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Re: Precession

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On 4/6/2017 2:07 PM, john wrote:
> Odd
> "A spinning object will resist having its spin axis changed, and the .."
> Okay.
> Question.
> Why, according to your understanding of science,
> does this happen?
>

Newton's 2nd law says F = dp/dt. This is shorthand for saying that if 
you apply a force, then the momentum will experience a change such that 
the *change* (not the new momentum, but the change) is in the direction 
of the force, and the rate of that change is given by the size of the force.

Newton's 2nd law for rotation says T = dL/dt. This is shorthand for 
saying that if you apply a torque, then the angular momentum will 
experience a change such that the *change* (not the new angular 
momentum, but the change) is in the direction of the torque, and the 
rate of that change is given by the size of the torque.

(Hopefully, you can see why physicists would much rather use T=dL/dt 
than all those words, because that short equation carries all the same 
information as all those words. Why you would refuse to learn 
mathematics is beyond me.)

I could show you a very simple demonstration of how this works with a 
spinning bicycle wheel whose axle is held up at one end with a rope. I 
could show you the direction of the angular momentum and the size of it. 
I could show you the direction of the torque. This would also then show 
you the direction of the *change* in the angular momentum. This would 
then make it clear which way the angular momentum would have to swing. 
Then you would see it actually swing this way, in what's called 
precession. Then I would increase the spin of the bike wheel, making the 
angular momentum bigger. Then you'd see that the same *change* in 
angular momentum applied to a bigger angular momentum results in a 
slower swing. But it's SO much easier to show this to you in a 
demonstration than it is with words that I'm not going to elaborate the 
words further.

-- 
Odd Bodkin -- maker of fine toys, tools, tables

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Precession john <johnsefton288@gmail.com> - 2017-04-04 07:01 -0700
  Re: Precession Serg io <invalid@invalid.com> - 2017-04-04 10:07 -0500
    Re: Precession noTthaTguY <abu.kuanysh05@gmail.com> - 2017-04-04 08:45 -0700
  Re: Precession moroney@world.std.spaamtrap.com (Michael Moroney) - 2017-04-04 15:27 +0000
  Re: Precession Odd Bodkin <bodkinodd@gmail.com> - 2017-04-04 10:49 -0500
    Re: Precession john <johnsefton288@gmail.com> - 2017-04-04 10:41 -0700
      Re: Precession Odd Bodkin <bodkinodd@gmail.com> - 2017-04-04 12:45 -0500
        Re: Precession Serg io <invalid@invalid.com> - 2017-04-04 14:32 -0500
        Re: Precession john <johnsefton288@gmail.com> - 2017-04-05 07:59 -0700
          Re: Precession Odd Bodkin <bodkinodd@gmail.com> - 2017-04-05 10:30 -0500
            Re: Precession john <johnsefton288@gmail.com> - 2017-04-05 10:10 -0700
              Re: Precession Odd Bodkin <bodkinodd@gmail.com> - 2017-04-05 12:23 -0500
                Re: Precession john <johnsefton288@gmail.com> - 2017-04-05 16:36 -0700
                Re: Precession john <johnsefton288@gmail.com> - 2017-04-06 07:02 -0700
                Re: Precession Odd Bodkin <bodkinodd@gmail.com> - 2017-04-06 09:19 -0500
                Re: Precession john <johnsefton288@gmail.com> - 2017-04-06 09:18 -0700
                Re: Precession Odd Bodkin <bodkinodd@gmail.com> - 2017-04-06 11:36 -0500
                Re: Precession "reber G=emc^2" <herbertglazier0@gmail.com> - 2017-04-06 10:26 -0700
                Re: Precession john <johnsefton288@gmail.com> - 2017-04-06 11:17 -0700
                Re: Precession Odd Bodkin <bodkinodd@gmail.com> - 2017-04-06 13:45 -0500
                Re: Precession john <johnsefton288@gmail.com> - 2017-04-06 12:07 -0700
                Re: Precession Odd Bodkin <bodkinodd@gmail.com> - 2017-04-06 14:31 -0500
                Re: Precession pnalsing@gmail.com - 2017-04-06 15:06 -0700
                Re: Precession john <johnsefton288@gmail.com> - 2017-04-06 12:32 -0700
                Re: Precession Odd Bodkin <bodkinodd@gmail.com> - 2017-04-06 14:46 -0500
                Re: Precession benj <nobody@gmail.com> - 2017-04-06 20:23 -0400
                Re: Precession moroney@world.std.spaamtrap.com (Michael Moroney) - 2017-04-07 03:51 +0000
                Re: Precession john <johnsefton288@gmail.com> - 2017-04-07 06:40 -0700
                Re: Precession Odd Bodkin <bodkinodd@gmail.com> - 2017-04-07 08:53 -0500
                Re: Precession john <johnsefton288@gmail.com> - 2017-04-07 07:38 -0700
                Re: Precession Odd Bodkin <bodkinodd@gmail.com> - 2017-04-07 09:58 -0500
                Re: Precession john <johnsefton288@gmail.com> - 2017-04-07 07:58 -0700
                Re: Precession Odd Bodkin <bodkinodd@gmail.com> - 2017-04-07 10:00 -0500
                Re: Precession Odd Bodkin <bodkinodd@gmail.com> - 2017-04-07 10:02 -0500
                Re: Precession moroney@world.std.spaamtrap.com (Michael Moroney) - 2017-04-07 15:32 +0000
                Re: Precession moroney@world.std.spaamtrap.com (Michael Moroney) - 2017-04-07 18:04 +0000
                Re: Precession benj <nobody@gmail.com> - 2017-04-06 20:22 -0400
                Re: Precession moroney@world.std.spaamtrap.com (Michael Moroney) - 2017-04-07 03:50 +0000
                Re: Precession noTthaTguY <abu.kuanysh05@gmail.com> - 2017-04-07 19:41 -0700
                Re: Precession noTthaTguY <abu.kuanysh05@gmail.com> - 2017-04-07 20:21 -0700
  Re: Precession Edward Prochak <edprochak@gmail.com> - 2017-04-04 11:38 -0700
  Re: Precession "reber G=emc^2" <herbertglazier0@gmail.com> - 2017-04-06 10:25 -0700
  Re: Precession Odd Bodkin <bodkinodd@gmail.com> - 2017-04-07 14:32 -0500

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