[Jon Francis (OP)]

If two objects are each traveling at almost the speed of light away from another object positioned between them. Are they travelling faster than the speed of light relative to each other?

[Murchie85]

If A is going in the opposite direction of B then the combined velocity will be A + B =Vab but one will be a positive direction and the other will be a negative direction. So Combined velocity would actually be (-)A + B =Vab. So in short it would not exceed light vel.

[Soul Surfer]

No they are not, but Murchie's explanation is not correct.  We are used to velocities being added or subtracted in a linear fashion but when the velocities become significant with that of light that is, velocity squared/speed of light squared becomes larger than say 0.1 (its maximum value is 1)  the relationship becomes non linear and the two velocities in opposite directions never add up to equal the speed of light.

[Jon Francis (OP)]

If there was an infinite number of objects expanding out from each other. Each traveling at almost the speed of light. Would it still be so that none of the objects, relative to any other of the objects, would be traveling at greater than light speed?

[reasonmclucus]

If two objects are each traveling at almost the speed of light away from another object positioned between them. Are they travelling faster than the speed of light relative to each other?

  If such a situation existed the two objects would be forever invisible to each other because the light from one could not reach the other. 

It's widely believed that travel faster than light is impossible, but that may be because something traveling faster than light could not be visually detected.  It might be that the reason we cannot see so-called "dark" matter is that it is moving faster than light.

It might also be that travel faster than light is impossible only in normal space because the speed of light functions as some type of dimensional barrier.  Attempting to travel faster than light would require shifting into some type of  alternate dimension or space. 

     

[Murchie85]

Soul surfer, I thought all objects that had velocities were added up in vector form to find combined speed?