Making Small Change...QuarterShrinking
Copyright 2010, Bert Hickman
This shrunken US Washington quarter was created using a technique called Electromagnetic Forming. This techniqueuses powerful electromagnetic forces to “shrink” a quarter to a diameter smaller than a dime. The process uses an invisible, but extremely powerful, pulsed magnetic field thatevenly “hammers” the coin inward with a powerful shock wave, forcing it to shrinkin the blink of an eye. The specialized equipment that performs this feat is called a “Quarter Shrinker”. The Quarter Shrinker rapidly discharges a group of high voltage capacitors through an insulated coil of wire, called a “work coil”, whichis carefully wrapped around the coin. Depending on the type of coin, we may force as much as 100,000 amperes through the coil. This causes as much as one million amperes of current to flow inside the coin through transformer action. The instantaneous power applied to the coil is comparable to the total electrical power consumed by a medium sized city. Since the current is rapidly changing, a phenomenon called “skin effect” forces this immense current to circulate within a very thin (~50 thousandths of an inch thick) ring along the edge of the coin.
The huge circulating current flowing within the coin creates its own powerful magnetic field. The magnetic fields produced by the coin and the coil strongly repel each other, creating tremendous forces between them. The compressive forces on the coin easily overcome its mechanical yield strength, and it uniformlyshrinks to a smaller diameter, becoming thicker in the process. The shrinking process is over in instant –less than 25 millionths of a second. Although the quarter’s new diameter is smaller than a dime, the coin still retains its original surface features! As the coin shrinks inward, it becomes thicker, so that a shrunken coin still has the same mass, volume and density as before. The energy used to shrink your quarter was 5,000 Joules (or watt-seconds). The peak current used in the coil was about 60,000 amperes, and the peak current developed within the coin was about 600,000 amperes.Applying higher energies creates even smaller, thicker, quarters. During shrinking, the coin is touched only by invisible, ultrastrong magnetic forces.
At the same time, similar magnetic forces press outward against the inside of the work coil, eventually causing the wire to disintegrate in a violent explosion of copper fragments. At the very beginning of the shrinking process, the “pressure” on the coil causes it to rapidly increase in diameter. The wire stretches, andultimately fragments from the irresistible forces. The wire’s insulation can’t stretch as much as the copper wire, and it’s blown off, leaving fragments of bare, work hardened copper. The coil fragments are ejected with the force of a small bomb. For safety, the work coil must be confined inside a bulletproof blast shield. The velocity of small coil fragments has been measured at over 3,600 miles per hour. Once the coil explodes, any residual electrical energy in the system is transformed into a ball of blinding blue-white plasma. And yes, shrinking coins does make a big BANG. Every shrunken coin requires its own carefully hand-crafted coil of wire, which isexplosively destroyed during the shrinking process.
The coinshrinkingtechniqueworks well with many, but not all, coins. It’s particularly effective on US “clad” coins, since these coins use a highly conductive core of pure copper sandwiched between thin outer layers of a nickel copper alloy that has a higher melting temperature. The Sacagawea and the new Presidential Dollars ("Golden Dollars”) also shrink well, since these clad coins are made with a pure copper core sandwiched between two layers of a manganese-brass alloy. Bronze pennies made before 1982 also shrink well. However, newer pennies use a thin copper layer plated over an easily melted zinc core. During shrinking, the copper layer vaporizes, and the penny disappears in a shower of molten zinc globules. US nickels (which are made from a nickel-copper alloy) shrink poorly since the alloy is harder and is a relatively poor electrical conductor. However, pure nickel coins, such as older Canadian nickels or quarters, shrink very well.
Bimetal coins (which have outer rings and circular centers made from different alloys) often show different degrees of shrinkage based upon the electrical conductivities and hardness of the alloys. In some cases (Euro dollars), the center portion may actually separate from the outer ring. Shrinking a coin with a hole in the center often causes the hole to shrink or even close up entirely. Large silver coins also shrink quite well, but energy levels must be reduced since the silver-copper alloy has a significantly lower melting temperature. For more information, search for “Electromagnetic Forming” on Google or Wikipedia:
1-800-728-6999<!-- PAGE TEXT ENDS HERE -->