Electromagnetically Shrunken Coins?

[Azathoth]

Greetings,

As one of the resident smart people in my group of friends, one of them asked me about this ebay auction (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3023993067&category=11974), featuring a shrunken Kennedy half dollar. Looking at his other auctions, you'll see that he offers a variety of different coins shrunk to different sizes. There's also a link to his Teslamania website (http://www.teslamania.com), which offers information on how he does it.

After poking around the website for a while, I came to the conclusion that this was probably legitimate, but I wanted to bring it up here to see what people had to say about it, and see whether this is something that has come up before. Here are some of my observations:

#1) Hickman notes that the mass and density don't change -- the coins get thicker as they get smaller in radius. This isn't mentioned prominently, but I wanted to point it out.
#2) I don't understand where the force is coming from that would act on the metal to squish it radially.
#3) The slight rearrangements of the surface features is sometimes odd, as when lettering runs into the portrait. Otherwise, the images seem to genuinely correspond to the originals in fine details like eagle feather placement and hairlines.
#4) He seems to have done too many different types of coins for this to be a hoax. If he were only selling Franklin halves shrunk to a uniform size, I would suspect trickery, but that's not the case.
#5) Despite my initial skepticism, especially when Tesla's name shows up, the site did not trip any BS alarms in my brain. The process hasn't been explained to my satisfaction, but nothing seemed obviously ludicrous to me. He's doesn't rant about free energy and anti-gravity, he just seems to have an unhealthy (?) fixation on running huge amounts of current through bits of metal.

Thanks for any help you can offer,

--Azathoth

[CurtC]

"Please Contact Me me to discuss YOUR custom shrinking needs!"

That's hilarious. I read the PDF description, and I don't understand exactly how it's arranged, but it sounds plausible. I did some work with pulsed power in college, charging banks of capacitors and discharging them as quickly as possible, and there are tremendous physical forces exerted when these magnetic fields and electric fields do their thing.

An example of this is a rail gun, which has a conductive projectile that can slide down a pair of conducting rails. Pump gobs of energy into the system quickly, and the projectile gets accelerated to unbelievable speeds (thousands of meters per second).

[Diogenes]

Wow! Fascinating! Thanks for sharing...

There are a lot of details here..

Coin Shrinking and Can Crushing (http://205.243.100.155/frames/shrinkergallery.html)

Wierd, but all on the up-and-up.......

[Mercutio]

Neat site. About the electromagnetic pulse this thing generates ("you don't want to be standing near it when it goes off" or some quote close to that from the website)--could this be the "pinch" that is used in "Ocean's Eleven"? (the recent one) I thought that was fiction:confused:

[Rocky]

If you don't know about the Sandia National Laboratorie's
Z Accelerator (http://www.sandia.gov/pulspowr/facilities/zaccelerator.html) check it out.

The pulse that drives Z lasts less than ten billionths of a second--20,000 times faster than a lightning bolt--and yet carries 1,000 times the electrical current in a typical lightning bolt. But, in that brief instant, the accelerator produces an impressive amount of x-ray power, as much as 290 trillion watts (terawatts), and an x-ray energy of 1.9 million joules.

With some cool photos too. :cool:

[Dr. Popalot]

Other than filling the world's desperate need for coin shrinkage, what practical application does this machine fill?

[arcticpenguin]

Originally posted by Dr. Popalot
Other than filling the world's desperate need for coin shrinkage, what practical application does this machine fill?
You could ask the Pentagon, but I doubt that they would tell you.

[William H.]

I bought one of the shrunken quarters and just got it the other day, it's really cool, everyone gets a kick out of seeing it. I recommend buying one if anyone is thinking about it. Thanks for posting the link!

Will

[Captain_Snort]

Originally posted by Azathoth

After poking around the website for a while, I came to the conclusion that this was probably legitimate,


Taking another tack than what you want.

I dunno about in the US, but it is illegal here to deface a coin (or note) of the realm. Doesn't stop most people though, the amount of notes I have had where someone has added specs, beard, scarlines or whatever to the queens face.

[LaserCool]

I'll take # 2:

The force comes from opposing magnetig fields. According to Lenz's Law, when a magnetic field changes in a conductor, the conductor sets up an "eddy current" that creates a field opposing the induced one. Mathematically:

Curl E= -dB/dt (note, these should be partial differentials, but this site doesn't support the font)

In layman's terms: Nature opposes a change in magnetic fields. In fact, the strength of the eddy current and induced magnetic field opposing the change is directly proportional to the rate of change of the outer field.

So you induce a very stromg reply from the coin as a result of applying a high intesity, high speed pulse. The force associated with opposed magnetic fields is:

F = iLxB with the induced current being i= E/R, the E term coming from the above equation.

The simple answer to the question is if the dB/dt is large enough, and the supporting structure holds, then the quarter can be shrunk purely by eddy forces.

To get a sense of other projects that use eddy forces alone, look at "jumping ring" or "EMF railgun" using a Google search. You should find enough information.

I intend to build one for fun in the future. I'll let you know my resuilts.

[RSLancastr]

Originally posted by Dr. Popalot
Other than filling the world's desperate need for coin shrinkage, what practical application does this machine fill? Well, when they perfect the model for use at home, the obvious answer is: metal Shrinky-Dinks!

[LW]

As a kid me and my cousins enlarged some pennies with the aid of a nearby railroad track. The though part was finding them afterwards.

Later in school we made some 70 penny coins. The ingredients were 50 p and 20 p coins and a 6-ton hydraulic press.

Ah, the memories.

[Soapy Sam]

So you could shrink them by running the trains backwards?

For other hairy tales of pulsed magnets, look up the crotchety englishman in the forum search menu.

[Dr. Imago]

I hope this doesn't violate the "telling how it works" rule, but I'm not really a magician so here goes...

Reminds me of this magic trick I had when I was a kid. It consisted of a magnetic, hollowed-out penny (that was just the face-half of Mr. Lincoln) and a tiny replica of a real penny, both heads and tails, that had the same date and shinniness as the trick (literally) half-penny. What you would do is put the mini-penny underneath the trick penny. You'd show your dupe a small device (that was really just a magnet) and tell them it was a magic penny-shrinker.

As you passed the magnet over the half-penny, it would make a small "clink". Then you're supposed to say, with all the drama that any kid magician can muster, "See, that sound was the penny shrinking down to it's new size."

As you pulled the magnet away, it revealed the tiny little penny. When the dupe was looking at the new little penny in amazement, you'd slide the half-penny of off the magnet, palm it, and hand the magnetic "penny-shrinking machine" to the spectator so they could see everything was on the up and up.

It was a really fun trick. Sadly, I'm sure that it got lost years ago through our various moves. :( I really wish I could find it again. That little, tiny penny was pretty cool.

(Oh, and I just remembered. The hollowed out side of the penny would also just perfectly fit a dime. So, you could alternately make it a "money changing" machine as well.)

[INRM]

It looks like the penny was crushed under tremendous pressure from all axes.

The Golden addition to the penny seems to be some of the copper from the coils electrically anodized to the surface.

-INRM

[bignickel]

I generally find that a cold swimming pool fulfills most shrinking needs.

Rather you want it to or not.

[William H.]

I was looking for something to shoot close-up and I thought I would take a few of the shrunken quarter that I bought a while ago after seeing this thread.

The first photo shows the shrunken coin (just a little smaller than a dime) with a normal quarter:


http://www.angelfire.com/oh2/robh/images/twocoins.jpg


These pictures show how the text on the coin somehow gets pushed behind the eagle:

http://www.angelfire.com/oh2/robh/images/twoeagles.JPG

This photo illustrates how much more relief there is in the shrunken coin, hit your F11 key for a better look at this one:


http://www.angelfire.com/oh2/robh/images/tcoin_006.jpg

[scribble]

There's video on the net of this being done that i've seen, but I can't be bothere to search for just this second. It's awesome.

It's good science, and good fun. All it's doing is applying INCREDIBLE crushing force for a split second. The trick is in how they get the force so perfectly even. The answer is electromagnets. Big scary ones powered by some kind of immense capacitor so you get all the force in one big SNAP.

There a reall nice video archive of this and a lot of other high energy physics demos online. They're cool. I'll find it later if no one else does (did).

[epepke]

Originally posted by Captain_Snort


Taking another tack than what you want.

I dunno about in the US, but it is illegal here to deface a coin (or note) of the realm. Doesn't stop most people though, the amount of notes I have had where someone has added specs, beard, scarlines or whatever to the queens face.

It's legal in the US, as long as there is no fraudulent intent. Which is good, because it means I get to cross out "In God We Trust" when I'm in a pissy mood. All the tourist traps have machines that let you flatten a cent and imprint a souvenir logo on it, but they worked a lot better with the old bronze cents than the new copper-plated zinc ones.

[Ladewig]

slightly off topic
(note, these should be partial differentials, but this site doesn't support the font)



∂ can be be made by using HTML code #8706 (put an ampersand before it and a semicolon after it.

[Agammamon]

Originally posted by arcticpenguin

You could ask the Pentagon, but I doubt that they would tell you.

You could, but then they'd have to kill you.


Well, ok, they they wouldn't really have to but they've got to keep their assassins in practice.

[phildonnia]

This was covered in Popular Mechanics last year.

A subsequent letter to the editor explaining that compressing metal was impossible elicited a further explanation: The total volume of the coins remains the same; they become thicker as they get smaller.

[Johnny Pneumatic]

All I want to know is can it shrink heads?

[Crotchety Englishman]

The forces generated by pulse magnets are huge, even those generated by the induced currents are significant. I've dug pieces of copper wire out of concrete walls after a magnet failure.
The walls of the UNSW lab in Sydney were reinforced with armor from a scrapped naval destroyer so that it could withstand a 2 pound object at twice (maybe three times) the speed of sound flung out by magnetic forces.
While the forces drop off pretty quickly with increasing radius, they are still significant enough to give cause for concern when planning a facility. One check we always had to make was whether there was steel reinforcement in the concrete floors. If the magnet decided it was going to align itself with some reinforcement....
You could always hear a pulse because all of the metallic equipment in the cell would give a little shudder.
On the other hand I never noted any biologic effects of pulsed field.