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You cannot travel at the speed of light. However, no matter how fast an object travels light that it emits will always travel at the same speed, ~300000 kilometers/second

Light travels at the speed of light, and it has mass. Why else would be affected by gravity?

Light travels at the speed of light, and it has mass. Why else would be affected by gravity?

If light had mass e would not = mc2 and atomic fission and fusion would not be possible. See A. Einstein, a prominant patent clerk and all around great guy.

Should have been in my last post.

Light is not affected by gravity because of any mass inherent Light is affected by gravity because gravity bends space-time.

Stretch a sheet of rubber taut. Place a marble in the middle of the sheet. The sheet barely deflects. Remove the marble. Place a bowling ball in the middle of the sheet. The sheet deflects (bends, warps, whatever) to a greater degree.

The sheet of rubber is a two dimensional representation of what happens in three dimensional space-time when a mass is present.

When Einstein predicted that space-time would bend due to the presence of mass, scientists initially scoffed at the idea. Then someone happened to watch the Sun occlude a star (the earth's orbital movement caused a visible star to appear to move behind the Sun). The light of the star continued to be visible even though a line passing from the star to an observer on Earth passed through the Sun itself. Einstein's prediction about the curvature of space-time, by gravity, was and continues to be, accurate to within the error of our instruments.

True it has mass/energy, but it has no rest mass. You and everything else except radiation, does. Anything with rest mass greater than zero cannot travel at the speed of light, because that would require infinite energy. However things with zero rest mass, such as light photons, can only travel at the speed of light.. well almost, it's true in a vacumn, but the speed in media, such as air, glass, etc, is lower.

Let's try this again. I got distracted by the clothes dryer stopping. :)

Light travels at the speed of light, and it has mass. Why else would be affected by gravity?

Light indeed does have mass, you can calculate the mass of a photon by using E=MC2 in the form M=E/C2. The energy is related to the frequency (i.e. color)

What light, in general electromagnetic radiation, does not have, is rest mass. The formulae for mass is:

Mass = Rest_mass / sqrt(1 - V2/c2)

where: V2 is the speed squared
C2 is the speed of light (in a vacumn) squared.

From this one can see that as the speed approaches that of light, the denoninator approaches zero and the mass increases without bound (that is infinity) UNLESS the Rest mass itself is zero.