...that I've never found time to actually test!

Every so often I'm messing around with a mildly interesting device, when some implications occur to me like so:

"wait a minute... is this feasible? OH MY GOD!!!"

Idea #1: HUMONGOUS SMOKE-RINGS

It's easy to make a small smoke-ring launcher. But I want to launch smoke rings that are 200ft across! Make vortices which are bigger than the volcano smoke rings! I'd have to build a building-sized chamber the size of a football field. But perhaps there is another, less expensive way.

It is possible to construct semi-rigid structures made from inflated cloth tubes. Solid walls of this sort will resemble an air mattress. My "smoke ring chamber" could be built using a sewing machine and some old parachutes. A tiny fan would supply the inflation pressure. I would build a 100ft "igloo"-shaped structure, with a 50ft hole in the center of the roof. It launches the smoke-rings upwards.

To launch a smoke-ring, I'd pressurized my chamber like so: have a "venetian blinds" valve over the smoke-ring launcher's hole. Start with the valve initially closed. Use another fan to pressurize the air in the chamber slightly. Maybe add a collapsible "plenum chamber" to the side of the main chamber, and wrap it with rubber cords so that it can be inflated like a balloon.

When the "venetian blinds" valve is suddenly opened, the air in the chamber would rush outwards and a ring-vortex would be formed. To make the vortex visible, I would have heated the air in the chamber and provided some water-mist sprayers to fill the air with fog. Upon meeting the outside air, the drop in temperature would form extra fog.

I expect that a 50ft smoke ring would have a very long lifetime. If launched upwards, the warm air would carry it much higher than the launcher would otherwise throw it. The ring-shaped cloud would be seen for miles. Maybe it would reach the stratosphere and form a genuine cloud. It'd look very strange on a cloudless day.

If the launcher was operated over and over again, then a string of 50ft smoke rings would rise into the sky. A vertical dotted-line miles tall against the blue sky. Lots like those searchlights they use for advertising at night. But this would be visible for miles in the daytime!

If a row of 10 huge launchers were built side by side, then perhaps we could generate enormous dot-matrix letters rising skywards...

If I were rich (or if somebody gave me a few $K) I would build one of these for next year's BURNING MAN festival. At the end of the celebration, we'd have to swap the water-mist sprayers with kerosene foggers... then shoot flaming arrows or incendiary Estes rockets at the resulting flammable white smoke rings. Oh, but that constitues a fuel/air explosive. The shock wave might be *too* impressive... impressing the onlookers right into the rocky dirt. Sell bumper stickers to any survivors "I was almost killed at BURNING MAN 1999"

NEW IDEA: Make a big smoke-ring launcher, but lay it on its side, and cut in in half so only the upper half is there. It will create "smoke-arches" which fly horizontally. Sort of like a pair of dust-devils which connect together at the top. People could duck into the center as they go by.

Idea #2: GHOST DETECTOR

For Children's Discovery Room at Boston Museum of Science, we built a "liquid crystal wall." Liquid crystal postcard material can indicate temperature to within a couple of degrees, and it responds fast when not against a surface.

So, build a "ghost detector" which visually reveals the shape of those unexplained cold spots in your haunted house. Obtain a large sheet of the material, stretch it on a frame, and mount the frame adjacent to an electrical heating sheet of equal size. Connect the heater to an AC dimmer, and set the heat level so that it "biases" the liquid crystal material to its most sensitive color-changing temperature. Any tiny changes in air temperature or IR radiation will create patterns upon the sheet. Mysterious "cold spots" would instantly become visible on this thermal panel.

Maybe a ghost will write you a message with an icy fingertip on your "thermal blackboard." Maybe a person with PK powers can create colored patterns without touching the surface. Or for some non-paranormal fun, just use a bright flashlight with IR filter and draw pictures with an "invisible heat-beam."

Link to Source of LC material
MUTR science toys UK

Idea #3: "ORB-SORTING" CAMERA

An idea for "Orbs" hunters. "Orbs" are bright sphere-shaped or disk- shaped objects which show up in pictures when photographing cemetaries, haunted houses, etc. But many of these are simply the photoflash-illuminated dust motes or mist droplets hanging in front of the camera lens. The circular "orb shape" is a blurred image of a bright dot, and the shape is determined by the camera iris edge. If your camera iris is circular, the "orb" will appear as a disk, but if the iris is octagonal, the orb will look like a little octagon.

Ooo, idea! To settle the matter, place an opaque object on your camera lens! E.g. stick a thin slice of black electric tape across the lens. Or even make an "X shape" from thin tape slices. Now whenever you photograph a bright, small, blurred object such as a dust mote, then the dark strips of tape will show up as part of the bright circular "orb image." The false orb will have a big black X drawn across it. On the other hand, if the "orb" is real, if it is large and distant from the camera, you'll see no shadow-image of the opaque tape cutting across the "orb." Presto: any possible "orbs" can be instantly separated from the dust-mote images; the real orbs won't have a big fuzzy "X" across them.

Idea #4: REALITY-DETECTOR GOGGLES!

Idea #5: SOUND CAMERA

A balloon full of carbon dioxide acts as a "sound lens". If you fill a fairly large balloon with CO2 and place a microphone at the right spot, it will act as a long-range listening device. But being a lens, the balloon actually creates a "sound image" at the focal plane. So, why not build a camera to detect this image? Place a row of closely-spaced microphones on the surface of a rotating drum. Give the drum some circuitry to amplify the sound from each mike and have the received sound signal drive an LED. If you place each LED on the opposite side of the drum from each microphone, then any sound that "shines" upon one side of the drum will become patterns of light on the other side. Maybe give each channel a low-cut filter, so it will only "see" the sharply-focused high frequencies. Now "illuminate" the room with a high-pitched white noise. This mimics white light and eliminates diffraction fringes and "laser speckle" effects. Spin the drum, aim the lens, and see what "acoustic scene" appears on the raster of moving LEDs.

Now if you built an UNDERWATER version of this, then you'd have a camera that could see through muddy water (maybe even see through mud and sand.) Water-filled human flesh would look almost invisible, and people would look like living skeletons covered with clear-jelly muscles, except for their silvery air-filled lungs and tracheas. And don't forget blobs of silver-reflective gas in their intestines.

UP

Idea #6: GIGANTIC DEATH-RAY PROJECTOR

Big Tesla coils produce arcs many feet in length. These arcs take on a sort of crawling fractal shape. What if they could be shaped into perfectly straight lines? Then we would have a "death ray" generator which resembles those found in hundreds of SF movies. Here's a possible way for tesla coil hobbyists to accomplish just this feat in the real world.

Build yourself a squirt gun. Power it with a couple hundred PSI air compressor. An old CO2 fire extinguisher would make a good water resevoir. Drive the tilt/pan motion remotely with cables and pulleys. Give it a mechanical valve, controlled by another cable.

Install the entire thing in the main terminal of a large Tesla Coil. Use nonconductive materials for the control cables and air hose, of course. When the TC runs and the squirt gun squirts, the arc discharge will follow the row of conductive water droplets! Looks just like a Phaser weapon from Trek! (maybe put some metal salt copper chloride in the water to give the arc's plasma a green color.)

If you REALLY wanted to get ridiculous, you could install the squirt gun with its aim fixed axially upwards, then TILT AND PAN THE ENTIRE TESLA COIL SECONDARY! Here's where a "magnifier" Tesla Coil might work better than a standard TC.

Remember those truck-mounted beam weapons used in the first Godzilla movie? Go for it!

The above is totally a thought-experiment. Perhaps the arc won't even follow the water jet for very long distances. Perhaps the steam will cool things down and quench the arc. Perhaps you'll have to use WD-40 oil and copper powder instead of water. (With some magnesium powder to make it brighter by... a bit.)

Prototyping test: poke a hole in a can bottom, suspend it from insulators, hook it to a neon sign transformer, fill it with various liquids, let it dribble into a grounded sink. Turn it on and see what kind of arcing effects are obtained.

Other ideas: put various salts in the water to color the arc. Or put powdered metal in insulating liquid such as oil. Sodium gives yellow/orange, strontium red, copper blue/green, etc. Use several water tanks with various metals/salts, and switch between them with a high-speed valve to get a multicolored tracer-bullet effect. Also, I've heard that there are particular salts which one can inject into flames in order to cause conductivity. If these materials were placed into the water jet, perhaps much longer "death beams" could be attained.

Obtain a 100hp gasoline generator, mount the whole affair on a flatbed truck, shave your head, wear a white lab coat, put some powdered copper in the liquid to get a nice green effect, then shave your head, get a white lab coat, and go hold up a bank while screaming:

I HAVE NO USE FOR YOUR PITIFUL CURRENCY, I SIMPLY WISH TO ATTRACT THE ATTENTION OF...

***SUPERMAN***!!!

YOUR PUNY MENTAL-WARDS AND EXCESSIVELY SMALL PROJECTILE WEAPONS ARE USELESS AGAINST THE POWER OF MY PLASMA BEAM GENERATOR!

SUPERMAN! WHERE ARE YOU! LEX LUTHOR SAYS COME TASTE KRYPTONITE DEATH!!!!!

See also: 100KV, 100 kilojoule DC taser cannon

Idea #7: TESTING PSYCHIC POWERS

If humans are sensitive to the "vibes" of others, can one person "feel" which box contains another person and which boxes are empty? Can a wife "feel" which box contains the husband, and which boxes contain strangers? If the human "vibes" sense is fairly strong, then this would be an easy way to demonstrate the existence of PSI.

Idea #8: MECHANICAL SMOKE RING

Rather than a circular stack of disks, perhaps it could take the form of several large football-shaped blimps, where the tips of the blimps are connected together. Six blimps? Or even four or two. Like this:

             _______
            /        \ 
           /          \
           \          /
       / \  \________/  / \
     /     \          /     \      "SQUARE DONUT" AIRCRAFT MADE FROM
    |       |        |       |      ROTATING BLIMPS
    |       |        |       |
    |       |        |       |
    |       |        |       |
     \     / _______  \     /
       \ /  /        \  \ /
           /          \
           \          /
            \________/

Heeyyyyyyy! Maybe they wouldn't need helium! If the "smoke ring" was oriented horizontally like a donut on the ground, and if the gasbags were spinning, maybe it would act like a helicopter and drive itself upwards. It would be VERY quiet, since the air flow would be almost laminar. It would look like a flying saucer. With the large surface area it would need, it may as well be a helium balloon. But with enough power, maybe helium wouldn't be necessary.

How would it behave? If it was hovering, and if the blimp-motors were suddenly cranked up, it would eject a "starting vortex" and be strongly accelerated. Being neutrally bouyant, it would only experience parasitic drag and not "induced drag," and because the surfaces are rotating WITH the air and perhaps maintaining laminar-flow conditions, the parasitic drag would be minimal. The craft would coast along like a big flywheel, just as smoke-rings do. If the spinning of the blimps was suddenly halted (use electromagnetic braking and recover the energy!), maybe it would create another starting-vortex in the air, and would stop on a dime? Maybe not.

Hmmmm. EM braking. What if the whole thing was powered by electric motors, so that the kinetic energy of the spinning blimps could be stored in big internal capacitors? This might give a high-G acceleration capability. A sort of "sledge hammer" fluidic propulsion, producing an odd vehicle trajectory of start-drift-stop. (Is that more efficient than slow constant vortex-shedding?)

The whole idea is SO STUPID!! Just think of a 50ft silver donut hovering erect above the air force runway. Turn the balloons one way and it moves forwards. Turn them a different way, and the whole thing rotates. Everyone laughs really hard. But then the pilot kicks in the ultracapacitors... and the whole aircraft blinks out of sight. Huh? It becomes a transonic laminar Hill's Spherical Vortex. It accelerates at 30G and unexpectedly goes tearing across the sky, but because this is a laminar-flow propulsion system, it is SILENT. Just don't aim your "exhaust" side at a building when you punch the accelerator, because it launches a huge "starting vortex" which has enough overpressure to do some serious damage.

Imagine getting into a dogfight with such a beast. It might not need weapons. It fights like an angry male hummingbird: launching invisible vortices. During sudden accelerations it would emit "clear air turbulences" which would have enough wind-shear to tear wings off of conventional craft. It would be like battling a Flying Saucer that's equipped with a titanic Wham-O(tm) air-puff gun!

Idea #9: GET INSTANTLY ARRESTED: Images made of lead paint

Back in 1982 I was using some adhesive "window burglar alarm tape" from Radio Shack, the metal stuff you burnish onto glass to detect breakage, and realized that it's made of lead. With just this lead foil and a razor blade, I could make some lead-on-paper signs, put them in my carry-on luggage, and send secret messages which are visible only to the X-ray operator at the airport security station! Are those x-ray systems live-video or freeze-frame? Maybe I could even make a motorized animated sign, a little lead-foil creature who waves at the x-ray operator. And newer modern x-ray units detect absorption spectra, displaying it in various colors, so materials such as silver-leaf from art supply stores will show up as colors on their video display. Hey, rather than using lead foil, I could use lead oxide white pigment, the old fashioned lead paint "litharge." Make some silver chloride paints that show up in color on the x-ray display. Use white paint on white paper and it would show up on x-ray, but to the eye it would be visible only as white paper. Print a litharge-ink silk-screen image of the x-ray photo of a human hand or head, and stick it in your luggage. Will you be arrested for smuggling invisible body parts?

Idea #10: ELECTROSTATIC X-RAY TESLA COIL UMBRELLA

Then I remembered the x-ray idea. If a powerful "x-ray searchlight" can form a cone-shaped conductive column in the air, what if we stuck the entire x-ray assembly on top of a big Tesla coil? During one half-cycle of the Tesla coil, all the raindrops in the x-ray beam would become charged to a single polarity. It would probably charge up the air molecules in the beam as well. If the x-ray tube was synchronously switched off during the next half-cycle, then the charged air/rain column would again become an insulator, and it would self-repel radially outwards. While the device was running, air would be sucked into the top and bottom of the x-ray beam, while being repelled radially outwards from the side, like an expanding disk. An expanding-disk flow would create a flow pattern identical to a pair of stacked vortex rings with opposite-sense polodial flow. Given sufficiently high voltage, the falling raindrops array should be split down the center and cast outwards in all directions to fall in a ring around the pulsed x-ray generator. A big wind would probably accompany this effect, with the lower vortex-ring trapped between the ground and the disk of outward-fleeing electrified air. It might be best to erect the device atop a hundred-foot tower. That would enlarge the toroidial air flow so at the ground it would only be a gentle breese blowing towards the tower.