Energy and momentum for a particle traveling at light speed

  • Level: Undergrad 
  • Thread starter Thread starter Felix Quintana
  • Start date Start date
  • Tags Tags
    E=mc^2
Join the discussion
Registration is free. Start your own thread to ask a follow-up.
11 replies · 3K views
Felix Quintana
Messages
36
Reaction score
0
Let's say we have a particle traveling at the speed of light, energy would be E=mc^2, momentum would be then p=mc, let's manipulate, m=E/c^2, momentum would then be p=E/c, but what energy does that equal, the particle only has kinetic energy correct? Then it would be p=1/2mc. Where is the other half?! In spring or gravitational?
 
Physics news on Phys.org
Partices with mass don't travel with speed of light.
 
Oh yeaaaah I was told that before, I forgot, but can we say what if theoretically ?
 
Felix Quintana said:
Oh yeaaaah I was told that before, I forgot, but can we say what if theoretically ?
No, That's asking "What would the rules be if I were allowed to break the rules?"
 
Interesting. Thank you very much sir... This, and all my abundant amount of strands.
 
Janus said:
No, That's asking "What would the rules be if I were allowed to break the rules?"
Finally someone who speaks my language.
 
I think, excuse me though, for I am a amateur, wild idea, but what if space creates the other half through spring, as if space is a flat plane but spring like, and it created the energy, I also think of the same thing with gravity and so one... I sometimes create hypothesizes and later find out I am correct, but not always...Think crazy outside the box ideas.:wink:
 
Keep that spirit, but pay some attention to what others have thought out over the ages too !
 
I'm usually beat to the punch! Especially members of the golden age and on.
 
Know the feeling :wink: , been there too !
 
  • Like
Likes   Reactions: Felix Quintana
Felix Quintana said:
Let's say we have a particle traveling at the speed of light, energy would be E=mc^2
E=mc^2 is the formula for an object at rest (p=0). The full formula (in units where c=1) is E^2-p^2=m^2. So if p=E then m=0.
 
  • Like
Likes   Reactions: BvU and Felix Quintana