Why 'Free Energy' Will Never Work

[monksod]

Isn't gravity continuous ie keeps applying force forever? What about planets & moons? They don't need constant jet thrusts to keep them in stable orbits, like artificial satellites. Isn't gravity free energy? Of course... how do we harness it... 

[Zero999]

Isn't gravity continuous ie keeps applying force forever? What about planets & moons? They don't need constant jet thrusts to keep them in stable orbits, like artificial satellites. Isn't gravity free energy? Of course... how do we harness it... 

No, it isn't an endless supply of energy.
http://en.wikipedia.org/wiki/Tidal_acceleration

[denelec]

Isn't gravity continuous ie keeps applying force forever? What about planets & moons? They don't need constant jet thrusts to keep them in stable orbits, like artificial satellites. Isn't gravity free energy? Of course... how do we harness it... 

Force and energy are two different things.

W = F x d   =>   Work (energy) = Force x distance

That why you can't extract infinite amount of energy from gravity or magnets.

[denelec]

However, the Star Trek reference has provoked a number of amusing comments. One board member pointed out in a PM that on a regular basis Cmdr Scott insisted to Capt Kirk that the laws of physics could not be broken, then at the end of the episode Lt Sulu flicked a switch and USS Enterprise zoomed off to the next planet at a speed faster than light.

Faster than light travel doesn't break the laws of physics.
http://en.wikipedia.org/wiki/Alcubierre_drive

So Star Trek is still a reasonable view of the future... 

[dannyf]

Isn't gravity free energy?

High school level physics can answer that question.

[Scotophor]

It never ends.  I just saw this on another board and it is new to me..... Gravity Generator
As follows:

3 arms made out of rods at 120 degree with each other in a vertical plane(in wind mill they have the blades).
These arms shall be fitted with 3 heavy balls at their ends (calculations needs to be done to derive their weight).
Once put in rotation it starts rotating at its own. (Of course there will be a retardation in motion due to
i) system inertia
ii) frictional loss and
iii) air resistance)
There is a small motor coupled to the shaft of this GRAVITY GENERATOR which is given pulse after each rotation(derived from the generated power). This input power is just sufficient to overcome the 3 types losses mentioned above. The NETT power available is the usable power.

So, taken to its simplest form, turning a wheel by using a motor to overcome losses = free energy?

[miguelvp]

Isn't gravity free energy?

High school level physics can answer that question.

Hydroelectric is based in gravity to produce energy, but it needs solar to evaporate the water and wind (solar based as well) to distribute the clouds so that it rains again in the mountains so it keeps the rivers flowing.

But it's not free because someone must build and maintain the turbines, generators and the grid in general; and for that you need materials and energy to build them.

But nature is for all purposes a self running system. But this is just a simplistic view of a very complex system that it's self regulating by nature.

[zapta]

Isn't gravity continuous ie keeps applying force forever?

Yes, it is. Free energy for lifetime is a very simple matter. Take two rocks, A and B, lift rock A and place it on B. Now rock B has energy forever.

More details here http://en.wikipedia.org/wiki/Potential_energy

[Gall]

The things get even more interesting...

It is quite easy to make semi-perpetual motion without any obvious sources of energy. I can make this with Nd supermagnets. The idea is, make things move by slowly consuming the potential energy of the magnet. The magnet acts like a battery and is degaussing slowly. The energy is not really free of course, it's the energy that was necessary to produce the magnet. Many electromagnetic "free energy generators" DO work and DO charge their batteries, but the energy is not really FREE.

[HighVoltage]

I read an older physics book from the early 1900th and the physics professor who wrote that book, claimed that "everything" in physics had been discovered.

Well, history teaches us, that we as a human race have been wrong before on almost all aspects of physics and chemistry. Many times we had to replace and extend our knowledge beyond our believe system. Why should this be over now. Hopefully we will get some good surprises in the future. I would expect something great to happen in the field of energy conversion. Not the stupid pseudo science new age stuff that we read about almost everywhere, no, some real science based new development. 

[max_torque]

Contrary to popular belief, the principal issue with "free energy" is nothing to do with science and engineering, and everything to do with Economics.  In fact, the concept of "free" in monetary  terms simply does not exist.  IE everything you do has a cost, even if that is sitting in front of the telly (because you could be using that same time to actively earn money, and hence, sitting doing nothing is "costing" you, and hence not free!)

So, even if you make a system that can somehow capture energy, even if you make it from parts you found in a dumpster (i'm think of you here Dave ;-) then it has cost you time. Time which you could have used to earn some money to simply buy that energy from another source.   So, the real crux of the matter becomes the ratio of cost to reward, no matter if that cost is actual money or your time.  Hence, these so called "free energy" systems that seem to harvest tiny amounts of power, are actually nothing like free.
  In fact, they make Grid power, generated by electricity companies look incredibly good value.  I mean, here in the UK, i can buy a kWHr of electricity for something like £0.12.

 Imagine trying to generate that yourself?  Here's an example:

On my bike at can manage to output around 150W continuously, but it's extremely hard work.  To generate 1kWhr, i'd have to sit on my bike (with a alternator attached) and even at some mythical 100% efficiency, pedal like mad for 6hrs 39 min to generate that!  And let me tell you, NO WAY would i do that for just 12pence........  ;-)

[zapta]

On my bike at can manage to output around 150W continuously, but it's extremely hard work.  To generate 1kWhr, i'd have to sit on my bike (with a alternator attached) and even at some mythical 100% efficiency, pedal like mad for 6hrs 39 min to generate that!  And let me tell you, NO WAY would i do that for just 12pence........  ;-)

You will also need to eat more to cover the lost calories, especially if you do it daily and then the initial investment and wear and tear of your contraption.

[Zero999]

On my bike at can manage to output around 150W continuously, but it's extremely hard work.  To generate 1kWhr, i'd have to sit on my bike (with a alternator attached) and even at some mythical 100% efficiency, pedal like mad for 6hrs 39 min to generate that!  And let me tell you, NO WAY would i do that for just 12pence........  ;-)

You will also need to eat more to cover the lost calories, especially if you do it daily and then the initial investment and wear and tear of your contraption.

Yes, the extra food (over 3300kCal extra calories per day on top of what you already need) will cost more than that the power you'd save and cost the earth more too. Such a level of exercise is also bad for your health and you need to be careful to avoid malnutrition too.

[dannyf]

he physics professor who wrote that book, claimed that "everything" in physics had been discovered.

That "professor" is making a religion out of science.

Just like our global warming nuts,

[Gall]

I read an older physics book from the early 1900th and the physics professor who wrote that book, claimed that "everything" in physics had been discovered.

Well, history teaches us, that we as a human race have been wrong before on almost all aspects of physics and chemistry. Many times we had to replace and extend our knowledge beyond our believe system. Why should this be over now. Hopefully we will get some good surprises in the future. I would expect something great to happen in the field of energy conversion. Not the stupid pseudo science new age stuff that we read about almost everywhere, no, some real science based new development.

The professor had right... to some point.

It is true that everything at certain technology level is discovered (almost always). That means, in early 1900s everything was discovered in the fields of mechanics, electricity and optics. Newer discoveries have been made in the fields of nuclear amd solid state physics. The same is still true now: everything is discovered in most "usual" physical fields, and all things that are still unknown are nearly inaccessible at our present technical level. Everything is discovered in the range of distances between size of an atom and size of the Earth, in the range of energies up to 10s of GeV and in the range of speeds from picoseconds to many years. All things that are not yet discovered reside outside of these ranges, i.e. in deep space or at extremely high energies.

This means that there is no single combination of usual things like electronic or mechanical components that violate the known laws of physics, unless these things are extremely large (larger than the Earth) or produce very high energies (higher than the LHC). You may however discover new laws by watching natural large objects like stars, as they are large enough to go beyond our "everything-is-discovered" range.

[Mechatrommer]

It is true that everything at certain technology level is discovered (almost always).

it was believed atom is indivisible. now everything of that belief deserve to be in the dustbin, or what they have discovered sometime ago was rubbish, no?

You do not see in the creation ... any inconsistency. So return [your] vision [to the sky]; do you see any breaks? ... Then return [your] vision twice again. [Your] vision will return to you humbled while it is fatigued.

[Jeroen3]

We are only starting to discover what single-atom layers of graphite (and other stuff) can do.
And we are almost out of Moore's law, of which I'm sure we'll be able to supersede if we change our conservative view on the problem.
Meanwhile we have to wait for that one smart guy with an epiphany.

[Gall]

It is true that everything at certain technology level is discovered (almost always).

it was believed atom is indivisible. now everything of that belief deserve to be in the dustbin, or what they have discovered sometime ago was rubbish, no?

No, it wasn't. It was believed to be indivisible by chemical means, but this is still true.

Every physics law has certain limits of validity. Every law is absolutely correct within these limits. We don't know what's beyond the limits of the known laws of physics but we know exactly what the limits are. This is like a geographical map: we don't know what's outside the area we've explored so far, but we know exactly how much we've explored, and we know exactly that the existing part of the map will not be affected by any future explorations. New laws of physics do NOT make old discoveries rubbish. They just adhere to the borders.

[Gall]

We are only starting to discover what single-atom layers of graphite (and other stuff) can do.

But this is not new! This has nothing to deal with new laws of physics. All the properties of graphene are fully predictable from the laws of quantum mechanics. The same laws predict the impossibility of "free energy" and many other interesting things like superconductivity.

[miguelvp]

Well, they didn't know that gravity affects time so all those formulas they had are just approximations.

[dannyf]

Every law is absolutely correct within these limits.

Probably not. You should view such 'laws' as approximation to what we observe. "Approximation" means two things here:

1) fitness is part of our judgment: new theories tend to find more observations better.
2) fitness also means you could have co-existence of multiple theories, sometimes incompatible with each other.

we know exactly what the limits are.

Probably not.

[Gall]

Every law is absolutely correct within these limits.

Probably not. You should view such 'laws' as approximation to what we observe. "Approximation" means two things here:

1) fitness is part of our judgment: new theories tend to find more observations better.

Not so. The accuracy IS one of the limits. Each physical law sounds like: "If the value of X lies between Xmin and Xmax, then Y could be determined by the equation Y=Y(X)  with at least dY accuracy."

2) fitness also means you could have co-existence of multiple theories, sometimes incompatible with each other.

That is incorrect. There is no incompatibility at all. In the area where several theories co-exist, they all give exactly the same predictions, just with varying accuracy. For example, the theory of relativity predicts all the effects of classical mechanics, as well as wave optics predicts all the effects of geometrical optics. This fact is widely used to check new theories, as all old theories are well-proven within certain limits. There are absolutely no incompatibilities between the proven 19th century theories and the modern ones. (We do not take into account the old hypotheses that had no proof at all, like the hypothese of phlogiston).

we know exactly what the limits are.

Probably not.

Believe me, we do. This is one of the most important things in a proof of any new theory. And that's what I learned to do for 10 years. 99% of the modern physics is about determining the exact limits. We are very careful about this. If unsure, we always take the worst case. But even the pessimistic case of modern physics covers everything one could build without very special equipment like high vacuum pumps or gigawatt power sources.

[Dave Turner]

If we as as the human race ever truly believe that we know everything then comes the question - why bother!

I prefer to believe that there is, and always will be, more to learn about 'Physics'

It is, in fact, dangerous to believe anything different. Galileo, amongst others, could have told you about that! Yes I do know that his persecution was for religious reasons. Religious! In an ideal world one should be able to challenge the status quo. In our world it takes money to challenge the scientific establishment. Possibly another word for religion these days?

I choose to be open minded, work with what I can and prey for a Cochrane or similar.

[dannyf]

they all give exactly the same predictions, just with varying accuracy.

Sounds like the socialist saying: "we are all equal, except that some of us are more equal than others",

True and profound,

[Rick Law]

Hmmm...  This sounds too much fun to not put in my two cents worth.

First, I think we are all in agreement that from a monetary sense, energy that doesn't cost money is a pipe dream.

Second, free energy (in the sense of breaking the first law of thermodynamic: i.e. law of conservation of energy) could be possible but harnessing it may not be possible.  Vacuum energy, if extractable, would indeed be energy free from the law of conservation of energy.  Steven Hawkings' theory on Black Hole evaporation is well accepted.  If black holes can do it, we may be able to do so as well.

Basically, quantum mechanics allows for "borrowing from nature."  Particle & anti-particle pair can "randomly appear" and then annihilate themselves.  If we can some how create something that behaves like a black hole and captures the anti-particle before it annihilates the normal particle, we can some how use that anti-particle to generate energy later.  While capturing the anti-particle, we would emit Hawking's Radiation.  Hawking's Radiation would also be "free energy" if we can harnessed some how.

One theory of the source of The Big Bang is such randomly appearing kernel of energy.  Assuming the "random kernel of energy" is correct, it follows that the whole universe is running on borrowed energy.

Someday, perhaps physics may find the borrowed energy (in this universe) actually come from some yet to be found phenomenon (in this universe).  Until such time, such "randomly occurring kernel of energy" giving me "an anti-particle for later use "would be by today's laws of physics "free".

they all give exactly the same predictions, just with varying accuracy.

Sounds like the socialist saying: "we are all equal, except that some of us are more equal than others",

True and profound,

Lastly, I think "we are all equal, except that some of us are more equal than others" is not a socialist saying, but instead it is a saying about the socialist and socialism originated by George Orwell, Animal Farm, seventh commandment.

Rick