Small Change, and Other Physics Fun 310
fishy jew writes "Ever want an easy way to make your 'small change' even smaller? Well, Bert Hickman has it - mix a home-brewed machine, 6.5 kiloJoules, and 100,000 Amps of current! On his website, he has descriptions and pictures of his many exploits with large quantities of electricity, notably including shrinking coins, building a Tesla coil, creating Lichtenberg figures (chaotic sculpture), and more! He has extensively outlined the equipment, procedure, and results for each of his experiments, and included many pretty pictures, too. Here are Google caches for when the site gets /.'ed: Main Page, Shrinking Coins, Tesla Coil, and Lichtenberg Figures."
ya know... (Score:5, Interesting)
his garage smelled great for a few months.
also, any time we'd point the tesla coil towards his neighbors house, they'd lose TV reception.
So.... why does this happen? (Score:3, Interesting)
Re:So.... why does this happen? (Score:5, Interesting)
A lot of electrons moving in a wire exert a lot of magnetic force.
If you use coiled wires, you get a cylindrical magnetic field.
If you put a coin inside a coiled wire with a lot of electrons moving through it, it gets smooshed.
Is this legit? (Score:4, Interesting)
Very cool, though.
Does the metal become more dense? (Score:3, Interesting)
I was under the impression that most solids wouldn't compress this much.
Re:Not a record, but... (Score:5, Interesting)
Even without the coolness factor, though, the risks are still rather slight with some attention to safety.
Electrocution actually isn't much of a risk with many HV devices - most will destroy themselves (or run up against current limiters) far before they output anywhere near the 200-250 mA needed to stop the human heart. While a shock from a tesla coil or other HV device will hurt terribly and pose a risk of burns, it probably won't kill you. Although some devices designed to deliver a high voltage and high current pulse can be extremely dangerous, keeping aware of safety at all times and never using jury-rigged solutions can mean that even a seemingly dangerous activity like playing around with Tesla coils and coincrushers is fairly safe.
As for ozone, all that you have to do to eliminate most risk is to work outside or in a ventilated area, and not stay around areas where arcing has occured. It's certainly not more dangerous than spraypaint, at least in the quantities produced by most amateur experiments. Bottom line: it's reasonably safe and a lot of fun, so why not do it?
Re:I own one of these coins... very cool (Score:5, Interesting)
For those who now can't get to the site: These coins are "shrunken" by being placed inside a wooden dowel, the dowel is then wrapped with electrical wire, and a ton of electricity is then discharged into the coil -- the resulting magnetic field deforms the coin (shrinks usually, but not always!), and causes the entire apparatus to explode :) Small shrinkings are done in blast chambers, larger ones have to be burried in a burm. Usually industrial capacitors provide power.
Magneforming (Score:5, Interesting)
Magneforming is just another less-common metalworking techniques. Others include hydroforming, water jet cutting, spinning, and blowing.
funny little story (Score:2, Interesting)
Re:Google Cache? (Score:4, Interesting)
There is no real distinction between the slashdot effect and a DDOS; Slashdot should think itself lucky this hasn't come up in the courts yet. It will. This guy does business through his website (selling the fruits of all the electricity). One day someone will be inconvenienced and have no sense of humour about it.
A proper mirror for small sites in an upcoming story is a necessity. Slashdot should already be contacting site owners to warn them before posting a story and knowingly sending them a huge flood of visitors that they may not be able to deal with, so copyright issues could be worked out then. A standard "we'll only mirror it for 24 hours" deal would be fine with most everyone. Some story submitters are already doing this, but it's not their responsibility - it's slashdots.
This problem will eventually result in a lawsuit if it's not addressed. It stopped being funny years ago.
Patent? (Score:5, Interesting)
Looks like the US Air Force's Rome Air Development Center [af.mil] thinks they have a patent [uspto.gov] on it. Am I the only one who thinks "United States of America as represented by the Secretary of the Air Force" should not be a valid patent assignee?
Re:Patent? (Score:4, Interesting)
huh? The U.S. government is a quite good patent assignee. Think of technology developed by or for NASA. In fact, I work on an image enhancment technology [truview.com] which was originally done by my company for a NASA contract. If you read the patent application, it has our employee's names on it along with the U.S. government.
After developing this we turned around and purchased a license so we could use the algorithm in our own software projects (i.e. PhotoFlair). That means that the government is able to use the technology and so are we. The government doesn't have to pay us anything to use our algorithms.
I don't think there's anything at all wrong with that. The algorithm was developed on their dollar and so they have the rights to implement the algorithm however they wish.
In fact, it seems to me that (for a change) the patent system is doing exactly what it is supposed to be doing!
interesting, but is it actually reversible? (Score:3, Interesting)
I am assuming there must be a way.
I think making coins larger would be a whole lot more interesting, and I'll assume by the details of this process that making a coin twice as large makes it half as thick... I'm talking coins here people! lol
the mass and weight would remain constant, has to, but I'd think large sized coins would be more of a novelty than small ones...
one method for doing this (works) is to put your coins on the railway track just before a train comes along... makes your coins all nice and squished out... kids - dont try this at home...
Re:I own one of these coins... very cool (Score:3, Interesting)
High Voltage Diamond Making Machine...? (Score:2, Interesting)
1. Form a dense carbon sphere. Form a dual halve alluminum sphere whose halves smoothly mate together. The sphere is actually a shell, with very thick walls, which surrounds the carbon sphere. For instance, a 3cm outer shell, 1cm thick wall, leaving a 1cm diameter inner sphere for the carbon. Pins hold the sides together.
2. Suspend this sphere in the middle of a very large version of the work coil as described on the site. The machine is also large - maybe building size capacitors, etc.
3. Charge the puppy up and fire it...
Could you end up with a diamond? Who knows...
Re:My Two Cents (Score:2, Interesting)
That isn't historical accident. It was intentional. Silver got pretty expensive in the late 1860s, and by 1873, the "half-dime," which had been an integral part of US coinage since 1794, would have had to shrink yet again to prevent its intrinsic value from growing greater than its face value.
The nickel five-cent piece, introduced in 1866, was the solution to this problem: a coin that didn't fall through tiny holes in one's pocket, had some substantial weight to it, and was far easier to deal with in general. It took another 91 years for the price of silver to get high enough to make dimes, quarters, and half-dollars impractically expensive. (This was at least in part due to the fact that many world governments were still on the silver standard as late as the mid-1960s, which kept silver prices artificially low.)
Ever seen a half-dime? They're pretty literally a half of a dime, maybe 2/3 as thick and 2/3 the diameter (don't have exact dimensions in front of me) of a modern US 10-cent piece.
BTW, it isn't historical accident that a US one-cent piece is larger than a dime, either, although the solution to rising copper prices in the 1970s was (starting in 1982) simply to copper-plate zinc cent planchets instead of making them from solid copper.
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