Brief Summary
This episode of StarTalk Cosmic Queries features Neil deGrasse Tyson and co-host Paul Mcyo answering questions about the universe. They discuss the existence of gas clouds in space, the Big Bang, gravitational waves, the nature of particles, observing early generation stars, and the relationship between time and mass. The episode highlights the importance of scientific truth, the limitations of our current understanding of the universe, and the ongoing search for answers to fundamental questions.
- The universe is a dynamic and fascinating place, with forces like gravity and turbulence shaping its structure.
- The Big Bang is not an explosion, but rather an expansion of space and time from something small to something big.
- Gravitational waves provide valuable insights into the structure of spacetime and the nature of gravity.
- Particles don't need to touch to interact, as their surrounding fields can influence each other.
- We can observe earlier generation stars by looking back in time, even though they may no longer exist.
- Time cannot be manipulated in the same way as space or speed.
Why Don’t Gas Clouds Disperse?
Brian from Roseville, California asks why gas clouds and nebulae exist in space, given that the vacuum should cause them to disperse evenly. Neil explains that while this is true on Earth, in space, gravity can overcome the dispersive forces at very low temperatures. The turbulence in space also contributes to the unusual shapes of nebulae.
What Went “Bang”?
Chris Win from Ottawa, Ontario asks what went "bang" during the Big Bang. Neil clarifies that the term "Big Bang" is misleading, as it refers to the expansion of space and time, not an explosion. He explains that the initial expansion was followed by a period of rapid inflation, which is analogous to a balloon suddenly expanding after being slapped.
What Will We Learn From Gravitational Waves?
Mitch from the UK asks what we can learn from gravitational waves. Charles explains that gravitational waves are like ripples in a pond, and by studying their properties, we can gain insights into the structure of spacetime and the universe itself. He also mentions that the detection of gravitational waves supports Einstein's theory of relativity, which predicts that gravity travels at the speed of light.
Do Particles Ever Touch?
A viewer asks if particles actually touch when they collide, or if they just get close enough for "magic" to happen. Charles explains that particles don't need to touch to interact, as their surrounding fields can influence each other. He introduces the concept of the "impact parameter," which is the distance within which two objects will interact and affect each other's trajectories.
Observing Early Generation Stars
Morton Lurar from Norway asks how we can observe earlier generation stars if our Sun is a third-generation star. Neil explains that we can see these stars because their light is still traveling to us, even though they may have died long ago. He emphasizes that when we look out into space, we are looking back in time, and we see the universe as it once was.
Could Slowing Time Make You More Massive?
Manad Shandy from North Wales asks if slowing down time would make everything infinitely massive. Charles explains that this is not how time works. He emphasizes that time cannot be manipulated in the same way as space or speed, and that our understanding of time is still incomplete.
Closing
The episode concludes with Neil and Paul discussing their upcoming projects and encouraging viewers to keep looking up. They also highlight the importance of asking questions and seeking answers about the universe.
