Recent content by hexrd

"Massless" Particle? What is meant by a massless particle? I know that a photon is massless and travels at the speed of light. Then how is it that a black hole ( or gravity) can affect it? I thought that gravity affects only objects with mass.

Is it true that if you dig a tunnel to the center of the Earth you will experience weightlessness? I heard that you will get heavier then become weightless.

Cogito Ergo Sum. I think, therefore I am. - Rene Descartes Can this be used as proof of one's existence? Can you prove that you exist?

Is this random motion caused by the bombardment of air molecules? Like Brownian Motion?

what makes the particles move from a high concentration to a lower concentration?

While registering, i unchecked the "receive email from administrators" box and did not receive the email required to activate my account. I had to register again differently (this time the box was checked) in order to activate it and post this