Summary
In a podcast episode featuring Neil deGrasse Tyson and Matt Kirschen, cosmologist Brian Keating joins the hosts to discuss various aspects of cosmology and the early universe. Keating explains that the Big Bang is widely accepted as a real event due to evidence that matter came from somewhere and that the universe is made up of leftover shrapnel from the explosion. He also explains the difference between inflation and expansion, describing inflation as a spark that gives the impetus for the universe to expand to its vast size today in an exponentially small amount of time.
The hosts and guest also touch on the misconception that the Big Bang is synonymous with the origin of time and the universe, and the importance of continually finding flaws in current paradigms to advance understanding. They discuss the concept of inflation, which was developed to explain peculiarities observed in the data and why the universe is so large, flat, and possessing tiny fluctuations. However, evidence for inflation is still circumstantial.
The hosts and guest also discuss the cosmic microwave background (CMB), which is an all-pervasive field of photons coming to us as if we are inside an enormous oven. It was discovered in 1965 in New Jersey by Penzias and Wilson. Keating explains that the universe is isotropic and homogeneous, meaning that it should have the same physical properties everywhere and look the same everywhere on average. However, departures from this can call into question the underlying symmetries of the universe.
The hosts also answer listener questions, covering topics such as interstellar navigation, the expanding nature of the universe, the BICEP project, and the possibility of multiple universes existing in parallel. They discuss the cyclic or bouncing cosmological model, which suggests that the universe could collapse and create multiple universes. They also address two questions related to the cosmic microwave background radiation and the expansion of the universe.
Overall, the podcast episode provides a detailed and informative discussion of various cosmological concepts and theories, as well as addressing common misconceptions and answering listener questions.
