Astrophysicist Janna Levin, a professor at Barnard College, dives into the cosmic depths alongside Neil deGrasse Tyson and comedian Matt Kirshen. They tackle mind-bending questions about black holes and the nature of time. Can you 'surf' gravitational waves? Is time merely a human construct? With humorous insights, they discuss the perplexing interplay of energy and matter. Janna also debunks myths about black holes and shares the emotional journey of studying these cosmic giants, all while keeping it light and accessible.
Black holes behave more like a unique 'place' in the universe, challenging our understanding of matter and gravity.
Time dilation reveals that proximity to massive objects affects aging, demonstrating the complex relationship between gravity and the flow of time.
Deep dives
Understanding Black Holes
Black holes are regions in space where gravity is so intense that nothing, not even light, can escape. The star that forms a black hole collapses in on itself, creating a singularity at its center. This results in an unusual state of matter, leading to the idea that black holes are more akin to a 'place' in the universe rather than a physical object filled with matter. Consequently, the area beyond the event horizon is essentially empty space where the effects of gravity dominate.
Gravity and Time Dilation
Time dilation occurs as gravity affects the passage of time; stronger gravitational fields slow down time relative to weaker fields. An observer near a black hole would perceive time normally, while an observer far away would notice that the person at the black hole appears to be moving slower. This phenomenon reveals how gravity can warp the flow of time based on the curvature of space-time surrounding massive objects. As a result, people can age differently based on their proximity to varying gravitational forces.
Wormholes and Theoretical Constructs
Wormholes, or theoretical passages through space-time, can be conceived mathematically; however, they require exotic forms of negative energy to keep them open, which we have yet to observe in reality. Even established theoretical frameworks for constructing wormholes suggest that these ideas are not compatible with the actual universe we inhabit. Although some cosmic phenomena like cosmic strings may allow for time travel, they demand conditions that are not currently feasible. Thus, while intriguing, the practical application of creating and utilizing wormholes remains purely speculative.
Hawking Radiation and Black Holes
Hawking radiation describes how black holes can emit particles due to quantum effects near their event horizons, suggesting that they have a temperature and can lose mass over time. The temperature of a black hole decreases as its mass increases, meaning larger black holes are colder and slower to evaporate than smaller ones. This process could eventually lead to the evaporation of black holes, culminating in the release of energy that may manifest as high-energy gamma radiation. This insight illustrates the connection between quantum mechanics and gravitational theories in understanding black holes' eventual fate.
Is anything real? Is time just a construct? On this episode, Neil deGrasse Tyson and comic co-host Matt Kirshen answer your far-out questions about black holes, dark matter, and the universe with astrophysicist Janna Levin.
(Originally Aired Tuesday, March 8 2022)
NOTE: StarTalk+ Patrons can watch or listen to this entire episode commercial-free here: https://www.startalkradio.net/show/cosmic-queries-stoner-edition-with-janna-levin/
Thanks to our Patrons Ivan Masjuk, c, Nathan Mitchell, Conner Kemmsies, Dustin Dewayne Hart, Kyle Reinsberg, Andrew Magri, Virginia Cohen, Cathleen Corrie, and David Claassen for supporting us this week.
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