Uploaded November 2020 | Updated September 2026, 2 hours ago
The observable universe is about 93 billion light-years in diameter. It contains around 100 billion galaxies, each with 100 billion to 1 trillion stars. Although scientists are not in agreement about what percentage of those stars are “sun-like” meaning similar in size, temperature, and luminosity, opinions typically range from 5% to 20%. Assuming the lower range of 5% still gives us about 500 quintillion sun-like stars. Furthermore, there is also a debate over what percentage of those sun-like stars might be orbited by an Earth-like planet. An Earth-like planet is one with similar temperatures and conditions that could have liquid water and potentially support life. Some believe it is as high as 50%, but recent studies have speculated around 22%. This suggests that there is a potentially habitable Earth-like planet orbiting at least 1% of the total stars in the universe giving us a total of 100 quintillion Earth-like planets. So common sense would tell us that there should be plenty of opportunities for intelligent life to develop and exist throughout the universe. Our universe should be teaming with life with spaceships everywhere like that of the Star Wars universe. But it isn’t. Where is everybody? In this video, we will talk about the Fermi Paradox and examine some of its possible explanations.
The observable universe is about 93 billion light-years in diameter. It contains around 100 billion galaxies, each with 100 billion to 1 trillion stars. Although scientists are not in agreement about what percentage of those stars are “sun-like” meaning similar in size, temperature, and luminosity, opinions typically range from 5% to 20%. Assuming the lower range of 5% still gives us about 500 quintillion sun-like stars. Furthermore, there is also a debate over what percentage of those sun-like stars might be orbited by an Earth-like planet. An Earth-like planet is one with similar temperatures and conditions that could have liquid water and potentially support life. Some believe it is as high as 50%, but recent studies have speculated around 22%. This suggests that there is a potentially habitable Earth-like planet orbiting at least 1% of the total stars in the universe giving us a total of 100 quintillion Earth-like planets. So common sense would tell us that there should be plenty of opportunities for intelligent life to develop and exist throughout the universe. Our universe should be teaming with life with spaceships everywhere like that of the Star Wars universe. But it isn’t. Where is everybody? In this video, we will talk about the Fermi Paradox and examine some of its possible explanations.
