- #1
mrcotton
- 120
- 0
I have just read an article in the new scientist "Forgotten force: The other great cosmic attractor"
Would anyone be kind enough to help me understand this paragraph please?
"Now we have a pretty good idea how the sun and Earth generate their fields. As molten iron in Earth's outer core (or plasma in the sun's case) moves across magnetic field lines, the effect is to induce electric currents. These give rise to a magnetic field that supplements the existing one. Thanks to this dynamo action, a small "seed" field can grow into a much larger one."
How does that work?
I had always assumed wrongly it was molten iron ions moving that caused the field.
So with the mechanism proposed above I would have thought that (from Lenz's Law) that the induced current's field would oppose the original field, rather than enhance it. How does this fit with conservation of energy?
Any thoughts gratefully received.
D
Would anyone be kind enough to help me understand this paragraph please?
"Now we have a pretty good idea how the sun and Earth generate their fields. As molten iron in Earth's outer core (or plasma in the sun's case) moves across magnetic field lines, the effect is to induce electric currents. These give rise to a magnetic field that supplements the existing one. Thanks to this dynamo action, a small "seed" field can grow into a much larger one."
How does that work?
I had always assumed wrongly it was molten iron ions moving that caused the field.
So with the mechanism proposed above I would have thought that (from Lenz's Law) that the induced current's field would oppose the original field, rather than enhance it. How does this fit with conservation of energy?
Any thoughts gratefully received.
D