Prince Vegita

This isn't the same thing at all, but has anyone actually ever seen somebody finish off 6 saltines in one minute? It's damn near impossible. Good way to make money.

perfessor

Yes - it's called the "hackenchoke effect."

The Lone Ranger

My understanding of the phenomenon is that if you put cool water into the freezer, little evaporation takes place before it begins to freeze. However, if you put hot water into the (cold) freezer, a lot of it will evaporate before the freezing process begins. This has two effects: 1.) evaporation removes a lot of the water's heat, and quite rapidly, and 2.) evaporation reduces the volume of water that must be cooled to freezing, so what remains can freeze quite quickly.

Cheers,

Michael

Bobinius

I meant I tried the effect on a hot stove, not by walking on coals. :rolling: I don't plan to.

The documentary was made by Arthur C. Clarke, I remember now, and the physicist hypothesised that the sweat could be protective via Leidenfrost effect.

It isn't of course, the only explanation. For example some old guys in India have a foot skin so thick that they did not feel a hot light bulb touching their feet. I mean they did not feel any pain until after some minutes. This happened because the old people did not wear shoes, unlike the young generation.

Schneibster

Actually, I did so when I was five, and not only that but we had to whistle to prove we were done. I was strongly motivated by the presence among the prizes of a model of a P-40 aircraft, and the fact that I was reading about the Flying Tigers at the time. Hmmm, perhaps it was only five saltines- but IIRC it was six.

dirtymatt

Yes, once. Out of about 6 people who tried it at lunch one day one managed to do it, just barely, but he pulled it off.

Daisy

I have trouble understanding this one because it seems to me that as the hot water cools, at some point it will reach the temperature the cold water was and at that point, it should act the same as the cold water, with the cold water having the advantage of the lapsed time to have gotten even colder than before.

Sarpedon

Whats that one effect where if you have exceptionally pure, still water, you can cool it until its actually below freezing, but it won't freeze unless it is disturbed? I once heard a story of a guy who went fishing in an alpine lake. When his sinker hit the water, it initialized the freezing process, and the lake was frozen solid in seconds.

Mageth

This is known as the "blind luck if you don't blow yourself up" effect.

Note: you can put out even a lit match in a jar or bucket of gasoline. However, if you've left it sitting for a while and gas vapors have spread around and you drop the match, or accidentally tip over the container or slosh the contents when you're approaching it with a match, etc etc etc, this experiment can have devastating results.

Here's some other tricks.

You can cook bacon and eggs on charcoals on a paper plate (charcoal briquettes; I'm not sure this would work on wood coals, as they generally put out much more heat than briquettes). The trick is to use a relatively thin, cheap paper plate, and completely cover the top surface with bacon grease. Then place the bacon and eggs on the plate, and set the plate on the charcoals. The bottom (and top) of the plate may get a little brown, but they shouldn't burn. In short order, you have a short order of bacon and eggs.

You can also cook an egg in an orange peel. Cut an orange in half, remove and eat the contents from the halves, and break an egg into one of the halves. Then place the orange on the charcoals (again, I'd recommend charcoal briquettes, but this might also work on wood coals). Presto; before long, you have one cooked egg, with just a hint of citrus flavor.

BTW, for both of the above, I'd recommend tongs or leather gloves to place and remove the finished product on the coals.

Another campout cooking trick: baking in a paper box. You can make a quite effective oven out of a paper box. Take a box such as one that copy paper comes in. Line the inside of the box and the inside of the lid with heavy-duty aluminum foil. Make sure the shiny side is facing in. Mount some sort of a grill or grid, such as one from an old toaster oven, about halfway up the box. And note that, other than holes that might be necessary to mount the tray, don't punch any extra holes in the box. Also note that the box oven is arranged with the long axis vertical, and the short axis horizontal.

Place an aluminum pie pan or tray at the bottom of the box. Put what you want to cook on the grill (biscuits, cake, pizza, pie; whatever can be baked in an oven), and place one burning charcoal briquette in the tray at the bottom of the box for each 40-50 degrees of heat you need to bake at. For baking at 350, seven or eight should do, though if they're fairly burned down a few extra may be necessary. Place the lid on the box to cook away.

Things will bake in approximately the time it would take them in a normal oven.

Silent Acorns

I don't think this is a named effect.

It's an interesting side note that we don't really understand why it is so easy for pure water to freeze solid. Our best guess is that once an initial ice crystal forms it forms a kind of seed around which more crystals can form. But the initial one requires 6 water molecules to combine simultaneously - which can be highly unlikely if the water is especially still.

On the question of hot water freezing faster than cold water, the key is that the increased evaporation means there's less water to freeze plus the "hot cubes" are thinner (so they take even less time to freeze).