Bose-Einstein Condensate Properties

[DrClaude]

Thanks. That brings up the concept of what do we mean by 'measurement'. I believe every interaction between everything in nature constitutes a 'measurement' and thus obeys the HUP at all times and situation. Thus every Rb atom in the BEC obeys the HUP at continuously. I assume you disagree? I never thought the HUP was principle about humans taking data.

This is getting off-topic.

But no, all interaction is not a measurement, especially not a particular type of measurement. Take the example of spin. If a prepare system in the spin-up state according to the z axis, it is in an undetermined spin state along x and y. If something interacts with that spin in a way that can't change the spin, by your account its spin would become indeterminate with respect to all axes. I expect it to stay in the spin-up state along z.

Anyway, you will find a few recent threads on the question of the HUP and its meaning. Please have a look at them.

 

[bob012345]

This is getting off-topic.

But no, all interaction is not a measurement, especially not a particular type of measurement. Take the example of spin. If a prepare system in the spin-up state according to the z axis, it is in an undetermined spin state along x and y. If something interacts with that spin in a way that can't change the spin, by your account its spin would become indeterminate with respect to all axes. I expect it to stay in the spin-up state along z.

Anyway, you will find a few recent threads on the question of the HUP and its meaning. Please have a look at them.

Thanks, I will.