Every human on this planet earth, at least once, has gazed into the moon. Some might take that chunk of rock orbiting our planet as the symbol of the vastness of the universe. Or, some may look at moon to make them remember that the problems they face in their daily life is insignificant compared to the scheme of the cosmos. But only a few realizes that the moon is the window to our past. It may not be very notable but when you gaze into the moon, you are looking 1 second into the past. In scientific terms, the moon is 1.28 light second away form the earth. Similarly, if you could see the planet Neptune, you would be seeing 4 hours into the past;the sun is just 8 light minutes way. Just imagine what this means of a grand scale of the universe.
This might imply that time travel may be possible after all. All the observations made till now have been based on the light produced by a far away star which reached earth through time. There are still millions of light that are yet to reach our galaxy. We just need more time. As a result nobody can ever predict the vastness of the earth exactly. If someone does, then either he/she is mad or it is from another universe.
"Time and space and the modes by which we think, not the conditions in which we live."
- Albert Einstein