A drink problem - No honest

This is no quite a problem, but may have been talked about in the past.

Here in the UK, there was a drink for sale called Zero Gravity. I don't know if it is still available.

It consisted of a liquid in a clear container the size of a coke can (330 ml). In the liquid are jellied beads the size of garden peas.

These beads are 'suspended' in the liquid, which may or may not be under pressure.

When the can is rotated thru any angle of rotation the beads still keep there position within the can.

My question is how does this work ?

Any light on this wonderful product would be great.

David. (in the UK but who has never encountered this drink)

'Stephen'

table top with the pull ring to the top, then if there is a bead near the bottom of the can, aprox 2cm from table top, and the can is rotated thru 180 degrees so that the plug ring is now on the bottom, the said bead is still in the same position in relation to the table not the can. ie it is still 2cm from the table top. bottom and around the can when move and it only when the can is shaken alot that the beads do move. expiry date of 10/2000.
http://www.energy.pulse.de/dosen/zerograv.html [see zerograv_lem.jpg]

Although the dynamics are not very apparent from the single .jpg, I guess the density of the beads and that of the suspending liquid are identical, so there is no motivational gravitational force to cause them to go up or down; presumably there would be very little in the way of inertial differences, so twisting or turning or upending, would do little [almost nothing] to change the relative positions.

[snip]

Kind of obvious to a physics type. Actually, there's a rather cool form of barometer that works this way. You have a container with a liquid in it. And you have a collection of floating objects in the container. Each object has a number. When the barometric pressure is high, most of the objects are below some line. When it's low, most of them are above the line.

There was also an old science fiction story about a concert meister in a Swiss town. It was his job to decide if the concert would be held indoors or outdoors on the following day. Chairs had to be setup and such. Well, he always got it wrong, every time. Then his wife got pregnant and had a mis-carriage. But the couple was sentimental as well as a bit macabre, and kept the aborted fetus in a jar, and called it 'Putzi.' Well, when the weather was going to be fine the next day, Putzi would float at the bottom. And when the weather was going to be bad, he'd be at the top.

Anyway, it works on the minor differences in density in a column of fluid. If a floating object is closely enough matched in density with the fluid, then it can float where the density profile crosses its own. If the floating objects are slightly compressible, as for example a small glass container with air inside, then barometric pressure increasing will cause them to compress a bit and so sink.

If you've still got this can, try giving it a gentle squeeze and see if the floaters move at all.

The fluid must not be plain water. There's an old Italian thermometer design where several glass spheres sit at the top of a column of water. As the temperature rises, they go to the bottom, one by one. Apparently, the density of the water is virtually the same from top to

^^^^^^^^^

You mean 'thermometer', don't you? Like Galileo's?

Actually, Galileo thermometers are incredible devices. I did not realise their sensitivity till I got one. The little balls correspond to two degree F intervals (obviously the Germans made it for the US market!) and I check it against a good old mercury darkroom thermometer. The accuracy and sensitivity are amazing!

Maybe you *do* mean 'barometer' as you base your explanation on pressure. But, the Galileo thermometers are completely sealed. The little objects are hollow glass spheres partially filled with liquid. I believe the key is the change in the buoyancy of the spheres as the temperature changes