Undergrad How does observation affect reality

[bhobba]

"We do not belong to this material world that science constructs for us.

We are just as much part of it as a chair, car or whatever.

Please, things have moved on a lot since the days of the early pioneers, its not wise to take on board their writings, instead study a modern text like Ballentine. Observation these days can be defined quite easily without observers in the sense Schrodinger etc were thinking of - indeed Von-Nemannn fell into the same trap.

Thanks
Bill

 

[bhobba]

Hm, poor Schrödinger...

And Von-Neumann and Wigner - but Wigner later saw the light and so would Von-Neumann had he not tragically died so young.

Thanks
Bill

 

[bhobba]

Feynman's explanation of how mirrors work is a delight. (As I remember it, in Six Not So Easy Pieces, but please correct me.) But back to the topic, I claim observation cannot possibly affect reality. Only the transfer of energy from one place to another affects reality. There you have it, no observer effect whatsoever. The Universe seems to work fine unobserved. When we look millenia later, it seems to have got on fine without us. There's a probability I understand the magnitude of the wave equation, but the real and imaginary components phase me :-)

Oh dear. Please don't use words like reality - they are very ill defined even amongst experts. You should see what Penrose thinks reality is - if you haven't read it please do and you might come to understand its a word, while not to be banished from physics, is to be used with great caution.

As to energy transfer I would first become aquainted with what energy is in a modern sense using Noethers Theorem. Its surprising subtle even defining it little alone its realation to affecting reality, whatever your conception of it is.

Thanks
Bill

 

[bhobba]

There's a probability I understand the magnitude of the wave equation, but the real and imaginary components phase me :-)

There is a deep reason from the mathematical theory of generalized probability models. The simplest generalized probability model is just good old probability theory. But it can be generalized further and the next most complex one is - wait for it - QM:
https://arxiv.org/pdf/1402.6562.pdf

The difference has to do with what are called pure states. If you want to allow continuous transformations between them then one must use QM - ordinary probability theory will not allow it. So in going from one pure state to another, physically, we would expect it to go through some other state while doing it. It turns out that's where complex numbers come in:
http://www.scottaaronson.com/democritus/lec9.html

Thanks
Bill

 

[PeterDonis]

Everyone, please bear in mind that this is a physics forum, not a history forum. Some recent posts about history have been deleted as they are off topic.