Yo Ho Ho

Don Rosa donrosa at iglou.com
Tue Mar 23 15:42:46 CET 2004

> From: Cord Wiljes [mailto:cord at wiljes.de]
> Subject: Yo Yo it is
> Forces in all directions except up and down cancel out because
> the opposing forces are of equal value - as masses on both sides
> are equal. Only in the vertical direction is the distribution of
> mass not equal (except at the center of the earth). So the only
> force which can be measured is the gravitational force pointing
> down.
> At the center of the earth there the acceleration has dropped to
> Zero - but by then you have gained the speed of 30,000 km/h.
> If there is
> no friction (in vacuum) then this YoYo effect will continue until
> the end of the universe.

I can understand the fun of trying to figure this out (it's the sort of fun
I base lots of my stories on)... but why is everyone considering it only in
a vacuum environment? Because we're referring to people doing the falling
and they would be, as I've said, squished by air pressure? Why omit air
friction from the equation? Consider a falling bowling ball. (But even it
would be squished to dust by the titanic air pressure of an 8000 mile tall
pile of air!)

> To sum it up:
> Hole only to the center of the earth: duck would crash
> Hole all the way to the other side: duck would yoyo

But only in a vacuum which is impossible if the hole is open at the ends.
Wait. I'll just test these theories with a practical demonstration. I'll get
a shovel. Be back shortly.

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