Can Wave Function Constants Be Both Positive and Negative?

[terp.asessed]

I am curious if the constants for wave functions for a particle in a box can be both +/-...because constants I've applied for wave functions have always been +...

 

[DrClaude]

Wave functions that differ only by an overall phase factor $e^{i \phi}$ represent the same physical state, as no observable changes due to this complex phase. Hence, multiplying the constant by $-1$ will not change the physics. Taking the constant to be real and positive is often simply a matter of convention.

 

[terp.asessed]

Thank you for the explanation!

 

[curiousman]

Hi guys,

Just started studying physics hence I obviously have a silly question for you.

Why the wave function Ψ (x,y,z) must be square. It seems wave functions themselves have no meaning if they don't have a physical meaning.

Thanks a lot in advance,
Rodos

 

[bhobba]

Just started studying physics hence I obviously have a silly question for you.

The deep reason is non-contextuality and Gleason's Theorem:
http://en.wikipedia.org/wiki/Gleason's_theorem

However that's advanced and requires considerable background. At a less advanced level check out the following:
http://www.scottaaronson.com/democritus/lec9.html

Thanks
Bill

 

[curiousman]

Thanks Bill. I will check it out.