I happen to be one of those cursed individuals
who can never just watch a movie without squinting at all of the scientific theories and results that it puts forth. Afterwards, I rush to the computer
and look up the 5 or 6 items that have been itching the back of my mind...
One of which, was Honey, I Shrunk the Kids
. If anyone remembers that, it was a movie with that geeky looking fellow who builds a shrink ray and accidentally shrinks his kids to the size of ants! Yes, ants! Now, I know what everyone is thinking about 'suspension of disbelief' and all that jazz about movie watching, but that's not it. I'm fine
with that whole shrinking thing. But, as a biologist, I must declare...Those kids should have died
And it's not because of bugs or air currents or something, it's a simple matter of physics. Specifically, it's an issue of surface area vs. heat output.
Now, as a full-sized individual of the human or monkey species, you have evolved to produce a certain amount of heat. You burn a certain number of calories automatically, just to maintain equilibrium
- part of which is a temperature. Your body is designed
to make enough expendable heat in order to keep you at the temperature of 96.8 degrees fahrenheit, the temperature at which you best function. Not only that, but your body has to burn an excess amount of calories to make up for the heat which escapes through your skin, primarily your head. That's why, when you're cold, just putting a beany on can do a whole world of good.
Therein the problems lie. Your body leaks heat
proportional to the surface area
of your body which is exposed to the environment per unit of mass
. I should also note that the outside temperature relative to your own body heat has an effect, but since we're not dealing with different temperatures of the environment, I'll leave it alone. To illustrate this, I'll use the example of something doubling in size - it works the same way, but much easier to understand.
Think of yourself as a cube
. A plain
cube. With polka dots
. Fine, fine, no polka dots. Now, if you double in size, how many cubes are you?
2? Wrong, you just doubled your height, you've got to double your SIZE! That means you double your width and your depth, too. A one cube creature doubles in size, it becomes 8 cubes of polka dotted fury.
Now for some simple math. When you're one cube, you produce one cube worth of heat, which then escapes through each of your 6 sides. You have been built that way; you enjoy being that way. When you get doubled in size
, you are now producing 8 cubes of heat, and that heat is escaping through 24 sides.
6 sides (surface area)/1 cube (mass) = 6, consider that your Heat Change
If you double in size...
24 sides/8 cubes = 3. You've now effectively cut your Heat Change
in half; that means, proportionatly, you're losing half as much heat as you used to. Therefore, when you double in size
, you trap too much heat inside, and you slowly cook yourself.
When you shrink
, the same process occurs, except in reverse. When you suddenly become half of your normal size
, you put out too much heat because you surface area to mass ratio
is greater; they lose too much to the environment.
And that's why Ray Szalinski
should have gone to jail for manslaughter.