What are characteristics of light?

Light can sometimes act like a particle and sometimes like a wave, known as the wave/particle duality. It is the visible (to us) part of the electromagnetic spectrum. Light does NOT always travel in a straight line, and DOES bend in the presence of a strong gravitational field. This can produce a phenomenon called gravitic lensing, when that bending of light makes what is in effect, a magnifying glass for objects behind it. In a vacuum, light ALWAYS travels at the same speed, roughly 186,000 miles per second (or for European readers, about 3 million meters per second) regardless of the situation of the observer. Incidentally, other species can see beyond our own spectrum. Bees, for instance, can see into the ultra-violet end, and colors of flowers look very different to them.