🚀 go-pugleaf

>1. If light is a particle, how can it travel at the speed of light
>without becoming an infinite mass?

The particle of light (the photon) has a particle wave duality.  It is
like a particle in that it is a "clump" ("pluse") of light waves transmitted
together.  It particle nature is not one of mass.  The photon has a 0 rest mass
and therefore can not be applied to the revelativistic equation.  Remember that
general relativity was structured arround light having the ultimate speed there
fore there is some technicalities in applying light to the equations.  (also,
in General Relativity Einsein defined light as massless and a wave)

>2. If light is a particle, when it leaves a flashlight why doesn't it
>have enough momentum to push the flashlight backward?

No mass, no momentum, no recoil.

>3. relativity states that to the observer, the mover's time always goes
>slower. Then how can one person's clock be ahead of the other's,
>considering that either one could be considered the mover or the observer?

Einstein gave a long explaination of this, but I try to state the main idea.
   - Each one looking at the other would seen the other's clock move slower.
so therefore neither would appear to be ahead of the other.  They can only
determine whose clock is ahead if they both stop and are brought together.
(Hope this is understandable)

>4. If you could stand in a black hole and shine a light straight up,
>would the light escape, turn around and come straight back down, or orbit
>to the right or left?

If you stood at the center of a black hole (yeah, right) and could shine a
light out of the hole.  You couldn't really do it the light would never be
able to get out of the source due to the gravational effect.

If however you could stand at the black hole boundary (called the Swartzchild
Radius) and shine a light it would orbit in a beam arould the black hole for
ever.

>5. If we could travel at speeds greater than the speed of light, could we
>travel back in time?
>

No. If we could travel at an infinite speed we could only stay were we were in
time.  We can never return to the past.  :-(


For a good explaination of some of this stuff read Stephen Hawking's "A Brief
History of Time".
                      -Gregory R. Snow (phys2shs@uriacc.uri.edu)
                       Smithfield High School Physics 2 Class