The densest objects that haven’t collapsed to black holes can tell us information about the Universe unlike anything else.
Swarming through our own galaxy, we’ve detected quite a few bizarre objects: pulsars. These rapidly spinning neutron stars are only a few kilometers across, yet contain more mass than our entire Sun. They’re denser than a uranium atom’s nucleus, and some of them possess the strongest magnetic fields in the known Universe. The fastest-spinning one known rotates about its axis 766 times per second, and they can travel at up to ~65% the speed of light. And outside of the ones we’ve found, we fully expect there might hundreds of millions or even as many as a billion such neutron stars hanging out simply in our Milky Way galaxy.
But they also emit their own light, and a good chunk of that light is polarized, giving us an incredible set of information. In addition, by coordinating the pulse times of many different pulsars, we can not only detect gravitational waves, but can detect the types of waves generated by objects that LIGO and even LISA will never see. I’m so pleased to welcome Haley Wahl, pulsar specialist and PhD candidate, onto the show, and I hope you enjoy what turned out to be a fantastic conversation!
Starts With A Bang is written by Ethan Siegel, Ph.D., author of Beyond The Galaxy, and Treknology: The Science of Star Trek from Tricorders to Warp Drive.