Tuesday Morning Coffee

Re: Tuesday Morning Coffee

John Veerkamp

Easy enough for a young person, but at my age my shoulder can't take the wind up.

I must be cheating!

Alex Y

Are we allowed to use the fingers of the right hand? I find it pretty easy to close the hand, grip the mug between fingers and thumb, and turn it in about 60-degree increments until it has made a complete revolution.

You are! 

Bill Earl

No 'digital' manipulation allowed.

In theory this principle could be also be demonstrated with the cup sitting on a ping-pong paddle held in your hand.

Re: Tuesday Morning Coffee

Gary Smyth

Do I have to move, anything at the end of my hand have to move? Do I have a day for it to make the trip?

Re: Tuesday Morning Coffee

Bill Earl

The rotation is relative to your body and the room you are standing in.

The (possible) maneuvers can be completed in a few seconds.

Try this

Gary Smyth

I'm standing still with arm extended, coffee in cup. Coffee is moving inside the cup from the pour. If the coffee makes a revolution the handle, while not appearing to move from my sight line is counter rotating relative to the coffee.

Clever, but...

Bill Earl

The problem is to "cause the handle to make one full rotation around the vertical axis and return your hand to the original position".

The rotation of the coffee cup is relative your your body and immediate surroundings. The purpose of the coffee is just to ensure that the rotation is in the vertical axis only.

Re: Tuesday Morning Coffee

karl jr

I think the key is having the palm up, but the hand is rotated all the way around, so the elbow is pointing up. I can only do one rev, however, not two. If my elbow was a ball and socket joint I could.

Re: Tuesday Morning Coffee

Alex Y

Okay, unlimited revolutions, with some challenge to shoulder flexibility.

Start with right palm out in most natural position, draw it in toward chest, under right arm, and back out with arm twisted [uncomfortably] inward. Then bring hand toward face, and around, over head, back to original position.

   Close enough *LINK*

Bill Earl

Actually, unlimited even numbers of rotations. Each execution of that maneuver will move the cup through two rotations before returning to the original position.

This move - also known as the "Phillipine Wine Dance" is closely ralated to the "Dirac String Trick" which is a model of electron rotation.


Air on the Dirac Strings

Re:    Close enough

Alex Y

That's the motion I was trying to describe in words, but in the opposite direction.

Intersting link -- thanks.