Anonymous asked in Science & MathematicsAstronomy & Space · 2 months ago

When I look up at a star like Polaris, 400 light-years away, why are the photons from it on a perfect trajectory to hit my retina?

I mean, isn't that an odd coincidence, considering the distance?

31 Answers

  • 2 months ago

    This nuclear furnace continually emits an ever expanding bubble of electromagnetic power/energy 360° on all three axis. It would be a coincidence if it didn't hit your photon detectors (eyes).

  • garry
    Lv 5
    2 months ago

    never knew you can see photons , arent they microscopic ..

  • Anonymous
    2 months ago

    It's an odd coincidence for those particular photons, among the gazillions that were emitted by the star. As a bad analogy, imagine you're standing in a room with a paint-filled balloon when it explodes. Paint droplets go in every direction including yours. You're going to get paint on your goggles but there's nothing special about those drops of paint.

  • zipper
    Lv 7
    2 months ago

    One there are no protons involved here, it is the light that is now meating your eye and that light is NOW!  Today this minute. and as far as your eye see's it the light is only inch's away!

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  • Tom
    Lv 7
    2 months ago

    Considering the photons are radiated out SPHERICALLY from the star at ALL angles, then some of those angles HAVE to coincide with photon paths to your retina if you look in that direction.

  • david
    Lv 4
    2 months ago

    No. Not all the photons hit your retina. You only see Polaris from one angle. The rest of the light gets seen by someone else, or nobody at all. 

  • 2 months ago

    Light is not a stream of particles.  Owing to the strangeness of quantum theory, light consists of a "wave-particle duality", which means that sometimes it acts like a wave, and sometimes like a particle.  

    When you observe celestial objects, light is behaving like a wave, so there is no surprise that you can see it no matter how far away you are.  If you throw a rock into a lake, don't the ripples spread out in all directions to reach all the furthest corners of the lake ?  Think of the light from a star in the same way.  Nothing coincidental about it.  

    When the circumstances are different, then light  appears to act like a stream of particles, but that does not apply in this case.

  • 2 months ago

    A star, such as Polaris, gives out light/photons in ALL directions.  It is not a straight line from the star to your eyes, but other a sphere that expanses outward in all directions.  If you end up in the path of the sphere (which is huge in size) then you will see the star.

  • 2 months ago

    the photons go equally in every direction. Some very very tiny percentage hits your eye.

    The percentage can be calculated....

    400 LY = 3.8e18 m

    the light is spread over the surface of a sphere with that radius.

       Sphere  A = 4πr² = 4π3.8e18² = 1.8e38 m²

    guessing, the area on your retina is perhaps 1 mm² or 1e-6 m²

    dividing we get 1.8e44

    so only that ratio hits your eye.

  • 2 months ago

    They do not hit just your retina, but everybody else's too.  With a big lens, you could collect those photons from a larger area and see Polaris better. (telescope).

          If you were far enough away (a lot further away) the photons would be spread out too far apart for you to see the star.  But you would not see it any better by moving over a few feet because the photons are evenly spaced apart.

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