Re: could a laser be used to create a pulse of light whose kinetic energy

Hi,
Unfortunately lasers are unable to produce such a high energy pulse as that
of a brick. Of course it would depend on the mass of the brick which you
didn't specify ;) So for a 1kg brick you're looking at a 90000000000000000
J laser pulse ignoring relativistic effects which would stop the light
brick ever reaching the speed of light. There are lasers being developed at
the moment which can blow up missiles and other projectiles but their
specifications are classified because they are important for defense
puposes. The most powerful lasers have a pulse energy of around 1J so
unfortunately it can't be done at the moment. 
Both the light brick and a pulse of light with the same energy would
interact with matter through the electromagnetic force so their effect
would be the same. At that sort of speed, the momentum of the light brick
would cause it to interact with matter as a wave rather than a particle so
it would pass through most matter and cause effects such as interference
and diffraction,
Ben