Back to Work
This is a continuation of the series of Free Work essays. Thanks to Abd for reading and responding to the last one with the points he found unacceptable, and I hope I’ve fixed those points this time. It’s also a lot less words, since I’ve missed off the history of how I got to this point.
Mass is a fixed form of energy, and the two are connected by Einstein’s equation E=MC². I’ll generally use the term mass/energy when I need to refer to the “stuff” the world is made of.
KE is kinetic energy, which is energy of movement. Heat is random-directionality KE.
PE is potential energy, which is stored in a way that can be released.
KEWork is work that is done where the energy goes into kinetic energy of something.
PEWork is work that is done where the energy is stored in some way as potential energy in the system.
Displacement Work results in a different configuration of the system, but does not store any energy or use energy to do it.
The sum of mass, KE and PE is conserved. There is no Free Energy, and we have to use what we have. We normally convert the PE of mass into the KE of heat to power our world, but we’re also using renewables where we divert a flow of environmental energy (solar, wind, waves etc.) for our use.
Looking further, we can see that KEWork is actually just the kinetic energy in the object of interest (say, a car moving) and that similarly PEWork is just the PE embodied in the object of the work, for example a brick has moved from ground level to the top of the wall. The terms “energy” and “work” only serve to determine whether this is energy coming in to the process or energy going out of it. In Displacement work things are a different shape or format – if you’re shaping a lump of steel by hammering it there’s no change in mass or potential energy when it’s the right shape, and all the work hammering it has gone into KE as heat in the environment. Though we have to put energy in to change that shape, it is not stored in the thing itself. When we move something from one location to another, there may be a change of gravitational energy involved, but the energy that is not stored there all goes into friction (heat returned to the environment) or other losses (which also mostly end up as heat in the environment). Moving something from one place to another at the same gravitational potential takes no net energy at all – it’s Displacement work and all energy put into the work goes into the environment as heat. As usual, this is a generalisation, and moving a charged object in an electric field will also store or release energy, but here I’m just concentrating on the simple mechanics rather than covering all the possible variations.
When we do work, therefore, we change the locations of mass/energy in our world, and since mass/energy is conserved we have exactly the same amount of mass/energy at the end as we started with. It looks a bit pointless when it’s been logically reduced that far. However, that mass in a different location may be you arriving at work, or coming home again, so it is actually pretty important. If you start off from home in the morning and return there in the evening, then overall that is no net work done, but our lives wouldn’t work too well without it.
From an energy viewpoint, all the work we do is simply changing the configuration of mass/energy around, and there is no gain or loss. Work is simply the name we give to the output configuration of mass/energy.
In our normal experience, heat energy always spread out from its source until all things are at the same temperature. Hotter things cool down and colder things warm up, and heat energy moves from hotter to colder. In order to produce a local hot spot we need to put energy into it, and though we call that doing work it is simply moving energy to where we want it. Heat is transmitted in two main ways, conduction and radiation. Conduction is by physical collision of molecules or atoms, or through the bonds between them in a solid. Radiation is however a quantum process and is covered by the Stefan-Boltzmann law. A body will radiate in proportion to the 4th power of its absolute temperature, so at any temperature above absolute zero it will radiate photons and this does not depend on the environment it is in – it will happen no matter what.
Whereas we are taught that for a system in thermal equilibrium there is no heat transfer, the Stefan-Boltzmann law tells us that all of the bodies are radiating heat as EM waves. For any one of those bodies, to remain at the same temperature means that it is receiving exactly as much energy as it is radiating, and we know exactly what amount of energy it is radiating. We thus know the radiation density available in any bandwidth.
If you can accept that this statement is true, then the methods of converting that flow of energy into usable electricity will make sense. If you deny it, though, and say that no energy is being radiated in thermal equilibrium (some people do say that…), then you’ll encounter various logical problems in considering a system that is physically large (and you’ll also have problems believing that a thermal camera can work).
Any electromagnetic wave (EM wave) can be received and turned into an AC electrical wave by use of the correct size antenna. This AC can then be rectified into DC by use of a diode. The combination of an antenna and diode is known as a rectenna, and for the THz radiation of room-temperature IR it is very small and is thus known as a nantenna. Any IR in the right bandwidth that hits that nantenna will be converted at some efficiency (less than 100% but more likely in the 5-10% range) into an electrical output.
We’ve seen that at room temperature there is a continuous flow of IR energy, and with most objects having an emissivity of around 95% in this range it’s not far short of black-body intensity. If we put the nantenna into this environment it will generate power from the incident IR even if it starts off at the same temperature as everything else. We can connect the nantenna output to a load such as a resistor and the resistor will heat up. By any usual definition, this is doing work, and any other use of the electricity would likewise be work. Since the nantenna must now be radiating less IR than it receives, because by Conservation of Energy (CoE) some of the incident IR is being turned into electricity and so there is less to keep the nantenna warm, if we measure the temperature of the nantenna it will be lower than the environment. There is thus an obvious reason for heat energy to go into the nantenna array – it’s colder.
The nantenna is simply redirecting the incident random-direction photon energy as unidirectional electrical energy in the connecting wires. There are no losses of energy and no gains here (CoE again), but just energy going in a direction we choose rather than being in random directions.
We already know that most of the work we normally do will end up as heat in the environment, apart from what we store as PE in lifted weights, springs or batteries etc., so if we do work using the power from the nantenna then for most types of work the energy will return to the environment immediately which will thus remain at the same temperature. If we do PEWork, then that amount of energy will be retained for a while and returned later (maybe much later when the house falls down) and the environment will cool a bit. The amount of energy in the environment is however vast, being approximately the specific heat times the absolute temperature, and from the Sun we receive around 100 times as much as we currently use in total. This resource is practically inexhaustible.
What we have done here is to set up an energy loop:
Environmental heat => IR radiation => nantenna array => electricity => work in load => heat energy => environmental heat
Alternatively: random direction EM KE => unidirectional electrical KE => random direction thermal KE => random direction EM KE
where thermal KE is the temperature of the bodies as measured with a contact thermometer and EM KE is the electromagnetic radiation that that warm body will radiate according to the Stefan-Bolzmann law.
This loop will continue to work as long as the devices last. It doesn’t need fuel to keep running, since it is using the radiated energy in the environment and redirecting it.
Et Voila! Perpetual Motion!
If you wish to read a longer version of this that goes into more history, go to http://revolution-green.com/theory-perpetual-motion/
The irony is that Free Energy machines in the past have tried to produce energy from nothing, which is why they don’t work (energy is conserved). Using environmental energy, on the other hand, works because energy is conserved so you can’t lose it. All we need to do is to convert random energy to directional energy and we can use it again and again, and we already have devices that do that.