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Science

Small Change, and Other Physics Fun 310

Posted by michael
from the physics-is-phun dept.
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."
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Small Change, and Other Physics Fun

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  • by Punchinello (303093) * on Friday March 19, 2004 @10:11PM (#8617698)
    I bought a shrunken Sacagawea Dollar from this site in May, 2003 (around the same time my Slashdot story submission about the site was rejected). The coin is truly amazing to look at and a hit at parties. The details of Sacagawea and the Eagle are perfect, only smaller (although the coin itself has a bit of an uneven surface caused by the rapid shrinking process). I'm happy to see the site finally get the news for nerds treatment it deserves.

    There is a cool Popular Science article [popsci.com] for more information.

    Now go buy some coins to fund Bert's efforts!

  • by Herkum01 (592704) on Friday March 19, 2004 @10:13PM (#8617711)
    Have redirected some of that current into getting a more powerful network connection.
  • by carcosa30 (235579) on Friday March 19, 2004 @10:13PM (#8617713)
    Apparently the slashdot effect is a kind of physics fun he didn't account for...
    • by Alien54 (180860) on Friday March 19, 2004 @11:32PM (#8618101) Journal
      Apparently the slashdot effect is a kind of physics fun he didn't account for...

      With any luck, he'll be out partying tonight, getting smashed. Then he comes home completely toasted, and has to rebuild the server from the pile of smoke he finds in his server closet.

      Hell is working on MS stuff drunk and plasted. You'll never know what will happen [ubersoft.net] [read the comics through to the end]

    • by Anonymous Coward
      "Slashdotted" ... we've acted over the past few years as if it is (1) funny (2) a fact of life (3) some sort of reward

      In fact it is none of the above.

      OK /., get off your/our collective arses and fix this. If /. doesn't get /.'ed, then why should articles directly referred to?

      Ok, mod this down. It is not essential to the topic in question. It is essential to those who create valuable content. Up till now, /. punishes them as much as it recognises them.

      All it takes is a little magic (SMOP) to make all lin
  • Google Cache? (Score:5, Insightful)

    by ResQuad (243184) <slashdot@kon s o l e t e k . com> on Friday March 19, 2004 @10:13PM (#8617715) Homepage
    Doesnt do anything, because it doesnt cache the pictures. And thats the largest problems of slashdoting. I think slashdot should try to temp mirror the pages for the first few hours it goes up, if its a small site.
    • Re:Google Cache? (Score:5, Informative)

      by Anonymous Coward on Friday March 19, 2004 @10:25PM (#8617781)
      To see check out auctions by him:

      Here, [ebay.com] Here, [ebay.com] Here, [ebay.com] And Here [ebay.com]
    • Re:Google Cache? (Score:4, Insightful)

      by La Camiseta (59684) <me@nathanclayton.com> on Friday March 19, 2004 @10:28PM (#8617793) Homepage Journal
      This is exactly the reason that I think that Slashdot should put up some Freenet [freenetproject.org] mirrors. At least then, when there's a big rush of requests, the little site's servers wouldn't get the big hits, and the bandwidth would distribute itself out like BitTorrent.
    • Re:Google Cache? (Score:5, Informative)

      by Jonah Hex (651948) <hexdotms AT gmail DOT com> on Friday March 19, 2004 @10:56PM (#8617953) Homepage Journal
      Check out these two posts on the topic of /.'ing small sites [slashdot.org] and why /. can't mirror sites [slashdot.org], you may find them informative.

      Jonah Hex
      • No, Taco's "I can't mirror because of copyright" is an excuse, not a reason. There is no good reason why they could not e-mail the webmaster and request permission to put up a temporary mirror. They don't do it because of laziness and because they like the notoriety of the slashdot effect.
        • I agree. And it wouldn't even need to delay the story: wget the page (but don't publish the copy yet), post the story, email the webmaster. If he tells you to go ahead and relieve his servers, then change the links to point to your copy, otherwise keep them and throw away the local copy you made.
      • I salute you. You have taken Karma whoredom to a new level. You just got a 5 Score for posting links to your own week-old slashdot posts.

        LK
    • Right, so that Slashdot can Slashdot itself. Recursion, anyone?
    • Google Image Cache [google.es]br
    • Re:Google Cache? (Score:4, Interesting)

      by Forgotten (225254) on Saturday March 20, 2004 @12:22AM (#8618453)
      Not only does it not help, it does harm, since the small site keeps getting hit for the inline images.

      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.

      • by general_re (8883)
        There is no real distinction between the slashdot effect and a DDOS

        Other than the critical distinction of "intent", of course. Suing someone for things that fall under the heading of "shit happens" rarely leads anywhere useful.

      • I wonder how much the inconvenience cost him vs the number of additional sales he might get from this free advertising...

        think about that for a second. How much would an advertising shop charge to guarantee even a 10th of the hits slashdot generated?

        I don't know how it would stand up in a court of law anyway. If you put up a web site for people to look at, and something like slashdot says 'Hey everyone, come and have a look at this cool site!', on what basis would a legal or civil case be mounted against
    • archive of teslamania.com [archive.org], which DOES have images.
  • Hmm.. (Score:4, Insightful)

    by Anonymous Coward on Friday March 19, 2004 @10:14PM (#8617716)
    I wonder how much I'd have to pay for an ad cleverly disguised as a slashdot main story.
  • by pla (258480) on Friday March 19, 2004 @10:15PM (#8617724) Journal
    No posts yet, but already slashdotted.

    Actually, though, I have seen his page before. really cool toys, but strikes me as something most of us would probably not want to play with.

    Worry about the health risks of frequent cell phone use? Doesn't even come close to the RF this sucker puts off. Not to mention ozone and the very real risk of simple death from electrocution...
    • I see he is using IIS. Poor guy. I think if the number of connections > 3 then that irritating microsoft 403.9 page gets spat out. grr
    • by PurpleFloyd (149812) <zeno20@@@attbi...com> on Friday March 19, 2004 @11:00PM (#8617971) Homepage
      Why wouldn't I (and many other slashdotters) want to play with equipment like this? To me, the extremely slight risk of cancer caused by short, high-intensity broadband RF pulses is more than offset by the sheer coolness factor of playing with something like this - a little like a geekier form of "extreme sports," perhaps (God knows I already drink enough Mountain Dew).

      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?

      • by atomicdragon (619181) on Saturday March 20, 2004 @12:06AM (#8618339)

        Judging by the description above (yeah it can be wrong, but the site is down for the moment) this sounds a lot like the capacitor bank in the lab I work in. Unlike a tesla coil, this think puts out some serious current. The one we have will output around 120,000 amps at 5 kV. It won't be that much if say a human were in between the connections, but that would be enough to give 250 mA of current to anything with less than 20 kOhm resistance. This sounds very similar to the setup this guy has, so I imagine it can be very dangerous. The lab seems somewhat lax about some of it, but that is because a huge amount of the wiring is well enclosed, which tends to be the exact opposite of all of my home projects.

        Even then you have to be careful around pulses of this much current, since often weird things happen with ground. The grounded vacuum chamber we fire this stuff into will often get potentials of several hundred volts across different parts of the same metal chamber. Or if you have something connected to ground in two ways, you can induce a current going from one ground to the other. So it is a matter of knowing what not to touch with your hands or certain equipment when the thing fires.

        • by PurpleFloyd (149812) <zeno20@@@attbi...com> on Saturday March 20, 2004 @02:31AM (#8619190) Homepage
          Of course it takes special knowledge to build and operate high voltage, high current devices in a safe manner; I never said otherwise. Also, if you jury-rig any wiring in order to make it work, you could very well pay with your life. High voltage and high current devices are incredibly dangerous in the hands of anyone who doesn't know exactly what they're doing. I don't dispute this. However, there are many devices in the world that are dangerous to build and operate without the proper training - aircraft come to mind immediately.

          Regarding the resistance of the human body (to calculate lethal voltages), I remember being told in several HV-safety courses in physics classes that the human cross-body resistance (index finger to index finger) is generally 100 kohms to 1 mohm, depending mostly on the level of sweat on the body, and thus on environmental conditions like heat and humidity. That doesn't mean that 5 kV isn't dangerous, though: remember the 1/10/100 rule: you can feel 1 mA, can't let go at 10 mA due to involuntary local muscle contraction, and at 100 mA you are presenting a serious danger to your heart. Thus, with your 5 kV supply, you'll probably find yourself unable to let go of the power supply's terminals should you touch them. Even the voltages in your house are dangerous, in the right situation (the bathtub scenario: drop a 110v appliance into your bathtub, with you providing a path to ground, and it might not take too much to cause unconciousness and drown you). It's all a matter of knowing what you can do safely.



      • the extremely slight risk of cancer
        YMMV but I prefer to keep cancer at bay, my Father just got the news of prostate cancer. Let me guess PurpleFloyd you are in your 20's (as am I) and you are going to live forever.

        Sera
      • by sploxx (622853) on Saturday March 20, 2004 @12:57AM (#8618654)
        > 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.

        Uh oh. Be careful with such statements. I charged a PC power supply filtering cap (electrolytic, 100uF) to 600V and (accidentally) touched it with both hands. I flew across the room with a loud "ieek". I'm happy I survived that. Really. That was more than 250mA.

        I have some other 10kV/1uF-Caps here, discharging them from 3kV (did not try more yet => destroyed my PC with them once because of EMI!) is enough fire, smoke and thunder to satisfy my pyromanic HV ego. I have never touched them, handle them with a 2m pole (literally!) and I'm also not going to go close to them (if charged) in any way.

        Someone stated that caps charged with energies less than 10 Joule are safe (i.e. unlikely to be lethal - no warranty!), but take capacitors serious. In the setups described, the caps contains KILOjoules of energy and will SURELY kill you if you even get close to them (because of that nasty gap-jumping property of HV).
      • by Idarubicin (579475) <allsquiet@hotmail3.14.com minus pi> on Saturday March 20, 2004 @02:13AM (#8619114) Journal
        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.

        It is true that you won't get a lethal shock directly from the high voltage side of a Tesla coil.

        One thing you have to watch is the shielding on the 'low' voltage side of homemade equipment. You're going to have components running off 120 V or 240 V line current. If the high voltage side arcs to a low voltage component, suddenly you've got a conducting path through the air (technically, a plasma) attached to potentially several amps of line current. It is possible to deliver a a deadly current this way.

        Aside--an arc back to the line can wreak all manner of havoc on other electrical equipment on the same circuit. Your computer won't like it, that's for sure. Please, have properly grounded metal shielding around all line conductors in your experimental area!

    • by ScrewMaster (602015) on Friday March 19, 2004 @11:19PM (#8618055)
      Not quite the same thing. The output of a Tesla coil is not in the band that ionizes living tissue (like, say a cell phone or a microwave oven in the 2.4 Ghz. range.) High-powered RF by itself is harmless enough: passes right through you. Generations of HAM operators have sat next to their transmitters with no ill effects.

      There is relatively little risk of electrocution from a properly-tuned Tesla coil, although you could easily suffer a nasty RF burn if you're not careful (those take a long time to heal, for some reason.) Skin-effect keeps the current from passing through your body, but if the unit has low-frequency harmonics superposed upon the RF waveform you can get a nasty shock. I've experimented with Tesla coils (many years ago) and could stand there holding a sharp metal rod in one hand drawing a two foot arc to the discharge sphere. Scary as hell but lots of fun.

      You are at far greater risk of electrocution from an electrostatic generator. A Van de Graaf or Wimshurst of even moderate size coupled with enough capacitance can kill you in an instant.
      • OOGG WISH CORRECT STATEMENT ON IONIZING RADIATION.

        ScrewMaster NOT REMEMBER PLANCK'S CONSTANT.

        RADIATION TO "ionizing living tissue" MUST HAVE PHOTON ENERGY ENOUGH TO IONIZE. ATOMIC PHYSICS USE UNIT "Rydberg" IONIZING ENERGY FOR HYDROGEN ATOM.

        ONE RYDBERG BE 13.6 electron volts. NOT ALL IONS REQUIRE SO MUCH, BUT CLEARLY ORDER OF VOLTS. THINK OF BATTERY; CHEMICAL BATTERIES PRODUCE VOLTS.

        Planck's constant [google.com] be equivalent to [nist.gov] 3.28 10^15 Hz. Even 1 eV be 2.41 10^14 Hz, or ABOUT TEN THOUSAND TIMES HIGHER than 2.
        • Posts like this are a big part of why I love slashdot. However you miss the point that the energy is not evenly distributed. Without a focussed signal you can get semi-random (as in, you don't know where they're going and you didn't plan for them) interference patterns. Good point about the fire, though. In order to get burned from that you're going to have to burn something 'interesting' like magnesium. and, I got a nice sunburn on my arms from arc welding while wearing a tee shirt, but that's not at all t
      • Just like to point out that although the skin effect does exist (in metallic conductors) it DOES NOT APPLY to humans. This is backed up by plenty of recent research - see the Pupman [pupman.com] mailing list. You do not feel a shock from a Tesla coil (in theory) because the frequency is high enough that your nerves can't respond - therefore it is much less dangerous than DC or low frequency AC because there is little risk of stopping your heart. However it can and does still cause deep internal RF burns.

        Actually on

    • You've probably seen his page before because this story is a three-year-old dupe [slashdot.org](posted by the same editor no less).
  • by Honig the Apothecary (515163) on Friday March 19, 2004 @10:16PM (#8617731)
    is shrinking right now before you eyes with the application of millions of /.ers.

    If it gets enough hits, will it become small enough to fit in a blade system?

  • ya know... (Score:5, Interesting)

    by abscondment (672321) on Friday March 19, 2004 @10:17PM (#8617737) Homepage
    tesla coils are really cool. a friend and i once took a 30,000 volt capacitor bank, a homemade tesla coil and a homemade spark gap and liquified my deodorant.

    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.
  • by LBArrettAnderson (655246) on Friday March 19, 2004 @10:20PM (#8617751)
    If you want to see pictures of the shrunken coins..... try popular science - http://www.popsci.com/popsci/science/article/0,125 43,490445,00.html
  • by Anonymous Coward on Friday March 19, 2004 @10:23PM (#8617759)
    http://www.thegeekgroup.org/

    These guys do a lot of the same stuff.
  • by mark-t (151149) <[markt] [at] [lynx.bc.ca]> on Friday March 19, 2004 @10:23PM (#8617767) Journal
    Since the site is slashdotted to the ninth circle of hell and beyond, and the google cache links don't refer to any of the theory pages, would someone be willing to explain exactly how this works and why it happens?
    • by multipartmixed (163409) * on Friday March 19, 2004 @10:30PM (#8617810) Homepage
      Electrons moving in a wire exert a magnetic force.

      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.
      • I wonder what would happen if this was done to a Canadian 2 dollar coin (also known as a twonee). Instead of being made with a single metal (or a bunch of metals mixed together), this coin has two seperate sections. The middle is mostly copper and the outside ring is nickel
        • American coins are sort of like this too [usmint.gov] - made of layers of differing metals or alloys. Quarters, nickels and dimes are pure copper inside, clad with a mixture of copper and nickel. Pennies are zinc plated with copper.

          I think that there is enough space between the particles in the metals at the newtonian scale that there should be no significant size difference between two different metals being shrunk by this method. At the atomic or subatomic scale, there might be a measurable difference difference, bu
    • From PopSci [popsci.com]:

      Bert's high-voltage equipment takes up most of his screened-in porch (from the looks of things, his wife drew a line at the sliding door?there's a clear border between tidy suburban house and chaotic suburban lab). Bert begins the coin-shrinking process by wrapping a quarter in copper wire and bolting the leads to copper bus bars, which are connected, by way of a triggered spark gap, to a 600-pound bank of 12,000-volt capacitors. A bulletproof blast shield encloses the coin and coil, and a hi

  • by Temporal Outcast (581038) on Friday March 19, 2004 @10:30PM (#8617811) Journal
    See Sam Barros' Powerlabs for similar stuff - the guy has got a lot of very cool and realy interesting stuff. [powerlabs.org]

    Especially interesting are his high-voltage stuff [powerlabs.org].
  • Is this legit? (Score:4, Interesting)

    by adept256 (732470) on Friday March 19, 2004 @10:34PM (#8617827)
    Can't you get in trouble for monkeying with currency?

    Very cool, though.
    • by Anonymous Coward
      Not sure, though I know for a fact that you can get in trouble for applying current to a monkey.
    • Re:Is this legit? (Score:4, Informative)

      by Peale (9155) on Friday March 19, 2004 @11:21PM (#8618061) Homepage Journal
      U.S. Title 18, Chapter 17, Section 331: Prohibits among other things, fraudulent alteration and mutilation of coins. This statue does not, however, prohibit the mutilation of coins if done without fraudulent intent if the mutilated coins are not used fraudulently.

      See http://www.pennysmasher.com/ [pennysmasher.com]
    • Re:Is this legit? (Score:2, Informative)

      by ProKras (727865)
      This stuff is covered in the US Code Title 18, Chapter 17 [cornell.edu].

      Companies selling souvenir penny-pressing machines [rockyrockholt.com] often cite Section 331, which says currency may not be defaced for fraudulant purposes. However, section 333 says that it is unlawful to alter the money "with intent to render such bank bill, draft, note, or other evidence of debt unfit to be reissued." I suppose the shrunken coins would be "unfit to be reissued," but then again so would souvenir squished pennies.
      • Re:Is this legit? (Score:3, Informative)

        by jaoswald (63789)
        Section 333 refers to "National bank obligations", roughly, paper money.

        The idea behind the "fit to reissue" concept is that paper money (when the U.S. was on the gold standard) represented gold in some bank vault, and the bank printed only as many bills as it had gold. If you brought the bill back to the issuing bank, you could get the gold, if you wanted, or the bank could destroy the old bill and print a fresh one. Always preserving the link between paper money and the gold backing it.

        If you alter the
    • C'mon, mods, this is NOT A TROLL. This is a serious question IMHO!
  • by OverlordQ (264228) on Friday March 19, 2004 @10:45PM (#8617893) Journal
    PowerLabs? [powerlabs.org].
  • by gopher_hunt (574487) <slashdot@0db.us> on Friday March 19, 2004 @10:46PM (#8617898) Homepage Journal
    I don't understand where the metal goes. Do the coins weight the same before and after?
    I was under the impression that most solids wouldn't compress this much.
    • by eclectro (227083) on Friday March 19, 2004 @11:09PM (#8618009)

      What happens is the coin ends up _thicker_ than before. Because it is thicker, the coin in turn becomes smaller. The mass is indeed the same before and after.

      There is no exotic atomic manipulation going on. Not that people have tried (aka alchemy).

      Here are his ebay auctions [ebay.com]


  • http://www.popsci.com/popsci/science/article/0,1 25 43,490445,00.html

    http://home.earthlink.net/~smalldollars/dollar/a dd 005.html

  • by SmackCrackandPot (641205) on Friday March 19, 2004 @10:50PM (#8617922)
    With some slight modifications, this technique could be used to shrink the national debt.
  • by Anonymous Coward on Friday March 19, 2004 @10:52PM (#8617935)
    * Theory of Operation
    * Results
    * EM Field Theory and Wire Fragmentation?
    * Isn't Defacing Money a Federal Crime?
    * So Who Invented this Crazy Device?
    * References

    Theory of Operation:
    The Quarter Shrinker uses a technique called high velocity electromagnetic metal forming, or "Magneforming". This technique was originally developed by the aerospace industry in conjunction with NASA, and has been popularized by Aerovox, Grumman, and Maxwell. It involves quickly discharging a high energy capacitor bank through a work coil to generate a very powerful and rapidly changing magnetic field which then "forms" the metal to be fabricated. While it works best with metals of relatively high electrical conductivity such as copper or aluminum alloys, it will work to a more limited extent with poorer conductors such as sheet steel.

    In my current system, I charge up a large capacitor bank consisting of a number of large capacitors, each weighing about 165 pounds and about 30" high x 14" wide x 8" thick. A High Voltage relay is used to connect the caps either to a high voltage DC charging supply, or to a high power bleeder resistor chain. A 15 kV 60 mA transformer and a set of 40 kV rectifiers provide the DC charging voltage for the capacitor bank. The primary of the transformer can be overdriven to 140 volts via a variable autotransformer to speed up the charging process. The electrical energy stored in the capacitor bank is proportional to the square of the bank voltage, and the degree of "shrinking" force is directly proportional to the capacitor bank's energy.

    The charged capacitor bank is quickly discharged through a single layer work coil made of heavy magnet wire. The coin is held firmly in the center of the coil by a pair of dowel rods so that it's axis of rotation is parallel to the centerline of the coil. This constrains the coin from twisting, and also helps balance the forces wanting to eject it from inside the coil. The two ends of the coil are stripped of insulation and firmly bolted to heavy copper bus bars. The high voltage "switch" that connects the capacitor bank to the work coil is actually a high power triggerable spark gap, called a "trigatron". The main gap electrodes are solid brass, 2.5" in diameter. One of the electrodes is drilled and tapped to hold the triggering electrode (actually a modified spark plug). A triggered spark gap is the only affordable device that can hold off the high voltage and then reliably and efficiently switch the high currents involved in the shrinking process (70,000 to over 100,000 amperes).

    The trigatron is fired by applying a high voltage (~40 kV) pulse to the trigger electrode, which then causes the main gap in the trigatron to ionize and fire. Once the main gap fires, current rapidly climbs in the work coil, the rate of change (di/dt) being of the order of 4-5 billion amperes/second. The natural resonant frequency of the LC circuit formed by the capacitor bank and work coil is of the order of 8-12 kHz. Through transformer action, a huge circulating current is induced in the coin, but because of skin effect, this current is confined to the outermost rim of the coin, typically penetrating to a depth of less than 0.050". In clad coins more of this circulating current flows through the better conducting copper center of the clad sandwich than in the outer layers. The coin and work coil magnetic fields oppose each other (Lenz's Law), resulting in tremendous repulsion forces between the work coil and the rim of the coin. The circulating current in the rim of the coin actually prevents the rapidly increasing magnetic field of the work coil from penetrating the interior of the coin.

    The large current that's induced into the outer rim of the coin can reach a million amperes or more! The initial bank energy is typically in the range of 3,500 - 8,500 Joules (or watt-seconds) but it is being discharged in microseconds. As a result, the instantaneous power is quite large, and for a brief instant is roughly
  • As seen on Ebay (Score:5, Informative)

    by Jim Buzbee (517) on Friday March 19, 2004 @10:56PM (#8617952) Homepage


    Check out the picture and prices of the some of his work on ebay [ebay.com]

    Try slashdoting that!
  • anti-spam (Score:5, Funny)

    by mnewton32 (613590) on Friday March 19, 2004 @10:58PM (#8617962) Homepage
    Please Contact Me me to discuss YOUR custom shrinking needs!

    Ah, now this is a welcome relief from all those spammers who seem to think I always need to make things bigger!
  • "Too many users attempting to access this site."

    I wanted to see his Tesla coil info. Damn.
  • Magneforming (Score:5, Interesting)

    by Animats (122034) on Friday March 19, 2004 @11:39PM (#8618160) Homepage
    Magneforming is a routine industrial operation. Because it produces a true radially symmetrical squeezing force, it's often used for operations that involve compressing a tube around something. I first saw it used in making hydraulic valve bobbins. These have a machined metal core with "piston rings" compressed around key areas.

    Magneforming is just another less-common metalworking techniques. Others include hydroforming, water jet cutting, spinning, and blowing.

  • My god (Score:2, Funny)

    by rune2 (547599)
    We've even Slashdotted the pics on the cached sites! Looks like the quarters aren't the only thing being crushed. I'm sure the webservers have imploded by now...
  • If he lives near las vegas, it might explain the mysterious EMP that in theory caused a bunch of car keys and other alarms to stop working. In any case, I hope his neighbors arn't trying to use WiFi to connect two computers, cause his work will probably knock anything off. Forget about FCC certification on his equipment...
  • by Ironsides (739422) on Saturday March 20, 2004 @12:11AM (#8618373) Homepage Journal
    Here is a link to a site on Tesla Coils, since so many of you seem to be interested in them.

    http://www.eskimo.com/~billb/ [eskimo.com]
  • Patent? (Score:5, Interesting)

    by Salamander (33735) <jeff@nOspaM.pl.atyp.us> on Saturday March 20, 2004 @12:26AM (#8618473) Homepage Journal

    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)

      by Jimithing DMB (29796) <dfe@@@tgwbd...org> on Saturday March 20, 2004 @01:05AM (#8618696) Homepage
      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?

      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!

      • If it was developed at public expense, it should be placed into the public domain, not patented and subject to royalties.

  • Wrong Fun (Score:3, Informative)

    by Jman314 (651648) on Saturday March 20, 2004 @12:40AM (#8618558)

    Submitter got it wrong: Physics is F=uN!

    (You know, force equals mu times N, friction and stuff? Never mind.)

  • by Anonymous Coward on Saturday March 20, 2004 @02:16AM (#8619126)
    so can any of the physics nuts out there tell me if this process is reversible? Is it possible to use the same/similar technique to make coins "expand" ?
    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...
  • You can see the web pages at http://www.archive.org/ [archive.org]. Just cut and paste any URL into the 'Wayback Machine' and you can see archived versions of the page.

    I noticed on some pages (the Quarter Shrinking Theory page) the text is 'invisible' using Firebird, but you can read it by selecting the entire page (ex. ctrl-a) which highlights everything.

    I've done this in the past with slashdotted sites and it seems to work most of the time.
  • by wildsurf (535389) on Saturday March 20, 2004 @06:47AM (#8619939) Homepage
    Finally, someone who can correct the historical accident that nickels are larger than dimes!!

    Now, if only he could find a way to GROW money... or would that merely consist of nickel-and-diming people to death?

Real computer scientists don't comment their code. The identifiers are so long they can't afford the disk space.

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