A weekly dollop of scientific perspective by Drew Olbrich. Don't forget to check out my personal web site. Please send feedback to csfacts4@traipse.com.
Space Shuttle

OK here is the deal with the space shuttle. It has three rocket engines in the back, but there's absolutely no room inside for all the fuel it needs to launch itself up into space. All of that fuel is stored outside the shuttle, in the big brown cylinder, called the external tank.

The tank containing all the rocket fuel weighs seven times more than the space shuttle itself! That's a lot of really heavy fuel, and the space shuttle engines aren't quite strong enough to push the combined weight of the shuttle and the big bloated external tank up off the ground.

That's what the two long white solid rocket boosters strapped onto the sides of the external tank are for. They lift the tank! Fortunately, it was not necessary to strap an infinite series of smaller and smaller rockets to the sides of the solid rocket boosters.

It is not widely known that just behind the main flight deck of the space shuttle is a small Starbucks adapted for use in zero gravity.

Body Hair

We have just as much hair all over our bodies as chimpanzees or monkeys or any other furry primate. Most of it is just very short and light. It's called "vellus hair" or "peach fuzz". I think it's bizarre that most of our thick hair is on the tops of our heads. Imagine if dogs looked like that! On second thought, maybe it's better if you don't imagine that.

Research shows that we humans lost all our body hair through evolution about a million years before somebody finally figured out how to purchase clothes at one of the first primitive Walmarts.

One theory says that we lost our all body hair in an attempt to avoid parasites like ticks, fleas, and lice, and that we've only kept the hair on our heads because other people think it's pretty. As proof, consider that you haven't seen many bald pregnant women.

There is a very special kind of louse that only lives in human clothing. DNA tests indicate that it evolved from a louse that only lives in human hair, and that this happened about 42,000 to 72,000 years ago. So, that's probably roughly when clothes first went on sale. There are no special lice that live in any form of footwear, so DNA testing cannot solve the troubling mystery of exactly at what point in the past Hello Kitty themed socks were invented.

More Moon Facts

The tidal forces of the Moon (and the Sun) don't only act on the oceans, they act on the land as well. If you stand on the equator, the land beneath you will go up and down by as much as 21 inches (55 centimeters) over the course of a day. You won't notice this though, because you will be drinking too much tequila.

Since the same side of the Moon always faces the Earth, each lunar day lasts a whole Earth month. Consequently, anybody could outrun the setting Sun on a bicycle. Well, maybe you could. I am old and fat.

When the Moon was created, it was a lot closer to the Earth, and appeared ten times larger in the sky. Each year, the Moon moves 4 centimeters away from the Earth. I'm not sure why this is. Maybe we smell bad and it doesn't want to be associated with us.