Time travel is the idea of going back in time to the past or forward to the future. Time travel can not be done, so far as we know now.
The speed of light[change | change source]
Light moves very fast, faster than anything else in the universe. The speed of light is 670,616,629 miles in one hour. Light can go around the earth three times in one second. Most cars can only travel about 100 miles in one hour. Most people can only run 12 miles in one hour.
Movies and television shows[change | change source]
Much later, the American movie "Back to the Future" tells a fictional story about a professor who builds a machine that can take people into the future or back in the past. The popular British TV program Doctor Who is about an alien who has adventures by time traveling.