April 16, 2021 7-9PM

Event Type: Lecture and Stargazing
Title: Endless Hunt for Black Holes
Lecturer: Wenbin Lu
Position: Postdoctoral Fellow
Institution: Caltech
Abstract: The existence of black holes is one of the most striking predictions of Einstein's theory of general relativity, but it has been a century-long journey to test whether these bizarre objects are actually formed in our universe. This question has been investigated in several different ways: by considering the evolution and eventual collapse of massive stars; by observing stellar motion around a "dark mass concentration" at the center of our own galaxy; by examining X-ray and radio emission from gas falling into "dense massive objects"; by viewing light bent by the gravitational potential of free-floating "invisible objects"; and most recently, by collecting gravitational waves from colliding "compact massive binaries". I will show that black holes predicted by general relativity have passed all these checks with scrutiny, and then I will discuss what additional ways astronomers can further test the existence of black holes.