# Einstien's E=mc^2 equation -- question...

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, lets 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?

BvU
Homework Helper
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 ?

BvU
Homework Helper
No we can't.

Janus
Staff Emeritus
Gold Member
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.

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.

BvU
Homework Helper
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.

BvU
Homework Helper
Know the feeling , been there too !

Felix Quintana
Dale
Mentor
2020 Award
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.

BvU and Felix Quintana