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AmatureLadyAstronomer3
2011-Dec-29, 12:07 AM
I have a big question for all of you. It might seem far fetched or unintelligent to most, but it is something that I've been seriously baffled about. This is concerning the center of white dwarfs. I have read and watched programs on the science and astronomy channels that they are diamond centers. So, here is my question..and please don't laugh..

Could the reason we have diamonds on Earth be because white dwarfs went supernova and fell to the Earth before life existed here? Therefore, littering our Earth with diamond rock?

I hope to hear an answer to this question. And thank you for your time, as well as knowledge.

antoniseb
2011-Dec-29, 12:54 AM
White dwarfs do not have diamond centers. They are made of Carbon (and Oxygen and Neon and other things in smaller amounts), but those are Carbon nuclei in a sea of electrons in a degenerate form that you cannot call solid, liquid or gas. It is actually a rare white dwarf that becomes a supernova. It has to either merge with another white dwarf, or accumulate a huge amount of matter from another star to make the transition, otherwise White Dwarfs are the end of the line. When they DO explode, they don't make diamonds. They make Cobalt and Nickel.

jfribrg
2011-Dec-29, 02:46 AM
As I understand the previous post, the center cannot be diamond because the carbon is way too hot to form crystals ( and of course a diamond is just a specific type of carbon crystal). However there is speculation that the center of Neptune is a gigantic diamond. I'm assuming that the temperature/pressure in the interior of Neptune allows for a diamond to exist. I'm curious. What is the maximum temperature/pressure in which a diamond can exist?

Swift
2011-Dec-29, 03:15 AM
While not all the details are know, the general mechanism for diamond formation on Earth is pretty well understood.
from the American Museum of Natural History (http://www.amnh.org/exhibitions/diamonds/formation.html)

Selfsim
2011-Dec-29, 03:32 AM
Some fairly up to date research info is here. (http://www.physorg.com/news/2011-11-pressure-ramp-compression.html)

These guys seem to have 'broken the record' for compressing diamond by taking it up to 50 megabars (50 million times Earth's atmosphere).

They seem to only now be investigating the physical properties at around 8 Megabars, however ...

Smith said shock experiments have made considerable progress in furthering understanding of the phase diagram of diamond in the vicinity of the melting boundary, and the pioneering ramp-loading work at the OMEGA laser has investigated the EOS and strength of diamond at pressures up to eight Mbar.

"The behavior of diamond in the solid state at 10 to 100 megabars, however, is wholly unexplored at present," Smith said. "This represents an exciting opportunity for NIF experiments." (Provided by American Physical Society)

Regards

grapes
2011-Dec-29, 03:21 PM
Diamonds are almost entirely associated with kimberlite pipes, narrow intrusions from over a hundred kilometers down. There is no evidence at all that they were scattered over the surface, sorry.