what is free energy?

Answer 1

Some are trying to extract useful energy from zero point energy. All of the arguments of the second law of thermodynamics apply to demonstrate that this is impossible. That is, until someone does it.

Answer 2

Free energy means any energy obtained in violation of the laws of conservation of mass/energy. These laws state that matter and energy are neither created nor destroyed in any reaction.

If you burn coal, you are simply converting some of the energy stored in the coal into heat by changing its chemical makeup. The end products of the burning take less energy to exist than the original form, and the excess is released as heat and light.

If you fuse hydrogen nuclei into helium nuclei, the mass is slightly reduced - somehow a helium nucleus weighs a little less than the two deuterium nuclei's masses combined. The difference is released as energy in the amount of E=mc^2.

The point is, all we can do is move things around and change their forms. If we're clever, we can find ways to do this that we can harness in order to get work done. However, the end result is that the net sum of all the components at the end is the same as it was at the beginning.

Imagine getting change for a dollar - You can get 4 quarters, 10 dimes, 20 nickels, 2 quarters and 5 dimes, etc - however you want, but it all adds up to a dollar both before and after.

Imagine that you got 9 dimes, one Peso, and a penny.... That would be the same monetary value (more or less, depending on the exchange rate of course) but one dime was split into a Peso and a penny. The Peso would be the equivalent of getting work done... you have less US currency than before because you converted some into a Peso - like converting the heat of combustion in your car's engine into mechanical work.

There's not as much heat at the end of the reaction as there would have been if it weren't being redirected into mechanical work. That mechanical work is like the Peso in the previous example.

Free energy would be like putting a dollar bill into a change machine and getting 4 quarters and one Peso. You could take the quarters, get another dollar bill for them, and put it back in the machine to get another 4 quarters + 1 Peso. If you repeat this enough times, you could earn limitless money, or at least until the machine ran out of quarters and Pesos.

This violates the laws of physics as we know them. Even if such a thing were demonstrated, I would maintain that it is coming from SOMEWHERE - even if that somewhere is from another dimension not in our universe. It would mean that our universe is not an isolated closed system, at least thermodynamically.

Answer 3

Free energy is energy that is available to do work. In chemistry, it is given the symbol ΔG (technically meaning "change in free energy"). If a chemical reaction releases free energy, then ΔG has a negative value and the reaction occurs spontaneously. If ΔG has a positive value for a particular reaction, then the reaction does not occur spontaneously. That doesn't mean that the reaction cannot occur at all, though. A non-spontaneous reaction can occur if it's coupled with a spontaneous reaction, just as long as the SUM of their free energy changes is negative.

Answer 4

Free energy, as in static electricity? As in a lightning bolt?