Theoretical Question about Milky Way

In summary, the conversation discusses the possibility of looking back in time by observing the night sky and the universe's expansion. It is mentioned that the light we see from the Milky Way is from about 30,000 years ago and the most distant parts of the galaxy are about 100,000 years away. The expansion of the universe does not affect the scale of a galaxy.
  • #1
Valcken
1
0
This may be a stupid question, but it just popped up in my mind a few minutes ago. Considering we are able to "look back in time" so to speak, because light takes so long to get here, is it possible for us to look in the night sky and see light that came from the Milky Way?

Considering the universe is expanding, and has been expanding ever since it began, wouldn't it be possible to say, look at the cosmic microwave background and actually see our galaxy as it was a few billion years ago?
 
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  • #2
It doesn't work like that.
We are in the middle of the galaxy, about 30,000lyr from the center - so when we look at the center we see light that left there 30,000 years ago.
The most distant bits of the milky way are about 100,000lyr away
The universe expansion doesn't do anything on the scale of a galaxy.
 

Related to Theoretical Question about Milky Way

1. What is the Milky Way?

The Milky Way is a spiral galaxy that contains our solar system and is home to billions of stars, including the sun. It is estimated to be about 13.51 billion years old and is one of the largest and most massive galaxies in the known universe.

2. How big is the Milky Way?

The Milky Way is estimated to have a diameter of around 100,000 light-years, meaning it would take light 100,000 years to travel from one end of the galaxy to the other. It is also estimated to contain around 200-400 billion stars and a mass of 1-1.5 trillion solar masses.

3. What is the shape of the Milky Way?

The Milky Way is a spiral galaxy, meaning it has a flat disk-like shape with a central bulge and spiral arms extending outward. However, the exact shape and structure of the Milky Way are still being studied and debated by scientists.

4. What is the role of the Milky Way in the universe?

The Milky Way is an essential component of our local group of galaxies and plays a crucial role in the structure and evolution of the universe. It provides a gravitational anchor for smaller galaxies and helps to shape the distribution of matter in the universe.

5. How do we study the Milky Way?

We study the Milky Way through various methods, such as observations with telescopes and satellites, computer simulations, and data analysis. Scientists also use techniques like spectroscopy to study the chemical composition and dynamics of stars and gas in the Milky Way.

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