PBS Space Time Season 2019 Episode 38 Is the Universe Finite?

Is the Universe Finite? This is the question that has intrigued humans for centuries. In the latest episode of PBS Space Time season 2019, episode 38, host Matt O'Dowd delves into the latest research and theories about the size and shape of the universe.

At the beginning of the episode, O'Dowd lays out some common misconceptions about the universe, starting with the idea that the universe is infinite. He explains that while the universe may seem infinite to us on Earth, due to our limited perspective, that doesn't necessarily mean that it truly is infinite.

To explore this question further, O'Dowd investigates the concept of the observable universe. This is the part of the universe that we are able to see and study, given the limitations of how far light can travel in the time since the Big Bang. O'Dowd explains that the current estimate for the size of the observable universe is around 93 billion light years in diameter.

However, just because the observable universe has a finite size doesn't necessarily mean that the entire universe is finite as well. O'Dowd goes on to describe several different theories about the shape and size of the universe, some of which suggest that the universe is infinite, while others propose a finite size.

One such theory is the idea of a curved universe, where the topology of space-time is curved in such a way that it loops back on itself. This would create a finite universe, where if you were to travel in a straight line for long enough, you would eventually end up back where you started. O'Dowd explains that there is evidence to support this theory, such as the observation of the cosmic microwave background radiation, which shows small fluctuations in temperature that suggest a curved space-time.

Another theory O'Dowd discusses is the idea of a multiverse, where there are multiple universes existing alongside our own. This theory allows for the possibility of an infinite universe, as there could be an infinite number of parallel universes. However, O'Dowd cautions that this is still a highly speculative theory, and there is currently no concrete evidence to support it.

Throughout the episode, O'Dowd also describes the concept of cosmic inflation, which is a theory that explains how the universe rapidly expanded in size just fractions of a second after the Big Bang. This theory has important implications for the size and shape of the universe, as it suggests that there could be parts of the universe that we can never observe, due to the rapid expansion of space-time.

Overall, Is the Universe Finite? is an engaging and thought-provoking exploration of one of the most fundamental questions about our existence. O'Dowd's clear and concise explanations of complex theories make the episode accessible to viewers of all levels of scientific knowledge, while the stunning visuals and graphics help to bring the concepts to life. Whether you're a seasoned physicist or someone with a passing interest in the mysteries of the universe, there's plenty to discover in this fascinating episode of PBS Space Time.