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Frederick The Monk
154036.  Tue Mar 06, 2007 5:36 am Reply with quote

Question: How do you make a monk jump?

Forfeits: Creep up behind him

Answer: Attach him to a Leyden Jar. That's how Antoine de Nollet proved that electricity travels 'almost instantaneously'.

Notes:
Jean-Antoine Nollet, known as abbé Nollet was a clergyman with more of an interest in science and experimentation than in God. As such he was appointed Preceptor in Natural philosophy to the family of Louis XV of France. His job was to develop his theories and produce demonstrations to explain them. In 1745 he developed the theory of electrical attraction and repulsion which he thought came from there being two types of electricity – positive and negative - which brought him into direct conflict with the ideas of founding father of the USA and extreme kite flyer Benjamin Franklin.

Nollet's experiments used the latest electrical apparatus of the day, a jar that could be used to store electric charge, invented by Pieter van Musschenbroek. As he came from Leyden, Nollet christened this the 'Leyden jar'. With a Leyden Jar Nollet could experiement with electrical current to see how fat it moved and how it affected things it passed through. In his most famous experiment he wished to demonstrate that electrical charge passes through a conductor almost instantaeously - but how to do it?

Nollet came up with a great wheeze - get 200 monks from the Grand Carthusian Convent in Paris to stand in a line, about 25 feet apart. Then link the line of monks together by getting then to hold iron wires between them, making a monkish daisy chain. Without telling them what was happening he then attached the monk at one end of the line to a series of Leyden Jars which discharged a few hundred Volts through the line. The shock made all the monks jump, curse and shout at the same time hence proving his point..

 
dr.bob
154039.  Tue Mar 06, 2007 5:54 am Reply with quote

I'm not entirely convinced that it would have made all the monks jump.

They did a similar experiment on Brainiac with about 6 people standing in a line. The one at the end held on to an electric fence (of the kind used to control livestock). When the electric fence was activated, the person nearest got a huge shock. However, as they progressed along the line, the shock became progressively reduced until the last person or two hardly felt anything.

This, of course, was due to the current being earthed by the first people in the line. They then repeated the experiment with all but the last person standing on insulating material. This time nobody felt anything apart from the last person in the line who got the full force of the shock.

I can't believe that Nollet would have been able to get an electrical charge to travel along two hundred monks unless most of them were insulated (in which case they'd feel nothing) or the first person was subjected to a charge strong enough to fry him instantly.

 
eggshaped
154067.  Tue Mar 06, 2007 6:58 am Reply with quote

Fred, this is an excellent point, don't you think? It hadn't occurred to me, but I must admit that the experiment now sounds implausible.

anyway, here's a story telling that China is now treating people it perceives as "internet addicts" with electric shock treatment.

 
MatC
154136.  Tue Mar 06, 2007 7:52 am Reply with quote

Via their keyboards?

 
Frederick The Monk
154203.  Tue Mar 06, 2007 9:32 am Reply with quote

eggshaped wrote:
Fred, this is an excellent point, don't you think? It hadn't occurred to me, but I must admit that the experiment now sounds implausible.


It might sound implausible but it appears to be quite well documented. Both Simon Schaffer and Dr. D. Allan Bromley (Yale's Sterling Professor of the Sciences) quote it. The original description of the experiment is in Nollet's own Recherches sur les causes particulières des phénomènes électriques, et sur les effets nuisibles ou avantageux qu'on peut en attendre and his demonstrations were carried out in pulbic. I'm just looking to se eif I can find an indepedent witness to one of these.

The story does appear in several forms however , the differences relating to how the monks are arranged and perhaps this might affect the result. I'n no monastic electrician but perhaps Dr Bob can explain if any of the following arrangements would make a difference to the result.

1 - Monks are standing in a line each connected to the next by an iron wire

2 - Monks are standing in a cirle, each connected to the next by an iron wire

3 - Monks are standing in a line each holding onto a continuous iron wire

4 - Monks are standing in a circle, each holding onto a continuous iron wire

 
dr.bob
154210.  Tue Mar 06, 2007 9:43 am Reply with quote

I could imagine that holding a continuous iron wire would make a difference.

If the wire only connects one monk to the next, then the electricity will have to travel through the monk. Not only does a monk have quite a high resistance (what, you've never measured the ohm rating of a monk?), causing a voltage drop across his body, but also some of the electricity will also leak to earth through his feet, adding to the drop in voltage. This is why, in the brainiac experiment, the person at the end of the line felt nothing.

However, if you have an unbroken wire linking all the monks, then things are rather different. There will be minimal voltage drop across the wire due to its low resistance. Thus, all the monks will experience essentially the same voltage between their hands and their feet, and all will receive an equal shock.

So I'd believe the story a lot more if either 3 or 4 described the experiment in question.

 
Frederick The Monk
154219.  Tue Mar 06, 2007 9:51 am Reply with quote

Thank you Dr Bob - I knew I could rely on you. That would certainly explain it.

Would it make any difference if the monks were in a line or formed a circuit?

I'd better go and see if I can find a copy of Recherches sur les causes particulières des phénomènes électriques, et sur les effets nuisibles ou avantageux qu'on peut en attendre.

 
Flash
154237.  Tue Mar 06, 2007 10:13 am Reply with quote

Facsimile text here: http://cnum.cnam.fr/DET/12CA21.html.

Allez-y!

 
dr.bob
154256.  Tue Mar 06, 2007 11:08 am Reply with quote

Frederick The Monk wrote:
Would it make any difference if the monks were in a line or formed a circuit?


I don't think it would make any difference.

To my mind the electricity is travelling along the wire. It's also travelling through the monks, and ending up going to earth (as electricity tends to do).

The wire will be at a voltage supplied by the Leyden jar. Since the wire is of low resistance, there will be a negligible drop in voltage along the wire even if the monks were in a line. The voltage change would then be across the monks. Since all their feet are touching the earth (zero voltage) and all their hands are touching the wire (effectively equal voltage due to low resistance of the wire), all the monks would experience the same charge through them whether they were in a line or forming a circuit.

An interesting question is what happens to the electricity when it goes to earth. Does it just vanish? Well, it turns out that the Earth itself is basically one huge spherical capacitor. Capacitance is a measure of the amount of charge required to raise the voltage of something by one volt. The aforementioned Leyden jar is a capacitor and so, it turns out, is the earth.

I recall in A-level physics it was possible to work out the capacitance of the Earth. It turns out to be not that high: only 700 micro farads. Or the same as one of these:

http://tinyurl.com/27bhlu

Possible interesting question: Stephen holds up a 700uf capacitor and asks what it has in common with the Earth?

I believe the earth remains charge neutral just because statistically there are as many positive charges being "earthed" as negative ones. It's possible that we could persuade everyone in the world to only earth positive charges and thereby charge up the earth. I'm not sure what that you do to electronics that need to be earthed, though :)

 
MatC
156447.  Wed Mar 14, 2007 8:21 am Reply with quote

“Electric cigarettes” - better for your health, and “no matches required”!

- http://hometown.aol.com/cigpack/page6.html

 
eggshaped
156448.  Wed Mar 14, 2007 8:22 am Reply with quote

From that link:

Quote:
"no nicotine can be taken into the system while smoking these cigarettes".


I've never smoked, but surely this defeats the object somewhat?

 
MatC
156452.  Wed Mar 14, 2007 8:28 am Reply with quote

It would certainly defeat one of the objects, yes!

 
MatC
156519.  Wed Mar 14, 2007 11:46 am Reply with quote

The Etruscans were very keen on lightning for divinatory purposes.

The Roman Philosopher Seneca summarized the Etruscans’ beliefs:
"Whereas we (the Romans) believe lightning to be released as a result of the collision of the clouds, they (the Etruscans) believe that the clouds collide so as to release lightning, for as they attribute all to the deity, they are led to believe not that things have a meaning in so far as they occur, but rather that they occur because they must have a meaning."

- http://www.domspe.org/etruscans/obsession.html

 
Jenny
157235.  Fri Mar 16, 2007 6:01 pm Reply with quote

When Gladstone met Michael Faraday, he asked him whether his work on electricity would be of any use. "Yes, sir" remarked Faraday with prescience, "One day you will tax it." .

Margaret Thatcher, The Path to Power, Harper Collins,1995, p176

 
Vitali
158394.  Wed Mar 21, 2007 12:20 pm Reply with quote

As promised last Monday:

Work No.227: "The lights going on and off", manipulating the gallery's existing light fittings in a room to create an unexpected effect, by Martin Creed won the Turner prize in 2001.

www.tate.co.uk

Can lead to some interesting visual effects during the show...

 

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