How We See The Past

Hi everyone! Here is my first Autumn post – it is not about travel, but something to contemplate with the change of season, as the stars become brighter with the coming of winter. We’ll have to find things to do when it’s cold! 

Did you know that every night you can look into the past?

Just gaze at the night sky. What you see is what happened hundreds and thousands of years ago.
To understand this better let’s look at what a light year actually means.
It is not a measure of time as the name deceivingly suggests, but in fact a measure of distance. To be exact it is a distance that light travels in one year – 9,500,000,000,000 kilometers. Because some stars are so far away, writing out distance in miles/kilometers would simply look unintelligible to most. Instead, light years measurement is used. Why light? Because nothing in cosmos travels faster than light, and because it is the light we see reaching us from other stars.
Let’s say we are in the same room and I turn on the lights. You see the light immediately. But were you to be on a different planet, say 9,500,000,000,000 kilometers away from me, you would see the light I just turned on only a year from now. Of course, in reality, it would have to be a larger source of light to be visible at such distance – an exploding star perhaps. If the star one light year away from us exploded a year ago, we would see that explosion only now.
A star you see in a telescope that is 1 million light years away may look entirely different now, or might had collapsed and become a black hole, but you are seeing it now the way it looked a million years ago because it takes light from that star a million years to reach us.

Stars visible to a naked eye are tens, hundreds, and thousands of light years away. What we see in the night sky HAD ALREADY HAPPENED…

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5 thoughts on “How We See The Past

  1. I have pondered this amazing concept on many ocassions under the Milky Way. Perhaps that is why it took millions of years for life to form on earth. We had the sun but the night sky was blank. When the energy of the universe arrived, life began. It’s also no secret we are made of the same elements as the stars and that the energy of distant suns create basic elements necessary for life and for the existance of the universe. So, it is from the universe of stars we come and the ancient uncountable years it took for the universe to give life and motion, solidity, gravity, water, and all the compounds and elements that allowed an endless palette of creativity to render the greatest masterpiece of life. There is no wonder we look to the sky when we face our Gods throughout history. Wonderful post, Natasha. Your skill for making complexity understandable and interesting is a gift we would all hope to share.

    Liked by 1 person

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