Ologies with Alie Ward – Cosmology (THE UNIVERSE) Part 2 Encore with Katie Mack

Intro

In this episode of “Ologies with Alie Ward,” Dr. Katie Mack returns to answer listener questions about astrophysics and cosmology. From the Big Bang theory to the possibility of vacuum decay, Dr. Mack delves into fascinating topics about the universe. She also discusses asteroid searches, methods to stop asteroids, the future collision of the Milky Way and Andromeda galaxies, and the importance of reducing light pollution for stargazing. Join Alie Ward and Dr. Katie Mack as they explore the wonders of the cosmos.

Main Takeaways

Asteroid Searches and Challenges

• Asteroid searches have improved with new observational projects, but satellite constellations make observations more difficult.
• We are not currently monitoring about half the sky for asteroids.
• Efforts are being made to create a better catalog and monitor more of the sky.

The Big Bang Theory and Inflation

• The Big Bang theory suggests that the universe was smaller, denser, and hotter in the past.
• When we look farther into the universe, we are looking farther into the past.
• The universe had a big event called inflation that we don’t fully understand.

Possibility of Vacuum Decay

• Vacuum decay is a theory where a quantum event could cause the universe to transition to another state, creating a bubble of death that expands at the speed of light in every direction.
• Vacuum decay is a probabilistic event but is unlikely and probably would have happened already if possible.
• If vacuum decay were to happen, it would be the best way for everything to end simultaneously.

Methods to Stop Asteroids

• One method is a gravitational tractor, which involves parking a massive spacecraft next to the asteroid to nudge it off course.
• Another idea is to capture the asteroid in a giant sack made of inflatable, metal mesh, or high-strength materials.
• NASA has introduced a plan to capture asteroids in giant bags made of inflatable, metal mesh, or high-strength materials.

The Future Collision of Milky Way and Andromeda Galaxies

• The Andromeda Galaxy is coming towards the Milky Way and will collide in about four billion years.
• The collision will combine the two galaxies into one big blob.
• Our solar system will probably not be affected due to the vast space between stars in galaxies.

Reducing Light Pollution for Stargazing

• National organizations advocate for better lighting in cities to reduce light pollution and promote stargazing.
• Stargazing can be done in cities by attending dark sky star parties or driving a few hours outside the city.

Dimensions, Universes, and Alternate Realities

• Other dimensions of space may exist, but we cannot perceive them.
• Universes can be defined as everything or just the observable universe, and there could be other universes separated by higher dimensions from us.
• The many worlds idea of quantum mechanics suggests that every time a quantum event happens, another universe branches out from ours, creating alternate realities.

Summary

Asteroid Searches and Challenges

Asteroid searches have improved with new observational projects, but the presence of satellite constellations poses challenges to observations. However, efforts are being made to create a better catalog and monitor a larger portion of the sky. This is crucial as we are currently not monitoring about half the sky for asteroids, and some methods from sci-fi movies may not be plausible for saving the planet from potential asteroid threats.

The Big Bang Theory and Inflation

The Big Bang theory suggests that the universe originated from a smaller, denser, and hotter state. When we observe distant parts of the universe, we are essentially looking back in time. Additionally, the universe experienced a significant event called inflation, which is not fully understood but played a crucial role in its development.

Possibility of Vacuum Decay

Vacuum decay is a theoretical concept where a quantum event could trigger the universe to transition to another state, resulting in the expansion of a bubble of death at the speed of light in all directions. However, vacuum decay is considered a probabilistic event and is unlikely to occur. If it were to happen, it would lead to the simultaneous end of everything without any consequences.

Methods to Stop Asteroids

In the event of discovering a potentially hazardous asteroid, there are various methods to divert its path. One method is the gravitational tractor, which involves positioning a massive spacecraft next to the asteroid to alter its course through gravitational interaction. Another idea is to capture the asteroid in a giant sack made of inflatable, metal mesh, or high-strength materials. NASA has introduced plans to capture asteroids using inflatable, metal mesh, or high-strength material bags. Additionally, the concept of spray painting half of the asteroid to change its trajectory using solar wind has been explored.

The Future Collision of Milky Way and Andromeda Galaxies

In approximately four billion years, the Milky Way and Andromeda galaxies will collide, resulting in a spectacular light show of gas and stars merging. This collision will trigger a burst of star formation, and black holes may become active, pulling in matter and emitting intense brightness. However, our solar system is unlikely to be significantly affected due to the vast distances between stars in galaxies.

Reducing Light Pollution for Stargazing

National organizations such as Darksky.org and the International Dark Sky Association advocate for better lighting practices in cities to reduce light pollution. This is essential for promoting stargazing opportunities. Even in cities, stargazing can be enjoyed by attending dark sky star parties or driving a few hours outside urban areas to areas with less light pollution.

Dimensions, Universes, and Alternate Realities

The existence of other dimensions beyond the ones we perceive is a complex and speculative topic in physics. While we cannot directly perceive these dimensions, hypotheses suggest that gravity may leak into them, potentially explaining why gravity is weaker compared to other forces. Furthermore, there could be other universes separated from ours by higher dimensions. The many worlds interpretation of quantum mechanics proposes that every quantum event creates branching universes, leading to alternate realities.

Conclusion

In this episode, Dr. Katie Mack provides insights into various aspects of astrophysics and cosmology. From asteroid searches and methods to stop them to the collision of galaxies and the possibilities of other dimensions and universes, the wonders of the universe are explored. Additionally, the importance of reducing light pollution for stargazing and the positive impact of science communication on academia are highlighted. Join Alie Ward and Dr. Katie Mack in their exploration of the mysteries and beauty of the cosmos.