Summary
In this episode of StarTalk, Neil deGrasse Tyson and his guests discuss various cosmic queries submitted by listeners. They explore the limitations of the universe and the laws of physics that prevent the existence of certain things, such as giant insects or reptiles. They also discuss the accuracy of our current map of the galaxy and the universe, with Matt O'Dowd explaining the tools and techniques used to create the map and the limitations and potential for errors. The conversation then shifts to the possibility of us being part of a simulation and the big bang being the seeding event of such simulation, but highlights the many assumptions required for this idea to be true.
The hosts also touch on topics such as the lack of a magnetic field on Venus, the concept of time before the Big Bang, and the search for dark matter. They explain that dark matter is not visible, but its effects can be observed through gravity. They also explore the idea of the fabric of space being ripped or pulled apart and whether an over-expanded black hole could cause a big bang.
Tyson discusses the possibility of the universe experiencing a phenomenon called vacuum decay, which could cause all physics to break down and particles to lose mass, swallowing up the universe. He also explains the concept of the Higgs field and reassures listeners that black holes are not giant sucking machines.
The podcast briefly mentions the Phoenix nebula and a question from a listener about how the Phoenix cluster was discovered and why it hasn't devoured our solar system. The hosts also discuss the possibility of a black hole the size of a pomegranate seed and how it would affect Earth. They delve into the multiverse theory and the different types of universes that could exist within it, including the quantum multiverse, the eternally inflating multiverse, and the universe of Lee Smolin where black holes create new universes.
Overall, the episode encourages listeners to keep looking up and exploring the wonders of the universe, while also highlighting the limitations and potential for errors in our understanding of it.
