Quanta discussion

[Tenek]

Hmmm... ok, teachers, I gots a question.

If you fire a stream of electrons at... what was it, a charged plate? ... half will go up, and half will go down, but you can't predict what any given electron will do. But...

With sufficient modifications to a spin filter, would it be possible to change the spin of all the electrons to 'up' or 'down'? I have a hunch it can't be done, but at least half and probably more could be filtered out and some changed.

 

[webboffin]

Tenek, I wouldn't know myself. Anyone else guess?

 

[lucaspa]

Originally posted by Tenek
With sufficient modifications to a spin filter, would it be possible to change the spin of all the electrons to 'up' or 'down'? I have a hunch it can't be done, but at least half and probably more could be filtered out and some changed.

This isn't the experiment.  The charge of an electron doesn't change and spin and charge are not complementary properties.

However, what you want to know is if you do manage to pin down the precise value of one value, the other immediately randomizes.  Let's use sweet/sour and hard/soft as the characteristics.

Take a detector and remove all the sour electrons. Now you only have sweet. Split them them into two beams and in each beam (all sweet) put in another detector and remove all the hard electrons.  Now, supposedly you should have only sweet-soft electrons.  Reconverge the beams and use a final detector and you will find that all the electrons are soft, but half are sweet and the other half are sour!  So, yes, one of the characteristics will automatically randomize again.

See Timothy Ferris' The Whole Shebang pgs 268-270 for a fuller discussion.

 

[webboffin]

What is the mass of an electron?

 

[Morat]

9.10956 x 10-31 kilogram