Summary of Is our universe the only universe? | Brian Greene 2020

00:00:00 - 00:20:00

In this video, Brian Greene discusses the possibility that our universe is just one of many. He suggests that if the laws of physics can't explain one particular value for dark energy, then we should ask why our universe has that particular value. This question can be answered by looking at the different distances between planets in our universe.

• 00:00:00 The Nobel Prize in Physics was awarded to two teams of astronomers for a discovery that has been hailed as one of the most important astronomical observations ever. The discovery was that beyond the earth, the Milky Way and other distant galaxies may find that our universe is not the only universe, but is instead part of a vast complex of universes. The idea of a multiverse is a strange one, most of us were raised to believe that the word universe means everything. I aim to convince you that there's a reason for taking it seriously, as it just might be right. Part one of the video starts with the great astronomer Edwin Hubble realizing that the distant galaxies were all rushing away from us. Publishing that space itself was stretching it's expanding now this was revolutionary. The prevailing wisdom at the time was that on the largest of scales, the universe was static. However, even so, there was one thing that everyone was certain of: the expansion must be slowing down. That as much as the gravitational pull of the earth slows the ascent of an apple tossed upward, the gravitational pull of each galaxy on every other must be slowing the expansion of space. Fast forward to the 1990s when those two teams of astronomers, inspired by this reasoning, measured the rate at which the expansion had
• 00:05:00 According to a recent study, the universe has a small amount of dark energy, which is unexplained. This suggests the existence of other universes. The theory of string theory, which is a possible explanation for dark energy, is still in development, and has many candidates for extra dimensions. However, some researchers have given up hope that string theory can ever be fully tested.
• 00:10:00 The video discusses the possibility of a multiverse, which is an alternative universe that is just as real as ours. The main point of the video is that if the laws of physics can't explain one particular value for dark energy, then we should ask why our universe has that particular value. This question can be answered by looking at the different distances between planets in our universe.
• 00:15:00 In this video, theoretical physicist, Dr. Brian Greene, discusses the theory of inflation, which suggests that our universe may not be the only one. According to the theory, our universe is likely the result of a quantum field exploding, which generated countless other universes. If this theory is correct, then the universe we inhabit is only one of many, and our understanding of the cosmos may one day change.
• 00:20:00 Brian Greene discusses the possible existence of other universes and how cosmology has evolved over the years. He suggests that we may always be asking questions and never be able to fully understand the universe, but that we are now able to understand how all universes exist and how to understand the data from the microwave background radiation.