5 Comments
Mar 2, 2021Liked by Kathy

Report a bug. In the quantum world, a particle actually can have either a definite position or velocity before being measured.

Expand full comment
author

Thanks for the comment. Do you mean the probability distribution for the location of a particle by path-integral formulation? Can you provide any references if possible? :)

Expand full comment
Mar 2, 2021Liked by Kathy

I mean, one can just create a particle with a definite position, and that particle will just be 'there' forever, no matter how or when it is measured. We can also call its state the eigenstate of X.

Expand full comment
Mar 2, 2021Liked by Kathy

I think he means, there exist a quantum state where one property is certain while another is not. This is actually the basis of quantum communication. two communicator can not reach to any agreement if everything is random.... and you can find a detailed description on wikipidia I think

Expand full comment

Half a year later, I have to say that this example was terribly given, since a free particle always has a Hamiltonian of $\frac{p^2}{2m}$ which alters the particle's position. It may be better to replace 'definite position' with 'definite momentum'...

Expand full comment