Fun With Antibubbles

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For those of you that haven't seen this yet, this "fun with antibubbles" video is rather impressive. Feel free to insert your own "Yo dog, I heard you liked bubbles, so I put bubbles inside your bubbles..." jokes here.
 
cool video, thanks for sharing! went to their website, 5 other videos he's done from the ISS. neat stuff.
 
This is Don Pettit doing one of many cool experiments on the space station in his off time, which he called his Saturday Morning Science Videos.
For many more absolutely cool videos for the curious and scientifically minded I direct you to his NASA web page.
http://spaceflight.nasa.gov/station/crew/exp6/spacechronicles_videos.html

There are a must see for anybody with the slightest interest in space. If you are a science geek, these videos go to 11.
 
Sounded like the astronauts were stoned when the filmed it :D

Btw if anyone wants to answer their challenge question the reason why the bubbles (air) center themselves is a combo of centrifugal action and surface tension. The surface tension keeps the water in a spherical shape, but the outward forcing of the water acts like gravity in that the denser fluids will fill in the "lower" areas (in this case the outer parts of the water sphere), and the less dense air bubble will "float" to the top... which in this case is the center.
 
...hang on...gimme a moment to catch up with you guys.

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sfsuphysics said:
Sounded like the astronauts were stoned when the filmed it :D

Btw if anyone wants to answer their challenge question the reason why the bubbles (air) center themselves is a combo of centrifugal action and surface tension. The surface tension keeps the water in a spherical shape, but the outward forcing of the water acts like gravity in that the denser fluids will fill in the "lower" areas (in this case the outer parts of the water sphere), and the less dense air bubble will "float" to the top... which in this case is the center.
Click to expand...

There is no such thing as a centrifugal force. The force involved is centripetal, pulling the water inwards, stopping it from continuing outwards and splatting all over the place :p
 
Zarathustra[H];1038641704 said:
There is no such thing as a centrifugal force. The force involved is centripetal, pulling the water inwards, stopping it from continuing outwards and splatting all over the place :p
Click to expand...

Did I use the term centrifugal force?

And before you get all pedantic with me as far as terminology, if there was only a centripetal force then the whole water bubble would squeeze the air to the outside :p
 
sfsuphysics said:
Did I use the term centrifugal force?

And before you get all pedantic with me as far as terminology, if there was only a centripetal force then the whole water bubble would squeeze the air to the outside :p
Click to expand...

But since the fluid is spinning, there is no need for a centrifugal force.

Forces only have to be equal in objects exhibiting no acceleration.

A spinning object is continuously accelerating inward. If you think of a circle spinning clockwise, the object on its perimeter is constantly turning right, and as such must have a force pulling it inward so that it can make that right turn!
 
Zarathustra[H];1038642102 said:
But since the fluid is spinning, there is no need for a centrifugal force.

Forces only have to be equal in objects exhibiting no acceleration.

A spinning object is continuously accelerating inward. If you think of a circle spinning clockwise, the object on its perimeter is constantly turning right, and as such must have a force pulling it inward so that it can make that right turn!
Click to expand...

Unless you're in a reference frame that is also spinning with it ;) Then the centrifugal term must exist, which is often why it's mentioned as a fake force depending upon your reference frame.

Trust me, I've been thoroughly deprorgrammed in my junior year mechanics class, only to be reprogrammed in my graduate mechanics class that everything really is relative to what reference frame you're in.
 
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