Argument about inteference experiments : help me win!

I guess you are asking for an explanation that "makes sense".
Well, that won't happen. Quantum mechanics does not make sense to us. It doesnt matter how long you study QM, it never stops being weird; but after a few years you get used to that.
In fact, the reason why we need math is that if we were to just use "common sense" we would get results that do not agree with the experimental data. Hence, the math is neccesary in order to "compensate" for the fact that our brains are only wired to understand the classical -non QM- world.

 

i) Is there an a priori reason for why math is not the best way do describe the physical world? Why is our daily life language better? And if our daily life language is better, why do we stick with the math at all?...

ii) if you don't have time to learn french, don't visit france. Mastering the language of what you want to learn and understand is essential, and the language of physical science is math.

iii) What is really happening in the physical world is beyond our reach (classic philosophy), so we MUST do models in order to describe the world around us, and it seems that the best way to do so is by using math.

 

No the math we use today is only 250yeras old (invented by Newton and Leibniz), then it have devolped by guys like Hilbert (early 1900) and so on, math is under research today as well.

Must nature and mathematical relationships a priori be understandable instincitively by everyone?

All things that come up from our physical theories exists in the real world, that is true - that is why physics is also an experimental science. If you think you can do better, then give it a try.

Einstein had several theories, please name the one you are referring to. I think you are referring to General Theory of relativity, and he basically starded in the same way as Newton did. Newton got an apple in his head, and Einstein imagined how physics would behave in a falling elevator (Free fall), and then he basically just started to elaborate. When he learned differential geometry, he got the tool come to formulate the theories.

This is what theorists do all the time, one starts from an idea, then trying to forumulate a coherent theory that can explain all known things and make predictions of new results.

Special theory of relativity is based on two axioms, imposed by einstein. Axioms can't be proven right nor wrong, but the theory that comes form these two axioms are one of the biggest triumphs of physical science, since it has so many experimental verifications.

What if it is not meant for the whole population to understand everything? Is there an a priori reason for why they have to?

What is the use for a language that only 0.1% of the population can read? 'Everybody' CAN learn math, everybody can learn chinease and so on.

 

If you do the bookkeeping of a small shop, what do you think is easiest ? Counting over and over again the money in the cash register, and the goods in the store, or just using some arithmetic (= a mathematical structure) ?

Well, the mathematics used in physical theories is similar. Only, the structures are more sophisticated. But it is still easier to do the math, than to try to find an equivalent of "counting the money".

 

Then you have a long time to wait for one. Quantum theory has always reeked havoc with common sense.

I don't understand. Either the photons are deflected to the left or they go straight through moving in the downwards direction in the diagram. They certaintly don't move to the right.

To be precise you'd have to move both mirror and source since if you move the mirror too far the laser light may just miss the mirror or the reflected beam may miss the detector.

Huh? Where did you get that idea?

I don't understand what that means.

You're using classical reasoning for a quantum mechanical system. The path that the photons takes cannot be spoken of until the photon is detected. Trying to make a statement about which path it goes through will lead to the wrong answer.

Photons don't get split. What happens is that there is a 50% chance that the photon will be defected and a 50% chance that it will simply move through the mirror and straight down after it passes through the mirror.

It is the intensity that drops, not the field strength. The intensity of the light is proportional to the square of the intensity of the field. And I don't think its meaningful to speak of the strength of the electric field of a photon.

The math isn't that hard. If you know calculus then it wouldn't take more than a several months to have a good understanding of it. However your TAs are wrong in that there is nothing mysterious about this problem.

The math will give you the correct answers if you resolve to think in quantum mechanical terms and stop asking what the photon is doing when nobody is observing it. Such questions have no answers in quantum mechanics in that such questions are meaningless.

Regarding math: Math is merely a language in which one can describe nature precisely. There's nothing more to it than that. Trying to describe nature without math is like trying to have a conversation about programming using machine language. While it might be possible I know I certainly wouldn't want to try! One can speak about the physics by translating the math into english but while it might take one line on a piece of paper to describe it mathematically it might take many pages to describe it using, say, English. I'm not even sure that such a thing is possible!

Pete

 

By "with common sense", you of course mean "with the intuition I have developed about classical physics". :tongue:

 

Absolutely.

Pete