What is quantum field theory and why was it developed?

[Nereid]

Guys, please (I think you're both guys), this isn't about 'winning' or 'losing'

I'd love to be shown to be wrong, but most readers of this thread can barely keep up with the concepts, let alone appreciate how much math is behind them.

It's an exciting time to be here; there's lots of really interesting ideas being proposed, examined, discussed, debated, ... even arguments There is an unprecedented access to experimental data, and the promise of vastly more to follow.

Let's have more discussions, without 'winners' or 'losers'.

 

[outandbeyond2004]

We need the truth to be a winner, never a loser. (This has more than one meaning).

 

[lethe]

Originally posted by selfAdjoint
Lethe, consider that you have won.

what are you saying? you have really confused me now. do you concede that action is not a multiple of h?

You know I just wondered, and you dragged me into this argument. But how would you explain that action is certainly expressed as a multiple of h?

i would explain it very simply: action is not an integral multiple of h, and anyone who says it is, is mistaken.

you told me outright that i was wrong, without providing any evidence. i wasn't trying to drag you into an argument you didn't want to have, i just want to know whether there is any reason why you think these things you think about action. it is very frustrating when you simply respond "you are wrong" or "you are silly", without any explanation, or even worse, explanations that contain arithmetic errors of a high school nature. if you were just wondering aloud about an idea you had, then you shouldn't put it forth as fact.

For that matter how can people do quantum mechanics over a Galois field?

what the **** does that have to do with anything?

 

[Janitor]

I skimmed through Selfadjoint's link to see if it looked like crankery. I found this statement in it:

Suppose we wish to verify experimentally whether addition is commutative, i.e. whether (a + b) = (b + a) is always satisfied. If our Universe is finite and contains not more than N elementary particles then we shall not be able to do this if a + b > N. In particular, if the Universe is finite then it is impossible in principle to build a computer operating with any large number of bits.

Whaaaa?

Is he saying what I think he is saying? Let us suppose the universe contains 10^80 particles. (I just pulled that number out of thin air. Supply your own number if you don't like mine.) Is he saying that an ordinary desktop computer cannot be programmed to add (for example) a pair of base-10 numbers each of which is 81 digits long, first in one order, then in the other order, and check that the results are the same? Surely he isn't that stupid? [?] Am I being stupid?

 

[selfAdjoint]

Well since all the registers in your computer (where you would store the intermediate and final results) could by assumption have less than 10^80 bits (at a minimum 1 electron per bit) it seems to follow. And if you choose to do the math with pencil and paper , consider how many electrons are in a sheet of paper. Even if you reused paper in your calculation, you would have to write down the final answer.

 

[Mike2]

Originally posted by selfAdjoint
Well since all the registers in your computer (where you would store the intermediate and final results) could by assumption have less than 10^80 bits (at a minimum 1 electron per bit) it seems to follow. And if you choose to do the math with pencil and paper , consider how many electrons are in a sheet of paper. Even if you reused paper in your calculation, you would have to write down the final answer.

So are you suggesting that the universe must be infinite? It does not take 10 billion particles to symbolize 10 billion particles. But you are right, we could never "experimentally confirm" by measuring that addition is commutative at high enough values if the universe is finit? What the point? I seem to have missed it.

 

[selfAdjoint]

I think the point of the paper was to see how far you could go in this direction. Notice that it gave them some nice things, but also some things that disagreed with experiment. There are a lot of papers like this on the arxiv, and every now and then one of them makes it into a reviewed journal.

 

[kurious]

If their is a sea of virtual particles interacting with electrons and protons, for example,then what is the temperature of that sea and does it have entropy and exchange heat with normal matter?

 

[selfAdjoint]

No it doesn't. It is possible, if not necessary, to think of virtual particles as just mathematical terms in a power series, with no physical reality at all. Even the Casimir effect, which seems to show their reality, can be explained as an interaction with the plates.

 

[rtharbaugh1]

I just read this thread, with interest but not satisfaction. I thought it was an interesting question, about whether action must occur in integer values of Planck's constant.

Is it possible that this argument reduces to the theory of Pythagorus regarding the sum of squares? For example, if an action involves two steps left and three steps up, the resultant action is the hypoteneus, sqrt 13, not an integer. This seems trivial. Have I missed the argument entirely?

 

[lethe]

No it doesn't. It is possible, if not necessary, to think of virtual particles as just mathematical terms in a power series, with no physical reality at all. Even the Casimir effect, which seems to show their reality, can be explained as an interaction with the plates.

i wonder what on Earth you were talking about before, silly