Why does quantum mechanics only predict outcomes, not mechanisms?

[fellupahill]

Seems like our general idea on the quantum level stops at predicting with great accuracy. The why, and hows seem to still evade us. Is my ideas accurate?

 

[Simon Bridge]

Accurate - don't think so. Current quantum theory is strongest on it's predictive ability.
Perhaps you are thinking of a particular example?

 

[mrspeedybob]

Seems like our general idea on the quantum level stops at predicting with great accuracy. The why, and hows seem to still evade us. Is my ideas accurate?

That is all that a physical theory can ever do. Feynman says it better then I can...

 

[Simon Bridge]

Ah that's a thought - I read that to mean that it does not predict with great accuracy.
Sure - the quantum models are good at predicting the numbers we get but do not do much to tell us how the Universe arrives at those numbers.

It is a philosophical point that the other models don't do this either.
I like Feynman's "Mayan" examples illustrating the danger of trying to interpret the models ... "it's got a 22 in it and 22 is a lucky number..."

QED let's us answer questions like: "how much light do we expect at point P" but won't tell us how those particular photons got there now we have detected them, but it can provide some insight into how photons may have got there in different circumstances.

That's statistics for you.

The "why" questions tend not to get answered in science much at all - that would be philosophy.

 

[fellupahill]

It just seems to me that QM is lacking in something, the way Newtons ideas of gravity was lacking. If that makes sense.

 

[Simon Bridge]

No it doesn't. "lacking something" is too vague to have any meaning. It's like there is a Je ne sais quoi about it.

 

[jetwaterluffy]

Erm.. I don't get what you are trying to say. All theories are likely lacking something, the problem is finding what.

 

[Simon Bridge]

Yeh - there are not a lot of certainties in this Universe but one of them is that our theories are lacking in some way. We do not actually know everything ...