Observer

[Little Bang]

If an observer is stationary WRT to an electron 50mm away could he even be aware of the electron?

[Little Bang]

Since the electron is a point particle could a very tiny observer get as close as say 10^-10m?

 

Hqas anyone seen this? http://www.electronspin.org/electron.pdf

[erKa]

Since the electron is a point particle could a very tiny observer get as close as say 10^-10m?

 

Hqas anyone seen this? http://www.electronspin.org/electron.pdf

what do you mean as "close view"? ...you cannot watch objects less than 10^-10m (1 angstrom) by way of indetermination principle. Curiously 5 cm are 5*10^+8 Angstroms so the solid angle visible at 5 cm of a spot having diameter 1 angstrom is alfa = arctan 1/(5*10^+8)= arctan (2*10^-9)= 2*10^-9 Rad or 1.27324*10^-7 Dec.degree. :lol: In the fictional sky of your nano-observer such spot fulfilled of your electron is like a very small star in the night sky over ISS... pratically not yet visible without any further magnification :mellow: This is not a "close view" indeed.

[Qfwfq]

If an observer is stationary WRT to an electron 50mm away could he even be aware of the electron?

It would be exceedingly difficult for a macroscopic contraption to distinguish the field of the single electron at 50mm from its own fields. If we consider instead another charged particle at that distance, they will both have a slight acceleration but it can't realistically have a smaller mass so the initially stationary electron will get at least as great an effect.

 

No doubt you can shoot a particle to [imath]10^{-10}[/imath] but, if it is charged, by that point the field will be very appreciable and they will both be deflected. The ideal best thing would be a tiny electric dipole moment but I don't know of any existing object that suits this purpose; classically it would be subject to a torque. In any case, at that distance scale it would be fictuous to consider them stationary even if one is neutral, so you might as well send in a neutron and reason on the effect on the moving magnetic dipole moment (which is easier if you view it as electron going past neutron).