The motorists here tried to censor me again.
in [UK Drivers]
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From: boltar2003 on 6 Jul 2010 11:54 On Tue, 06 Jul 2010 16:32:19 +0100 Cynic <cynic_999(a)yahoo.co.uk> wrote: >>>A living tree is not, of course, an insulator. It contains ionised >>>water throughout and will readily pass an electric current. Dry wood > >>Ionised wood?????? > >No, ionised water. Or more precisely, water that contains ions. Try >reading more slowly. Yes, my mistake. Shouldn't skim read. >The water in the wood contains ions of dissolved substances which is >why it passes a current of electricity (the ions move rather than only Long dead trees also get struck. >in water. Non-ionised water (such as distilled water) is an insulator Not a particularly good one. I suggest peruse this page: http://en.wikipedia.org/wiki/Dielectric_strength >ignorant. It might even provide the basis of a possible mechanism >whereby water might retain a "memory" of things that were once >dissolved in it. Water is a pretty complex substance. >http://www.isis.stfc.ac.uk/science/chemistry/perturbation-of-water-structure-by >dissolved-ions-8338.html So what? Take the ions out and theres no electrical attraction to hold the structure in place and it breaks apart. No one has ever argued that water can't form structures WHEN THERES SOMETHING IN IT or when its losely bound to another substance. Thats how a long of chemistry works! What do you think hydrates are? However in homeopathic remedies theres nothing of the original toxin/substance left and so nothing to hold the water structure together any more. >>Next time you get an electric shock from a nylon carpet have a long think >>about which part of its molecular structure was altered. > >Perhaps *you* should have a long think about whether the nylon is >*conducting* electricity. If it *did* conduct electricity it would >not create a triboelectric buildup of static charge. It would if the charge wasn't great enough to flow through whatever the carpet was sitting on. Which is usually the case. Then you come along and touch something which is earthed such as a PC and zap. >>Yes , some materials heat up and break down before they start to conduct but >>its not a requirement. They'd end up conducting anyway. > >For many insulators it is definitely a requirement. No breakdown = no >current flow. Try again with a 10s of million volts and see what happens. Insulators on high tension power lines are rated for a certain voltage. Beyond that they're likely to fail. B2003
From: Paul on 6 Jul 2010 12:03 boltar2003(a)boltar.world wrote: > On Tue, 06 Jul 2010 16:37:20 +0100 > Derek Geldard <impex(a)miniac.demon.co.uk> wrote: >>>> What about an absolute vacuum ? >>> You think electrons can't traverse a vacuum? >>> How do you think a cathode ray tube works you dolt. >>> >> By what process does this happen ? > > Have you not heard of wikipedia? > Wikipedia is the process by which it happens? Learn something new every day!
From: Cynic on 6 Jul 2010 12:14 On Tue, 6 Jul 2010 15:54:58 +0000 (UTC), boltar2003(a)boltar.world wrote: >>ignorant. It might even provide the basis of a possible mechanism >>whereby water might retain a "memory" of things that were once >>dissolved in it. Water is a pretty complex substance. >>http://www.isis.stfc.ac.uk/science/chemistry/perturbation-of-water-structure-by >>dissolved-ions-8338.html > >So what? Take the ions out and theres no electrical attraction to hold the >structure in place and it breaks apart. No one has ever argued that water >can't form structures WHEN THERES SOMETHING IN IT or when its losely bound >to another substance. Thats how a long of chemistry works! What do you think >hydrates are? I said "form the basis of a possible mechanism". I am well aware that it would not of itself provide such an explanation. There are all sorts of remarkable facts about the properties of water, and as the article states, some of them unknown. Differences in molecular arrangements between one vial of water and another would not necessarily be able to be detected non-destructively by any method we have today. >>For many insulators it is definitely a requirement. No breakdown = no >>current flow. >Try again with a 10s of million volts and see what happens. Insulators on >high tension power lines are rated for a certain voltage. Beyond that they're >likely to fail. They fail because their molecular structure breaks down and they turn into a different material. Not because electrons start moving through them as they do in a lump of copper. Unlike the situation when a conductor passes electricity, once the insulator has failed it is usually no longer the same substance. Glass has a breakdown voltage of over two megavolts per inch. Glass insulators usually fail due to the heating effects of high currents passing *around* them rather than through them. A glass insulator may be well able to withstand the voltage across it, but the dirt or water that is coating it can still provide a path. -- Cynic
From: boltar2003 on 7 Jul 2010 06:18 On Tue, 06 Jul 2010 23:15:13 +0100 Derek Geldard <impex(a)miniac.demon.co.uk> wrote: >I'll lend you my copy of "Electronic Processes in Materials" (L V >azaroff and JJ brophy) if you like. Why, don't you need a doorstop anymore? The beam coming off a cathode in a CRT is electrons (and hence current) flowing through a vacuum. See if that book can argue otherwise. B2003
From: Albert T Cone on 7 Jul 2010 09:10
boltar2003(a)boltar.world wrote: > On Tue, 06 Jul 2010 23:15:13 +0100 > Derek Geldard <impex(a)miniac.demon.co.uk> wrote: >> I'll lend you my copy of "Electronic Processes in Materials" (L V >> azaroff and JJ brophy) if you like. > > Why, don't you need a doorstop anymore? > > The beam coming off a cathode in a CRT is electrons (and hence current) > flowing through a vacuum. See if that book can argue otherwise. Point of order - it isn't a vacuum, 'cos it has electrons in it. Also, I reckon you are being a bit disingenuous in bringing thermionic emission into this. That said, whilst electrons can't pass through a vacuum, electric fields can and it is quite possible to have a vacuum-filled capacitor - an example of electrical power being coupled through a vacuum. |