Dr. Abigail Polin -- Astrophysics Q & A #3

Shockwaves are a familiar phenomenon here on Earth. In astrophysics, they play a role in some of the most powerful events in the universe, from exploding stars to gamma ray bursts. Shockwaves can transform enormous amounts of energy and carry information about events that are otherwise impossible to observe directly. Dr. Chris Irwin studies how these shocks form and evolve, and how we can use them to learn about cosmic explosions.

The Theory of Relativity was discovered by Einstein over a century ago, and it tells us how time and space are distorted when moving close to the speed of light. We mere earthlings don't get the opportunity to move that fast, but there are some phenomena in astrophysics that move very fast; more than 99.9999% of the speed of light. Ranadeep Dastidar is a computational modeler who writes code to predict and interpret these "relativistic" phenomena.

Abigail Polin is back, and we are doing another astrophysics Q&A! This time, our questions come from a class of third graders in Indiana. You'll be surprised at how some of the simplest questions can lead us down a very complex path!

This episode we get back to the objects that inspired the whole field of astrophysics -- stars. Those little points of light that first inspired us as children are incredible physics laboratories that we can still use today to learn about plasma physics, turbulence, and nuclear reactions. Dr. Jeff Gerber tells us why he made his career out of studying how stars work, and how much we still have to learn about these giant balls of plasma.

Just how much do we know about how the planets formed? How much of this can we learn from getting images of young solar systems? Why does it help to look at the disk using radio waves instead of optical wavelengths? Dr. Charles Law discusses these questions and more as we talk about radio astronomy and the birth of the solar system.

The Vera Rubin Observatory has just started taking its first data this month. We have a special guest (Dr. Daniel Polin) who helped in the construction of the camera for Rubin. This digital camera was a major feat due to the very large amount of data contained in each exposure, requiring clever techniques for reading and transmitting data quickly. Let's find out what it takes to build the biggest digital camera in the world.

Most of the mass in the universe is invisible. We call it "Dark Matter", and the only reason we know it's there is because we can see how it gravitationally interacts with regular matter. For example, in our own galaxy, Dark Matter comprises most of the mass, in a large spherical "halo" that binds the smaller spiral of gas and stars that we can see. As all our stars orbit the Milky Way, they are passing through a sea of dark matter, and this should create observable consequences that allow us to test theories about the nature of dark matter itself. Dr. Gurtina Besla develops large-scale computer simulations of the Milky Way to compute these observational signatures, allowing us to put our theories of dark matter to the test inside our own galaxy.

What's the deal with black holes?

How did our solar system form? More generally, how does any solar system form? We get some of our answers to these questions by looking at newly-forming planetary systems in the first million years of their lives. But getting a complete picture also requires a lot of theoretical work, understanding each stage of solar system formation, which often entails big computational models of the early solar system. Dr. Kaitlin Kratter is a leader in the practice of building these big models and using them to improve our understanding of how the planets first formed.

A white dwarf star is the compact, dense remnant of a once-thriving solar system. Long after the original star has died and turned into a white dwarf, it can still interact with its solar system. We can even see white dwarfs eating up the rocky debris that once made up their solar system, and apparently making sense of all of this requires a detailed understanding of how convection works in these dead stellar remnants.