sci.skeptic FAQ: The Frequently Questioned Answers Summary: This posting contains a list of Frequently Asked Questions + about scientific skepticism and various fringe topics. It + should be read by anyone who wishes to post to sci.skeptic. Date: Wed Mar 30 17:52:37 MET DST 1994 Followup-To: sci.skeptic Organization: GEC-Marconi Research Centre, Great Baddow, UK Supersedes: X-Newsreader: TIN [version 1.2 PL1] Archive-name: skeptic-faq Last-modified: 94/02/23 Version: @(#)skeptic-faq.text 1.17 [... lots of interesting stuff on other topics deleted] Strange Machines: Free Energy and Anti-Gravity ============================================== 8.1: Why don't electrical perpetual motion machines work? --------------------------------------------------------- Electrical perpetual motion machinists usually present a machine that causes a small battery to generate a huge amount of power. The most common problem here is that the "huge amount of power" was incorrectly measured. AC power measurements are tricky; you can't just multiply the voltage and current, because they may be out of phase. Thus, measuring 10 Volts and 10 Amps could indicate anything from 0 to 100 Watts, depending on the power factor. In addition, most AC meters expect a sinusoidal wave; if they are given some other wave they may be totally wrong. A simple argument against these machines is; "If they can provide so much energy, why do they need the battery to keep going?" 8.2: Why don't mechanical perpetual motion machines work? --------------------------------------------------------- Mechanical perpetual motion machines depend on rising and descending weights. The problem is that the amount of energy that you get out of a descending weight is exactly the same amount that it took to raise the weight in the first place: gravity is said to be a "conservative" force. So no matter what the weights do, you can't get energy out. 8.3: Why don't magnetic perpetual motion machines work? ------------------------------------------------------- Magnetic motors have a clever arrangement of magnets which keeps the motor rotating forever. Not surprisingly, whenever someone tries to build one, the motor rotates for a while and then stops -- this is usually attributed to the magnets "wearing out". These motors usually rely on using magnets as low-friction bearings, meaning the "motor" can coast for a long time, but it doesn't supply any power. Magnetism is like gravity; you can store potential energy and get it back, but you can't get more energy no matter what you try. 8.4: Magnets can levitate. Where is the energy from? ----------------------------------------------------- Levitating magnets do not require energy, any more than something resting on a table requires energy. Energy is the capacity for doing work. Work can be measured by force times distance. Although the magnets are exerting a force the levitated object is stationary, so the magnets aren't supplying any energy. 8.5: But its been patented! So what? Patent offices will not grant a patent on a "perpetual motion machine" (some just require a working model) but if you call it a "vacuum energy device" and claim that it gets its energy from some previously unknown source then you can probably get a patent. Patent offices are there to judge whether something has been invented before, not whether it will work. The ban on devices labelled "perpetual motion" is a special case because the patent officers dislike being cited as some sort of approval by con-men. 8.6: The oil companies are conspiring to suppress my invention -------------------------------------------------------------- This is a conspiracy theory. See the entry on these in section 0. In most of the US the utility companies are *required by law* to buy your excess electricity if you produce your own. If you've got an energy machine, build it in your basement, phase match it to the line, and enjoy. 8.7: My machine gets its free energy from --------------------------------------------- A number of machines have been proposed which are not "perpetual motion" machines in the sense of violating the law of conservation of energy. Mostly these are based on bogus science. One inventor claims that atoms of copper wire are being converted to energy in accordance with Einstein's "e=mc^2". However he fails to explain what causes this transformation and how this energy is converted into electrical energy rather than gamma rays or heat. Occasionally one sees a machine which could work in theory but would produce very tiny amounts of energy. For instance, one can set up a gyroscope which always points in one direction (this is how the gyrocompass in an aircraft works). The earth will rotate underneath this once every day (to an observer standing on the Earth it looks like the gyro is rotating). So you could attach gears and a generator to the gyroscope and use this rotation to get electricity. The 4,320,000:1 gearing required is left as an exercise for the student, as is naming the source of the energy it would generate. 8.8: Can gyroscopes neutralise gravity? --------------------------------------- Gyroscopes (or gyros) are a favorite of "lift" machine inventors because many people have come across them and they behave rather oddly. However there is nothing all that mysterious about the behaviour of gyros. You can use Newtonian physics to explain them. Briefly, if you imagine a bit of metal on the edge of a spinning gyro, then to turn the gyro you have to stop the bit of metal moving in its current direction and start it moving in another direction. To do this when it is moving fast you have to push it rather hard. Nothing about this makes the thing get any lighter (in fact to be pedantic, the gyro gets very slightly heavier when it spins, in accordance with Einstein's theory of relativity.) 8.9: My prototype gets lighter when I turn it on ------------------------------------------------ Weighing something which is vibrating on ordinary scales is a sure way of getting a wrong answer. The vibration from the machine combines with "stiction" in the scales to give a false reading. As a result the weight reductions reported for such machines are always close to the limits of accuracy of the scales used.