Posted on 01/17/2010 3:44:54 AM PST by LibWhacker
By melting and resolidifying diamond, scientists explain how such liquid diamond oceans may be possible.
Oceans of liquid diamond, filled with solid diamond icebergs, could be floating on Neptune and Uranus, according to a recent article in the journal Nature Physics.
The research, based on first detailed measurements of the melting point of diamond, found diamond behaves like water during freezing and melting, with solid forms floating atop liquid forms. The surprising revelation gives scientists a new understanding about diamonds and some of the most distant planets in our solar system.
"Diamond is a relatively common material on Earth, but its melting point has never been measured," said Eggert. "You can't just raise the temperature and have it melt, you have to also go to high pressures, which makes it very difficult to measure the temperature."
Other groups, notably scientists from Sandia National Laboratories, successfully melted diamond years ago, but they were unable to measure the pressure and temperature at which the diamond melted.
Diamond is an incredibly hard material. That alone makes it difficult to melt. But diamond has another quality that makes it even more difficult to measure its melting point. Diamond doesn't like to stay diamond when it gets hot. When diamond is heated to extreme temperatures it physically changes, from diamond to graphite.
The graphite, and not the diamond, then melts into a liquid. The trick for the scientists was to heat the diamond up while simultaneously stopping it from transforming into graphite.
Ultrahigh pressures, the kind of pressures found in huge gas giants like Neptune and Uranus are some of the places where ultrahigh temperatures and ultrahigh pressures exist. Eggert and his colleagues placed a small, natural, clear diamond, about a tenth of a carat by weight and half a millimeter thick, and blasted it with lasers at ultrahigh pressures.
The scientists liquefied the diamond at pressures 40 million times greater than what a person feels when standing at sea level on Earth. From there they slowly reduced the temperature and pressure.
When the pressure dropped to about 11 million times the atmospheric pressure at sea level on Earth and the temperature dropped to about 50,000 degrees solid chunks of diamond began to appear. The pressure kept dropping, but the temperature of the diamond remained the same, with more and more chunks of diamond forming.
Then the diamond did something unexpected. The chunks of diamond didn't sink. They floated. Microscopic diamond ice burgs floating in a tiny sea of liquid diamond. The diamond was behaving like water.
With most materials, the solid state is more dense than the liquid state. Water is an exception to that rule; when water freezes, the resulting ice is actually less dense than the surrounding water, which is why the ice floats and fish can survive a Minnesota winter.
An ocean of diamond could help explain the orientation of the planet's magnetic field as well, said Eggert. Roughly speaking, the Earth's magnetic poles match up with the geographic poles. The magnetic and geographic poles on Uranus and Neptune do not match up; in fact, they can be up to 60 degrees off of the north-south axis.
If Earth's magnetic field were that far off it would place the magnetic north pole in Texas instead off a Canadian Island. A swirling ocean of liquid diamond could be responsible for the discrepancy.
Up to 10 percent of Uranus and Neptune is estimated to be made from carbon. A huge ocean of liquid diamond in the right place could deflect or tilt the magnetic field out of alignment with the rotation of the planet.
The idea that there are oceans of liquid diamond inside Neptune and Uranus is not a new idea, said Tom Duffy, a planetary scientist at Princeton University. The new Nature Physics article makes diamond oceans "look more and more plausible," said Duffy. More research on the composition of Neptune and Uranus is needed before a truly definitive conclusion can be made, however, and this kind of research is very difficult to conduct.
Scientists can either send spacecraft to these planets, or they can try to simulate these conditions on Earth. Both options require years of preparation, expensive equipment, and are subject to some of the toughest environments in the universe.
Which is why I refuse to ever buy another diamond.
People should use common sense. Go to any mall and there are jewelry stores all over selling diamonds but yet they are supposed to be "rare".
I often expect good humorous comments from FR. But yours is one of the best in several years.
Listen to a group of Astrophysicists some time try to explain the unified theory. They are constantly making up the existence of particles they "think" exist to match the equations they come up with to explain the origins of the Universe, all the while acting as if these particles actually exist and have been observed. For anyone with an engineering background, it's downright comical.
You’re right, once it melts it loses its crystal structure and becomes just a bunch of carbon atoms doing whatever. I’m guessing it’s considered liquid diamond because of the pressure they’re melting it at, which causes it to form diamond again when it cools rather than disorganized carbon.
Are you in the business of manufacturing Twinkies by chance?
I used to work at U.S. Steel. We had graphite up to six inches thick covering everything in the BOP shop. It played havoc with the resistor banks on the cranes.
It’d be cool to go back there and take a couple of shovelfuls of graphite, toss it into your basic super-duper high pressure oven, and turn the graphite into a thousand caret diamond. Frustrating! We know how to do it. It’s just the technology getting in our way.
Who said anything about manufacturing, Twinkie?
Soooooo, lets all just jump into our George Jetson Mobiles and fly up, over, around there and just grab a handfull for the glovebox.
Oh yea, George Jetson Mobiles haven’t been invented yet and if anyone here thinks this government is going to fund any kind of new space technology soon has truely got their heads in some other place not of this planet. They are already doing everything they can to cut the Constellation Project which was originated to replace the Shuttle Program.
They are talking 11 million atmospheres and 50,000 degrees (C or F?).
My tire guage and outside temperature guage don't hold up under these conditions.
But it looks as if the scientists here could use some proxies and come up with 'value added' temperatures and pressures.
It worked for Jones.
Yeah...and they got flying pigs also.
Has DeBeers purchased the rights yet?
Yes, but these physicists are relatively harmless, and they at least follow the Theory > Hypothesis > Conclusion > Revised Theory flowchart.
The AGW 'priests' come up with a theory from incomplete or flawed observation; make little-to-no effort to create testable hypotheses; and yet 'demand' immediate reorganization of human civilization.
Yeah, they have their own boondoggles, like the 54 mile, $12 billion hole in the ground we paid for in Texas that Congress canceled in 1993, aka, the Superconducting Super Collider. There are many other examples. They just don't get as much press as AGW. Plenty of waste to go around, all in the name of "science".....
I would lay that boondoggle at the feet of Congress. The competing facility in CERN Switzerland has made significant scientific contributions — discoveries that would have been made in Texas if not for the cancellation.
Really? Like what? Last I heard they were having trouble with it tripping breakers every time they try to bring it to full power. I have not heard of any significant new discoveries coming from the Swiss LHC yet. Doesn't mean that there haven't been any, I just haven't heard about it. Maybe I missed something. What did they find?
Well, Twinkies immediately jumped to mind when you mentioned your line of work relied on science. Twinkies are as much a technology as a food, packed as they are with synthetic compounds that only scientists understand.
DeBeers will be building a Death Star to take care of this problem.
Y'know what? You're right. They haven't really done any experiments beyond power-level tests with the LHC. They've had problems with the equipment & their website says that they are shutting down in 2010 for a systems upgrade.
Have to apologize to you & eat a little crow here. I thought I saw/heard something on the News a few weeks ago about the LHC at Cern. One of those stories that blows past you when your attention is divided. Could have been one of those year-end, filler-stories (as in "not really News)?
>:0)
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