studiot

I'm not sure I understand what you are getting at here. Surely solenoids are beyond grade 10 ? Yes as the length of wire making the solenoid increases so will the resistance (I think that is grade 10) but the resistance of winding wire in any coil is generally insignificant compared to the magnetic effect causing an opposition to change of current, which is called reactance. I don't think reactance comes into it until later grades, but I will explain if you wish. Swansont mentioned that each turn or loop of the coil adds to this effect so the number of coils is significant. This is rather like (but not exactly the same as) the force that can be generated by a pressure depends upon the area the pressure acts over. The larger the area the greater the force a given pressure will generate. You have probably done something like this in mechanics with say the principle of the hydraulic lift

Perhaps I did not state my case very clearly. I was just trying to point out the illogicality of stating that a device which cannot increase in temperature needs any form of cooling, which was matthew's proposal not mine. It has always been my case that in fact the device must increase in temperature, unless something is actively done to cool it. Of course any such active cooling automatically becomes part of any thermodynamic system and should be included in any thermodynamic consideration. If the device needs cooling there must be an energy inflow promoting heating. But such would run contrary to the proposal that the device converts all energy input to electricity.

My mistake, apologies. I meant to say "But if you choose to define efficiency as the conversion of just radiation the correct frequency, then yes 100% conversion efficiency is theoretically possible." Consider a gambler at las Vegas who claimed he could beat the system. So he put a dime into the slot, pulled the handle and out came a dollar. Hey this has a 1000% efficiency he says. Now applying that to radiation say you fired one photon at a time at the photocell and got a small burst of current as a result. After the first photon converted, you could say that is 100% conversion efficiency. Assumed maybe, but not stated in your description. It doesn't matter since a photocell that does not absorb heat will not need to be 'held at temperature'. However you are still allowing the hot object to radiate sort of according to the the laws of Physics, but disallowing the cold object (photocell) from doing the same thing.

You will go far with your approach +1 I agree with swansont, it's not a waste.

You can't pick and choose which Physics Laws you will allow to operate and which you will suspend. (That could be a subject for speculation, but this is Modern and Theoretical Physics) The best you can do is to show that the effect of the Law you wish to suspend is insignificant. Then you can ignore it. But you have not done this. All objects will heat up if placed near to an object at a higher temperature. They will also radiate heat in their own right, something you originally ignored. I have already said that there are different definitions of 'efficiency', stemming from the basic one. And you are still ignoring that. I also said that two such measures are absorbtivity and emissivity, that you are ignoring. 100% absorbtivity is a theoretical possibility. But 100% absorbtivity does not make for 100% conversion. Swansont has already told you that any conversion cell can only convert certain frequencies by virtue of the only available conversion mechanism. Energy at all other frequencies emitted by the emitter and absorbed by the cell will be converted to - heat. But if you choose to define efficiency as the conversion of just radiation the correct frequency, then yes 100% conversion efficiency is possible. But as Swansont has said several times and I have now pointed out, Thermodynamics requires there to be a frequency spread of the radiation from a body at 1000oK. Since this effect is highly significant at this temperature, it cannot be ignored. Swansont also said That is why there is a Physics Quantity known as 'the work function'. https://en.wikipedia.org/wiki/Work_function This is also linked to what is known as the threshold frequency, below which any radiation from the emitter could not generate electricity. And we have already noted that Thermodynamics requires some of these lower frequencies to be present. https://www.electrical4u.com/work-function/

Well of course an unconnected battery is a simple example of a voltage without a current. That was the easy one. So a current is a coordinated movement of charge. That can occur if the charge carriers are moved by something that affects their other material properties (remember I said they were all material ?). Since they all have mass, some force that can move their mass and they wil take their charge with them. For instance a thermal current, or a photocurrent in suitable electronic devices can be observed to flow when there is no voltage supply connected. A particularly interesting example employs Newton's Laws of dynamics to light up the screens of old fashioned cathode ray tubes. Here the electrons are initially accelerated by a voltage, but then they pass beyond the electric field and move under Newton's First Law until they hit the phosphor to make it glow.

So it is not then a possibility.

When you have two opposing forces clearly the stronger one will 'win', regardless of how the forces are generated. The Magdeburg Hemispheres is a famous experiment to demonstrate this. https://en.wikipedia.org/wiki/Magdeburg_hemispheres Clearly the atmouspheric pressure force will win until Guerike harnesses enough horses. Then the horses will win. Similarly a given gravitational force can be stronger than, weaker than or even equal to a given electromagnetic force.

I have never heard such rubbish. When I was in primary school we did an experiment where we laid out different colour objects in the sunshine and measured their respective temperatures after a few hours. Even at the age of 9 I knew your statement to be wrong.

If you start from basics you would not make statements such as this Basics. 1) Heat flows from a hotter body to a colder one. This is non negotiable. 2) General possible modes of heat transfer are:- Convection, conduction, radiation. Radiation is the appropriate mode in this case, although since you have not properly described your system, you have not excluded the other two.

I was afraid this was another back door attempt to introduce religious dogma. It seems my fears were justified. Have you not heard of feedback and feedforward systems ?

No I am sorry if I did not make this clear. I think your youtube demonstration is a hoax or fake. We have discussed such demonstrations here before, if anyone can remember the reference. Hidden under the table or behind the background screen will be a generator of a changing magnetic field. The magnets you see are just showmanship.

This is not a thermodynamic model of this It is simply a discussion of one of the three participants in your proposed process. You have a temperature difference of 700oK. Why would it not increase ? It is just plain wrong to suggest that then photcell is neither an emitter nor an absorber of radiation. There is no electric circuit described in your opening post or your thermal model. Forget exergy, entropy and go back to basics. If you start from there you might be able to come up with something sensible.

The internet is a wonderful resource. Unfortunately there are those souls who take delight in posting misinformation. Youtube hosts some really good videos of science and scientific explanations. Sadly it is also a target for hoaxes like this sounds to be. The 'bulb' is commonly a flourescent bulb, not an old fashioned filament or more modern LED type.

Whilst we are on the subject here is a question for you to think about. It is often thought that you cannot have a current without a voltage or a voltage without a current, but you can have either situation. Can you give an example of either or both cases, you should be familiar with at least one of them.

Glad to help, come back if you want more detail.

Yes 'beating carnot efficiency' is not appropriate or meaningful in this case +1 @Matthew99FYI Efficiency is defined as as output divided by input expressed either as a fraction or percentage. Nothing in the basic definition refers to energy, although the ratio quantity most often used is indeed energy. It is therefore important to always qualify a statement of efficiency by an explicit statement of the quantity or property measured. For the three processes you describe, the appropriate terms are emissivity, absorbtivity, and conversion efficiency. Google will help if you do not know what these mean. Carnot efficiency refers specifically to a cyclic process in which a working fluid is taken round a (thermodynamic) cycle from one state to another ..to another.. and finally returned to its original state. In the process energy is taken form a heat reservoir at one temperature and a different quantity of energy is added to a different reservoir. Heat reservoirs do not change temperature during this process, which is why I asked about the photocell heating up. Work is carried out as a result of this process. Entropy is not required to increase at every stage, only as a net result of one transit around the cycle. Your diagram shows reservoirs but no working fluid.

Good morning ans welcome, 10th grader. NO it is not dumb or magic to wonder about electricity. But electricity is a huge and very important subject. So you have to start somewhere, your teachers cannot tell it all to you at once. Since you mention the electron let me start there. Britannica puts is so well. The carrier of electric properties in matter. The basic electric quantity is electric charge. As far as we know electric charge is always attached to some particle of matter or another. Any particle of matter that has attached charge becomes a carrier of charge as it moves about. These particles could be electrons, protons, ions and are known as charged particles. Some are bigger than atoms (ions) some are smaller than atoms (electrons, protons). Atoms themselves are not charged, they are electrically neutral. Charge endows matter particles it is attached to with extra properties, that interact with matter's own mechanical properties. It also has some additional properties of its own. It is these properties that hold the sub atomic particles in atoms together and hold larger assemblies of atoms together as molecules. One of the special properties of charge is that there are two types of charge. We use the sign convention of positive for protons and negative for electrons and neutral (=no charge) for atoms. Ions can be positive or negative. I say sign convention because it is simply a way of distinguishing. It does not imply any special importance of one over the other. There are many such sign conventions in Science. Back to Britannica. A great deal of electrical theory was developed between about 1850 and 1900. As Britannica notes, the electron was not discovered until the end of that period. And the charge carried by the electron was not confirmed until 1910. So the electrical theory considered electricity as some sort of weightless fluid (they tried to weigh it) that could be transferred or flow from one body of matter to another. The flow of this fluid was called 'electric current' and supposed similar to currents of material in fluids like water. However this theory was shown to be inadequate and that there are, in fact, several types of electric current, even before the discovery of the electron. Nowadays we distinguish Direct Current which is made up of a flow of current carriers which could be electrons, protons or ions in solution. Alternating Current which is actually a flow of energy, no particles actually move anywhere though they could be said to move slightly backwards and forwards. Does this start to answer you questions ?

I should like to see a proper thermodynamic workup of what you mean by this. What is your working 'fluid' ? What is your working cycle and how is the working fluid recycled ? Why does the photocell temperature not increase ?

🤣 Thank you for that word, I must remember it in future as too many find unsubstantiated too much to chew on. +1

Remember 'no equal' also applies to the rabbit at the bottom of heap as well as the dog at the top.

Congratulations to the moderators/administrators for vaccinating ScienceForums against cranks. Today's clearout provides evidence of > 90% success against all cranks and 100% against 'anti-vaxxers'

But I could have written those numbers in a different order; the set would still have been the same. It has no centre. That is the point. It should be noted that it is also a representation if used to illustrate properties of the universe since it only shares some properties with whatever manifold the universe actually is.

It's a good job that Science does not follow those Greek Philosophers (Plato) who believed that we should adopt as groundwork our imaginary notion of perfectionand claim it is the universe's fault if our observations do not follow our imaginings.

Where is the 'centre' of my example set ?