SSS 2011-08-25(在线收听) |
This is Scientific American’s 60-SecondScience. I’m John Matson, got a minute? Say you need a diamond. You could go downto the jeweler, or you could put some carbon deep underground and let it sitfor a couple billion years. Or you could hop in a starship and cruise 4,000light years over to a dead star called pulsar J1719-1438.
The pulsar is exotic on its own—it's a super-dense remnant of a star spinningat about 10,000 rpm. But far more curious is the world orbiting it, which mightbe called a planet if it weren't so strange.
It's about as massive as Jupiter, but much more compact. It may be the remainsof a carbon-rich white dwarf star. But it's been mostly cannibalized by itspulsar companion, and is now just a shadow of its former self.
The object’s incredible density makes it subject to great internal pressure.And that pressure, acting on the carbon-rich makeup of the white dwarf, mayhave crystallized much of it to the particular form of carbon we call diamond.That's according to new research in the journal Science. The next step forastronomers is to find out if the diamond planet has rings.
Thanks for the minute. For Scientific American’s 60-Second Science, I’m JohnMatson. |
原文地址:http://www.tingroom.com/lesson/sasss/2011/8/155336.html |