What is a refrigerator? it is a machine for slowing down time by cooling, A time capsule for food. The longer you want to preserve food, the colder it must be. However as food becomes colder and freezes, the water inside it turns into ice. The ice expands, breaking the walls of the cells that make up the food and irreversibly damage it. This means that we cannot store fresh food for long periods of time. However food is often seasonal. In one winter you may get an abundance of, say, really great pineapples, but there are too many of them to eat, so many end up being dried, in jams, or simply thrown away. Cooling won't help us when we want to preserve fresh food for long periods of time.

 

But is cooling the only way to slow down time? No. There is another way. A way that keeps the food in prime condition, untampered, for as long as you want. A real time machine. And it's simple, at least in principle. You just have to make the food move really really fast.  Hold on, I hear you say, what does moving have to do with slowing time?

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We tend to think of time as a separate dimension from the three dimensional space that we occupy. Movement, the process of

changing our location in space, seems to us as something that has

no effect on time. We think that there is one master clock for the

entire universe.

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But as Einstein has discovered, this is an illusion. The truth is that

time and the three dimensions of space are really one

four-dimensional space-time system. When we don't move in space,

we move through time at maximal speed. When we start moving

through space our speed through time diminishes. When we move at

the maximal possible speed (the speed of light) time stands still.