Sunday, April 11, 2010

Will a lava lamp work on Jupiter?

Let's start out the new week on a lighter note. I came in on the end of an email conversation among several of my MIT classmates. (We have exchanges like this. It might come from taking physics and calculus together. It might be indicative of some other problem. I'm not sure.)

Dave to Bill and Doug:

OMG. Look at this:

Lava Lamp Centrifuge

Would a Lava Lamp work in a high-gravity environment such as Jupiter? Would the wax still rise to the surface? Would the blobs be smaller and faster? With broad disagreement on the answers, I built a large centrifuge to find out.

Aside from being highly dangerous (the builder describes several scenarios), he did get the answer.

Bill to Dave and Doug:

Well, inquiring minds want to know

Doug to Bill and Dave:

This falls under the heading of what I call "rabid research", wherein some nut job decides to answer a seemingly unimportant question with a proper scientific experiment. Correctly done, it should involve serious overkill & inventiveness.

Nicely done!


Mr. Fraser's video is below. If you can't see it, click here:

As he notes:

The centrifuge is a genuinely terrifying device. The lights dim when it is switched on. A strong wind is produced as the centrifuge induces a cyclone in the room. The smell of boiling insulation emanates from the overloaded 25 amp cables. If not perfectly adjusted and lubricated, it will shred the teeth off solid brass gears in under a second. Runs were conducted from the relative safety of the next room while peeking through a crack in the door.


Anonymous said...

Fascinating! Only problem is the lamp is mounted wrong- it should be with its base pointing outward. What they did is the equivalent of leaving it lying on its side here on earth. So close...

Anonymous said...

Thinking like a wife, I would think a garage would have been a better venue for this experiment....


Anonymous said...

From Facebook:

Jim: I am curious to know why some people thought the lamp wouldn't work. The high gravity works equally on all of the lamp's ingredients so I would have guessed that its operation would be exactly the same as long as all of its constituents parts could withstand the pressure.

Unknown said...

Cool! Seems to me, however, that the kitchen would have been the better venue. Burning questions about gravies, and all.

nasov said...

For this to be accurate, we must also duplicate the gravitational influence of Jupiter's moons. Would this mean that the room should contain another 63 or so little centrifuges? Or just alcohol?

Dave Harmon said...

Anonymous at 6:39: I would assume that basket swings outward, so that the lava lamp's position matches local "down". If the lamp was fixed horizontal to the centrifuge arm, you'd get a tilt from combining the centrifugal force with Earth's constant 1G.

Paul Levy: I'd expect it to move somewhat faster, as the buoyancy would scale with gravity, but the viscosity wouldn't. (Probably -- it would depend on both fluids' compressibility, and possible non-Newtonian behavior.)

Engineer on Medicare said...

I think the second order effects would cause observable differences. The gravity gradient (variation "g" forces over the height of the lamp) would be negligable on Jupiter but significant in the centrifuge. Also, the pressure variations along the length of the "blob" would be greater; which could be the cause of what appears to be more breakup of the "blobs".

If that erector set arrangement came apart the door and the walls would probably not do much more that provide shrapnel.

Anonymous said...

The answer is still no, it won't work on Jupiter. Jupitonians use different outlets and plug heads there.