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Electromagnetic Emission Art 198

Posted by CmdrTaco
from the wonder-what-its-doing-to-your-nervous-system dept.
mr_lithic writes "The artist Richard Box has used the electromagnetic field generated by overhead transmission cables to power 1300 fluorescent lightbulbs positioned underneath. Some pictures available. Professor Denis Harshaw at Bristol University explains "There's an interactive element to all this, too, for those who go to the site itself. 'You affect the lights by your proximity', explains Richard Box, 'because you're a much better conductor than a glass tube. And there's sound as well as light - a crackling that corresponds to the flashing of the lights. There's a certain smell too, and your hair stands slightly on end.'" Sounds cool and it is on until February 29th. Directons here."
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Electromagnetic Emission Art

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  • by FePe (720693) on Sunday February 22, 2004 @10:32AM (#8355516)
    This is what the future is going to be like. [zen.co.uk]

    Yeah, yeah chips in your hair. 2000.

    A3 x 30. Taken in the studio this series of photographs depicts the artist fending off a swarm of silicon chips as if they were flying insects. The work deals with the effect, intended or not, of technology on the individual.

  • Re:Wrong physics (Score:5, Informative)

    by Anonymous Coward on Sunday February 22, 2004 @10:48AM (#8355587)
    Its called mutual inductance. The changing magnetic field in the power lines causes a changing magnetic field in the 'pylons'(which are most likely a coil oriented correctly). This causes a current in the coil due to Faraday's law. This current itself then generates its own EMF which Lenz's law then shows will have the opposite polarity of the power line magnetic field. Thus, this new magnetic field attempts to generate a current in the opposite direction in the power lines, increasing their resistance.
    In short, he's using the power companies' power to light his bulbs. There are no 'waste emmisions'.
  • by weeble (50918) on Sunday February 22, 2004 @10:52AM (#8355609) Homepage
    http://openapps.harkness.co.uk/junk/ [harkness.co.uk]

    There is a copy of the article and the picture covered by the Daily Mail.
  • Re:Stealing or not? (Score:5, Informative)

    by Rosco P. Coltrane (209368) on Sunday February 22, 2004 @10:54AM (#8355617)
    Does arrangements like that actually "steal" any power from the powerlines, or would it be lost anyway if it was just air instead of neon tubes?

    They do draw energy from the line. If they weren't there, the voltage differential in the static field would stay high and no (or little) current would be sinked into the ground under the tube.

    Another proof: assume each tube spits out the equivalent of 10W in light, there must be like 1000 tubes in that field, so they burn about 10kW all the time. I don't think the ground underneath normally sinks 10kW for each 100mx100m square : if it did, it would heat up, and very long lines would lose so much power over the distance that they would bankrupt the power companies.
  • Re:Stealing energy (Score:5, Informative)

    by Rosco P. Coltrane (209368) on Sunday February 22, 2004 @11:01AM (#8355655)
    Whatever sucking up EM fields is, it sure isn't theft, no matter what the french say

    You shouldn't have slept through your EE classes.

    Having a coil under the Eiffel tower is exactly similar to having a secondary coil in a transformer : whenever you have a load drawing current on the secondary coil, the primary coil (in this case, the Eiffel tower's antennas) have to provide that power, despite the fact that there's no physical connection between the 2 coils. So if you have antennas putting out 50kW and a coil drawing 10W nearby, that's 10 less Watts in radio power.

    This guy's art also draws energy from the power line. The tubes don't light up for free do they?

    But I'll tell you what : if sucking up EM fields isn't theft, tell me where you live and I'll coil a long copper wire around a mile-long stretch of the powerline that goes to your house and power my trailer with it. I'm sure you won't mind the higher bill from the power company in your mailbox, since I'm not stealing anything...
  • by G4from128k (686170) on Sunday February 22, 2004 @11:01AM (#8355658)
    Microwaving chocolate [about.com] is a fun way to both measure the speed of light and get some edible artifacts of the patterns of the electromagnetic fields inside a microwave oven.
  • by Anonymous Coward on Sunday February 22, 2004 @11:08AM (#8355680)
    The power company deserves to have their power stolen because they are too cheap to reconfigure their lines to reduce the electromagentic output:

    http://tdworld.com/ar/power_line_designs_reduce/
  • Re:Stealing energy (Score:2, Informative)

    by RandyOo (61821) on Sunday February 22, 2004 @11:54AM (#8355953) Homepage
    You said:
    "But I'll tell you what : if sucking up EM fields isn't theft, tell me where you live and I'll coil a long copper wire around a mile-long stretch of the powerline that goes to your house and power my trailer with it. I'm sure you won't mind the higher bill from the power company in your mailbox, since I'm not stealing anything..."

    Since the meter is normally located at/inside the residence, he wouldn't get a higher bill from the power company, would he?
  • by MidiSaxMan (755371) on Sunday February 22, 2004 @12:55PM (#8356259)
    Oops,sorry forgot the links, check it out yourself.
    I also forgot to mention that animals can be sensitive to ground differentials as small as 0.5 to 1 volt depending upon conditions.

    This engineer testifies under oath citing research performed by Doug Reinmann at University of Wisconsin stating those same facts.

    Doctor Reinmann's research paper can be found here
    (pdf reader required for some links)
    http://www.uwex.edu/uwmril/stray_voltage/s vmain.ht m
    http://www.strayvoltage.org/stories/index.php3? Sto ry=20010221_utility.inc
  • by enosys (705759) on Sunday February 22, 2004 @01:33PM (#8356500) Homepage
    The time domain reflectometer (TDR) injects a signal into a wire and then gives you some info about reflections that happen. It essentially measures impedance along the line and so it will show anything inductive, resistive or capacitive on it.

    I'm sure a lot of people here have heard about TDRs being used to troubleshoot network cables.

    As for electric companies being called hydro, I'm in Canada (A former British colony and in the Commonwealth) and it's the same here. It really doesn't make that much sense anymore because most power comes from other sources.

  • by glesga_kiss (596639) on Sunday February 22, 2004 @01:42PM (#8356535)
    Neither does ecstacy to be honest. The only study that "proved" permament damage was recently dubunked as they had done the experiment with amphetamines and not E! [www.cbc.ca]. Of course, the original study [hopkinsmedicine.org] is still cited as proof about the "dangers" of the drug despite this (and many other papers by the same research scientist) being completely thrown out by the scientific community. FACT: Going fishing carries about the same risk of death as going out clubbing on E. Horse riding is many times more dangerous! And with all three, if you understand the risks and take precautions, you can reduce the risk of death to practically zero.

    But the parent post did mention beer. That does kill brain cells. You do it every time you get drunk. That's what drunk is; the poisioning of your brain by alcohol. And death on alcohol? Go and ask an ER doctor. Lots, never published in the news.

    Of course, when the majority of anti-drug messages are funded by the booze industry you have to laugh. I quite like the one on DrugFreeAmerica.org, telling how Ecstacy almost killed a girl [drugfreeamerica.org], until you actually read the article and find that it was GHB. Actually, all the articles on that site are just as bad, and they seem to have been written by the same person, very similar style etc. ALL LIES I TELL YOU!! ;-)

  • by HPNpilot (735362) on Sunday February 22, 2004 @01:47PM (#8356556) Homepage
    Nobody is running jumper leads to multihundred kV transmission lines. That would be outrageoulsy dangerous and difficult to do.

    Even attaching to a 7 kV local HT line is beyond what most people could survive doing unless they were EXTREMELY lucky and had a decent amount of knowledge.

    STAY AWAY FROM THESE LINES. NEVER NEVER NEVER ATTEMPT TO ATTACH TO THEM. DON'T EVEN THINK ABOUT IT. SERIOUSLY!
  • by jimmyswimmy (749153) on Sunday February 22, 2004 @02:17PM (#8356705)
    The article references using "passive loop shields" - sounds like additional wires running the length of the transmission line. Those wires are expensive! In school we once did a project similar to this. It turns out that the minimum time-varying flux (voltage) is created below the lines when the three lines are in the equilateral-triangle orientation with the point towards the ground. That way you get some cancellation for free. I remember my power lab TA from some South American country telling us an interesting story. Evidently where he is from they often run a different line configuration known as the wye, which has four wires instead of three (delta, like we have here). The extra wire carries almost no voltage and is there for balancing currents. Most of the time as long as everything is okay the extra line is almost unnecessary. He said all the time people would actually climb the towers and steal the neutral. The value of the copper is worth the risk of cutting the wrong line. Every once in awhile he said they would screw up and try to cut the wrong line. That must be spectacular to see.
  • by Ambient Sheep (458624) on Sunday February 22, 2004 @02:38PM (#8356815)

    > Why are British power companies referred to as 'hydro?'

    Um, they aren't. Or if they are, I've never noticed in all my years of existence in the U.K. We also tend to have "secondary schools" not "high schools", so I'm pretty sure the grandparent poster wasn't British.

    Hydro isn't the main method of production over here in the U.K. The figures for England and Wales are:
    35% - Gas
    34% - Coal
    15% - Nuclear
    7% - Pumped Storage & Renewables
    5% - Interconnectors
    4% - Oil
    (Source: http://www.electricity.org.uk/media/documents/pdf/ Intro_UK_Elec_Ind.pdf [electricity.org.uk]
    There's more hydroelectric stuff in Scotland, which those figures don't cover though.

    While I'm here, the power-line in question is a major National Grid line (Melksham - Seabank / Imperial Park) carrying 400kV, with a peak power-flow of 161MW along one circuit and 481MW along the other, according to the National Grid website. Even before I saw the directions I knew where it was as it's very distinctive - most pylons in the U.K. don't look like that, they have the three phases stacked one above the other on each side of the tower. The cable configuration in the photo is usually only used for brief hops over sudden hills, as it is in this case. I wonder if the fact that it has four sets of conductors nearest the ground rather than just two was a factor in him choosing that site? (Yes, it's quite near Bristol, however there are other lines, indeed stretches of that line, that are much nearer.)

  • by afidel (530433) on Sunday February 22, 2004 @04:06PM (#8357226)
    Since high power lines are set back from the road at least 30m in most of the US and EM falls off at the cube of the distance I think there is a BIG difference between being right under them and driving past them.
  • Re:directions (Score:2, Informative)

    by Soruk (225361) on Sunday February 22, 2004 @06:31PM (#8357982) Homepage
    What? No GPS coordinates?

    The car park is at ST 756 778 (in OSGB notation), or 51deg 29min 52sec north, 2deg 21min 7sec west.

    From there, walk as per the directions on the website [zen.co.uk].
  • Re:Science and Art (Score:5, Informative)

    by jrockway (229604) * <jon-nospam@jrock.us> on Sunday February 22, 2004 @09:02PM (#8358922) Homepage Journal
    OK. Done. I emailed them this message:

    To: rights@diaart.org

    Hello. I recently happened upon your page for "The Lightning Field". I
    was curious about how you could protect your metal poles from being
    photographed by copyright law. Copyright law prevents the
    redistribution of one's original work, but not the creation of new
    work. If I sold pictures that you took, I would be in violation of your
    copyright. Unfortunately, there is no law that prevents me from
    photographing anything.

    If there were, perhaps you would consider suing Microsoft and the USGS
    for the infringing aerial photograph at
    http://terraserver.microsoft.com/

    On second thought, perhaps you shouldn't consider that. Because if you did, you would be laughed out of court.

    Sincerely,
    Jonathan Rockway
  • by yuri benjamin (222127) <yuridg@gmail.com> on Sunday February 22, 2004 @11:15PM (#8359697) Journal
    So you're telling me that the electric pole that has the poles going in my property (backyard) contains power that I own? -- That I can legally tap into it even if I don't pay my electric bill, simply because one of the power polls sit within my backyard?

    If the power company does not have an easement (aka right of way) to transmit power across your property, then their power lines are trespassing, in which case you COULD argue that you have the right to that power. The easement would have been arranged with whoever owned that backyard at ther time the poles were erected. If you didn't check out the land title before you bought it - tough luck.

    In the case of the farmer - I'm sure the power company has its paperwork in order so the power belongs to the lines transmission operator, not the landowner.
    In the case of some satelite TV company, they definitely do NOT have an agreement to broadcast their signal through my property, therefore I own whatever radiation enters my house.
  • by Anonymous Coward on Monday February 23, 2004 @01:39AM (#8360266)
    EMF from a linear source (powerline) falls off at R^-2.
  • by e144539 (556142) on Monday February 23, 2004 @02:32AM (#8360474)
    EMF from a linear source (powerline) falls off at R^-2.
    I wish I could mod that up
    Inverse Square Law, General
    "Any point source which spreads its influence equally in all directions without a limit to its range will obey the inverse square law. This comes from strictly geometrical considerations. The intensity of the influence at any given radius r is the source strength divided by the area of the sphere. Being strictly geometric in its origin, the inverse square law applies to diverse phenomena. Point sources of gravitational force, electric field, light, sound or radiation obey the inverse square law."

In seeking the unattainable, simplicity only gets in the way. -- Epigrams in Programming, ACM SIGPLAN Sept. 1982

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