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Astronomers Solve Magnetic Fields Mystery
An anonymous reader writes "It is a long-standing and unsolved mystery why 80% of all planetary nebulae are not spherical. Theories suggest that magnetic fields play a role in shaping planetary nebulae. A team of astronomers from Germany has now discovered the first direct clue that magnetic fields might indeed create these remarkable shapes. Planetary nebulae are expanding gas shells that are ejected by Sun-like stars at the end of their lifetimes."
"The First Direct Clue" While this may seem monumental, there will be many, many more clues and each will most likely lead the researches to a completely different conclusion.
Plasma physicists have been saying this for a long time.
I'm confused. The title suggests they've solved the mystery, but didn't they just find a huge clue? I mean, I can't come upon a murder, find a footprint, and say I finished. There's much more to it than that. Yes, this is a huge step, but no, everything isn't "solved." In fact, they could be completely wrong...
I know you're joking but there's a serious question there which some may seriously wonder about. Magnetic fields by their nature repel others of the same polarity. You can think of the fields as rubber bands or strings reaching from a north pole to a south pole and pushing away from each other. You can see a better description and a picture (of magnetic field lines - not galaxies) here.
Magnetic fields not important in EE??? Ever heard of a transformer?
Uh, no. The iron has nothing to do with it--or, at least very little. Ferromagnetism really has nothing to do with it. It's all about plasma effects: charged particles can't travel transverse to a strong magnetic field since the v-cross-B force bends the path--think cyclotron.
This is a fairly nifty result--they're combining existing technique (Zeeman splitting measurements have been established for quite awhile as the means of measuring the field of sunspots) with some pretty serious equipment, and likely a lot of patience, to verify that the fields are strong enough to determine the shape of the plasma. Not a surprising result but a good piece of work just the same.
No, no, no. Mass causes the warping of space which causes gravity, not gravitational "distortions" and the inverse square law still holds just as it does for the Newtonian model; relativistic gravity "looks" the same as Newtonian from any dirction.
As it must, because we can see that gravity does and one expects, in the absence of other forces, for phenomenon such as planetary nebulae to be symetrical.
By the way, you might be interested to know that the density of material in a such a nebula may well be lower than in an earth bound, artificial vacuum chamber. They may look massive from here, but that's because we see the entire mass of the florescing gases from a distance. If we were in the middle of it it might well look like empty space.
Think of a hazy day. You're not in a fog at all and it's only when you try to look across great distances that you realize the air isn't "empty."
KFG
Four words:
Correlation.
Is.
Not.
Causation.
Have a nice day...