Hubble's Expanding Universe Red Shifts The Big Bang

Summary

In the 1920s, Edwin Hubble's work at Mount Wilson Observatory revolutionized our understanding of the universe. Using advanced telescopes, he discovered that distant galaxies, including the Andromeda galaxy, were much further away than previously thought, indicating a universe larger than the Milky Way. Hubble's observations of galaxies' light wavelengths revealed that the universe is expanding, a concept known as Hubble's Law. This foundational discovery supports the Big Bang theory, suggesting the universe began 10-20 billion years ago. The Hubble Space Telescope, deployed in 1990, continues to advance our cosmic knowledge by capturing images of distant stars and galaxies, helping to measure the universe's age and size.

Takeaways

• 🔭 Edwin Hubble worked at the Mount Wilson Observatory in the 1920s, utilizing advanced technology to study the universe.
• 🌌 Hubble's observations of Cepheid variable stars allowed him to calculate vast cosmic distances, revealing that galaxies like M31 were much further than previously thought.
• 🌟 He discovered that the universe is much larger than the Milky Way, with billions of galaxies, each containing hundreds of billions of stars.
• 📊 Hubble's Law describes the relationship between a galaxy's distance and its velocity, indicating that the universe is expanding.
• 🚀 The concept of an expanding universe supports the Big Bang theory, suggesting the universe began with a massive explosion and has been expanding ever since.
• 🔍 Hubble's work laid the foundation for modern cosmology, influencing our understanding of the universe's age, size, and expansion.
• 📸 The Hubble Space Telescope, launched in 1990, continues Edwin Hubble's legacy by capturing high-resolution images of distant stars and galaxies.
• 🌐 The telescope's location above Earth's atmosphere allows for clearer observations, contributing to the study of the universe's expansion.
• 🛰️ The Hubble Space Telescope orbits Earth at about 380 miles, providing continuous observation of the cosmos.
• 🌠 The data collected by the Hubble Space Telescope helps scientists measure the age and size of our expanding universe, building on Edwin Hubble's original discoveries.

Q & A

Who was Edwin Hubble and what was his primary contribution to astronomy?

Edwin Hubble was an astronomer who worked at the Mount Wilson Observatory in Southern California. His primary contribution was discovering that galaxies, including the Andromeda galaxy, were much further away than previously thought, indicating that the universe was much larger than the Milky Way galaxy.

What was the significance of the Mount Wilson Observatory for Edwin Hubble's work?

The Mount Wilson Observatory provided Edwin Hubble with access to advanced technology, including George Ellery Hale's magnificent telescope, which was crucial for his observations and subsequent discoveries about the scale of the universe.

What type of star did Hubble discover that helped him calculate the distance to galaxies?

Hubble discovered a Cepheid variable star, which varies in brightness over time. By studying its brightness variation, he was able to calculate the distance to the star and, by extension, the galaxies it was part of.

What was the distance to the Andromeda galaxy that Hubble calculated?

Edwin Hubble calculated that the distance to the Andromeda galaxy, M31, was about two million light-years away.

How did Hubble's discovery change the understanding of the universe's size?

Hubble's discovery showed that the universe was much larger than previously thought, with billions of galaxies, each containing hundreds of billions of stars, existing outside of the Milky Way.

What was the significance of Hubble's second major discovery regarding the movement of galaxies?

Hubble's second major discovery was that galaxies are moving away from each other, with their velocity proportional to their distance from us. This observation led to the concept of an expanding universe.

What is Hubble's Law, and how does it relate to the expansion of the universe?

Hubble's Law states that the velocity at which a galaxy is moving away from us is proportional to its distance from us. This law is a fundamental concept supporting the Big Bang theory, which posits that the universe is expanding.

What was the Big Bang theory, and how is it connected to Hubble's discoveries?

The Big Bang theory is the idea that the universe began with an enormous explosion of energy, density, and compression between 10 and 20 billion years ago and has been expanding ever since. Hubble's discovery of the universe's expansion supports this theory.

What was the purpose of launching the Hubble Space Telescope in 1990?

The Hubble Space Telescope was launched to orbit about 380 miles above Earth's surface to view the cosmos without the interference of Earth's atmosphere, allowing for clearer observations of stars and distant galaxies.

How does the Hubble Space Telescope assist in measuring the age and size of the universe?

The Hubble Space Telescope collects images of stars and distant galaxies, which help astronomers measure the age and size of the universe by observing the light they emit and their distances from us.