Dinner Questions

Question:
If you had a bicycle with square tires, would there be any way to ride it?

Hints:

• The answer is 'yes', how?
• You would need a special road
• You would probably not be able to turn on this road

Answer:

Here's a page with a picture which explains it all. Basically, you would need a road that has bumps in a special shape. The tires would be aligned so that the corners would end up between the bumps. The special shape is an inverted catenary.