The Sky in 350 Billion Years

TL;DR

The universe is expanding, causing billions of stars to become unreachable, yet our observable universe is getting bigger. Experts discuss the mind-bending implications of this phenomenon.

Transcript

billions of stars are disappearing in a in the real sense our horizon is getting smaller because we're able to see fewer things yeah and the strict physics measurement sense it's getting bigger but in a way that kind of doesn't matter yeah millions of stars are becoming unreachable to us every day but what does unreachable mean because we also know... Read More

Key Insights

• ⚖️ The discovery of other galaxies in 1924 revolutionized our understanding of the universe's size and scale.
• 😒 Edwin Hubble's use of the 100-inch telescope at Mount Wilson Observatory resulted in the groundbreaking discovery of an expanding universe.
• ⚡ The observable universe is defined by the speed of light and the age of the universe, and it is constantly growing.
• ❓ Dark energy, which constitutes a significant portion of the universe, is still not well understood and could impact the future expansion of the universe.
• 💨 The expansion of space itself causes distant galaxies to move away from us faster than the speed of light.
• 👾 The concept of motion in the universe becomes complicated when considering the expansion of space.
• 🙂 Our ability to see and gather information from distant galaxies is limited by the speed at which light can reach us.

Questions & Answers

Q: How did Edwin Hubble's discovery challenge our understanding of the universe?

Edwin Hubble's observation of redshift in galaxies led to the realization that the universe is expanding, challenging the notion of a static universe.

Q: What is the difference between the whole universe and the observable universe?

The observable universe is the part of the universe that we can see and gather information from, while the whole universe extends beyond our reach.

Q: Why are distant galaxies moving away from us faster than the speed of light?

The expansion of space itself is causing the galaxies to move apart faster than the speed of light, even though nothing can move through space faster than light.

Q: Will the universe continue expanding forever?

It is uncertain. The discovery of dark energy, which accelerates the expansion, raises questions about the ultimate fate of the universe.

Summary & Key Takeaways

• In 1924, astronomers discovered the existence of other galaxies, expanding our understanding of the universe.

• Edwin Hubble's use of the 100-inch telescope at the Mount Wilson Observatory led to the discovery of the expanding universe.

• The observable universe is getting larger due to the expansion, but the number of galaxies within our reach is decreasing.