A question for fluther's astro and quantum physicists: Is there a way to extract usable energy from quantum vacuum fluctuations?
First of all, of course, is to acknowledge that at its base state, energy can not be extracted because you can not go below the zero point of the energy level of empty space.
But, here is my question:
Would subjecting space to the intense gravitational effects of a black hole (which we might create artificially), cause a momentary density spike of these fluctuations (due to space being compressed), raising the energy level of empty space above the zero point, even if just for just a moment, so that then this small excess of energy could be harvested?
Observing members:
0
Composing members:
0
7 Answers
Great question. One theory of the origin of dark energy is that it’s from quantum fluctuations of zero point energy. I’ll check my sources though and get back to you.
Rather outside my area, but how would you create the black hole in the first place? How large would it need to be?
How about taking any convenient black hole, and simply harvesting the Hawking Radiation emitted by the quantum vacuum fluctuations of the empty space at its event horizon. Thus you can harvest the free energy of the black hole itself for a few trillion years before Hawking Radiation causes it to evaporate.
I just love the thought of “taking any convenient black hole” so much I had to suggest this. Imagine The Black Hole Cookbook beginning with that simple instructions, then listing ways to prepare delicious dishes cooked entirely with Hawking Radiation.
Doesn’t the second law of thermodynamics mean that you can’t get any more energy out of the black hole than what went into making it?
I think @ETpro has a good idea here. All we have to do is travel to the center of our galaxy, some 27,000±1,000 light-years from Earth, harvest the energy and ship it home.
Yes, you can extract energy from vacuum fluctuations. A classical example is the Casimir effect. In the experiment, the energy of the vacuum causes two small metallic plates to be attracted to each other. The amount of energy that can be extracted is ridiculously small, but non-zero.
Here is an answer from a physicist friend of mine.
My quick draw answer would be that you can evaporate small black holes due to vacuum pair product toon where the particles are on opposite sides of the event horizon. So you could retrieve the energy of the black hole back into normal space time. Not as clearing how many homes you could light that way.
On a larger scale, the fluctuations are random, so the energy would broadly fall under ‘heat’ as unorganized energy. Such can often be harnessed, though less often at full efficiency, particularly so when there isn’t a gradient to perch on – i.e. where the creek runs down a hill, on in between the high heat and low heat spots. Finding the gradient… There’s likely the rub.
Answer this question 
This question is in the General Section. Responses must be helpful and on-topic.
Composing members:
0
