Understanding Star Light

Star Light pic

Star Light
Image: abc.net.au

A nature lover based in Westbury, NY, Valerie Varnuska is interested in astronomy and the general beauty of the night sky. While in Arizona, for example, Valerie Varnuska had the opportunity to observe a particularly vivid night sky alive with hundreds of stars.

Most people understand that the stars they see twinkling back at them on a moonless night are almost unfathomably distant from Earth, but they may not comprehend that, upon viewing the stars, they are actually looking “back in time.” If a a star is 50,000 light-years from Earth, it would take light from that star 50,000 years to reach Earth since light travels at a constant speed. Therefore, when people gaze up at that star, the light that enters their eyes and creates the image is 50,000 years old, making the image itself reflective of conditions 50 millennia in the past.

This information has profound scientific implications. Physicists and astronomers can use this insight to examine the conditions of the universe in the very remote past by searching out light from stars and galaxies originating billions of years ago. Though light from a remote region of the universe is quite faint, scientists can use modern telescopes to amplify it, giving them an impression of the state of affairs that existed long before the Earth or even its sun existed.

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