"Jean" wrote in message om...
My Query is quite simple........


Why can't a body simply accelerate and exceed the velocity of light????????

Just increase the velocity by some m/s for some time to reach the C ....!

This may not be quite the answer you were expecting
but you need to consider what you mean by 'why'.

If you mean 'why' in its most fundamental sense then the
question is outside the scope of physics. All we can say
is that no one has ever observed an object to travel faster
than light.

If you mean, how does our current theory of space and
time (relativity) deal with an attempt to travel faster than
light then I can give some examples below.

Suppose you fire one particle in one direction at three
quarters of the speed of light and another at the same
speed in the opposite direction (which is quite easy to do).
You now have an observer on one of the particles (a
little harder to do but possible, in principle) who measures
the relative speed of the other particle. According
to traditional (Galilean) physics, the observer would
measure a relative speed of 1.5 times the speed of light
but relativity has a formula for calculating the relative speed
(which you can find in any relativity text book) that always
gives an answer of less than the speed of light.

Suppose you have a rocket that produces constant
thrust and thus accelerates indefinitely. (It would have
what is known in relativity as a constant proper
acceleration.) If we observe this rocket from the
frame of reference in which the rocket was originally
at rest, we would find that the measured acceleration
would decrease (according to a formula you might
search for under 'relativistic rocket') as the speed of light
was approached such that the speed of light is never
exceeded.

Finally, consider applying a force to an object in
order to try to maintain a constant acceleration
in its initial frame of reference. As the velocity
increases, it is found that the force required to
maintain a constant (coordinate) acceleration
increases in such a way that to reach the speed of
light an infinite force would be required.

Overall, we have one theory (relativity) which
mathematically describes motion in world in
which we live, and which has been found to be
in complete agreement with experiment. This
theory makes it impossible for an object to
reach the speed of light.

Martin Hogbin