Talk:Electricity
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"there is a force between these charges that is directly proportional to the magnitude of the charge of the objects and inversely proportional to distance between them."
Is that correct? Should it not rather be " ... and inversely proportional to the square of the distance between them."?
The subsequent formula seems unnecessarily awkward.
S.
Can anyone remember reading a short science fiction story about someone who is granted a wish, and decides that the best way to solve the world's problems is to abolish electricity? Unfortunately he doesn't know that electricity is what holds atoms together. His wish is granted, and the universe falls apart. If I knew the name of this story, I would add a reference to it in this article. - Heron
- Perhaps, Electricity (Sci-fi) if it is long enough.
Hmm. I have to say this article is phenomenally America-centric. And pretty much glosses over everything before Ben Franklin, whose significance (on the other tentacle) to what followed, really is blown totally out of proportion. I mean, really! -- Cimon Avaro on a pogo-stick 20:08, Sep 19, 2003 (UTC)
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Removed from Current
Accuracy aside, the following 'graph does not belong in the section on Current. It may have some value elsewhere.
- It is often important, particularly for safety reasons, that one side of a circuit be electrically bonded to an earth terminal. Such an earth terminal is usually connected to an electrode buried in the ground. The potential of earth (ground) is defined as zero by convention, and the electrical conductivity between similarly buried electrodes is considered to be low enough that all earth terminals are effectively at the same voltage.
--Jerzy 01:35, 2003 Dec 12 (UTC)
Main focus of this article ??
Many of the pointers to this page seems to mean electricity in the meaning electrical energy. Perhaps there should be a separate article about electrical energy, with all relevant pointers so directed? -- Egil 07:46 Feb 7, 2003 (UTC)
If I had started this article, I would have made it a disambiguation article with links to "electrical energy", "electrical power", "electric current", "electric charge" and all other electrical phenomena. The present article is about electric charge, so it could perhaps be merged with the article of that name. -- Heron
I believe this article should focus on the commonest meaning of electricity, i.e. electric current. One proof of this is to look at the articles that link to here: most take the "electric current" view. It should start with a disambiguation paragraph linking to other electrical phenomena. Pcarbonn 19:21, 5 Sep 2004 (UTC)
On the contrary, the commonest meaning of electricity is electrical energy. It is a widespread misconception that electric current is a form of energy. No, an Ampere is not a Joule. Just because many authors incorrectly give electric current the name "electricity" doesn't mean that reference works should support the error. In non-science topics, common usage *is* the correct usage, but in physics, a common misconception remains incorrect no matter how many people aquire that misconception. Physics books play by very different rules than dictionaries. ------- I agree that "Electricity" should become a disambiguation entry. In addition to articles on Electric Charge and Electrical Energy (etc.,) the present article can split off into an article about common misconceptions regarding the term Electricity. Because even the authors of many reference books have a fairly poor understanding of charge vs. energy, disambiguation becomes a proper topic for the science and education community, not just the usual Wikipedia issue. Wjbeaty 16:19 Dec 27, 2004 (PST)
How electricity kills
Electricity kills in either of these ways:
- Current of at least 50 miliamps passing through the heart can cause it to stop. To get 50ma to the heart, there must be sufficent voltage to overcome the body's natural resistance.
- The body's natural resistance can cause it to absorb the electricity and convert it to heat. Given enough power, this heat will cause the body to cook. For this, it does not matter if it is low voltage or low power, as long as the product of the two is high enough for the power to heat the body faster than it can dissipate the generated heat.
As stated in the main article, Ohm's law gives the relationship between current, voltage, and resistance. When resitsance is present, both current and voltage must be non-zero for the other to exist. Power is the product of current and voltage. --ssd 20:08, 13 Mar 2005 (UTC)
I've tried to explain it to you, if you are not interested then too bad. Voltage DOES NOT EXIST in a physical manner, it is simply the difference of potential between two points.
- That's silly. I can measure it, it exists. No, it isn't a physical substance. I can't see voltage. I can't see current. I can't see wind either, does it not exist either? Voltage, as you say, is the electrical potential between two points. If there is no potential, there will not be any current either. Neither current nor voltage alone are sufficent to describe electricity. Both must be considered. If voltage was not important, Ohm's law would also not be important. I suppose you could argue that given <math>V = I R<math> you have two independent variables and one dependent variable. However, which one you pick for the dependent variable is really just a matter of semantics or point of view. --ssd 20:22, 13 Mar 2005 (UTC)
You are misunderstanding what I am saying. When you pull out your voltmeter, you are not actually measuring voltage - you are measuring the DIFFERENCE in "pressure" between two points. In a wye connected system, for example, if your line voltage was 480v, your phase voltage would be 277v.(480/1.732, or the root of three). Now measure from phase to phase, and what would you have? exactly. --Vega007
By the way, no disrespect, but you CAN see current when it is arcing and sparking. Are you an electrician like myself or just an educated observer?
- When you see arcing, you are seeing voltage high enough to ionize the air and form a conductive path. If it is high current, the arc lasts longer and is thicker. If it is low current, you will see short lived thin arcs that will reoccur as the voltage becomes high enough for a new arc. (Technically, you don't see current or voltage, you see photons, but that's just being pedantic.) --ssd 05:32, 16 Mar 2005 (UTC)
- Voltage is a relative difference between two points. If you want to say that a single point has a voltage, then you have to choose a single reference point for the circuit, and you are implying a measurement relative to that point. That point is called ground. Although there are conventions for which point you call ground, you could technically define any point in the circuit as 0 V and measure all other points relative to it. - Omegatron 00:55, Mar 14, 2005 (UTC)
I agree mostly with everything now here. A couple of fine points... Everything Omegatron said about voltage is exactly correct. However, when I think of voltage, I think of a power source. When I think of voltage from a power source, I think transmission line, which has (at least) two wires, and thus two points of reference from which to measure. If you grabbed those two with one hand, you'd be burned. If you grab one in each hand, there's a good chance voltage (and current) will pass through your body, and thus through your heart. For those purists that say "voltage does not exist, only current matters", I'd like to remind them that only ideal power sources can supply infinite voltage when met with high resistance, where a real power source won't get sufficent current through to matter if it can't supply the needed voltage. Likewise, the real power source when faced with zero resistance can't supply infinite current to keep voltage constant. Thus, all real power supplies have a maximum voltage and maximum current rating, and even if they are constant current (rare except battery chargers) or constant voltage (most are), when the maximum voltage or maximum current is surpassed, it will be unable to keep the other from sagging. This is why both ratings are important. It is thus incorrect to say only current or only voltage is important. This was my original point, more correctly stated.
(These incremental changes from discussion like this I like to think make points clearer and help all parties see their errors and fuzzy thinking. Some of this probably should be integrated into a relevant article once it's all correct. --ssd)
Proposed focus
I was surprised to see how the focus of the article changes rapidly as you read into it. I'd suggest putting all the electric power discusions as links to those articles, and leaving "electricity" as more of a discussion of the fundamental physics. Static charge, dynamic charge, all the pith-ball-and-compass-needle history, etc. - and leave applications to other articles. --Wtshymanski 22:38, 16 May 2005 (UTC)