Relativity in Action
Sjef Frenken

I had just exchanged some coins for a medium-size cup of New York Fries, had added the requisite amount of salt and vinegar, and was walking toward a free seat in the food court on the third level of the Bayshore Shopping Centre. The two halves of my conscience were up in arms: against the fact that fries in general do nothing for the free flow of blood in your arteries and veins, there was the argument that the fries were thick-cut, and therefor presented less surface area for the grease to adhere to and penetrate, and moreover most of them had at least some of the potato peel still attached, and that was, according to my mother, where all the vitamins and minerals and other dietary goodies were hiding out. In other words, it was a nutritional stand-off, I tried to convince myself.

I was about to sit down when I heard my name mentioned by someone sitting farther away. It was my old friend Jack, having a coffee. I went over and deposited myself on the opposing seat. With reluctant charity I held out my fries to him. He declined: "coffee and fries don't go together." Jack had strong opinions. On everything.

I asked him what he'd been up to. Jack said he'd had an epiphany.

"As I was sitting on the toilet this morning -- that's where I do my best thinking, incidentally -- I realized all of a sudden that Copernicus, Kepler, and Galileo were wrong."

I said: "How so?"

"All three maintained that because the Earth circled around the Sun, it couldn't be the centre of the Universe."

"Well," I said, "Isn't that a convincing argument?"

"Not at all!" said Jack.

"But Jack," I said, "Astronomy has shown that the Earth is just a tiny speck on the edge of the Milky Way, our galaxy."

"So what?" said Jack. "The Universe is a lot bigger than the Milky Way."

Jack pointed a finger West, toward the Hudson's Bay store. "How far does space stretch in that direction?" I realized that Jack had adopted the Socratic method; he was going to lead me into a trap. I could feel it.

I said "According to the latest information, space goes on to infinity."

"Fine," said Jack. He pointed the other way, toward Zellers. "How far does it stretch that way?"

I said: "Same answer: to infinity."

And Jack proceeded to point to the remaining directions of the six points on the Amerindian compass: North to Moxie's, East to Roots, Down to the Phone Booth on the main floor and Up toward the glass windows overhead in the roof.

Each time my answer was the same: "To infinity." Where was he going with this?

"Now, which three-dimensional figure is the same distance from the centre?"

"A sphere, I suppose", I answered.

"Right, and where do you have to be in that sphere to have it extend the same distance in all directions?"

As reluctantly as if I had to depart with even one of my New York Fries, I answered: "the Centre."

"There you are!" exclaimed Jack triumphantly. "Galileo was wrong; the Pope was right! The Earth is the centre of the Universe."

"Yeah, but maybe the infinite distance in one direction is longer than that in another."

"No sir," said Jack with great fervour, "Once you're into infinity, it's all the same. Infinity plus one mile, is still only infinity." He swallowed the last of his coffee.

"But maybe the distance from some other star or planet to the end of the universe is also infinite," I countered.

"Nobody has been out there yet to prove it, and maybe no one ever will." was Jack's answer. "I'll have some of your fries now."

Well folks, there you have it: the Earth is the centre of the Universe.

Feel better now?