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Here is an example: https://press.cern/backgrounders/matterantimatter-asymmetry I've heard many theoreticians physicists saying the universe is dominated by matter because after the it is what it has left after some period of annihilation processes. I don't know if this is very well...

It is only an example in classical terms related to the Big Bang theory. Classical physics works accepts infinite precision in principle so if you start with a symmetrical system, the symmetry is preserved all the time. We know classical physics doesn't hold at fundamental levels.

What does quantum mechanics have to say about this aspect? Matter usually differs by antimatter having opposite charge. It is said that the Universe in the early stages should have created equal amounts of matter and antimatter. The total charge is conserved no matter the interactions and if...

I've seen some analogies trying to explain gravity to general public using as a model water flowing towards a sink hole in the place of some massive object. I've also seen scientist talking about simulations using air instead of water for a 3d effect, and sound waves. Sometimes close to...

Gravitational waves spread-out in all directions. How is it possible to have them spinning around each other? Light can modeled as plane waves where all individual waves are parallel to each other, as part of a beam. Will gravitational waves do the same thing in principle? I suppose they can...

Thank you. I thought quantum graviton models gravity so that it gives the same effect for macroscopic objects but not manipulating spacetime curvature but by considering gravitons force carriers similar to photons as force carriers of the electromagnetic field. Quantisation of spacetime...

Thank you. But my example is not important anyway. I was only an example of some concept that is easier to explain which of course it doesn't apply to our reality. But the concept of a graviton can be taken into consideration. Even gravitons through a flat spacetime are simpler to understand...

Thank you. I mean in SR (and we imagine we don't know anything about GR) you can treat gravity as a regular force, generated by a field around massive objects and have waves in that field similarly to the electromagnetic field. But it's only an example that if gravity was like that it would have...

In flat Minkowski spacetime, everything that travels at c, relative to some observer, it travels the same speed relative to any observer. If we refer to gravitons as bosons through this flat spacetime, it is clear they can be defined as traveling at c. And you can even some classical...

I understand that for this kind of experiments you use a laser source which is a light beam that is then passed through a filter can let only a low amount of photon passing through in a given time. I suppose you first need to adjust the apparatus without the filter in place.

But for the setup above the CC is replaced by photon counters. It says in the OP. The detectors are supposed to capture most of the beams so that after some number n of photons entering the double slit, I suppose we will get n on D0 and n/2 for D1 and D2.

Here is a setup that only uses fixed detectors. Will the ratio between the number of detections at D0 and the sum of the numbers detected on D1 and D2 be close to 1? For this question instead of the coincidence counter, 3 simple counters are needed. Also the detectors D1 and D2 need some lenses...

I know that a high frequency light beam is more likely to generate a virtual electron-positron pair than a low frequency one. Can this probability depend on the reference frame? It seems there is a paradox. How do we explain it?

Yes, but in a non uniform field pointing down (N-S) why would they precess to point up? QM uses these mathematical concepts to model systems so that the results matches the experimetal results but also can give answers to more complex situations before you will actually perform the experiment...

That means the electrons that go up will have magnetic moment pointing up and there should be a force pointing down because the north pole repells the north pole of the electron. I understand you get the entanglement as spin up goes up, spin down goes down, but why the force is in opposite...

If electrons have a magnetic moment (or behave like they have) why don't all orient North Up in a magnetic field (pointing down)? Plus, if thought as magnetic dipoles, like poles repel, therefore all should point the same direction. In a Stern-Gerlach apparattus shouldn't the magnetic moment...

It is the same as having a dice with 3 faces, two green, one red, the probability of getting green is 2/3.

The classical prediction results are similar to the experimental results. But I've seen many presentations (not conclusions from scientific research) that say the magnets will do roughly an even distribution between the two poles...

I mean you can prepare some particles by a measurement for example for up/down axis, then all particles that were found in up state, will be found in an up state on the following measurement that needs to be also for Up/down. "Remember" is not the right word, though.

In the experiment with real magnets it seems that unlike iron balls, the magnets would separate into two groups. The smaller the magnets, I suppose, the better they would separate. However, electrons can remember states from previous measurements. I don't expect these little magnets to do that.

There are ways of manipulating individual atoms but I'm not sure if you can make them keep their magnetic moment lined up to their lattice. But I was only interested in some experiments tracking normal magnets.

Thank you. I still don't understand why this conclusion. I can only deduce that we cannot send information using entanglement (there is nothing we can do on a entangled particle to be detectable by measuring its entangled pair), not even at lower speed than c. I'm not arguing that information...

I'm sorry. I only wanted to clarify this. Does "No communication theorem" alone demonstrate information cannot travel faster than light?

"Einstein, Podolsky, and Rosen argued that "elements of reality" (hidden variables) must be added to quantum mechanics to explain entanglement without action at a distance. Later, Bell's theorem suggested that local hidden variables of certain types are impossible, or that they evolve...

Oh, in fact my intention was to delete the word real. There should be an advantage of using small regular magnets (neodymium for example), that would consist of a number of atoms like from 1 micron total size down to even 10 atoms (at this size I suppose we don't need magnetic materials anymore)...

Is there any study involving real magnets behaviour shot through Stern-Gerlach gates? I've seen something using rather large magnets[1], but still the pattern showed two bulges. I if suppose using very small magnets the split-up would be much clearer. After all these magnets are not simply...

If the events are spacelike separated they cannot be cause and effect and since they states are ways opposite there should have a common cause which points to a hidden variable. If there is no hidden variable then there is an instant effect at a distance. It is clear that there is no effect at a...

It is said that the measurement done on a particle instantly affects its entangled pair because Bell's theorem excludes a hidden variable. That means there is a cause and an instant effect at a distance. Say we have two entangled particles A and B. If there is no hidden variable then the state...

When the water level exceeds the height of the end of the pipe the water will flow through it. For this rule the tanks need to have no lid You only need to be careful a about details. (The answer is clearly F). For example if you let the water go between C and D and block the pipe between D and...

If you plan to use the motor to take you at 25-30 kph its fine you can have some advantages like better acceleration more ground clearance (also less prone to break the pinion shifter) less likely for the chain to come off. But if you think the motor can take you to 40-50kph or more where you...

In a high gear the pedal torque required(proportional to the force applied by legs) is higher. The bike has some rolling resistance from terrain and tyres. There is a point where the torque required only to overcome rolling resistance is higher than the maximum you can do. A bicyclist should be...

What about the other particles (leptons and quarks)?

From that I understand the waves propagate and the photons simply pop-up (where they are observed for example) at fixed locations , but they don't propagate of travel. Is that correct?

It looks similarly to the uncertainty principle. But I 'm not sure how much impact has when analysing a light pulse of high energy and very high number of photons.

In classical physics, EM waves propagate this is one of the main features of all waves in general. Usually for mechanical waves the elements (like molecules) that vibrate do some little motion. For example a string can move up and down, but the waves travel further through propagation. The...

If we move towards a source of EM waves, in our reference frame the frequency appears (and it is) higher than what a stationary observer will see due to Doppler effect. The field transformations show that these two observers will se static fields differently so I would also expect that the peak...

The photoelectric effect shows there is more than that. Electrons seem to only absorb one photon at a time. Even if we increase the light intensity, and we can have more photon density, the electrons don't seem to jump on higher levels or get knocked out from the orbit. That would mean they are...

Thank you. That is clear, but what about the electric / magnetic field peak amplitude? If we have two light pulses of the same length and diameter but different frequencies and the same total energy (the average energy density is the same), what will be the difference in the E or B field peak...

I know that if the intensity of a light beam with of a certain frequency varies it means the number of photons the light beam is composed of varies and not the individual photons energy. That would mean the E and B field amplitudes vary. This would mean that that the amplitudes of the E and B...

The transformation of fields between inertial frames, should explain how higher frequency wave packets have more energy. I suppose just as increasing the frequency of a wave packet increases its total energy, increasing the oscillation frequency of a charge increases the emitted wave packet energy.

Yes the more acceleration the more power, but this doesn't show why increasing the frequency increases the energy of a limited duration wave.

That would mean there is no proper acceleration but the charge is in equilibrium, but in GR if we think of gravity as curved spacetime the charge accelerates at 1g. Now, for the forces that repel the charge you can perhaps add new dimensions and say there are not forces either and we restore the...

If we complete an oscillation in a certain period of time and the waves travel at c, we can have the frequency of the classical EM wave.

The energy spent to aceletate the charge should be radiated as EM waves.

I wonder if it is possible to express a simple principle into a mathematical form. The simple principle says if at time t0 an isolated system is composed of some elements with some properties then at t1 it is composed of other elements with different properties, then in principle it is possible...

my objective is to see if the energy of the wave generated depends on frequency. So constant acceleration should be a reasonable approximation. The charge should have mass but I think the energy required to move the mass can be initially calculated separately. The massive particle resists to a...

For a mass, the total energy over an x distance is E=max. The greater the acceleration the greater the energy. But for a charge I would need some time to write the equations and to compare them to an harmonic oscillator.

Lets suppose we have a charge and we want to accelerate it from a point A to B and back. Does the energy requirement increases if we move the charge quicker? I can make an analogy with mass. To accelerate an object over a distance d requires energy. The objects resist to change in velocity. The...

Thank you, I agree with the above statements. My example uses them but if what I said is correct (to me it looks clear) it may not be so obvious to say how it the thought experiment works.

Thank you. Of course, less than 2c. But in this case, I think, if the observer remains in the frame where both spacecraft were at rest, it will only see a maximum just below c. (In this second example one of the spacecraft remains in the initial position) In order to see a difference of just...