Potential Energy of Quantum Field?

You know function defined on real numbers right? A function is defined if you assign a number to every point on the real line. As a starter, a quantum field is just a function, but the value it takes is from some abstract space, and the points on which the function is defined is 4-dimensional spacetime.

 

Log in or Sign up to hide all adverts.

"What is a quantum field made of?" is not really that great a question. Think of temperature as a field - it is something that has a value at all spacetime points, and your question It's akin to asking what is the field of temperature made of. It's not made of anything as such, but it is a property of spacetime that has a particular property at all points. Spacetime contains fields that have particular properties that, when the laws of quantum mechanics are applied, give rise to the spectrum of particles we observe.

 

Log in or Sign up to hide all adverts.

See, there you go right there.
Sorry, but understanding electromagnetism is a prerequisite in any tertiary quantum physics course.
Professors would simply not waste their time on students who had no idea what charge or current (and a few other things) are. Like convolution integrals, say, or what "wavefunction", or "wavenumber" means. Stuff like that.
What a Laplace transform does, hyperbolic functions; and that's just (some of) the basics.

 

Log in or Sign up to hide all adverts.

Good. We have at least one common point that we agree on. We should try to build on this now. So if a theory is to have any chance of describing the Nature accurately, it should include an element that is able to evolve. right?

 

Isn't "quantum field" as good as any other phrase to describe spacetime with properties? Basically, I am talking about the invisible ether like substance from which particles spring and which has properties. Do you have another name for that phyiscal thing I am referring to?

 

you mean vacuum?

 

You completely misunderstand what I am asking. I am not asking you what your physics professors would teach in class. I am asking you about what they wouldn't teach in class,i.e. their limits of knowledge. I simply want to ask a question on the most basic substances of reality where your professor's got nothing to explain, because he doesn't know. What is so hard about understanding this?

 

I would think so.

 

What's hard (at least for me) is that you seem to be asking: "who can explain something that a physics professor can't tell me about?".
And you haven't been to any lectures, right?

 

"Vacuum" will work, but there are different fields, so there would have to be different vacuums. However, you physicists seem to like using the word "field" in differentiating between fields, not "vacuum". For instance, you guys don't say the Higgs vacuum, you say the Higgs field. Do you see any difference between a vacuum and a quantum field?

 

I've been to plenty of physics lectures and symposiums, but not for 20 years. And no, I am not asking who can explain something that a physics professor can't tell me. No such person exists, unless you want to get into philosophy or religion - which is not yet where I am going with this.

 

Yes, there are different vacuums corresponding to different fields in theory. But the idea is that in the end you take the collection of all these fields and mutual interactions, and you have just one big ass field that is defined as the collection, and there will be one vacuum corresponding to this big ass field.

 

This answers your question "why should quantum field evolve?".

 

Then no, I think "field" is the better word. Now, you just suggested that different quantum fields interact. Now, that means there are different fields "overlapping" each other - no? What is the boundary between those fields made of? But, if there is no boundary between different fields, than how can they remain distinct fields?

 

You pretty much admited to it. You don't believe what I'm saying about some things and you plan to keep asking me till I admit it.

Why not learn the axioms of say quantum field theory then? You do know what axioms are, right?

Within physics, you'll never find the limits of my knowledge of say quantum field theory or relativity, not because I'm all knowing but I'm sufficiently knowing enough that you don't know enough to know the right areas to ask me on the right questions to show my lack of understanding.

"Charged particles interact with photons" might be a give away, yes.

The big bang?

You give the distinct impression you think yourself as some kind of 'search light' for truth and I would guess some kind of philosopher or 'free thinker' and when you find the point where one of us says "We don't know" you'll be compelled to give your 1.5 cents on the matter, as if you have something to contribute. Of course you'll justify that by saying how you don't need to know any science to contribute since science has reached it's limit and any idiot who thinks watching Donnie Darko and smoking a lot of cannabis with his equally idiotic friends counts as 'philosophy of physics'.

You didn't answer mine.

No, the existence of the universe is more fundamental than the existence of particles. It's possible to have space-time without particles.

Quantum fields and space-time are different. As is the 'aether'.

No, a vacuum, in the sense of say the standard model, is the superposition of all the various quantum fields at their minimal excitation level. All the fields overlap and the vacuum would be when there's no particles.

Different vacua, in the sense of string theory, is when the various fields have different properties at different points in phase space, which is a different kind of space from physical space (and it's a concept you'd be instantly familiar with if you'd studied physics properly and we'd not need to explain it, like we undoubtedly will....).

 

No, it doesn't. You are only stating that quantum fields evolve. So what? That doesn't explain what is going on in the quantum fields to explain why they evolve.

 

Until we have a better understanding of how quantum theory combines with gravity then we can't really say all that much about space time and quantum fields - there's the limit of physics right there - quantum gravity. String theory is a very good contender for quantum gravity but it's still very far from being universally accepted in the same way as the standard model is.

 

O.K. now. It looks like at the most basic level we are indeed talking about quantum fields and perhaps different vacua. As for the Big Bang, who needs it? If branes and bulks can explain the Big Bang, then I really only need to question about branes and bulks. Now, are branes and bulks also made of quantum fields and different vacua?

 

Wow! You are the first person on this threat to admit to a limit!

Please Register or Log in to view the hidden image!

You deserve a prize (which will undoubtably come in the form of ridicule from AN). However, aren't strings still just quantised quantum fields? So, the real mystery is still quantum fields - no?

 

You're assuming there's something that you aren't being told.
A field evolves; if it didn't there would be no particles.
Since we know there are particles, then fields "evolve" them into existence; fields have creation and annihilation events, or evolutions.