Q&A 26: Faster Than Light Into the Past?

TL;DR

Astronomer answers questions about black holes, star formation, time travel, Dyson Spheres, dark matter, fusion energy, and the Milky Way.

Transcript

back again with another question show as always wherever you are on the channel on watching any video whether this question show or any others you have a question pops in your mind just type it in I'll gather them all up and answer them here and did you like the present last week from dr. Paul Metz utter we've got another one this week another gues... Read More

Key Insights

• 🖤 Dark matter can interact with gravity and fall into black holes, despite not interacting with regular matter in terms of radiation.
• 🤩 Stars have a limit to their size and mass due to solar winds and the inability of more material to fall onto them.
• 🗺️ FTL travel allows seeing into the past, but not physically traveling to it. Turning back brings the traveler back to the present.
• 💨 The Breakthrough Starshot mission could be a faster way to explore the Oort cloud and improve our understanding of the solar system.
• 🥵 Dyson Spheres leak out infrared radiation due to the laws of thermodynamics, as heat cannot be entirely contained.
• 💁 Dark matter is essential for the formation of galaxies and prevents them from flying apart due to their rotation speeds.
• ⛽ Fusion reactors produce more energy than they consume as long as they have a continuous supply of hydrogen fuel.
• 🚀 Water is used during rocket launches for acoustic dampening, preventing damage from excessive vibrations and noise.
• 😒 The SETI program scans for alien broadcasts, assuming that advanced civilizations would send signals and use radio waves for communication.

Questions & Answers

Q: Can black holes consume dark matter?

Dark matter, being influenced by gravity, can fall into black holes. However, what happens inside a black hole is still unknown.

Q: Can stars become so large and hot that they stop emitting visible light?

No, there is a limit to the size and mass of stars due to solar winds and material falling onto them. They cannot become black and stop emitting visible light.

Q: Can traveling faster than the speed of light allow time travel to the past?

Traveling faster than light allows seeing into the past, but once you turn around and return, your time catches up with the present. Physical travel to the past is not possible.

Q: Is there a faster way to explore the Oort cloud?

The Breakthrough Starshot mission, involving tiny solar sails, could be a faster method to explore the Oort cloud and map out the solar system.

Q: Why would Dyson Spheres leak out infrared radiation?

According to the laws of thermodynamics, some radiation will escape due to the heat generated by the trapped light absorbed by the Dyson Spheres.

Q: Do all galaxies contain dark matter?

Yes, all galaxies have dark matter, with roughly 10 times more dark matter than regular matter. It is crucial for galaxy formation and preventing them from flying apart.

Q: Do fusion reactors consume more energy than they produce?

Fusion reactors produce more energy than they consume because the fuel (hydrogen) is used in the fusion reaction itself. As long as there is a continuous supply, the reactor will run.

Q: Why is water used below rockets during launch?

Water is used for acoustic dampening during launch to absorb excessive noise and vibrations that could damage the rocket.

Summary & Key Takeaways

• Dark matter, a hypothetical type of matter that doesn't interact with regular matter, can be consumed by black holes due to its interaction with gravity.

• Stars cannot become so large and hot that they turn black and stop emitting visible light. There is a limit to their size and mass due to material falling onto them and producing strong solar winds.

• Traveling faster than the speed of light allows seeing into the past, but not physically traveling into it.

• The Breakthrough Starshot mission, involving a tiny solar sail, could be a faster way to explore the Oort cloud and map out the solar system.

• Dyson Spheres, theoretical megastructures surrounding stars, would leak out infrared radiation due to the laws of thermodynamics.

• All galaxies contain dark matter, which is crucial for their formation and for preventing them from flying apart due to their high rotation speeds.

• Fusion reactors do not consume more energy than they produce as long as they have a continuous supply of hydrogen fuel.

• Water is used beneath rockets during launch for acoustic dampening to absorb excessive noise and vibrations.

• The SETI program scans the sky for alien broadcasts, assuming that advanced civilizations would send signals to us and be using radio waves.

• The location of the Milky Way and its shape, a spiral galaxy, have been determined based on measurements of distance to stars and globular clusters.