On 29 Mar 2006 00:06:06 -0800, in uk.sci.astronomy , "Martin Brown"
wrote:

wrote:
You can make the end of a light beam sweep along a screen at any
arbitrary speed though - but nothing physical is actually moving faster
than the speed of light. Same with a very narrow angle pair of scissors
the crossing point can be made to advance at c (at least in
principle).

Er, no it can't. The classic mistake is to apply non-relativistic
equations of motion.

Yes. It can.

No it can't. The contact point moves at less than c at all times.
You're not reading the explanation properly

See the Relativity
Physics FAQ for details:

indeed.

http://jcbmac.chem.brown.edu/scissor...lScissors.html

And note this part:
"We have mistakenly assumed that the scissors do in fact close when
you close the handle. "
....
".The point at which the blades bend propagates down the blade at some
speed less than the speed of light."
Mark McIntyre
--