Re: Basketball and Global Warming

[Steve Clark <sclarkphd@MINDSPRING.COM>]

When the ball started back down, wouldn't the earth have to begin to
move back toward the ball to conserve linear momentum? Thus, no net
change in the center of mass of the earth/basketball system. But don't
let the newspapers get wind of this problem. They'll get it wrong and
soon we'll be crashing into the sun "within the year'!

Steve Clark

On Monday, December 29, 2003, at 12:57  PM, Gary Turner wrote:

> A nice easy puzzle for the holiday season - I was reminded of this by
> the
> recent conservation of (angular) momentum discussions.  I have used it
> in
> the past to demonstrate the problems of assuming linear momentum is
> only
> conserved in "collisions" (whatever they are).
>
> Consider a basketball, about to hit the ground.  I has linear momentum
> downward.  A short while later, the ball will be moving up.  It now has
> linear momentum upwards.  Where did the downward momentum go?  Well
> that
> one is easy, into the ground - but that means the ground is now moving
> down.
>
> Now, bounce a ball over and over, and eventually, the ground will start
> moving down at an appreciable speed.  This is where basktball and
> global
> warming come in.  Most basketball games are played at night. It does
> not
> matter where on the world you are, night is always on the opposite
> side of
> the Earth to the sun.  So basketball games must be pushing the Earth
> towards the sun - hence global warming.