Black Hole Blues and Other Songs from Outer Space

by Janna Levin

Or, moving up a few dimensions, astrophysical calamities are the mallets, spacetime is the skin of a three-dimensional drum, and the apparatus records the modulations in the shape of the drum to play the silent score back to us as sound.

The idea: Suspend mirrors so they’re free to rock parallel to the earth and watch them toss on the passing gravitational wave. Keep track of the distance between them, and their motions will record the changing shape of spacetime. Since light’s speed is a constant, the time it takes for light to race the track measures the length of the course. If the light travel time is a little longer, the distance between the mirrors has stretched. If the light travel time is a little shorter, the distance between the mirrors has squeezed.

Gravitation as a discipline was not under the purview of the Department of Energy or the Department of Defense or even NASA.

something truly important came gradually. As is often reported, the regularity of the signal earned the sources the internal nickname of LGM, for “little green men.” It turns out that there are even more precise clocks than those manufactured by the civilizations of little intelligent green men. And those would be pulsars. Pulsars are highly magnetized, rapidly spinning neutron stars. The strengths of the giant astronomical magnets are millions, trillions, or, in the extreme, thousands of trillions of times the strength of the Earth’s magnetic field. Neutron stars, always less than twice the mass of the Sun and less than 30 kilometers across, can spin rapidly, roughly once a second or even many hundreds of times a second. Particles accelerated near the speed of light along the magnetic field radiate to create a lighthouse beam that sweeps around as the nearly perfect sphere of condensed nuclear matter spins. Famously, a teaspoon of a neutron star would have the mass of a terrestrial mountain. The gravitational pull is so strong on its surface that a person would essentially liquefy and merge with the nuclear packing of the star. As a result of the strong gravitational effects, a neutron star is intolerant of imperfections. The gravitational pull overcomes any escalating mountainous formations. The imperfections on a typical neutron star’s surface are so small that a 10 centimeter irregularity qualifies as a mountain, although this depends on unknown details of the neutron ...