1. Qulaey

    Qulaey New Member

    In a Youtube video documenting an expariment done by youtuber MrThriveandSurvive. He observes a mirror flash of the sun through an inferared modified P-900 at a distence of 17.61 miles or 28.24km. See if you guys can help me debunk this.

    Video link:

    Source: https://www.youtube.com/watch?v=2_PHDgOS3ro


    Here are the atmospheric measurements that he took in order to calculate refraction using a snells law calculator.


    He also did a "three way mirror flash" in order to show that atmospheric refraction did not interfere with the results. the way that he explains it in the video is not extremely clear so I might have interpreterted it wrong but in essence, he has set up mirrors at all three points of the lake: A, B and C. he claims that in his experiment he flashes the mirror at point A and this flash can be obesrved at both point B and C. then the team at point C will flash the mirrors at both point B and A. The flashes are claimed to be seen again by the both teams and finially he flashes the mirrors at point B, the flash is seen by people at point A and C.

    He concludes that because of these three way triangular flashes, refraction could not have played a role in the observations as different densities in the air would not allow all three mirrors to be seen at all three points.

    This stage of the experiment was not documented in the video.

    A couple of issues with the expariment that I see already:

    1. he does not explain the way he handles the mirrors while making the observations. we do not know if they were stationary set at a static angle or the teams were just wildly shaking them around until someone saw a reflection.

    2. he did not account for the divergence of the reflected beam which means that we could be purely seeing the light on divergence, making the "3 way test irrelevant"

    3. he failed to observe any moving vehicles or any of the team members on the infrared red camera, if the earth was indeed flat we should be able to see him and his team entirely, and be able to identify IR bloobs in the pictures of the mirror flashes.

    Attached Files:

  2. Mick West

    Mick West Administrator Staff Member

    Essentially this is the same thing as a laser test. I cover that here:

    Note that a water temperature of 65° and an air temperature of 80°+ is guarenteed to create significant bending of light near the surface, so so there will be a band of highly compressed shoreline, which will contain the light, but everything else will be too compressed to see.

    Snell's law has very little to do with refraction in a medium with a gradient, especially where the gradient is nearly perpendicular to the light path. You need a form of ray tracing. Like this:


    Metabunk 2019-05-04 23-35-44.

    Here I've set a laser at 5 feet, camera at 5 feet, 18.8 miles apart. There's a relatively steep temperature gradient.
  3. Qulaey

    Qulaey New Member

    Does that mean the three way mirror test is invalid in proving that there is effect on the results by atmospheric refraction?

    I didn’t really see how it would in the first place. He never explains it in his video.

    Also a more clearer video to this one would be from a YouTuber named

    Mike Boll who was one of the members in the experiment.

    Video names: salton sea 18 mile mirror flash where he explains it in more detail.
  4. Mick West

    Mick West Administrator Staff Member

    Yes it makes no difference. The light from the flash is widely spread. So some light will get thrrough. Here's the spread zoomed in x200 vertically with a narrow laser beam. This is for 18 miles.
    Metabunk 2019-05-05 07-56-01.

    Doing it over 10 miles with the same temperature gradient just makes the flash more visible.
    Metabunk 2019-05-05 08-00-11.

    And with a very different temperature profile, the light for the laser is still visible.
    Metabunk 2019-05-05 08-01-09.

    The important light is the light that skims the horizon. With something like a torch/flashlight or a sun mirror flash, it's a trivial matter to have a light path from light to camera via the horizon, with even a very small temperature gradient. Lasers are slightly more limited in angles, but if you point it at the horizon then it will probably get through over cold water for very long ranges. Here we've got a sun flash which is a pretty broad beam aimed at the horizon. Of course it's visible.
  5. Mick West

    Mick West Administrator Staff Member

    This effect can be seen if we make a more realistic gradient, where the cooling effect of the water is limited to a relatively narrow band.

    Metabunk 2019-05-05 08-15-47.

    Notice the compression of the floors of the white building on the right
    Metabunk 2019-05-05 08-16-26.

    Compare with flat earth no refraction view
    Metabunk 2019-05-05 08-19-31.
    (Lasers are broken in FE mode in the simulator right now)

    The entire building is compressed in the real world (curve, refraction) view, but at least the upper portion is recognizable. The region near the horizon is all squashed into a thin band where you can't make out any details, but you can see lights and lasers.
    • Like Like x 1
  6. Qulaey

    Qulaey New Member

    Alright cheers mick!