Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: asterisk on 29/05/2012 22:47:56

Title: Are two photons in a superposition until they are measured?
Post by: asterisk on 29/05/2012 22:47:56

how do we know two photons are in a superposition until they are measured ?

[i]when a single photon is split into two, measurement on one influence the other[/i]

 i hope you are familiar with this 

Title: Re: Are two photons in a superposition until they are measured?
Post by: Soul Surfer on 30/05/2012 00:13:01

Because they were created as a pair in a single interaction.  Photons are their own antiparticles and when you create new particles from the energy of an interaction you have to create a particle and an antiparticle.  the main point of the superposition is that we do not know which of the two is which until we interact with one of them.

Title: Re: Are two photons in a superposition until they are measured?
Post by: asterisk on 30/05/2012 12:37:42

Quote from: Soul Surfer on 30/05/2012 00:13:01

the main point of the superposition is that we do not know which of the two is which until we interact with one of them.

that's obvious isn't it ? how do we supposed to know something before measurement??

and when we measure we are measuring definite pre definied.. let's say spin up photon 

the other photon will always be spin down  ?what is being spooky here ? i dont understand


what is the implication of measurement? and what is being communicated FTL speed ? spin up will always be spin up and spin down will always be spin down from the moment of their splitting




well you may have guessed by now... i have no idea about quantum stuff i just saw a vid on youtube

Title: Re: Are two photons in a superposition until they are measured?
Post by: imatfaal on 30/05/2012 14:58:34

No information is ever communicated FTL.  I will have a deeper read and see if I can answer your other questions.