Rest Energy of Electrons in Particle Accelerators: Zero or Not?

  • Context: Graduate 
  • Thread starter Thread starter Mizies
  • Start date Start date
  • Tags Tags
    Electron Energy Rest
Click For Summary

Discussion Overview

The discussion centers around the rest energy of electrons in particle accelerators, specifically whether it is considered to be zero or not. Participants explore concepts related to energy calculations for electrons at rest and in motion, touching on theoretical aspects of particle physics.

Discussion Character

  • Debate/contested

Main Points Raised

  • Some participants assert that the rest energy of an electron is 0.511 MeV, regardless of its speed.
  • Others argue that the kinetic energy of an electron at rest is zero, while its total energy increases when it is in motion.
  • There is a mention of the formula for total energy, ##E=\gamma{m_0}c^2##, and its implications for energy calculations.
  • Some participants humorously remark on the incorrectness of stating the rest energy as 511 MeV, suggesting it would imply an unusually large electron.

Areas of Agreement / Disagreement

Participants do not reach a consensus on whether the rest energy of the electron is zero, with multiple competing views presented regarding its value and implications.

Contextual Notes

There are unresolved aspects regarding the definitions of rest energy and kinetic energy, as well as the implications of relativistic effects on energy calculations.

Mizies
Messages
3
Reaction score
0
Electrons in a particle accelerator reach a speed of 0.999c relative to the laboratory. Is the rest energy of the electron equal to zero?
 
Physics news on Phys.org
The kinetic energy of an electron (or anything else, for that matter) at rest is zero.

The total energy of the electron, calculated from ##E=\gamma{m_0}c^2## or ##E^2=(m_0c^2)^2+(pc)^2"##, is .511 511 MeV when the electron is at rest and greater when it is moving and the kinetic energy is non-zero.

[Edit - left the decimal point out the first time around]
 
Last edited:
Mizies said:
Is the rest energy of the electron equal to zero?

The rest energy of an electron is 0.511 MeV, regardless of how fast it is moving.
 
Nugatory said:
The kinetic energy of an electron (or anything else, for that matter) at rest is zero.

The total energy of the electron, calculated from ##E=\gamma{m_0}c^2## or ##E^2=(m_0c^2)^2+(pc)^2"##, is 511 MeV when the electron is at rest and greater when it is moving and the kinetic energy is non-zero.

.511MeV or 511keV bro, 511MeV is some ginormous electron.
 
  • Like
Likes   Reactions: Nugatory
Matterwave said:
.511MeV or 511keV bro, 511MeV is some ginormous electron.
:)
 
Matterwave said:
511MeV is some ginormous electron.

It's overweight even for a muon. :oldruck:
 
thanks..
 

Similar threads

High School Photon Energy Without Rest Mass – How?
  • · Replies 19 ·
Replies
19
Views
3K
High School What is m in Kinetic Energy? Relativistic mass or Rest mass?
  • · Replies 55 ·
2
Replies
55
Views
6K
Undergrad If electrons can be pointlike particles, why can't black holes?
  • · Replies 16 ·
Replies
16
Views
2K
Undergrad The answer for the total mass of the Universe?
  • · Replies 36 ·
2
Replies
36
Views
3K
Undergrad If energy is relative, is the rest mass also relative?
  • · Replies 36 ·
2
Replies
36
Views
4K
Undergrad E=mc^2 and acceleration
  • · Replies 26 ·
Replies
26
Views
2K
Undergrad Charged particles and electromagnetic waves in transparent media
  • · Replies 22 ·
Replies
22
Views
2K
Undergrad EM Faraday tensor transformation for conductor carrying current
  • · Replies 9 ·
Replies
9
Views
2K
High School Does a hot coffee have bigger mass than a cold coffee?
  • · Replies 102 ·
4
Replies
102
Views
7K
Graduate Intuitive Interpretation of Rest Energy
  • · Replies 4 ·
Replies
4
Views
3K