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Thread: How we see light

  1. #1 How we see light 
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    If I remember right , it takes about 8 minutes for the suns light to reach earth. And it takes about 2 seconds for the light of the moon to reach earth. What if your on a mountain top waiting for sunrise. Then suddenly the sun hits a peak off in the distance lets say 25 miles. The light that your seeing on that peek took time to get to your eyes, right? If thats so, is that how we see everything? Even in our home when we switch on a light?


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  3. #2  
    Brassica oleracea Strange's Avatar
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    Not sure what the problem is. We can hear sound from different distances even though the relative delay is much larger.


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  4. #3  
    Comet Dust Collector Moderator
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    Light travels at 186,000 miles a second (300,000 km) no matter where it comes from. From the distant peak, it took 8+ minutes to get there from the sun and 0.13 milliseconds to travel from the peak to you. (actually, a little longer, since it's traveling through air from the peak to you)
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  5. #4  
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    Thankyou both. Bear with me. I don,t explain things too clearly sometimes. I need to go back to my old highschool science teacher. But its been too long and he is no longer alive filix.
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  6. #5  
    Quagma SpeedFreek's Avatar
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    Light always takes time to reach your eyes, so you never see anything as it is "right now". The further away something is, the longer the light took to reach you.

    We see the Moon as it was a second and a quarter ago. We see the Sun as it was 8 minutes ago. We see the stars in the sky as they were years ago. The light from the nearest star to the Sun takes over 4 years to reach us, and the light from the centre of the galaxy takes around 30,000 years.

    Even your computer screen is seen as it was a tiny fraction of a second ago.

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  7. #6  
    Comet Dust Collector Moderator
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    No problem filix, welcome!
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