How Much of the Past Do We See When We Look at the Sky?

The sky is actually like a giant mirror. When we look up we see not only the stars We are watching billions of years ago.

let’s see how many light years are we looking?

Let’s go into a little more detail about the speed of light and distances in the universe.

Speed ​​of light, approximately per second 300 thousand kilometers expresses. Of course, although this is a magnificent number, it is a bit modest when it comes to the size of the universe.

For example Light coming from the Sun to the Earthtravels in approximately 8 minutes. So, when we watch the Sun, we actually see it as it was 8 minutes ago.

This doesn’t just apply to the Sun either. Distant stars, galaxies and we can even say the same thing for all objects deep in the sky.

Many of the stars we see in the sky are quite far from Earth.

Distance traveled by a light year in 1 year approximately 9.5 trillion km. Take Sirius. It is approximately 8.6 light-years away from us. So, we actually see it as it was 8.6 light years ago.

There is something more impressive. Room Andromeda Galaxy. It is 2.5 million light years away from us.

We can’t do without mentioning the HD1 galaxy.

The most distant object humans have ever seen It is approximately 13.3 billion light years away. It is estimated to have formed shortly after the Big Bang, when chemical elements were almost non-existent. This means that we are observing it as it existed in the very early universe.

However, when we look at HD1, we cannot say that we see it because space telescope It was detected with . But while we’re on the subject, information is information.

In astronomy, this concept is called “cosmic time machine”.

In fact, each celestial body represents a different time period of the universe depending on the distance. Hubble Space Telescope Thanks to observations made with instruments such as, we can reach the state of the universe billions of years ago.

Right after the formation of the universe With these observations, which mean witnessing, we actually see traces of many things and add new ones to our knowledge about space.

What if some of the stars are dead?

Maybe some of those bright stars we see in the sky are already destroyed in a supernova explosion and we still see its past light.

Next time you look at the sky history book of the universe You can now feel like you are reading in the light of this information.

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