The question itself is pretty self explaining. I found some answers on the internet but all of them refer to the experience where an electrons mass was measured by observing its curvature in a known magnetic field. I always heard that an electron and other fermions behave like light and is neither a wave, neither a particle but still can behave like one of the two states. So how did they measure its mass?
Asked
Active
Viewed 1,960 times
-2
-
4Possible duplicate of How to measure the mass of the electron? – Wrichik Basu Nov 10 '17 at 20:38
-
2J. J. Thomson determined the mass-to-charge ratio of the electron. Robert A. Millikan and Harvey Fletcher perfomed the Oil drop experiment and determined the charge of the electron. The mass of the electron is $m=\frac{e}{e/m}$ – Nemo Nov 10 '17 at 20:42
-
Does electron in wave form have mass? – Nemo Nov 10 '17 at 20:45
-
@Arthur that’s what I’m trying to figure out. How could they calculate it then? – user175035 Nov 10 '17 at 20:46
-
Wave Nature of Electron – Nemo Nov 10 '17 at 20:46
-
@user175035, J.J. Thomson's experiment and the charge-to-mass ratio of the electron – Nemo Nov 10 '17 at 20:54
-
Related and interesting, sorry if it's already covered. Speaking personally, I have great difficulty imagining an electron having mass in anything like the same way as, say a brick has mass....https://profmattstrassler.com/2012/11/27/why-the-electron-cant-have-a-mass-without-the-higgs-field/ – Nov 10 '17 at 21:52
1 Answers
0
I always heard that an electron and other fermions behave like light and is neither a wave, neither a particle but still can behave like one of the two states. So how did they measure its mass?
You have forgotten or never noticed that the particle and wave duality depends on the boundary conditions of the experiment and the very small number h_bar, the Heisenberg uncertainty principle.
The track of an electron in the bubble chamber is a particle because its dp.dx uncertainty is well over the bounds of h_bar
If one knows the bending magnetic field mv^2=Bqv/r one can solve for the mass as as the charge is independently known.
When J.J. Thomson experimented with cathode rays in the 1890s, he measured the ratio of the electronʼs charge to its mass. He was unable to measure either value individually, because he needed to know the other one first. The charge of the electron was measured in the early 1900s by Robert Millikan, and then the electronʼs mass could be calculated.
anna v
- 233,453