Dark Mysteries of the Cosmos
March 23, 2018
Black holes, dark matter and mapping distant galaxies may sound like plot elements of a Star Trek movie, but they were also the subjects of this year’s WTMA Distinguished Lectureship in Science Honoring Dr. Roy E. Moon.
Noted theoretical astrophysicist Dr. Priyamvada Natarajan, a professor in the Departments of Astronomy and Physics at Yale University, gave two presentations on the ASU campus explaining how scientists study black holes and dark matter without actually being able to see them.
Her first and more technical lecture was on black holes, what she calls “the most enigmatic objects in the universe.” She took the primarily student-and-faculty audience on a journey of scientists’ growing understanding of black holes, from how they started as a mathematical concept to explain other phenomena in the universe, to how they were proven to exist and how they alter the nature of space and time.
“There are aspects and properties of black holes that we understand quite well,” Natarajan said. “But there are also many mysteries that remain to be solved…The future is really bright for black hole physics.”
“I want to show students that science is a really viable, fun and exciting career.”
In her evening public lecture, Natarajan focused on dark matter: what it is and how it is distributed throughout the cosmos.
“Most of the matter in the universe appears to be dark matter,” Natarajan said, “and it’s called ‘dark’ because it doesn’t emit, absorb or reflect light. We know it’s there because of the gravity it exerts. So we map it indirectly, and we’re really trying to get to the bottom of what dark matter is made of. It has to be some kind of exotic particle that was made very early in the universe, but we don’t know what it is.”
“It does not exhibit properties of ordinary matter,” she continued. “So it is not anything that we are made of, anything on the Periodic Table or anything we’ve been able to synthesize in a lab. My work has been trying to map this dark matter to get a clue to its true nature.”
Throughout her lectures, Natarajan also acknowledged the contributions of other scientists, from Copernicus and Newton to Einstein, Hubble and Stephen Hawking.
“There are lots of misconceptions about science and scientists,” Natarajan said. “I want to show students that science is a really viable, fun and exciting career. Scientists are not these objective, neutral people wearing lab coats. Science is a human endeavor, and there is a human psychological side of science. I want students to get a flavor of that and show that science is not so unfamiliar, alien and distanced from us.”
“Plus, every time you answer a question and think you’ve understood it,” she added, “it opens up many more questions. Our current knowledge is based on the best conceptions, data and instruments we have today. But tomorrow, when we invent better instruments that can gather more and better data, our understanding is apt to change. That is what is exciting for scientists who are in this game.”
Natarajan also explained why she was happy to take time out from her teaching and research to deliver ASU’s Distinguished Lectureship in Science.
“We live in an increasingly scientific and technology driven society,” she said. “To be good citizens, we need to understand the basics of science. So I feel it’s important for scientists to take the time, make the effort and reach out to explain what science really is.”
“A lot of my colleagues are great at describing scientific discoveries. I am interested in de-mystifying the process of science, not just the results.”