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

[iamthewheat]

Tilt it. If it is indeed half-full, the water will form an exact diagonal line from the bottom corner to the opposite top corner.

Such puzzles are a hobby of yours, are they?

[puzzledprof]

You are correct on both counts.

[iamthewheat]

Of course. It seems a good way to pass the time, at least...

[puzzledprof]

I promised a puzzle every Saturday some time ago -- to help with everyone's mental exercise, and to also keep my communicator from shocking me. Obviously, my schedule has been slipping.

[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.

[Text]

[guardianjoker4]

Ah, more puzzles. Jeez, I think I'm terrible at these.

[Text]

[puzzledprof]

There now, you've done well in the ones I've given you so far. Would you like a hint?

[Text]

[guardianjoker4]

Yes, please.

[Text]

[puzzledprof]

Fluids can change shape, but not volume. The bottle is a solid, which can neither shape nor volume. So if you can't change the volume, what can you change to see things more clearly?

[Voice]

[jazz_enpsyche]

Tilt the glass.

If the water winds up even with the bottom corner then the glass is exactly half full. If it doesn't meet up then it's more or less depending on where it falls.

[puzzledprof]

That's quite correct. Have you solved puzzles before, Miss...?

[battledancing]

Is this a habit of yours, Professor?

[puzzledprof]

Of course; I'm known for it, back home.

Wouldn't you like to give the puzzle a try?

[battledancing]

Ah, I see. I remember you had posted one of these puzzles, when we first talked. It's a very interesting hobby!

And I would, but it seems everyone else beat me to the answer already!

[puzzledprof]

I try to post one every Saturday, when I can. Obviously, events sometimes conspire against that.

Ah... well, I suppose I could come up with some way to keep the answers secret.