Due to the huge distances in space, it is very difficult to show the size of the universe through known units of measurement. That’s why there is an astronomy unit, a light year, One light year equals the distance a beam of light travels in one year in space vacuum. Since light travels in vacuum at a speed of approximately 299792458 metres per second, light travels an absolutely inconceivable distance of 9500 billion kilometers in a year. The letters are written – nine and a half thousand billion kilometers – just one light year. Light from the Sun that is close to 150 million kilometers travels for 8 minutes and 20 seconds. From the moon a second and a half. This means that you see the Sun with a delay of 8 minutes and 20 seconds. If a catastrophe were to occur in the sun, you would still see the sun as if nothing had happened. But don’t be fooled by this, as the distances from the sun and moon are still bearable.
The nearest star
Where are we? Our closest Proxima Centauri star is about 4.3 light-years away. When we see this star today, we actually see her as she was 4.3 years ago. Proxima Centauri distance calculation from Earth: 9500 x 4.3 = 40850 billion kilometers. Forty thousand, eight hundred and fifty billion km to the Earth closest to the star. Inconceivable distances that our mind cannot comprehend. The MACS0647 Galaxy is one of the remotest objects we have ever seen. It is as much as 13.3 billion light years away, and it took so much light to reach us. This means that we see her as she looked in the past very shortly after the Big Bang. Where she is now no one can assume. In these expanses, the light year loses its meaning. Parsec is a unit of measurement that should help with this, but about this another time …
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WHAT IS A LIGHT YEAR ASTRONOMY