**Ask a monkey a physics question thread**

[Savy]

I like Ongs answer, it's like 99% complete bullshit and 1% touching on some ideas that may actually be relevant. 100% believable though.

I like putting ice in my drinks and this causes the outside of the glass to get wet. This in turn makes the coaster that I use stick to the bottom of the glass when I pick it up creating a whole shit tonne of issues. Solutions to stop this happening?

[OngBonga]

I like putting ice in my drinks and this causes the outside of the glass to get wet. This in turn makes the coaster that I use stick to the bottom of the glass when I pick it up creating a whole shit tonne of issues. Solutions to stop this happening?

Humidity is the problem. The water is in the air, and is condensing on the glass as it cools. Get a dehumidifier, they can be bought from £75 or so bottom-of-the-range appliances, a bargain considering the hassle a slightly moist glass can cause.

I like Ongs answer, it's like 99% complete bullshit and 1% touching on some ideas that may actually be relevant. 100% believable though.

I think you're being a bit harsh here. I think I might have at least 3% logic in there somewhere.

[Savy]

Humidity is the problem. The water is in the air, and is condensing on the glass as it cools. Get a dehumidifier, they can be bought from £75 or so bottom-of-the-range appliances, a bargain considering the hassle a slightly moist glass can cause.

I was thinking of spending about £0 to fix this problem. I do want a dehumidifier for my room though but not happening any time soon.

I'm also aware of what's causing it, wouldn't have thought a dehumidifier would make that much difference though. Surely it doesn't need to be all that humid for this to happen?

I think you're being a bit harsh here. I think I might have at least 3% logic in there somewhere.

I like a lot of the ideas I just think things like strength of knot due to strength is going to be incredibly minimal as we aren't putting in huge force when tying shoes, my right arm is stronger than my left but I can easily apply equal output assuming that is low enough for both arms. If there is a difference it's going to be small and I can't imagine that small effect is going to cause that big of a difference.

I imagine he is just doing something weird when tying his shoes.

[MadMojoMonkey]

I like putting ice in my drinks and this causes the outside of the glass to get wet. This in turn makes the coaster that I use stick to the bottom of the glass when I pick it up creating a whole shit tonne of issues. Solutions to stop this happening?

Let's take a closer look at what's going on.

The cool cup causes the water vapor in the air to condense, transferring heat energy to the glass, and thus your drink. Those condensed molecules are still being bombarded by other molecules in the air, and every collision statistically tends to average out the temperature of the things which collide. They're also still transferring energy to your drink, so some balance is reached, where some evaporation is happening and some condensation is happening as the energy of the environment is transferred into your cool drink, forcing its temperature to tend toward that of the ambient temperature. Neat, huh?

The problem isn't really due to the condensation causing water to collect into macroscopic drops on the outside of the glass. It's really due to the capillary effect of the water being pulled into the thin space where your cup meets the table (and gravity pulling the drops toward that space accelerates this). This quickly fills the circular space and creates an air tight seal. When you pick up the cup, the air can't get in-between the cup and the coaster, so... the coaster goes with the cup.

One solution is to change the environment.
You could try pointing a small fan (like computer fan small) at your drink to accelerate the re-evaporation of the water. Maybe a hair dryer. A dehumidifier in the room is going to create a lot of heat, in my experience. The double punch of heat and dry air could well keep your glass dry on the outside. Your ice will last about 10 minutes and you'll be sweating balls, but you'll have a dry glass.

A better solution is to prevent that circular seal from forming in the first place.
The way to do this is to break the geometry.

We can break the geometry of the cups, but only on the cups we own. To wit:
On plenty of cups, the bottom ring isn't complete. There's a divot in the ring, where it doesn't form a complete loop when it touches the coaster / table / etc. Buy these when you acquire new cups and glasses.

If you're out using someone else's cups and glasses, or don't want to replace the cups and glasses you already have, then change the geometry of the coaster. Try to break the plane where your glass meets the coaster.
Maybe put a toothpick under one side of the glass, so it sits unevenly. Maybe put 2 coasters with a small gap in between them and put your drink over the gap. I haven't tried it so do the science on this and report back.
It's prob not expensive to find a coaster set which has indents on the surface which solve this problem.

[Savy]

If you're out using someone else's cups and glasses, or don't want to replace the cups and glasses you already have, then change the geometry of the coaster. Try to break the plane where your glass meets the coaster.
Maybe put a toothpick under one side of the glass, so it sits unevenly. Maybe put 2 coasters with a small gap in between them and put your drink over the gap. I haven't tried it so do the science on this and report back.
It's prob not expensive to find a coaster set which has indents on the surface which solve this problem.

This is fucking genius and what I wanted, thanks. I mean the toothpick bit isn't that's going to result in split drinks the two coasters however is.