Why There Is Time

A long, long time ago in high school I read that according to Einstein, space and time cannot exist without matter. Ever since then, I have tried to find a simple way to explain this, and it finally came to me on Sept. 7, 1999.

Photons (energy packets of light) have no mass and travel at the speed of light. At the speed of light, time is zero, so to the photon, the clock is stopped. At the speed of light, length is zero, so to the photon, it travels zero distance in zero time, so space does not exist. The photon doesn’t know it exists.

Sprinkle a tiny bit of mass on the photon. It can no longer travel at the speed of light and slows down. The clock starts running. Time happens. The "photon" now knows it is moving, so space happens.

Therefore, you can say that matter causes time, and matter causes space.

All the matter plus all the gravity in the universe adds up to zero, and time exists because of the matter.