- CRITTER TALK
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Well, here it is on Sunday….sitting around at work doing some boring paperwork and contemplating life.
Lunch hour so I thought…hey, instead of eating some fast food and putting on 2 more pounds, why not write a Science Sunday post. Haven’t done one of those in awhile…
But what to write about? Hmmm….
Can’t write about lasers or plasma generators because it involves high voltage and I would probably get sued.
Writing about how to make explosives with common household items would probably get me kicked off of MMA and on the evening news, so that’s out.
Of course, this completely rules out plutonium and linear implosion lens theory. Hell, just Googling that will get you on 10 different lists and a blacked out SUV across the street.
So…how about some basic physics? I know what you’re thinking…Arrrrghhh!!
But this won’t be too painful and it’s something most people don’t realize.
Why do people float around in space capsules when they’re orbiting the Earth?
99 out of a 100 people would say because there’s no gravity. And they would be completely wrong. I’ve even seen it wrong in school science books.
I know, I know..this is what your thinking…..So tell us Mister Smarty Pants Krell, why do they float around then?
Before I tell the answer, let me go into a couple of things.
Drop a baseball and what happens? It starts to fall towards the Earth. Of course…can’t avoid it.
Fall off a ladder, your going to hit the ground and probably start cussing.
Drop a glass and it’s going to hit the ground. Basic gravity stuff.
Okay, now throw a baseball parallel to the ground. It goes out at a fast speed, but it still is going to fall to the ground at the same gravity rate. Just because one thing is happening, doesn’t mean that it effects the other and it goes away.
Now the Earth is a big nice round ball. Look out on the ocean and it just goes on and on. Can barely tell it but over the distance it curves down.
When sailing ships were discovering new continents, the first thing the natives would see is the top of the ship sails, then more of the ship mast, then finally the full ship.
Unfortunately, it was too late to start running by that time… but that is a different story.
They saw the top of the ship first because the Earth is curved. That nice big round ball effect.
Now imagine this…Suppose you were magic and you could throw a baseball so that it would never slow down horizontally. Gravity of course would still effect it and it would just hit the ground after a certain distance.
But suppose that you could throw the baseball so fast that the amount that it drops due to gravity is the same amount that the Earth curves down? What do you think would happen?
If you guessed that the baseball would stay the same distance to the ground all the time, you win!
It’s still falling but the Earth because it is curved down, keeps the baseball at the same distance to the ground.
That is the same concept that’s used for satellites and those manned space capsules. Of course there’s still gravity up there when a satellite is orbiting. But the satellite is going so fast that the amount that it drops to the Earth just happens to be the same amount that the Earth curves.
Go faster than this falling rate / Earth curve thing and it’s called escape velocity and you will break free of the Earth’s orbit. Go slower and you will fall back to the Earth.
But you say…”What a second, that’s fine and good. But what about the weightless floating around bit?”
Assuming that you have grasped the concept of a satellite falling but still staying in the same relative distance to the Earth, what happens if you were in an elevator and it suddenly went into a free fall? Besides the obvious of you dying…
Well, you would be floating around because both you and the elevator are falling at the same rate.
When you go on that roller coaster and it plummets rapidly on the track from a high part to a low, you are experiencing a decrease in weight. That’s the butterfly in you stomach effect.
To give a weightless feeling for longer periods, there is a special airplane that would go to a high altitude and suddenly plummet towards the Earth at the same acceleration speed of gravity.
Everybody inside would become weightless and float around.
I think it was called the “Vomit Comet” for obvious reasons. Tom Hanks and Kevin Bacon got to take a ride when they were making that excellent movie…”Apollo 13″
Well, so there it is. You have gotten a rudimentary physics lesson without too much anguish and my lunch hour is over and it’s time to get back to work.
Enjoy your Sunday evening!
Originally written by former author D. Williams and published by MadMikesAmerica on December 5, 2010