Magnetic Field In Meteorite Provides Clues About Formation of Solar System 26
An anonymous reader writes Scientists have discovered a meteorite that provides evidence that intense magnetic fields caused the formation of the solar system. A meteorite called Semarkona crashed in northern India in 1940 and is now being studied for signs of primordial magnetic fields. Lead researcher, Roger Fu, a planetary scientist at MIT says: "It's a very primitive meteorite, which means that since it formed about 4.5 billion years ago, not much has happened to it, this means it preserves the properties it had when it first formed, helping shed light on that time." From the article: "This meteorite is made up of mostly tiny round pellets known as chondrules, which formed droplets that quickly cooled in space. According to the study, the scientists focused on these chondrules that possessed iron-bearing minerals, known as dusty olivine crystals, and if they appeared to have a magnetic field present while they were cooling, then the magnetic properties of these crystals might have recorded the strength of the magnetic fields."
Because annealing doesn't affect matnetism (Score:5, Interesting)
It's not like the annealing heat of descent wouldn't cause the material to take on the local field, right?
Re: (Score:3, Interesting)
The xkcd "What If?" article "Steak Drop" [xkcd.com] seems to say that while the outer surface may be charred and even blasted off, the interior remains completely untouched.
Then again, IANA Astrophysicist, Cartoonist, or Chef.
Re:Because annealing doesn't affect matnetism (Score:5, Informative)
Think about how long it takes a meteor to descend through the atmosphere and decelerate to terminal velocity. It's a few seconds.
Now, think about how quickly metal or rock conducts heat, and how quickly heat dissipates into moving air or solid ground.
Nearly all the object's kinetic energy goes into compression heating of the atmosphere. Of what's left, nearly all goes into ablating the object's surface. When the object hits, its interior is still cold.
Re: (Score:3)
Um, but I think OP was trying to build a case to justify sending people to Mars or something. Because we *need* to explore or some such romantic nonsense.
It would appear that this says a lot more about your thought processes than about anything OP actually wrote.
Lead researcher, Roger Fu (Score:3)
Ironically, a lead researcher made a discovery on magnetism.
(Thank you. I will be here all week. Tip your waitress.)
(Yes, I did use the thousandfold cursed "Morissette irony" on purpose, to elicit rage, hair pulling and lamentations.)
Re: (Score:1)
Ironically, a lead researcher made a discovery on magnetism.
(Thank you. I will be here all week. Tip your waitress.)
(Yes, I did use the thousandfold cursed "Morissette irony" on purpose, to elicit rage, hair pulling and lamentations.)
Ironically, irony present in an article about iron-bearing meteorites.
Re: Makes no sense that (Score:2)
I can magnetize a rod of iron by hitting a rock with it.
And you can, too.
Fucking magnets, how do they work? (Score:2)
Re: (Score:2, Offtopic)
Re:Fucking magnets, how do they work? (Score:4, Informative)
You mean, as in "read a physics textbook"?
Seriously. Depending on how much physics you've already studied, the right place to start will vary. A passable (free) intro is in my free online physics textbook http://www.phy.duke.edu/~rgb/C... [duke.edu], or wikipedia articles. A good intermediate treatment might be Griffiths' Classical Electrodynamics. If you want the pure quill uncut stuff, J. D. Jackson's Classical Electrodynamics is excellent, but it is not for the faint of heart or the wussy of PDE-fu.
In a nutshell, parallel currents of electric charge attract; antiparallel charged currents repel, changing charged currents radiate electromagnetic energy, and there are electrostatic forces happening in there somewhere too, in the cases where the currents are produced by unbalanced moving charge. Oh, and there is a fair bit of twistiness to the magnetic fields (called "curl") and forces, and the currents in question in "magnets" (or the general magnetic susceptibility of materials) tend to be non-dissipative (quantum) nuclear, atomic, or molecular circulations of charge, not Ohm's law type currents in a resistor. Ferromagnets in particular are what is being referred to, and they are characterized by long range order and a "permanent" magnetization in the absence of an external field below a certain temperature.
Hope this fucking helps:-)
rgb
gas giants' origins? (Score:1)
Re: (Score:2)
Does not show cause, only shows involvement (Score:2)
RTFA does not use the word cause, but it does say "magnetic fields were large enough to be important in the accretion process". Wrong. The chondrules cooled in a strong magnetic field, but that does not mean that they were formed in space. There are just too many assumptions made, and leaps of faith, in the article to believe the scientists involved had impartiality. Bias showing in the cooling state of scientific hypothesizing. What it shows is that the chondrules cooled in a strong magnetic field. End of
Really a question of: Where did chondrules form? (Score:2)
The linked article is not really even an article, but I think the interesting science topic is that we don't understand where chondrules form. They are somehow formed in the early solar system by melting refrectory elements together. But how and where that melting occurs in not known (http://en.wikipedia.org/wiki/Chondrule#Formation [wikipedia.org].
It is thought that the formation might be related to dissipation of magnetic fields in the protoplanetary disk or the young sun (so-called magnetic reconnection) but it is n