# I sleep in an electromagnetic field. Is that bad? **URL:** \ **Category:** Factual Questions\ **Created:** [March 12, 2004, 6:06am UTC](https://boards.straightdope.com/t/i-sleep-in-an-electromagnetic-field-is-that-bad/233860 "2004-03-12T06:06:27Z")\ **Posts on this page:** 10\ **Page:** 2
**Author:** ![Small\_Clanger](https://avatars.discourse-cdn.com/v4/letter/s/9fc348/32.png) [@Small\_Clanger](https://boards.straightdope.com/u/Small_Clanger)\ **Post date:** [March 12, 2004, 2:54pm UTC](https://boards.straightdope.com/t/i-sleep-in-an-electromagnetic-field-is-that-bad/233860/21 "2004-03-12T14:54:33Z")
Who the heck buys this crap? People who line their hats with foil to block out controlling rays get institutionalised. Can we use ownership of healing-magnets energy bracelets etc. as proof of cerebral difficiency and get the sellers locked up and the buyers sterilised? There’s a stall in the shopping centre here that sells nothing but magnetic braclets and the like (it may do crystals too) :mad: Maybe I’ll set up my own stall selling good-ole Radium pills, give everyone that healthy Monty Burns glow. At least they’ll do something for your money. I’ve seen ad’s for magnets to put round your car’s fuel pipe to improve milage (I promise I am _not_ making this up). What possible mechanism are they envoking to explain this? Could you sell dashboard “magic fuel” gonks to wave over the petrol flow as you filled up, might be worth a try. Einstein: There are two infinite things, the Universe, and human stupidity. And I’m not sure about the Universe. ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [March 12, 2004, 2:59pm UTC](https://boards.straightdope.com/t/i-sleep-in-an-electromagnetic-field-is-that-bad/233860/22 "2004-03-12T14:59:00Z")
Do you often find yourself facing north for no apparent reason? If not, you probably have nothing to worry about. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 12, 2004, 3:16pm UTC](https://boards.straightdope.com/t/i-sleep-in-an-electromagnetic-field-is-that-bad/233860/23 "2004-03-12T15:16:39Z")
> [@Desmostylus](#): > > Stick your tongue in a power point, and _then_ tell me that a voltage or current at the skin surface is of no consequence. It really depends on what, precisely, the effects of a low frequency EM field are on various tissues. That fact is, we don’t really know, although most reasearch tends to show no link between EM and health problems (and I think that’s probably correct). Your point is taken about the skin surface, however, one can’t ignore the possible effects on deeper tissue, either. No, I don’t think there are any, but we haven’t yet completely ruled it out. ---
**Author:** ![Pleonast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pleonast/32/1183_2.png) [@Pleonast](https://boards.straightdope.com/u/Pleonast)\ **Post date:** [March 12, 2004, 4:02pm UTC](https://boards.straightdope.com/t/i-sleep-in-an-electromagnetic-field-is-that-bad/233860/24 "2004-03-12T16:02:03Z")
> [@Hari Seldon](#): > > There is no such thing as an electromagnetic field! There are electric fields, there are magnetic fields and there are electromagnetic waves (including radio, light, UV, X-rays,…, covering different ranges in the EM spectrum. For everyday purposes you are correct. But once you go relativistic (special or general), you’ll find that electric and magnetic fields become inextricably intertwined. Similar to what happens to space and time. So, properly speaking, there are no electric or magnetic fields (except in certain frames of reference), only an electromagnetic field. ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [March 12, 2004, 6:23pm UTC](https://boards.straightdope.com/t/i-sleep-in-an-electromagnetic-field-is-that-bad/233860/25 "2004-03-12T18:23:04Z")
> [@don't ask](#): > > Alright so which one should I buy? Maybe one of each? Sure. Then the only thing they are likely to have any affect on is your wallet. But serially, folks, here is [a FAQ about powerlines and cancer,](http://www.mcw.edu/gcrc/cop/powerlines-cancer-FAQ/toc.html) from the Medical College of Wisconsin. ---
**Author:** ![stpauler](https://avatars.discourse-cdn.com/v4/letter/s/9d8465/32.png) [@stpauler](https://boards.straightdope.com/u/stpauler)\ **Post date:** [March 12, 2004, 7:45pm UTC](https://boards.straightdope.com/t/i-sleep-in-an-electromagnetic-field-is-that-bad/233860/26 "2004-03-12T19:45:13Z")
I work for an insurance co. and we do insure electric companies for EMF. We’ve never had to pay out on a claim and it’s highly unlikely we would. (But sadly, get a money hungry person, a gullible jury, and a quack scientist and it _might_ happen) ☹ . ---
**Author:** ![Mr\_Salads](https://avatars.discourse-cdn.com/v4/letter/m/c2a13f/32.png) [@Mr\_Salads](https://boards.straightdope.com/u/Mr_Salads)\ **Post date:** [March 12, 2004, 10:57pm UTC](https://boards.straightdope.com/t/i-sleep-in-an-electromagnetic-field-is-that-bad/233860/27 "2004-03-12T22:57:00Z")
I have to admit the comparison to power lines sounds a bit misguided. I mean, they’re power lines for god’s sakes. And this is a blanket atop other blankets. I think electric blankets do have a physical effect on the body though. I don’t recommend using one on a constant basis to try getting to sleep. From now on I’m shutting it off to depend on the residual heat. ---
**Author:** ![swansont](https://avatars.discourse-cdn.com/v4/letter/s/5fc32e/32.png) [@swansont](https://boards.straightdope.com/u/swansont)\ **Post date:** [March 13, 2004, 11:34am UTC](https://boards.straightdope.com/t/i-sleep-in-an-electromagnetic-field-is-that-bad/233860/28 "2004-03-13T11:34:48Z")
> [@Desmostylus](#): > > Take a look at one. The wiring _does_ loop back on itself. However, the wires are spaced several (about 5) centimetres apart. The field cancellation is ineffective at distances smaller than that. Your body is too close to the blanket for the cancellation to prevent currents being induced. > > P.S., you’ve got your reasoning a bit backward with this: “it rapidly looks like no net current, and thus no field”. It’s actually that there _is_ no field at a distance of, say, a metre, which _looks like_ no net current. For all I know, some company is taking advantage of people frightened about fields, and wiring them up with much smaller spacing. That’s why I said 'it depends on the wiring." If the OP linked to an actual picture of his blanket, I missed it, and apologize for the confusion. The reasoning goes both ways. It’s Ampere’s law - the field depends on the net current. Saying there’s zero field implies no net current. Saying there’s no net current implies no field. ---
**Author:** ![Desmostylus](https://avatars.discourse-cdn.com/v4/letter/d/c57346/32.png) [@Desmostylus](https://boards.straightdope.com/u/Desmostylus)\ **Post date:** [March 13, 2004, 1:46pm UTC](https://boards.straightdope.com/t/i-sleep-in-an-electromagnetic-field-is-that-bad/233860/29 "2004-03-13T13:46:34Z")
Well, yes, and for all you know electric blankets may actually work by boiling water and circulating it through steam pipes. Stop with the hand waving. If you have some actual information, please post it. And you are still having some kind of problem with “net current”. The field in the situation we’re talking about here does not depend on “net current”. If you have two wires comprising the source path and the return path in an electrical circuit, it’s possible to say that there is no “net current” in them. Is is _not_ possible to say that they have no external magnetic field at any given point in space. Conversely, given a zero measurement of the magnetic field at some point , it is _not_ possible to say that the net current in them is is necessarily zero. IOW, you’re just waving your hands again. Do it a bit faster, and we can use you as a windmill. ---
**Author:** ![swansont](https://avatars.discourse-cdn.com/v4/letter/s/5fc32e/32.png) [@swansont](https://boards.straightdope.com/u/swansont)\ **Post date:** [March 13, 2004, 2:11pm UTC](https://boards.straightdope.com/t/i-sleep-in-an-electromagnetic-field-is-that-bad/233860/30 "2004-03-13T14:11:52Z")
> [@Desmostylus](#): > > Well, yes, and for all you know electric blankets may actually work by boiling water and circulating it through steam pipes. > > Stop with the hand waving. If you have some actual information, please post it. > > And you are still having some kind of problem with “net current”. The field in the situation we’re talking about here does not depend on “net current”. If you have two wires comprising the source path and the return path in an electrical circuit, it’s possible to say that there is no “net current” in them. Is is _not_ possible to say that they have no external magnetic field at any given point in space. Conversely, given a zero measurement of the magnetic field at some point , it is _not_ possible to say that the net current in them is is necessarily zero. > > IOW, you’re just waving your hands again. Do it a bit faster, and we can use you as a windmill. The field in this case most certainly does depend on the current involved, and the geometry. This is exactly why one uses a coaxial geometry if you’re worried about generating a field. Are you always this rude, or is it only when you’re wrong? [Previous page](https://boards.straightdope.com/t/i-sleep-in-an-electromagnetic-field-is-that-bad/233860.md?page=1)