Maybe watch it again and pay attention? He said nothing of computer simulations....

In an isolated system (our galaxy) where there is angular momentum (the spinning about the galaxies central axis), the angular momentum is conserved (it never stops spinning with respect to how much mass is in it, and how far from the centre that mass is).

The objects floating above and below that central plane are NOT in an angular momentum vector, just simply moving about in a chaotic motion. Given enough time, these objects will collide, cancelling out their non-plane motions.....

None of this was derived from a computer model, but it does show it in practice near the end by using one.

The distinction is important.

my favorite was by the still-probie @DrivelsAdvocate in this video:

http://videosift.com/video/The-double-pendulum-gives-an-example-of-chaotic-motion

the comment was:
"That reminds me, I need to wear tighter fitting pants the next time I go jogging."

**ahem** (in Jon Stewart voice) Nailed it!

It's amazing to me how hard it is for people to understand the difference between random and chaotic.

Congratulations! Your comment has just received enough votes from the community to earn you 1 Power Point. Thank you for your quality contribution to VideoSift.

>> ^HaricotVert:
Attach an LED to the end, turn off the lights, and then take a long exposure picture until the motion gets boring.
Do this as many times as you want with different colored LEDs. Post all results onto DeviantArt. Profit.


http://en.wikipedia.org/wiki/File:DPLE.jpg

>> ^syncron:
I'm sure it's not hard to write a formula to calculate the moment and potential of a double-pendulum system given initial conditions and duration.


It is hard actually, because the second pendulum rotates around a moving axis, which fucks up your equations royally.

It's not really that big, especially at this time of the year with the cold weather.


In reply to this comment by residue:
oh man that's awesome

In reply to this comment by DrivelsAdvocate:
That reminds me, I need to wear tighter fitting pants the next time I go jogging.

if you want to see chaotic motion, just get on a bus and wait for a granny to get on after, with the bus pulling away before they manage to sit down.

oh man that's awesome

In reply to this comment by DrivelsAdvocate:
That reminds me, I need to wear tighter fitting pants the next time I go jogging.

>> ^poolcleaner:
If you drop it from the precise point it was dropped from in this video and observe again, will it be random? What other conditions would factor into its perceived random movement? (These aren't rhetorical questions. I'm curious.)


It is indeed chaotic motion -- if you attempt to recreate the exact same conditions of movement you will get different results. The reason is that there are many "balance points" where the motion could go either one way or the other, and there is no way to predict which way it will move. Sort of like balancing a ball exactly at the top of a curve -- you know it will fall one way or the other, but you can't predict which.

Chaotic Motion Pendulum is Chaotic!

Your video, The double pendulum gives an example of chaotic motion, has made it into the Top 15 New Videos listing. Congratulations on your achievement. For your contribution you have been awarded 1 Power Point.