Ep 6. Did The Big Bang Really Happen?

In season 7 episode 6 of How the Universe Works, titled "Did The Big Bang Really Happen?", experts explore the hypothesis that the universe might not have started with a big bang. The episode examines the scientific evidence for both the big bang theory and a new theory that proposes a static universe that has always existed and will continue to exist indefinitely.

The episode begins with a discussion of the big bang theory, which is the prevailing model for the origin and evolution of the universe. According to this theory, the universe began as an infinitely dense and hot point, or singularity, before rapidly expanding and cooling down to form the cosmos we see today.

But some scientists have recently proposed an alternative theory called the "steady-state theory," which posits that the universe has always existed and will continue to exist in the same state forever. This theory challenges the big bang model by suggesting that the universe is infinite, eternal and unchanging.

To understand these theories better, the experts on the show discuss the observational evidence for the big bang. They talk about the cosmic microwave background (CMB), the afterglow of the big bang radiation that was discovered in the 1960s by the Bell Labs antenna. The CMB is considered one of the strongest pieces of evidence for the big bang theory since it matches the predictions made by the theory with a high degree of accuracy.

The experts also discuss the abundance of light elements in the universe and how they can provide clues as to what happened during the early stages of the universe. They also talk about the large-scale structure of the universe, which can be observed through telescopes, and how it supports the idea of a rapidly expanding universe that started with a big bang.

Next, the show delves into the steady-state theory and how it challenges the big bang. According to this theory, the universe is infinite and has always existed. New matter is created continuously to maintain a constant density while the galaxies move away from each other at the same rate as new matter is created. The experts acknowledge that this theory was once favored by some in the scientific community, but it has since lost popularity due to observational evidence that challenges it.

To further compare these two theories, the experts on the show talk about the concept of entropy, which is the tendency of the universe to become more disordered over time. They explain how the big bang theory predicts that the universe started in a highly ordered state, with low entropy, and that it has been increasing ever since. But the steady-state theory challenges this by suggesting that the universe has always been in a state of high entropy.

Finally, the episode explores the philosophical implications of both theories. The big bang theory suggests that the universe has a finite age and that it had a beginning. This raises interesting questions about the nature of existence and the possibility of a creator. The steady-state theory, on the other hand, suggests that the universe has no beginning or end, which could challenge some religious and existential beliefs.

Overall, "Did The Big Bang Really Happen?" is a fascinating episode of How the Universe Works that explores some of the most fundamental questions about our existence. The experts on the show provide a balanced and thoughtful analysis of the evidence for both the big bang and the steady-state theories, helping viewers to understand the scientific debates that underlie our understanding of the universe. This episode is a must-watch for anyone interested in cosmology and the nature of existence.