Abstract at nature.com (Paywalled)
The conditions deep inside large planets, such as Jupiter, Uranus and other planets recently discovered outside our solar system, have been experimentally recreated. This allows researchers to re-create and accurately measure material properties that control how these planets evolve over time (information that is essential for understanding how these massive objects form).
Using the largest laser in the world, the National Ignition Facility at Lawrence Livermore National Laboratory, teams from the Laboratory, University of California, Berkeley and Princeton University squeezed samples to 50 million times Earth's atmospheric pressure, which is comparable to the pressures at the center of Jupiter and Saturn. Of the 192 lasers at NIF, the team used 176 with exquisitely shaped energy versus time to produce a pressure wave that compressed the material for a short period of time. The sample diamond is vaporized in less than 10 billionths of a second.
Though diamond is the least compressible material known, the researchers were able to compress it to an unprecedented density greater than lead at ambient conditions.
"The experimental techniques developed here provide a new capability to experimentally reproduce pressure-temperature conditions deep in planetary interiors," said Ray Smith, LLNL physicist and lead author of the paper. Such pressures have been reached before, but only with shock waves that also create high temperatures hundreds of thousands of degrees or more that are not realistic for planetary interiors. The technical challenge was keeping temperatures low enough to be relevant to planets. The problem is similar to moving a plow slowly enough to push sand forward without building it up in height. This was accomplished by carefully tuning the rate at which the laser intensity changes with time.
"This new ability to explore matter at atomic scale pressures, where extrapolations of earlier shock and static data become unreliable, provides new constraints for dense matter theories and planet evolution models," said Rip Collins, another Lawrence Livermore physicist on the team.
(Score: 0) by Anonymous Coward on Friday July 25 2014, @01:17AM
The ol' "pull my finger" experiment, eh?
(Score: 4, Interesting) by stormwyrm on Friday July 25 2014, @01:49AM
I wonder if they can get to the point that hydrogen behaves as a metal [wikipedia.org]. Might be interesting to see some actual degenerate matter and study its properties. 50 million atmospheres is something like 5 TPa, somewhat more than the theoretical hundreds of GPa supposedly needed to make metallic hydrogen.
Numquam ponenda est pluralitas sine necessitate.
(Score: 2) by Dunbal on Friday July 25 2014, @11:45AM
Dear Government, need more money for funding. Research is going well but I am running out of diamonds. Am planning another trip to Antwerp to buy some so that I can, er, vaporize them.
(Score: 3, Interesting) by TK on Friday July 25 2014, @03:32PM
As a materials nerd, I'm always excited to hear about anything that expands material phase diagrams in either axis.
Obviously we can't make things out of, for example, metallic hydrogen, in the real world, but maybe we can gain some other insights into funky material behavior at extreme conditions that predict behavior at more reasonable pressures and temperatures.
I could imagine a future of resistance-less transmission cables made out of light elements bound with a sheath of rigid materials to keep them compressed.
The fleas have smaller fleas, upon their backs to bite them, and those fleas have lesser fleas, and so ad infinitum
(Score: 1, Interesting) by Anonymous Coward on Friday July 25 2014, @06:01PM
I agree. Under pressure is some of the least understood material properties. I think it could be interesting if something could be created under pressure then act a different way when it is under 1 atmosphere. That could get interesting...