Ping Pong

[iago]

Nancy claims that she can throw a ping-pong ball so that it would go a short distance, come to a  dead stop, then reverse itself and come back.  She also added that she wouldn't bounce the ball off anything or tie anything to it.  How is this possible?

[Ergot]

vacuum ? throw it up?

[Newby]

Throw it up a hill? :p

[Sidoh]

She throws it straight up? :P

Things thrown up follow a parabolic path in space-time (which do come to a complete stop a the vertex of the parabola) due to the force of gravity.

[Quik]

Palm the ball, then throw it while tilting your hand at a 45° angle, allowing the ball to slide off the tip of your fingers before force is applied. The ball will come to a stop when it hits the ground, then roll backwards because of backspin.

[Sidoh]

Palm the ball, then throw it while tilting your hand at a 45° angle, allowing the ball to slide off the tip of your fingers before force is applied. The ball will come to a stop when it hits the ground, then roll backwards because of backspin.

Occam's Razor. I win.

[Blaze]

Roll it with a backwards spin. :P

[Sidoh]

Roll it with a backwards spin. :P

I don't see anywhere in the riddle where it says it has to be a horrizontal throw.  Besides, rolling isn't throwing. :P

[Blaze]

Roll it with a backwards spin. :P

I don't see anywhere in the riddle where it says it has to be a horrizontal throw.  Besides, rolling isn't throwing. :P

I ment throw it with a backwards spin. :P

[Sidoh]

I ment throw it with a backwards spin. :P

Once again, I win (theoretically) due to Occam's Razor.  :P

[iago]

I ment throw it with a backwards spin. :P

Once again, I win (theoretically) due to Occam's Razor.  :P

Yes, you are correct.  Occam's Razor is indeed appropriate here. 

We had a poster at work about Occam's Razor I should have taken a picture of. It is so important in security :)

Technically, Ergot was right first. 

[Sidoh]

Technically, Ergot was right first. 

He edited it before I posted, I swear.  His original post only contained "vacuum."

Haha, at least I'm pretty sure.  :P

[iago]

Technically, Ergot was right first. 

He edited it before I posted, I swear.  His original post only contained "vacuum."

Haha, at least I'm pretty sure.  :P

It doesn't say "edited by..."

But if you thought of it independently, then you can still feel good about yourself.  Even if you ARE a dirty cheater.. :)

[Blaze]

He edited it before I posted, I swear.  His original post only contained "vacuum."

Its still a good twenty minutes before you posted. :P

[Sidoh]

It doesn't say "edited by..."

But if you thought of it independently, then you can still feel good about yourself.  Even if you ARE a dirty cheater.. :)

Hehe, I did.

If you edit your own post within the next minute or so after you post something, the "edit" tag doesn't appear.

Its still a good twenty minutes before you posted. :P

I still thought of it on my own.  I didn't take the time to read his stupid three word post! :)

Honestly, I didn't read his post.  I think I remember reading "vacuum" and kind of laughing because it made no sense, but I thought of my answer almost instantly after I read the question.

I also provided reason for why it was the way it was :)

AAANND I pwned you with Occam's Razor.  :)