Neutron Star Glitches: Solved in the Lab ⚡ экспресс
Neutron stars — the ultra-dense remnants of dead suns — sometimes exhibit glitches: sudden increases in rotation speed. The culprit is thought to be quantum vortices in the star's superfluid interior, which can pin to the crust and unpin abruptly. A new study combined experiments with helium in aerogel (a porous material) and computer simulations to investigate two modes of such pinning. It turns out that in 'crust-like' aerogel, vortices unpin when the flow is fast enough, whereas in 'core-like' aerogel, they never detach, but instead new vortices are born in an avalanche. This sheds light on the nature of neutron stars and may change how we interpret astronomical data.
A neutron star is a spinning top with the mass of the Sun, crushed to the size of a city. It's born in the fire of a supernova and usually only slows its spin. But sometimes, for no apparent reason, it suddenly speeds up — such a jerk is called a glitch. Many neutron stars become pulsars: they beam out rigid radio pulses like cosmic lighthouses. Their discovery in 1967 by Jocelyn Bell Burnell gave the first clue to these extreme objects.
Inside the star, matter enters a frictionless state — superfluidity. In the lab, its role was played by porous aerogel soaked with superfluid helium. It turned out that in the outer layer, akin to a crust, tiny whirlpools (quantum vortices) break loose and slide when the spin is too fast. But in the dense core, they stick tight to the pores, and the slightest change triggers an avalanche of new vortices. Both processes whip the star forward, like a gust of wind spinning a top. A surprise: glitches aren't a nuisance, but a gift. By tracking these jerks, like seismic waves, we can peer into the star's interior, beyond the reach of any telescope. The concept of neutron stars was laid down by Fritz Zwicky and the calculations of Subrahmanyan Chandrasekhar, and now the lab analog turns every glitch into a session of cosmic tomography.
🎯 A typical glitch changes the star's rotation period by one billionth of a second. To put it in perspective: if Earth jerked like that, the day would lengthen by a hair, but the planet itself would crack from the stress.
🎬 In David Brin's novel 'Startide Rising', intelligent beings live on a neutron star, exploiting its complex rotational dynamics.