This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Some of the strangest weather in the solar system doesn't happen on Earth or even in Jupiter's Great Red Spot—it happens in the interiors of ice giants like Neptune and Uranus. Specifically, scientists have long believed that, at certain pressures and temperatures, it literally rains diamonds inside these planets.
For the first time, scientists have mimicked the process they believe creates this phenomenon. A new paper by physicists at Lawrence Livermore National Laboratory (LLNL), published in Nature Physics, resolves the 20-year-old scientific mystery and shows how the same physics that makes it rain diamonds inside Neptune could also help us triple our fusion energy output. Let's talk about the actual experiment first.
The LLNL scientists set up their experiment at the University of Rochester's Omega Laser Facility—which does exactly what its name suggests. In this case, the laser vaporized the outer layer of a diamond sample, and the scientists watched it with as many sensors as they could, including an ultrafast technique called X-ray diffraction. That vaporization sent a huge shock wave through the interior of the diamond itself, compressing it to pressures more than three times that of Earth's core, with resulting temperatures equivalent to the surface of the sun—but only for a billionth of a second.
What they saw helped solve a 20-year-old mystery. This wasn't the first time scientists had melted diamond. However, previous physical measurements of diamond's melting point disagreed with computer models based on quantum mechanics by up to 20%.
That might not sound like much, but in the context of these experiments, that 20% represented a difference of more than 1,000 kelvins between the theoretical and observed melting points. Despite their best efforts, scientists couldn't get the two numbers to match—until now. Armed with the new X-ray diffraction data, the authors were able to confirm that their measured melting point of diamond was consistent with modern quantum physics-based models.
But that wasn't their most interesting finding—they also discovered that, under the right conditions, diamonds would float on a sea of carbon. As a press release from LLNL points out, we're all familiar with one specific example in which the solid version of a material is less dense than the liquid version—ice and water. But finding that solid diamond is actually less dense than liquid metallic carbon was somewhat surprising for the researchers.
Extract — continue reading at the source.
