Any yet another Physics Question

The space shuttle has been fitted with laser pointers on very high quality pivot mounts. The beams can be made to intersect and as the lasers are pivoted to point out the point of intersection can be maintained (like two swords crossed near the handle and then swung till they are touching at the tip). The point will increase in speed as the beams swing forward until they finally diverge. Can the point of intersection be made to go faster than the speed of light if you pivot the lasers very quickly?

If you like Start Trek it might work. Einstein taught us that the speed of light is it. That's all she wrote (Warp speed hasn't yet been invented, well, can't exist except in Star Trek and the like where they have to get places quicker). So, even though the shuttle is moving forward at a nice clip and the light is being beamed forward as well, the speed of light is the speed of light. (And matter is transformed into energy as the speed is approached, but that doesn't matter in this case.)

Yes - but nothing is actually moving faster than the speed of light. The intersection of two light beams, being as it isn't an actual object, isn't restrained by the light speed limit.

Before the days of space shuttles and laser beams I believe the question was posed as "if you had a pair of scissors as long as the universe, and you closed them very quickly..."

Jim

>Yes - but nothing is actually moving faster than the speed of
>light. The intersection of two light beams, being as it isn't
>an actual object, isn't restrained by the light speed limit.
>
>Before the days of space shuttles and laser beams I believe
>the question was posed as "if you had a pair of scissors
>as long as the universe, and you closed them very
>quickly..."
>
>Jim


OK, maybe I am reading this wrong. I look at the question as it was defined, including the statement as follows: "The beams can be made to intersect and as the lasers are pivoted to point out the point of intersection can be maintained (like two swords crossed near the handle and then swung till they are touching at the tip). "

The key for me was "Crossed near the handle and then swung till they are touching at the tip." As such, the point of intersection would be fooving farther away from the ship, and nothing moves faster than the speed of light. The light beams themselves would have to catch up with that point of intersection and the increased speed of the shuttle would not matter. However:

You would be correct if the question were asking it the other way around (and maybe it was). If we start with a point of intersection far, far away and then move the point of intersection close in, the point of intersection would, yes, appear to be moving faster than the speed of light, but only because the light beam at intersection would be closer and not have to be moving as far.

Two answers from two different perspectives. Which was intended? (Perhaps yours?)

You make a good point - I guess I didn't really think it through. I just remember the old scissors question and jumped to the same conclusion.

Jim