Science Sunday: Please Help Me, I’m Falling…

Falling off the ladder means hitting the ground and hurting yourself

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

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16 Responses to Science Sunday: Please Help Me, I’m Falling…

  1. Gwendolyn H. Barry Reply

    December 5, 2010 at 3:35 pm

    velocity = lower cancer rates too? Actually, I’m remembering the storyline in Contact when the rich fella was living in space to halt the matastesizing of the cancer he had. Why?

    And another thing…
    how come plants grow in space of disease is retarded in confined space?
    oh, ok. It’s sunday. Disney on?

    • Krell Reply

      December 5, 2010 at 7:20 pm

      You just mentioned one of my favorite science fiction movies of recent years. Contact.

      I don’t really know anything about the cancer in space aspect. May have been just part of a movie…

  2. Robert Douglas Reply

    December 5, 2010 at 3:40 pm

    Good post Krell. It’s good to reinforce the basics.
    But what about the reduction in gravity at increasing distance from the Mass?

    I know it’s not that far from the Earth in LEO, but shouldn’t you be able to resolve the differential even at that distance?

    • Krell Reply

      December 5, 2010 at 3:47 pm

      Okay, Robert. Just from that question I can tell that you have either taught science OR have some sort of science degree OR still have a very healthy interest. Which is it?

      With different orbital heights it requires different velocities. There are formulas and math, but I did want to keep my audience till the end of the post.

      Math, especially calculus, has a way of REALLY making people go arrghhh!

      • Robert Douglas Reply

        December 5, 2010 at 6:57 pm

        Hi Krell,
        Yes, well spotted, I’ve got two degrees, an honours (BSc)in Microbiology and a Masters in Computing. None directly related to Physics, but I’ve always believed that Science is an absolute prerequesite to everyday living, so I keep up an active curiosity in Science in general, not just in my specialities.

        to Quote Robert Heinlein:
        “A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.

        and to quote Heinlein again:
        “One man’s theology is another man’s belly laugh.:

        Says it all for all religions, I think.

        • Krell Reply

          December 5, 2010 at 7:12 pm

          Computing and MicroBiology?? You must have been exceptional in eliminating “bugs” in your programming…get it bugs…programming…uh never mind.

          • Robert Douglas Reply

            December 5, 2010 at 7:21 pm

            LOL…. I’ve never heard that one before!

            But it does help me eliminate computer viruses. Soak a hard drive in a MegaCurie X-Gamma bath, and I can guarantee that no viruses will survive. It might glow a bit in the dark though.

  3. Holte Ender Reply

    December 5, 2010 at 4:44 pm


  4. osori Reply

    December 5, 2010 at 6:24 pm

    Krell this is great, you’re the Elizabeth Warren of science. Really interesting, and I was able to grasp it entirely due to your measured explanation.

    One question – how did you get Collin to pose for the pic throwing the baseball? That is Collin, right?

    • Krell Reply

      December 5, 2010 at 7:09 pm

      ROFLMAO!! I was going to put a caveat that the picture was in no way a representation of how I or any people that I know throw a baseball.

      I believe that is the standard throwing method for cricket though.

  5. SagaciousHillbilly Reply

    December 5, 2010 at 10:02 pm

    Not bad.
    When describing orbit, I like to talk about the object falling toward Earth but going so fast that it misses every time. There is the aspect that an object in orbit is usually losing and gaining velocity and altitude.
    Yes, Apollo 13 The Movie, was an entertaining SciFi piece. Too bad it left such a bad taste in my mouth and a twisted tale of Apollo.

    • Krell Reply

      December 6, 2010 at 9:55 am

      Sagacious Hillbilly..

      Okay, your last paragraph has me curious. Can you comment with your opinion of the Apollo movie and the actual Apollo 13 mission.

  6. lazersedge Reply

    August 21, 2011 at 4:21 am

    Krell old friend, so good to hear from you, and a wonderful piece it was, is, whatever. Now I understand why, a number of years back why when I got drunk one night and flung myself down the hill behind my house I didn’t hit the ground til I got to the bottom … I think. 🙂 🙂
    Great post Krell.

    • Krell Reply

      August 21, 2011 at 12:00 pm

      Thanks Lazer, glad you liked it. I hope your experience with gravity wasn’t to painful or you were drunk enough not to care.

      • Collin Hinds Reply

        August 21, 2011 at 4:17 pm

        I missed that the first go around. If you had asked me about why people float in space, I too would have said, no gravity. That is exactly what I was taught growing up, along with a lot of other erroneous crap.

  7. Dorothy Anderson Reply

    August 22, 2011 at 4:51 pm

    Excellent, Krell! Thanks for the post. I think I suffer from dyscalculia… never got past pre-calc, although I’m fascinated with cosmology. I hope you and Robert will school me a bit.

    Speaking of physics, who among us have been glued to the Science Channel watching Through the Wormhole?

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