large oblate spheroid of gas moving in a particular direction contracts to form an oblate spheroid shaped star moving in that same direction that shines and emits light. And it is perfectly capable of making models that predict all the observations that any observer would make. Frankly, its a ...

2

This is only true if the source is perfectly collimated, and that is never the case. If the source is not perfectly collimated, then it will produce a fan of rays and each of these rays will appear at a different place of the detector. One such ray, for example, will interfere like this: Image source. A ray sent slightly downwards as shown in the image ...

2

Your relative velocity can not be determined. Lets say you have a space ship that is very long, say 300,000 km long. If light passes from one end to the other, say rear to front, your clocks will tell you that it took 1 second for the light to cover this full length since the speed of light is 300,000 km/s. If again light passes from one end to the other, ...

2

Your question has several flaws. First, you say the electron is at rest at the origin. As John Rennie noted, this implies that the position and momentum are both sharp, which contradicts the uncertainty principle. There is no such thing as an electron at rest at a particular point. An electron is described by a wave function spread over an extended region ...

1

Any finite physical system can be simulated by a universal computer. This includes quantum systems, which could be simulated by a universal quantum computer if we knew how to build one. Quantum mechanics is deterministic in the sense that the state of the whole of physical reality at one time can be worked out from the state at an earlier time given the ...

1

If $\vec{A}$ is timelike then we can find an inertial frame in which: $$\vec{A} = (a, 0, 0, 0)$$ Can you take it from here?

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Since I am not aware of any aspect of gravitational theory which corresponds to magnetism, I do not see how gravitational theory can account for the effects of motion. Gravitomagnetism is in fact a known and measured phenomenon. It emerges from Einstein's general relativity, rather than Newtonian gravity (which, as has been noted in other answers, is ...

1

Whenever you have mass you have energy too, lots of energy for a tiny bit of mass. And it is energy not mass, that is related to spacetime curvature. Your idea that mass curves spacetime and energy does not, is a lie, completely 100% baseless and simply untrue. It's just that the energy associated with mass is the largest energy you are used to seeing ...

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