Vortex Cannon

[Tom]

I'm planning to make one for Physics.

[NickT]

So you are going to make a box with a hole in it

Then what

[Ciro Pabón]

C'mon, Nick_T, you are talking about the "basic idea". It is like saying that an F1 car is a sort of chariot. There are ways to enhance the thing, as Chapman would say.

For your physics class:

You can charge a "high capacity capacitor" to 400 volts, drive the current to a solenoid, attach the solenoid to a diaphragm, fill the cavity with propane and then you get this:


I only hope Tom does not kill himself trying this.

For your scuba diving class:

You can do something similar (no electricity!) underwater. It is very useful for your UN presentations...

For your Earth Sciences class:

If you feel in need of doing something really spectacular, simply follow this recipe:
1. Take a medium sized volcano, preferibly italian (they rule!)
2. Add a sunny morning
3. Produce a short tremor
4. Release some gas from the vent of one of the craters...

Finally, for after-class:

If you use perfume instead of smoke, you can "puff" her with some scent from several feet away... it could be an excellent way to catch her attention. I have no photos of this, but you get the idea.

[Tom]

I deliberatly went a little short there to see what reaction came out, although Ciro immediattly got the jist. Here's the plan...http://home.comcast.net/~t129wojce647/vger/index.html

The only problem is getting enough air through the hole to go down the corridor. I was planning on making one that could just about knock someone over, but that's very optimistic. I was also conidering making different sived exit holes to see if distance/power is affected. I want to make one at least 1m tall.

Ciro, your perfume idea has promise, i may well try that.

[Carlos]

Vortex Cannons take a variety of technologies: This may be of value.

http://www.cabinetmagazine.org/issues/5 ... sofwar.php

Tom: A vortex cannon can use many technologies and forms. A vortex can be considered a propagating energy source. That makes this anecdote relevent. In the early 60's the Cooper F1 mechanics amused themselves by building a "spud gun." A steel tube, with a threaded hole, filled with propane, a spark plug screwed into the hole, a pototoe inserted in the muzzle, as a shell. When Colin Champman of Lotus heard about this, he was sure his team could build a better spud gun that would fire much father than Cooper's "weapon." It is said he devoted a morning of his engineering prowess to the task. He was sucesssful. The range of his "gun" exceeded all expectation. The "spud " travelled a distance beyond all expectation---and went through the roof of a glass greenhouse in the distance! The Lotus mechanics quickly dismantled their "artillery piece" and ran out of sight--- back into the garage!

[Ciro Pabón]

... The only problem is getting enough air through the hole to go down the corridor...

I believe the distance does not depend on the amount of air, but on the impulse you give to the "rolling wave". It is self-sustained, like the soliton wave mentioned in the reference you provide.

A soliton is a different kind of wave, but its dynamic is similar: the longer wavelengths of the wave and the shorter ones interact to shorten and lenghten their wavelenght respectively, interchanging places: the longer ones become shorter and viceversa.

They can keep doing this for a long time. This way, the wave never changes and keep moving along without desintegrating, like normal waves, where the shorter wavelengths move faster and "left the wave behind".

This kind of self-sustaining waves can travel far: the first soliton transmited over a fiber-optic network reached 14.000 km. The first application of a soliton over a commercial Internet network was in 2001.

I swear I saw one in the Canal del Dique, in Colombia, between Cartagena and the Magdalena River. At least, I saw a wave (I was standing in the road at the side of the river) that moved for a kilometer or more on the channel, upriver, like Jhon Scott Russell once did.

Unfortunately, in your vortex cannon, the ring has friction with the air as it "rolls on itself" and this is what desintegrates it. But the problem, I believe, that you confront is to move fast enough the diaphragm, not to move a lot of air (not that they are not related somehow). This is why the vortex cannon using a solenoid impulsing a diaphragm can give so much energy to the "wave".

I cannot resist to mention that we have a vortex box, that uses dry ice, at Maloka, in Bogotá, a permanent science display, and it is probably one of the most popular "attractions".

This photo shows Bogota's Maloka. I worked on their computer network, when it was built: the semi-sphere is an I-Max theater and the crystal structures are the entrances. The whole thing is underground. It is the most beautiful science divulgation site I've seen.