So is this just saying that a particle traveling at .75 c will appear to be moving at 1.5 c to another particle moving towards it at .75 c? If so then duh?
> So is this just saying that a particle traveling at .75 c will appear to be moving at 1.5 c to another particle moving towards it at .75 c? If so then duh?
The real DUH is that it doesn't. A particle that is moving at .75c towards an observer going at it at .75c would appear to move at .96c. Velocities cannot be composited like that when you are moving really fast.
If:
V(a)=0.75c (relative to observer at (c))
and
V(b)=0.75c (relative to observer at (c))
and (a) and (b) appear to be on parallel and oppositely signed vectors from (c)'s vantage point, the observed velocity of (b) @ (a), or (a) @ (b) will not equal 1.5c.
Tuna-Fish|13 years ago
The real DUH is that it doesn't. A particle that is moving at .75c towards an observer going at it at .75c would appear to move at .96c. Velocities cannot be composited like that when you are moving really fast.
unknown|13 years ago
[deleted]
sageikosa|13 years ago
If: V(a)=0.75c (relative to observer at (c)) and V(b)=0.75c (relative to observer at (c))
and (a) and (b) appear to be on parallel and oppositely signed vectors from (c)'s vantage point, the observed velocity of (b) @ (a), or (a) @ (b) will not equal 1.5c.