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FizixFreak
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does Earth has a megnatic field and if so how?
pythagorean said:yes. I don't think it's known for sure how, but a good guess is the motion of liquid-state metals in Earth's core, like iron.
FizixFreak said:but the megnatic field is caused by moving charges only how can movement of liquid state metal cause megnatic field?
Pythagorean said:There are moving charges in it ;)
Don't worry you're not as embarrassed as physics.FizixFreak said:i m definatly missing something here
mgb_phys said:Don't worry you're not as embarrassed as physics.
The Earth's magnetic field is amazingly poorly understood even today, which is why we get away with handwaving explanations of the 'dynamo effect'.
There are possible explanations from second order effects of a moving conductive (but overall uncharged) fluid moving in a field - a little like how the corriolis effect is a second-order effect of a rotating earth.
FizixFreak said:what are the efffects which are seen because of the megnatic field of Earth ?
FizixFreak said:electric field due to spin WOW that is some question
my guess is that the Earth spin with a CONSTANT anguler velocity (no accelaration ) if the Earth were accelerating our days would be shortened with time!
but that's my personasl opinion could be wrong
dacruick said:even with CONSTANT angular velocity don't you get acceleration. towards the centre maybe? and then an electric field would be created magically causing a magnetic field to form perpendicular to a vector towards the centre of the earth, thereby pointing maybe to a north and south pole? . just speculating.
dacruick said:Well average acceleration is 0, but so is the average electric field. At any given moment there would be a changing electric field, which induces a magnetic field perpendicularly to that. I doubt I would provide you a fulfilling explanation. They do spin magnets in many devices though, try googling that.
FizixFreak said:so the in that case megnatic field will also be zero (overall) but we will get some instantaneuos values right
is that what you are trying too say ?
but in that case the megnatic field it self would not be non uniform and an non uniform megnatic field will show non uniform effects which is not the case (if i m not wrong)
dacruick said:the magnetic field isn't uniform to my knowledge. is it?
mgb_phys said:Important ones are:
Compass needles point north.
FizixFreak said:so the in that case megnatic field will also be zero (overall) but we will get some instantaneuos values right
is that what you are trying too say ?
but in that case the megnatic field it self would not be non uniform and an non uniform megnatic field will show non uniform effects which is not the case (if i m not wrong)
jreelawg said:A book I read from the seventies questions the dynamo effect as the cause of magnetic fields
jasonRF said:The magnetic field of the Earth is approximately a dipole, which is the magnetic field of a loop of current. So no, it is not uniform. And yes, it shows non-uniform effects. Consider two compasses, one in London and one in Tokyo. Do their needles point in the same direction? No! They both point towards the magnetic north pole, which is a different direction from London than it is from Tokyo.