Free energy (pseudoscience)
|Style over substance|
“”There ain't no such thing as a free lunch.
Free energy is the idea that a low-cost power source can be found that requires little to no input to generate a significant amount of electricity. Such devices can be divided into two basic categories: "over-unity" devices that generate more energy than is provided in fuel to the device, and ambient energy devices that try to extract energy from the environment, such as quantum foam in the case of zero-point energy devices.
Not all "free energy" claims are necessarily bunk. There certainly is energy to be had in the environment that may be harvested at zero cost. For example, in 2009 Nokia announced they expect to be able to gather up to 20 milliwatts of power from ambient radio sources such as broadcast TV and cellular networks, enough to slowly recharge a typical mobile phone in standby mode. This may be viewed not so much as free energy, but energy that someone else paid for.
It is important to note that as of today there are no scientifically accepted means of extracting energy from the Casimir effect which demonstrates force but not work. Most such devices are generally found to be unworkable. Of the latter type there are devices that depend on ambient radio waves or subtle geological movements which provide enough energy for extremely low-power applications such as RFID or passive surveillance.
Free energy is a popular research subject for fringe inventors, but because of a lack of positive results that meet scientific standards, the field has become a haven for investment fraud and pseudoscience.
Free energy runs in paradox with the first and second laws of thermodynamics; because of the relationship of entropy and work, either the amount of mass/energy in the universe would have to increase (in over-unity devices), or the amount of entropy would need to decrease for a free energy device to function.
 But what abouts
Several ideas are often cited to continue claims of free energy.
- Maxwell's Demon - a thought experiment raised by James Clerk Maxwell in which a Demon guards a hole in a diaphragm between two containers of gas. Whenever a molecule passes through the hole, the Demon either allows it to pass or blocks the hole depending on its speed. It does so in such a way that hot molecules accumulate on one side and cold molecules on the other. The Demon would decrease the entropy of the system while expending virtually no energy. This would only work if the Demon was not subject to the same laws as the rest of the universe or had a lower temperature than either of the containers. Any real-world implementation of the Demon would be subject to thermal fluctuations, which would cause it to make errors (letting cold molecules to enter the hot container and vice versa) and prevent it from decreasing the entropy of the system.
- Casimir Vacuum Fluctuations - takes place between two uncharged plates in a vacuum. It demonstrates a force exerted by the known virtual photon field, but not work.
 See also
- Free energy suppression, the associated conspiracy theory
- Fusion woo, in particular cold fusion
- Joseph Newman
- Nikola Tesla
- Water powered car
- Perpetual motion
- ↑ Dates back to the 1930s; popularised by Robert A. Heinlein in The Moon is a Harsh Mistress
- ↑ Nokia researching passive energy gathering technology
- ↑ And are therefore not vastly different from solar cells. The skeptical television show MythBusters aired an episode addressing free energy in 2006; only the RF-capture device using a long-wire antenna proved workable.