This seems as good a spot as any for us to talk shop. Ask questions, get answers, point out new and interesting papers, consider new research, talk about cool demonstrations and how to go about building them...

The possibilities, as they say, are endless.

Like, science and science only, or physics, etc included?

The question doesn't really make sense. Physics is a science.

Eh, nevermind..

Hmm... should I start off by, say, digging up demonstrations of electromagnetic effects? Ring cannons and Tesla coils, that sort of thing?

Ooh, science. The sciences were pretty much my best subjects in school, especially biology and chemistry.

Anyway, I am on kind of a "dry ice is awesome" kick right now. Not just because it looks cool and mad science-y, but it's just interesting to me. I wish I could get my hands on some (er, not literally get my bare hands on it, you know what I mean.)

Well, yes. While you can, I wouldn't recommend prolonged contact. :p

Any substance that sublimates at room temperature is pretty neat, really.

Non-Newtonian fluids are fun.

Ooblik!

Also, There's this one liquid that turns into a spiky solid when an electromagnetic field is introduced...

Ferrofluids. They are awesome.

Is a ring cannon the same thing as a coil or Gauss gun?

Yeah, Ferrofluid.

It's cool..

YOU GOT FERROFLUID AND YOU GOT A MAGNET
FERROFLUID'S GOT MAGNETIC PROPERTIES BUT DON'T YOU GRAB IT
FERROFLUID MADE OF IRON
MAGNETIC IS THE FIELD

YOU GOT FERROFLUID AND YOU GOT A MAGNET
IF FERROFLUID STARTS TO MOVE IT'LL GET SPIKED UP
SPIKE UP MADE OF STEEL
FERROFLUID SHAPED LIKED DRILL

DON'T PUT FERROFLUID ON A PLATE
IT'LL USE MAGNET TO ESCAPE
IT'LL JUMP RIGHT UP AND DANCE AROUND
AND THEN THEY'LL CALL IT AAAAAAARRRRRRRRRRRTTTTTT

FERRRROOOOOOO FLUUUUUIIIIIIDDDDD
FERRRROOOOOOO FLUUUUUIIIIIIDDDDD

edited 26th Jun '10 11:29:28 PM by newtonthenewt

Deboss: Yes, I believe so. Coil of wire in a column, put a ring down around the column to the base, then turn on the magnet slowly and cut power quickly.

The resulting change in field rockets the ring upwards. How fast depends on how conductive the material is. Copper works better than aluminum.

edited 27th Jun '10 8:12:51 AM by GoggleFox

Nope, slightly different principle. Coil/gauss guns use a solenoid.

Solenoid = coil of wire. I'm sorry? The primary difference is that the solenoid is outside on a gauss gun, and inside on a ring cannon. Here I'll get a video if I can.

Edit: Found one.

There were an awful lot of these that didn't demonstrate just how far the ring flies up. By the way, aluminum rings will fly much farther when nitrogen-cooled.

edited 27th Jun '10 8:38:44 AM by GoggleFox

Okay, yeah, my head's a little fuzzy right now. I thought it was using something else. I know we've got a host of them under Rail Gun.

...my physics teacher did that once.

Yes! MAD SCIENCE!

Rhetorical question: On broadleaf plants, which side of the leaves do aphids prefer to feed on?

Answer: The majority of aphids feed on the bottom. This gives them shade, protection from rain, protection from the honeydew excreted by the aphids on the leaves above, and the raised veins on the leaf underside give a measure of protection from getting knocked off when leaves brush against each other in the wind.

Another question: On pecan trees, which side of the leaves do the aphids prefer to feed on?

Another answer: There are three aphid species normally found on pecans. Two of them, the black-margined aphid and the yellow pecan aphid, feed almost exclusively on the leaf bottoms. The third—and most economically important—species, the black pecan aphid, is funny: the adults prefer the bottoms, but the nymphs are split evenly between the top and bottom. This is not something that's been noted in the literature, but something I've observed and documented myself.

So the big question: Why do black pecan aphid nymphs feed on the tops of the leaves? That's what I'm currently trying to find out.

edited 2nd Jul '10 6:08:15 PM by MetaFour

Can predators see the nymphs on the top of the leaves? /clueless

The leaf tops are a relatively enemy-free space. In fact, that's my hypothesis for what's going on.

The predators responsible for the most aphid mortality are the lady beetles and lacewings. The literature I've found so far says that these and other arthropod predators primarily forage on the leaf bottoms. My own observations are consistent with this.

On the other hand, there are some aphid-attacking parasitoid wasps that search the leaf tops.

edited 3rd Jul '10 11:21:46 PM by MetaFour

Vaguely related, but very cool art inspired by biology: in video form.

...

:o

Anyone been keeping some tabs on the U.S. Navies rail gun weapon project?

Of course the humans had to be represented by war. We've never done anything else, amirite?

But still, that was very impressive.

edited 8th Jul '10 4:25:17 PM by Wicked223