JesusA (imported) wrote: Thu Dec 04, 2008 5:23 pm This would require placing one magnet on an anvil and using a hammer on the other magnet if you wanted to produce any harm.

Well, not really.

Ever saw a magnetic junk yard crane? Just set two of 'em close together, hang what you want smashed flat in between then and then power them up.

CRUNCH!

...

IbPervert (imported) wrote: Sun Dec 07, 2008 1:27 am the power company's send workers out to work on the wires when the high voltage is going through them. The workers have to follow very strict procedures. If the high voltage lines got turned off when they were inspected they would be off a good deal of the time.

Inspecting the lines is one thing. That can be done live using binoculars, from the ground or from a chopper . That is relatively low risk and there are no immediate consequences.

Tasks such as cleaning insulators for example? Surely that cannot be done live.

There is some live line working done. It is deemed to be cost effective. The 'very strict procedures' are merely to guard against the very obvious and immediate risk from the high voltage. Some studies were made to discover the effects on the people doing the work.

They concluded that as long as the workers could not detect any effect, such as electric shock or induced currents circulating in their bodies, then it was safe. They ignored the guys who reported their hair standing on end.

Stand by for a class action suit in decade or so. It's gonna be asbestos or Gulf War syndrome all over again.

Kortpeel

Kortpeel (imported) wrote: Wed Dec 10, 2008 12:01 am Inspecting the lines is one thing. That can be done live using binoculars, from the ground or from a chopper . That is relatively low risk and there are no immediate consequences.

Tasks such as cleaning insulators for example? Surely that cannot be done live.

There is some live line working done. It is deemed to be cost effective. The 'very strict procedures' are merely to guard against the very obvious and immediate risk from the high voltage. Some studies were made to discover the effects on the people doing the work.

They concluded that as long as the workers could not detect any effect, such as electric shock or induced currents circulating in their bodies, then it was safe. They ignored the guys who reported their hair standing on end.

Stand by for a class action suit in decade or so. It's gonna be asbestos or Gulf War syndrome all over again.

Kortpeel

Yes the linemen work on the wires live. The wires that are on the large metal towers. The ones with hundreds of thousands of volts going through them. They work from a bucket truck or from a helicopter. Often they will wear a chain metal suit. They first hook the bucket that they are working in to the wire. Then they work with the wires live. Almost all repairs are done while the lines are live as well. Taking a line down is very expensive.

You can be hold of a wire that has a million volts on it and not feel a thing. You only notice the voltage when there is a flow of current. That is when electrons are moving through your body. The hair standing on end is electrons setting up an electrical field in your hair.

moi621 (imported) wrote: Tue Dec 09, 2008 2:54 pm Yes I wonder what will happen when one is driving

a car powered by 4 large electric motors regardless

if the electric energy comes from hydrogen, battery, gasoline, etc.

Back in the 1950's the "Pearl Chain Effect" was described as

it was acknowledged that such fields cause protein molecules that

all have a weak + and - side to line up like a chain of pearls.

Not healthy !

Think about the cell tower a few hundred feet from a home.

High power lines governments insists are safe to live near.

The increase in broadcasting since the 1950's when just

a few radio, TV and short waves units broadcast.

Time for clothing that incorporates shielding from EMF

as well as UV ! No doubt here.

Well if the vehicle is NOT made of steel I would be a little concerned but the most efficient electric motor don't have stray magnetic fields as that reduces efficiency of the motors! 99% of the stray magnetic fields would be from the power leads from the power source to the motor. Also most hybrid cars now the batteries are above 100 volts and some at 400 volts and the currents are very low compared to a 12 volt system. 1,000 watt at 12 volt is 83.3 amp but at 400 volts it's only 2.5 amps much less magnetic fields and copper, and now days copper is like gold a spool of wire which was $100 in 2004 is now about $800 (I got the quote on 12/8/08).

moi621 (imported) wrote: Tue Dec 09, 2008 2:54 pm Time for clothing that incorporates shielding from EMF as well as UV ! No doubt here.

And to be effective, this clothing shouldn't have holes with size of more than about 1/10 of a wavelength of signal...

For 2.4 Ghz - wavelength is 0.12 meters. So no holes more than 1cm in size...

Oh, and I forgot, new WiMax and WiFi use 5Ghz - so... wavelength is twice as small...

Looks like fashion statement to me... . Any suggestions on style?

Very interesting subject!

To begin with, magnetic fields follow that law of Physics known as the inverse square law. What this means, roughly, is that the intensity of a magnetic field is reduced to 25% of its original strength when you double your distance from it.

If you would go from one foot to three feet from that field, the intensity of the field decreases by the inverse of 3 squared or, to one ninth of its intensity. And so forth...

Of course, Maxwell's equations express so eloquently, a changing magnetic field across an electrical conductor at a right angle will generate a flowing current in that conductor, just as a conductor when moved through a stationary magnetic field at a right angle to the field will cause a current to be induced in the conductor.

The main effect of very, very intense magnetic fields on human tissue is heating which occurs because the human body is mostly water, and water is 2/3 hydrogen. The hydrogen atom has only one positive charge in the nucleus and one negative charge in the electron and as such is always sort of lop-sided. A magnetic field will line the spin of the hydrogen atom with the magnetic field and if the field changes or the body moves, the hydrogen will stay aligned with the magnetic field.

A magetic field strength is commonly measured in Gauss. The magnetic feld strength of the Earth that makes compasses work is from 2.5 to 4 gauss, according to your position on the Earth's surface. 1 Tesla, (another measure of magnetic field strength in MKS) is the equivalent of 10,000 Gauss.

Electric transmission lines vary in voltage but generally range form 115,000 volts to 230,000 volts (http://www.eia.doe.gov/cneaf/pubs_html/ ... _sale.html). This is done to reduce the current and therefore reduce heating losses during long-distance transmission. The magnetic field strength of these lines is generally NOT significant unless you lve right under them or in a very close proximity. Transmission lines are not a problem if kept a distance from people. (http://www.answers.com/topic/electric-p ... ansmission)

Most of the danger is from electrical shock, not magnetic fields. (http://www.youtube.com/watch?v=PXiOQCRiSp0) Be sure to click this one, it is shocking...! ...but only if you are close enough...

Putting this into perspective, you get more cellular heating in the presence of a microwave oven than you do a transmission line. In fact, if you live close to a Microwave telephone transmission tower, that is when to start worrying. It can actually cook a goose in the path of its transmission, if they are too close for too long.