Marvin the Martian awards

"I'm going to blow up the earth, it obstructs my view of Venus......"

quite often there are posts i see, that remind me of this classic cartoon line. common subjects are EMP generators, lasers (in the Megawatt or Gigawatt range), and other devices in the "infernal machines" class. usually the interest in these devices is from some type of annoyance factor ("my neighbor plays his stereo too loud", etc...)... in fact i've been known to dabble in the "infernal machine" category myself from time to time (once built a Tesla coil that blanketed the 4-story apartment building i lived in with wall-to wall RFI, and burned out every CMOS chip within 50 feet). my interest was just plain curiosity, i wanted to build one just to see it work. while i have no problem with experimenters trying stuff out to see it work, i do have a problem with annoyance driven projects whose purpose is to intimidate or exact retribution. grow up, and tell your neighbor his stereo is too loud.

fortunately, for the rest of us as well as the tinkering megalomaniac, the laws of physics imposes severe limitations on the ability for the average tinkerer to create anything that will have much of an effect for more than a few feet. EMP devices are a commonly attempted construction project, but considering the number of watts one can tap from their typical home AC supply, and the physical limitations of the components available to the experimenter, i highly doubt anyone could build something that could do much more than erasing one's computer hard drive from 5 feet away. one of the limiting factors here is the Inverse Square Law. the intensity of an electromagnetic field decreases by a factor of the inverse square of the distance. when it comes to homebrew lasers of any significant wattage, the limitations on the tinkerer are very severe. many of the materials used in making lasers are somewhat pricey. you can't just go down to the hardware store and ask for a ruby or sapphire rod. to make gas lasers is less expensive in terms of materials, but the expertise required in glassblowing, as well as the tolerences in the mirror alignment (two optically flat 1/4" diameter mirrors a foot or so apart, aligned to within a 1/4 wavelength parallelism) still place these out of the abilities of the average tinkerer.

so, when i see "i'd like to build an EMP device to shut down my neighbor's stereo" or "i want to build a huge laser to burn my neighbor's dog when it barks all night long" don't expect any helpful comments from me. i WILL however, award you a Marvin-the-Martian award, because you need to grow up and learn to deal with your neighbors face to face.