When I put large bed sheets in the tumble dryer they sometimes roll up into a ball and are still wet when the drying cycle has finished.Since smaller items do not seem to do this is there a threshold at which the area of the fabric gets too big for the dryer and rolls up? Would folding it a few times to make it smaller help and what effect would this have on drying time as if you fold it too many times this would have the same effect as it being rolled into a tight ball and it not drying properly? Has anyone devised a cunning method of putting their large sheets into the dryer that stops them from rolling up?Paul GaultNewcastle-under-Lyme, UK.

Even as a physics major I have to scratch my head looking at the varied descriptions of why there is a tidal bulge of water on the side opposite the moon.  Some argue it's centrifugal force, some argue it's gravitational gradient. So here's a serious question -- if the Earth and the Moon were simply held apart by a big stick, and not rotating, would there still be a bulge of water on the side away from the moon?

If you attach a straight pole to an axle so that it revolves at a right angle to the axle (like spokes on a bicycle wheel) and spin it, the outside of the pole will move faster than the inside. The longer the pole, the faster the movement around the circumference.

If I built a pole that was long enough, it would get to a point where the end -if spun - should reach the speed of light, or even exceed the speed of light. However, I know that nothing can travel as fast as the speed of light. What would happen to the pole?