Nikola Tesla has a fair claim to being both one of most influential and one of the most forgotten scientists of the 19th and 20th centuries. His work laid the foundation both of the wireless network you are using to access this webpage and the distribution system that allows you to power it. He patented around 300 inventions during his lifetime and most of the patents were stolen to make other people famous.
Nikola Tesla was born in 1856 to a Serb family in modern day Croatia. In 1884, he emigrated to the United States to work for Thomas Edison's company. Edison allegedly offered Tesla $50,000 to redesign his inefficient generators and motors. When Tesla did this, Edison instead offered him a $10 raise to his $18 salary. Tesla resigned and formed his own company, which soon cracked the problem of long-distance distribution of electrical power.
Tesla's invention of the Westinghouse system of distributing electrical power using transformers and alternating current is the basis of the modern world (go to Greerton to see it in action) and sparked the infamous "War of the Currents", in which Thomas Edison sought to discredit Tesla's invention, by publicly electrocuting an elephant, among other things, but Tesla's system proved superior.
Tesla also invented radio communication and built the first radio-controlled device (a boat) but almost all his patents were stolen by Guglielmo Marconi, who gained fame, and a Nobel Prize, from Tesla's work.
Tesla always played up the "mad scientist" persona, sitting quietly whilst bolts of lightning arced around him, but in his later years, his ideas became increasingly strange, working on a "death ray" that would regularly black-out homes near his laboratory in Shoreham, New York. His last patent, in 1928, was for a VTOL aircraft. He died in relative poverty in 1943 and was almost completely forgotten for nearly 50 years.
In 1960, the unit of magnetic field strength was named the Tesla in his honour and, in recent years, his contribution to the modern world has been increasingly recognised. I thought this was an appropriate theme for this cache.
Radio (and television and wi-fi and mobile phones etc. etc.) works by resonance. Circuits containing an inductor, a capacitor and a resistor (an LCR circuit), have a natural or resonant frequency. An incoming signal will produce a large current in the circuit but only if it matches the resonant frequency. Thus a television set actually receives all TV and radio stations at the same time, but only the station it is tuned to will produce a large signal through resonance.
So, here's the puzzle. You need'll to work out the resonant frequency of each of these circuits in Hertz (ignore any decimal places). It will require either an hour or so of Googling or the help of a reasonably good Level 3 Physics student.
South
East
