Recent content by Pring

That's a horror idea! I just think of the key idea 'from data to model' in physics instead of investigating it.

Nowadays, the machine learning of computer science is hot. It is based on data, and drove by data. Thus, a question is naturally coming out: the data in physics, and the models of data. I think it is a really empirical way to know how physicists do the same thing as the computer scientists. So...

That's really helpful from the point of annihilation reaction in the early universe. I have concluded that (i) Energy always exists in the front and back through annihilation reaction because of energy conservation; (ii) Mass is equivalent to rest energy, and is a special case of energy in the...

Yeah, we discuss mass meaningful in rest frame. There are some differences in individual and systematic cases. Mass is equivalent to rest energy, and include all the necessary energy in the rest frame. So I think mass or rest energy is a perspective or concept to express the rest energy state...

Does this case be black hole?

Yeah, you are right!

If I consider some frame in which two electrons have equal but opposite momenta. The total energy of the two electrons equals the mass of the system. So the system rest energy includes not only kinetic energy, but also their individual rest energy. Moreover, the potential is not considered for...

So single photon is less massive. But from the perspective of multi-photon system, we select the rest frame, and the total energy is equivalent to mass. If we have a sphere symmetry system in a box, which always appears pairs of photons with opposite momentum in all directions by lasers, the...

Yeah, nothing different. Aha, I am so clumsy.

The perspective is impressive. We know photon has no rest energy, can I suppose that the universe is full of photon at the very beginning, and then generate rest energy?

Thanks. At the very beginning of universe, first energy or mass?

OK. Thanks, I have understood that nothing is called pure energy but rest energy, potential energy... In addition, is there any experiment that the total rest mass increase after particles collisions? This case means that rest energy change into mass. Finally, mass is equivalent to rest energy...

Can I understand the photon, which has no mass, as pure energy? If I just treat it as an assumption, it would take me any problems?

Energy comes from material. Is there any experiment that the total rest mass increase after particles collisions?

So first energy or mass?