Carton of Orange Juice

This may sound weird, but here's a puzzle that I already know the answer to...and I don't understand it!

Question: What can move and be still at the same time?

Answer: A carton of orange juice.

I found this in a published book of similar brain teasers, but out of the 50 or so puzzles in the book, this is the only one that I could not figure out. So I checked the answer...and I still can't figure it out! Please help if you can.

still = not carbonated

Perhaps it's not fizzy.

But why orange juice? Cartons of milk aren't fizzy either.

You can move it, but it's still orange juice :0)

A car-ton of orange juice ???

From a physics point of view there are many answers. Suppose Person X is standing on the earth looking at a carton of orange juice sitting on the table. X would say that the orange juice is not moving. But person Y sitting on the sun (ouch!) would see the earth as moving around the sun. Since the orange juice is on the earth, which is moving around the sun, the orange juice is moving according to Y. Who is right, X or Y? Physics says that motion is relative so from X's point of view the orange juice is not moving RELEATIVE TO X and from Y's point of view the orange juice is moving RELEATIVE TO Y.

Going back to the orange juice, at the atomic level the atoms are vibrating. This vibration is movement. Although Y would say that the orange juice is still, from the atomic level it is moving.

Finally, one could shake the carton of orange juice and place it back on the table. From the outside the carton is still but the juice inside is still moving inside. A wonderful experiment in this vein is to take a raw egg still in the shell. Give the egg a good spin. Now using your fingers, stop the egg for a fraction of a second and than lift your fingers. Although you have stopped the egg from rotating, as soon as you lift your fingers the egg magically starts to rotate again. Why?? Try this with a hard-boiled egg in the shell. Something different happens. Why?

Note: For thoes who know physics well, X is in a non-inertial frame. So X can say that X is moving relative to any inertial frame because Newton's laws are not valid in a non-inertial frame. So from any inertial frame, the carton of orange juice can never be still. But there is nothing that says I must look at the carton of orange juice from an inertial frame. We can choose any frame of reference we want and describe events from that perspective. Let's choose the Earth's non-inertial frame of reference. From this point of view, neither X or the carton of orange juice is not moving. If we require Newton's laws to hold and we don't want to introduce fictitious forces, than we have to choose an inertial frame. Sometimes is much easier to look at a problem from the non-inertial frames reference point. In this case, we introduce factitious forces and then Newton's laws hold.

released on 26 Sep 2004 02:17:17 GMT bearing the following fruit:

Milk is unlikely to be fizzy whereas orange often is.

Jan Hyde (VB MVP)

Any container of a non-carbonated beverage can move and be still (that is, non-carbonated) at the same time. But I'm not sure why that particular answer.

carbonated orange juice moves my bladder in a way that still orange juice dont !!!

But are fizzy drinks ever sold in cartons?