Joatmon

We seem to be making a meal out of Ohm's law. Put as simply as I can and assuming other factors like temperature remain constant it applies only to resistance (not inductance or capacitance). For any resistance in a circuit there will be a voltage across it (V volts) This voltage will drive a current through it (I amps) The resistance being considered can be called R ohms. The relationship between V, I and R is constant and usually stated R=V/I ohms. If you make V the subject of the calculation the formula can be changed to V=I*R volts. If you make I the subject of the calculation then I= V/R amps. Examples:- You measure the voltage across a resistor as 20V and you measure the current through it as 2A.The value of that resistor is 20/2 = 10 ohms. You know you have a resistor of 10 ohms and measure the current through it as 2A . The value of the voltage across it is 2*10 = 20V You know you have a resistor of 10 ohms and measure the voltage across it as 20V. the value of the current through it is 20/10 = 2A. However, going back to the original question it is unwise and generally of no value to use an ohmmeter in a live circuit which is why R=V/I can be very useful.

In the cathode ray tube (and other thermionic devices) particles with a negative charge travel through a vacuum towards a positive potential. I wonder what you might call these negatively charged particles? Electrons perhaps?

A couple of points. If the three fridges are working from one fused extension cord you should beware the following. When a fridge thermostat switches the compressor on there will be a short lasting heavy current drawn from the supply. If the three fridges switch their compressors on at the same time it is quite likely the extension cord fuse will blow. Most fridges will not work efficiently if the temperature of the environment is too low. This is because the pressurised refrigerant will not be vaporised by the action of the compressor. Because of changes in refrigerants in an attempt to reduce global warming the more modern refrigerators are more badly affected by low temperature environments. Domestic refrigerators are designed to work efficiently within the range of temperature expected within the home.

I think you will just be arguing about definitions. There are rules of logic for the quantum level and also rules of classical logic. However they can be different(IMO) http://en.wikipedia.org/wiki/Quantum_logic

Perhaps this isn't actually an answer to the thread. Also I haven't gone right through the thread, but make of these statistics what you will:- USA Gun deaths per 100,000 of the population = 0.1 (2009) GB ,, ,, ,, ,, ,, ,, ,, = 0.02 (2011) http://en.wikipedia.org/wiki/List_of_countries_by_firearm-related_death_rate

It is certainly possible to obtain energy from the rotation difference between the earth and the moon. Any system that uses tides to generate electricity does that.

I am the father of two girls and had what I assume to be the normal feelings of only wanting to protect them. However I understand that it is quite common for siblings who have been separated by adoption to feel sexually attracted to each other when they meet as adults. You might like to read:- http://en.wikipedia.org/wiki/Genetic_sexual_attraction

The news reader announced his death and he just couldn't disappoint the listeners

Over 50 years ago when I was a young airman we used to play a trick on the N.A.A.F.I. girls. We would fill a saucer with coffee dregs, roll up a small ball of paper, float it on the top, set the top of it alight and place the upside down cup over it. The coffee would be drawn up into the cup and then we would wait for the girl to clear the table!

There seems to be a sensible question here followed by some nonsense. The sensible question, or it seems sensible to me, is "Why does water in the form of vapour rise and how and why does it change into relatively heavy particles that fall?" The nonsense concerns it travelling through the earth and rascism.

The junction of two different metals can convert heat (say of the sun) into an electrical potential which would drive a current. Such an arrangement is known as a thermocouple. I don't know of the application providing useful amounts of power though. http://en.wikipedia.org/wiki/Thermocouple

Ok it's obvious that I haven't made my initial question completely clear. Let me try to make it clear. An atom consists of a nucleus and electrons but mostly space. How would you describe the space? Absolutely empty of anything (i.e. a vacuum) or in some other way?

I think you have probably not really understood the, admittedly, strangeness of my question. It really was if your atoms completely collapsed so that they occupied a very small volume, what would be outside that collapsed mass? To achieve this the electrons and the nucleus would have no space between them and so no similarity to a gas. (For example think of them having the same charge). I am happy with Spyman's idea.

Surely a pile of nuclei and electrons is different to a plasma?

I think we agree (see #5). I used the term "dust" as it was used previously. but this very thin layer of collapsed atoms would weigh so much that perhaps dust is not the best way to describe it. It seems then describing us as walking (near) vacuums is correct?

I tend to think that a vacuum would be expected, however unless in a weightless environment the very tiny amount of atom dust would weigh the same as you and rapidly fall to the floor.

I know the question is hypothetical, but would the container contain a vacuum? It seems that it should.

I was wondering about the bulk of the volume of an atom. If electrons stopped moving (whether particle or wave function) in the atoms of your body you would be the slightest layer of dust on the floor. If you were in a hermetically sealed container only just big enough to contain you and this hypothetical event happened would the container contain almost a vacuum or would it be full of air? Are you a walking vacuum or a walking bag of air?

Dinosaurs didn't do so well.

You ask "How did evolution get it right?" The fact is that it hasn't yet and never will, but it will keep on trying to find small improvements in its quest to "get things right".

As Spyman says you need a series resistor . However if you have 9V available you can buy what are advertised as 9V LED's. These have a resistor inside them that does the job. If you get these you can just connect them in parallel to your battery. LED's operate on DC and transformers operate on AC so I wouldn't go down that path.

Why do you want to rotate the rod? Is it connected to anything that has inertia or is expected to do work?