Confessions of a Rocket Scientist
Wednesday, January 19, 2005
  How Fast Is It REALLY Moving
I was watching one of my favorite cheesy sci-fi movies a few nights ago, "When Worlds Collide." It was made in the 1950's and was based on a novel written in the 1930's. The screenplay basically dumbed-down the already questionable science of the novel and "updated" it to fit the times. The premise is that a huge "star" called Bellus would crash into the Earth and destroy it. Fortunately for the purposes of the movie, it was accompanied by a smaller Earth-like planet called Zaira. A rocket ship would fly a small group of humans to Zaira, along with livestock, seeds, machinery, and other stuff needed to preserve the human race.

Yes, it's a really corny concept. The plot and the acting are just as corny. But it features some really cool special effects of the Space Ark blasting off and then skidding to a landing on the new planet. The Space Ark is one of those great silvery space ships that were so popular in 50's sci-fi, and was designed by one of the great sci-fi artists of that time, Chesley Bonestell.

I have seen this picture so many times that I practically have the dialog memorized. But for some reason, one of the lines stood out. The astronomer, Dr. Bronson, states, "These two bodies have moved over a milloin miles in only two weeks."

A million miles in two weeks. Pretty fast, eh? Or is it?

To satisfy my own curiosity, I decided to calculate just how fast our own planet Earth is moving.

Now the Earth is 93 million miles from the Sun, and revolves about the Sun in 365.25 days, give or take a few minutes. We don't need to be too exact for this example. And to be perfectly accurate, Earth's orbit is not exactly circular but more of an ellipse. But it is close enough to a circle that we can approximate.

So how far does the Earth travel in a year? We can calculate this by multiplying the distance from the Earth to the Sun by two times pi (pi= about 3.1415926535). This equals about 585 million miles. Let's divide this by a year (365.25 days) and we get about 1.6 million miles a day.

So compare the Earth's 1.6 million miles a day to the speed of the approaching planets, a million miles in two weeks, and we see that on a cosmic scale they are really dragging their butts!

Today's cup of coffee is Colombian Supremo, smooth and strong with a medium body.
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Location: Quakertown, Pennsylvania, United States

Two time cancer survivor, happily married, LaSalle Alumnus

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