No matter how fast I swing, I can never travel outside this loop! Maybe space outside it doesn't exist! But I bet it does. This tire came from somewhere.

"Cosmologist on a Tire Swing", by Randall Munroe, licensed under Creative Commons Attribution-NonCommercial 2.5 License

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No matter how fast I swing, I can never travel outside this loop! Maybe space outside it doesn't exist! But I bet it does. This tire came from somewhere.