Fifty-Ninth Journal Entry

[puzzledprof]

[Backdated to Saturday. Voice, repeated in text]

Ah... I've been neglecting my puzzles, haven't I? I hope this one will be entertaining.

You have a glass with fluid inside, about half full. Without using any instruments, how can you tell if it is exactly half, more than half, or less than half full?

Comments

[luke_triton]

What shape's the bottle, Professor?

If it's a rectangle, you can tip it on it's side and look to see the diagonal line. If it's perfectly straight then it's half full!

If it's not a rectangle, then I'm not sure.

[puzzledprof]

It doesn't matter what shape the bottle is, as long as it's symmetrical. You're close in your answer -- what should the ends of the line coincide with if the bottle is exactly half full?

[luke_triton]

If it's exactly half full, the top corner on the bottom of the bottle, and the bottom corner at the top of the bottle.

It would be awfully hard to see if the bottle is exactly half full if the bottle isn't square or rectangular, Professor. There are no corners on a cylindrical bottle, so it would be hard to see if they lined up. I know you can still tell, though.

[puzzledprof]

Even if it's not rectangular, the top and bottom are usually flat -- so those, at least, have corners.

[luke_triton]

If you say so, Professor. I don't think I can picture it, but I'm sure you're right!

[puzzledprof]

You could try the puzzle for real, if you'd like.

[luke_triton]

I guess that's right--I'll try later when I can get a bottle that's the right shape!