Time is a very complex thing; some say that it is infinite, while the other says that it's just an illusion. We all are very familiar with the concept of seconds, minutes, and hours. It's a tool that is used for measuring time.
But have you ever heard of a light second, light-year, or light centuries? If not then these are the tools for measuring extreme time.
This is Now You Know and in this video, we will tell you what is a light-year and where is it used?
Light is the fastest thing that we know, it is so fast that we use it to measure enormous distance, by how long it takes the light to travel them. In the time period of one year light travels around 6trillion miles and that distance is known as one light year.
The moon is just 1 light second away from the earth, while the nearest star beyond the sun is Proxima Centauri is just 4.24 light-years away.
Andromeda is 2.5 million light-years out, the closest galaxy to earth. So the Andromeda we see today is And, is 2.5 million years in the past.
This will be incredibly difficult and ineffective to calculate space distance in miles or kilometers. The Orion Nebula is only seven,861 trillion miles, we can also say 1,300 light-years away, in our neighborhood galaxy.
While calculating light-years, it also enables astronomers to determine how far they look back in time. As light needs time for our eyes to move, so whatever we are looking at has already happened in the past in space. In other terms, you see that is just one light year away, you see it in the same away as did it happened one year ago.
Astronomers also use parallax second as an alternative to calculating the distances of the stars by observing its position shift in the sky whenever the earth rotates halfway around the sun.
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