[binx44]

I need to compare the magentic field of a house magnet to the earths magentic field. And I can't fiugre this out at all... does anyone know a website where I can do this?

[Capuchin]

What on earth is a house magnet?

[binx44]

Like one that goes on a fridge I am guessing.. or a bar magnet
(spelling?)

[Capuchin]

Okay, well if you get a compass, and one of these magnets, you can measure the distance you need to move the magnet to to deflect the compass.

Or do you need a more theoretical approach?

[binx44]

A more theoretical approach I believe. I need to know about the magnetic feild(s) and compare them...

[Capuchin]

Okay, the earth's magnetic field is essentially a lot like a bar magnet. However it does have some discrepancies due to it not being a perfect bar magnet.

I've been looking at geomagnetism recently, however I have to leave for home soon, if you want to contact me on MSN messenger, Or meet me back here in about an hour and a half, I can show you some data on the earth's magnetic field.

You can then compare the shape of it to that of a household magnet

Does that sound like what you're meant to be doing?

[binx44]

I need to know the discrepancies.. that soundds right.. I added you to my msn

[Capuchin]

This is quite big (several MB):

http://geomag.usgs.gov/charts/ig00d.pdf

It's a very good picture of the field on the surface of the earth, you can see that it's very irregular
You have to keep in mind that the field is always changing. Every 250,000 years the south and north poles reverse.

I'll talk to you more when I get home.

[Capuchin]

Oh, you are interested in the red lines in the above picture :)