Genady

Imagine a box with internal walls covered with mirrors. A light /photon bounces inside the box from mirror to mirror. The box is placed far away from gravitating bodies, somewhere in the homogenous and isotropic universe. As the universe expands, will the light inside the box redshift? (My answer, No.)

No, I just mean mirrors. I take a box with internal walls being mirrors, let light in, say, through a little opening. Light just bounces inside from mirror to mirror (we can close the opening to make sure it doesn't escape). The mass of the box increased.

This is surprising. We once had adopted a rottweiler from a foreign speaking family and she had to do the same, except one other dog rather than two. She was fluent in a couple of weeks. She was 2 yo, maybe that was a factor, if your shepherd was older. It was interesting to observe how the other dog taught her the rules of the house.

Of course. I should've said "such as that of light" or something similar. Otherwise, yes, this is what I mean. I have a picture in mind where the light remains light, i.e. is not absorbed in a sense of being converted into something else. It will be there with no mass, but the entity will gain mass still.

They do "go hand in hand" ( @exchemist) but they are different nevertheless. Energy is additive, mass is not. Energy with no mass, such as light, can be added to something and that something will acquire extra mass.

I think that - in the right handed coordinates - if the angular momentum of the spinning tube is toward Z and the wind is toward Y then it moves toward X.

If there were an actual evidence of a real J of N, wouldn't everyone know it by know? Would Church let it go?

I think so as well. I just don't see concepts behind this ability, but rather memory, recognition, association, learning, which even a worm with 300 neurons can do. Perhaps, 'arbitrary' is a wrong word. What I meant is that this categorization is not universal ("objective"), but rather individual, cultural, temporal, conditional, etc. It is not about evolution of a language or languages, but rather about evolution of brain that allowed a language. There is nothing special about English in this respect. All languages have differences in how they categorize outside world. English is a first language for a child growing up in an English speaking environment, etc. Later they might learn other languages, and they will have to adjust some concepts because these other languages segment world differently. There are many aspects to 'language'. Most obvious is a communication tool. Surely other animals have this. Plants and bacteria have it too. However, communication is not the only characteristic feature of a human language. Among others are: Displacement; animals seem to communicate only about a given environment at hand; we can refer to past and future times, removed or even not existing places, things, and events Cultural transmission; dogs speak dog language and cats speak cat language, but we speak a language that we acquire from the culture we grow up in, i.e. we don't inherit any language, only an ability for a language (I know that some birds and whales learn their songs from others; but without the others, they will sing anyway, just not that good; humans growing without others don't produce any language) Productivity; human language is continuously changing, adding new words and structures, is "open-ended", potentially infinite; communication systems of other creatures are essentially pre-set, they have fixed references, they apply the same repertoire in the new situations There are no indications that other animals have a language with such characteristics. OK, this is a different hypothesis.

I assume that words in a language represent concepts in the brain. The concepts seem to be discrete categories made up by the brain from a continuous experience, more or less arbitrarily. Here are some examples: the English concepts 'shade' and 'shadow' correspond to one concept in Russian, represented by the word 'tien' the English concepts 'table' and 'desk' correspond to one concept in Russian, 'stol' the English basic color 'blue' doesn't have a corresponding concept in Russian, but is rather covered by two distinct basic color concepts, 'sinij' and 'goluboj' I hypothesize that other animals perceive and process outside world as a continuous signal, while our brain evolved an ability to 'digitize' the continuous signal and to process it in discrete categories. This ability became a basis for our ability to use language.

Watch this movie about Russia at the times of Mongol occupation, circa 1400.

Today I learned a new term: WEIRD societies = Westernized, Educated, Industrialized, Rich, and Democratic.

I do have some idea what 'nothing' and 'something' means, but I don't have any idea what is 'potential for /of /to something'. If you mean that it happened because it could happen, then it seems just circular, i.e. it could happen because it happened.

No need, it's ok. They didn't call it SI then, I guess.

"Centuries"? It is only 62 years in existence.

Here are two slides from Alan Guth's lecture 1 in the MIT class on Early Universe. He has explained there how something can come from nothing while obeying the energy conservation. Don't worry about his use of word "miracle". He uses its meaning as "a very amazing or unusual event, thing, or achievement" (Merriam-Webster)

When I Heard the Learn’d Astronomer BY WALT WHITMAN When I heard the learn’d astronomer, When the proofs, the figures, were ranged in columns before me, When I was shown the charts and diagrams, to add, divide, and measure them, When I sitting heard the astronomer where he lectured with much applause in the lecture-room, How soon unaccountable I became tired and sick, Till rising and gliding out I wander’d off by myself, In the mystical moist night-air, and from time to time, Look’d up in perfect silence at the stars. Perhaps Walt Whitman came to the lecture unprepared. He didn't know how much depth, beauty, perspective he missed. I wonder, who the "learn'd atronomer" was?

(I retracted an erroneous edit only.) It is correct that all these masses have to be put in by hand. Finding the Higgs boson supports the mechanism, nevertheless. (I don't think the OP had any of this in mind. It asked about a mass of the field.)

It would work for me. But, how it reconciles with the SM where particles get their mass from interaction with the Higgs field? Edit: Retracted.

Yes, I wondered where the subject has changed from 'field' to 'electron'. And with no input from the OPer.

Right. Back of a very tiny envelope calculation shows that to have a drop in acceleration 1% over 10 m the radius needs to be 1 km. Here comes the real question: How do I type Greek letters here? I wanted to put 'omega' for the angular velocity...

What my question (see above) relates to, can be found in a variety of sources. A "simple", Feynman-style explanation on how the principle of least action emerges in the path integral picture, is in his book "QED: The Strange Theory of Light and Matter". On pp.42-45 he applies this picture in an example of reflection of light and "derives" the principle of least action, in this case. He concludes, "And that’s why, in approximation, we can get away with the crude picture of the world that says that light only goes where the time is least" (p.45). More generally, on p.123, "This brings us all the way back to classical physics, which supposes that there are fields and that electrons move through them in such a way as to make a certain quantity least. (Physicists call this quantity “action” and formulate this rule as the “principle of least action.”) This is one example of how the rules of quantum electrodynamics produce phenomena on a large scale." More formal derivation is in Zee, A.. Quantum Field Theory in a Nutshell. On p.12, "Applying the stationary phase or steepest descent method ... [to a path integral] we obtain ... the “classical path” determined by solving the Euler-Lagrange equation ... with appropriate boundary conditions." (I've removed the math expressions.) Edit: After re-reading these sections in the books I got the answer to my question. Thus I don't have any more open questions in this thread.

Thank you very much for a very good explanation of what the principle of least action is. Unfortunately, it doesn't relate to my question. But it's OK. You don't necessarily know what my question relates to.

I remember that stationary action "emerges" from the Feynman path integral. Doesn't QM "explain" it?

Do you mean a station is spinning to create 1G at the circumference? Then, acceleration of a circular motion is v2/R. Equate it to 1G and find R for a given v.