Why they getting old in the earth?

On this weekend, Me and my wife took our son to the science museum. That was looked like built in old days around when girls were still dancing on the stage of disco with those colorful holding fan. All the exhibitions and atractions reminded me the sets and items in an independent low budget movie. I have no intention of accusing. I had been expecting it and the cheapness no problem for me. Truly said, I am a man who loves those independent low budget movies. I can enjoy any of them even if it's the bad quality. So this old fashioned museum also rung the bell in me.

What kind of attractions were there? A space shuttle rider with the TV monitor. Huge Hubble telescope model the size of Three-quarters. The three dimension glasses theater, which was the most favorite for my son. The several models of Soyuz, international space station, and space rockets. There's also a toilet in the space shuttle model. Of course, there were bunch of panels explaining the histories of space development or the structure of rocket's engine.

In those somewhat nostalgic exhibitions, I found my favorite. The space-time tripper. It's like a shape of telephone box. Entering into it, I found a computer monitor and console panels. "Start" button, "Confirm" button, and a rotating ball which seems functioning like a mouse pad. Beside of the console, I found the message on the plastic board saying "Sorry for the unsmoothly movement of a rotating ball. It's been old now. I wish you have mercy and patience or may your pray would be recieved to the God. Have a fun!" And as they mentioned, the rotating ball didn't work right. It's like moving a computer mouse on the gravels. Anyhow, my son tried to move it to keep the story goes on. The story is simple. Choose the partner whom you want to go with, choose the planet where you want to go. And the spaceship travels by the speed of light, arrived at the aimed planet, then back to the home planet. There, other partners were waiting for our charactor. But something wrong. Partners who were waiting in the earth were old with white hairs, while our charactor hadn't seemed getting old. The doctor cuts in the story and explained what had happened. Theory of Relativity. The speed of light never changes in any situation, so the time and space including us changes. If we move faster more and more as nearing the speed of light, the time itself goes slower more and more. The time which partners in the earth spent with was usual, while the time which space traveler had been spent was slower than that. So we came to find them getting old with those mussy mustache.

My son didn't seemed to understand what's happened to them. "Why they got to be old?" I kind of explained with no gain. Anyway, I like that old machine with almost broken console. Somebody have to fix it!