Re: WHAT GETS WARMER SAND OR DIRT?

Dear James:

I'm assuming that your 'dirt' is the same thing as my 'soil' =). Well, first we'll have to think about what's sand and what's soil/dirt. Sand is mostly quartz crystals. If you look at it closely you'll find that the small jagged bits are sparkle in the light if you clean them. This is because sand comes from rocks that are weathered down by wind and water, so that they become little particles -- sand.

Soil, on the other hand, contains some sand particles, as well as humus, or decaying organic matter. For example, old leaves that drop to the ground decompose after a while to become a part of humus. If you dig up some soil from the garden and examine it closely under a magnifying lens, you might notice some small bits of leaves and wood, which is the organic matter which has not broken down completely yet.

One important thing that soil has that sand does not is water. If you add water to sand it isn't sand any more, it's mud. So when you say sand I assume it's dry sand that you're playing with. Now, you know that when you heat up water it evaporates. From the liquid state, it becomes a vapour. Think about sweat. When you sweat, it's mostly water that's on your skin. It evaporates and takes away your body heat. Likewise, when you heat up your soil, the water in there gets heated up too, and some of it evaporates away. When it turns to the vapour state, it takes away some of the energy that you put in there through heating it. In contrast, sand does not have anything to take away the energy that you're pumping in with your heater or flame. Therefore, it heats up faster than your soil. Once again, we can compare this to a sweating person. If you're all hot after a run around the field, you'll feel cooler if you're sweaty and the sweat is carrying off some heat when it evaporates, than if you're completely dry and burning up.

One last thing, don't type in all CAPS because when you do, people assume you're SHOUTING, and that's quite rude, even if you don't mean it.

Well, I hope my answer's been helpful to you! Good fortune to you... =)

Thiam Hock "Hot Potatoes" Tan