Frictionless Superfluid Found In Neutron Star Core

intellitech writes "NASA's Chandra X-ray Observatory has discovered the first direct evidence for a superfluid, a bizarre, friction-free state of matter, at the core of a neutron star (abstract). Superfluids created in laboratories on Earth exhibit remarkable properties, such as the ability to climb upward and escape airtight containers. The finding has important implications for understanding nuclear interactions in matter at the highest known densities."

Comments

Re:airtight? big deal

[khallow]

Now, if you can put this stuff in a seamless glass sphere, and it still leaks out, I'll be impressed.

Normal helium can leak out of a seamless glass sphere, so I imagine you'd see supercooled helium leaking out as well from the same mechanism. Not that exciting, but gives you an idea of how hard some things are.

Re:airtight? big deal

[gstoddart]

Normal helium can leak out of a seamless glass sphere

Really? What, it just seeps out through the actual glass? Are the helium atoms small enough to squeeze through the gaps between molecules, or just really sneaky?

I continue to be awed by all of the wacky shit that is apparently everyday physics.

Re:airtight? big deal

[PotatoFarmer]

Are the helium atoms small enough to squeeze through the gaps between molecules, or just really sneaky?

Yep, pretty much. Practically speaking, it's one of the things that keeps a helium-based Stirling engine from being one of the most efficient methods of solar power production - the stuff leaks out at every opportunity.

Re:airtight? big deal

[fractoid]

Yep, that's how it goes.

Although I was disappointed to find that the "climbs the walls of the container" thing was actually just in a one-atom-thick layer. (At such scales, surface tension beats gravity, and with no viscosity to hold it in check, the fluid flows up the sides molecule-by-molecule. It looks like it's just dripping through a hole in the container. :( )

The actual physics

[Required Snark]

The Chandra x-ray satellite can measure the spectrum of x-rays emitted by the neutron star, which is relatively close, only 330 light years away. From this they can infer the temperature. Over the last ten years they have seen the roughly 4% temperature drop.

According to the two teams of scientists who analyzed the Chandra x-ray data to determine the cooling rate, these observations provide strong evidence for superfluidity in neutron-star cores. Indeed, the onset of neutron superfluidity opens a new channel for neutrino emission from the continuous breaking and formation of neutron pairs.

The energy is leaving the star via neutrino emission, which in turn is a result of the neutron superfluid inside the neutron star. That's the important discovery.

This is very interesting physics, because there is no way to produce these conditions in the lab, or anywhere outside a neutron star.

Of course you could just read the abstract and get all this information yourself, but this is Slashdot so knoledge takes a back seat to bad jokes and uninformed opinion.