In this case, I’m using a standard, small, mid-range speaker placed on a level surface, with a plastic food lid serving as a membrane. The lid has a raised edge and a flat, recessed central area, so it turned out to be perfect for the experiment. The lid is then secured to the speaker’s mounting frame hardware with small strips of duct tape.

On the top of the lid, I poured a small layer of water to serve as the visualization mechanism. This provides a great resolution and clarity in the visualization. You can also use sand, ferromagnetic fluid, and a variety of other liquid/semisolid substances for this medium.

To power the speaker, a function generator was used connected directly to the speaker’s terminals, to ensure decent accuracy for the frequency range. The function generator’s range was 0 to 2mhz.

The audio frequency range used was 52 to 150 hz initially, then higher frequencies at higher amplitudes.

The videos have been edited for a variety of visual effects, with at least a few seconds of unaltered footage in each.

[Show as slideshow]

[View with PicLens]

PS – Do not attempt to make this device at home. I’m a completely untrained professional assembling this, and I make no assurances whatsoever about its safety.  I accept no responsibility if you choose to make this device on your own.

[Show as slideshow]

[View with PicLens]

And before everyone says “well, there goes the neighborhood!”, the vortex ring cannon has a variety of safety features to prevent blowouts and gas leaks around the main mechanisms. Gas is fed through a one-way valve, and the gas is physically disconnected from the combustion chamber and tube assembly further preventing any issues that way. the chamber itself has two give points to release overpressurized gases, and the assembly is open in the direction of the slow amplifier and stabilizer tube.

With any luck, it will be able to knock down a paper airplane!

This device, using the same basic principles as a smoke ring generator (like the kind sold as a novelty during halloween), “shoots” a ring of air using a small combustion chamber.  The device is mostly completed, with only a couple of parts still needing to be acquired.

Inside, a combustion chamber with two outer layers for blowout mitigation provides the pressure, which subsequently feeds into a threaded area which initializes the vortex, then feeds into a gradually expanding tube which finally stabilizes. Without going into the finer details, this process creates the rings at the edges of the tube, which are then shot out the end of the barrel.

With the project, I’m hoping to simply be able to visualize the concept in a fog-laden “cloud chamber”, and maybe have a little fun with a new mad science project. Check out the prototype in progress below!

[Show as slideshow]

[View with PicLens]

Hypothesis:
That binding agents added to the plaster of paris mixture will strengthen the resulting hardened mixture in terms of tensile strength and compressive forces.

Experimental steps:

1. Measure out and record an amount of plaster of paris in the powdered form

2. Add a pre-determined percentage of an additive or adulterant, or an equal weight of plaster of paris for the control group mixtures

3. weigh and add a volume of water, along with additive or control plaster,  to create the plaster of paris mixture

4. Prepare mold.

5. To prepare each sample, measure out a constant volume of the mixture and pour it gently and slowly into the mold, taking care not to cause air bubbles.

6.  Dry the prepared samples for 24-48 hours or until as dehydrated as possible.

7. As soon as dried, remove the samples gently from the mold. How you do this will depend on the mold provided, but if it’s a simple cup you can invert the cup and tap the sample out onto a soft surface (I’d suggest a paper towel)

8.  Follow one of the experimental ideas below for each sample prepared:

Experiment 1.A : determining  strength

1. Prepare a weight application rig. This can be something as simple as two books or 2×4 boards spaced apart so that the sample just barely covers the gap resting on both ledges.

2. Add an incremental amount of weight to the top of the sample. Start very light, and add more weight in progressive steps. Record each step, and any respective observations or physical changes (like cracking, flaking, etc)

3. At the failure point, record the amount of weight it took to break the sample.

These instructions assume you have thoroughly cleaned and removed any debris from the specimen before starting, as any remaining tissue may produce undesirable fissures or bubbles. If you have a dirty specimen, there’s a handy guide to cleaning and preparing skulls [PDF] from the university of arizona (but it works great for most bones and specimens)

Materials:

1. Transparent Acrylic Sealant. I recommend a glossy transparent sealant for skulls, and matte transparent sealant for turtle shells and other related specimens.Also make sure the acrylic sealant is completely transparent, as some sealants will have a milky consistency if applied to thickly.

2. Vinyl or Latex gloves (be careful with vinyl, since some of the solvents used in the the sprays are corrosive. Be sure to check the label if unsure.)

3. wax paper

4. a table or place to lay the specimen in a well ventilated area (I can’t emphasize the last part enough, as acrylic fumes are a suspected carcinogen, and they’ve got staying power)

Instructions:

1. Lay the wax paper out on the flat surface you’ll be spraying on, leaving at least 6″ of wax paper around each side of specimen.

2.Brush the specimen off one last time, and inspect for any loose dirt.

3. Once totally clean, place the specimen on the wax paper, centered.

4.With gloves on, spray one coat of the acrylic on the specimen, coating the entire visible area.

5. Let the first coat dry. As soon as it’s completely dr, flip the specimen over.

6. Repeat step 4 for the uncoated areas on the specimen.

7. Repeat steps 4-6 once to twice more, to ensure a good protective layer.

8. Let the last coat dry, and you should have an enviable specimen with a shiny new coat!