1. Abishua

    Abishua Member

    So, if moon is trully reflecting suns light, the quality of light should remain the same, that is warm, yet when we measure the quality of moons light the results show that moonlight cools things that are exposed to it.

    This means that measured temperatures of things that are in moon shade are higher than those exposed to moonlight.

    I find this interesting because this implies that moon is self iluminating object.. with a completeley different quality of light than sun has.

    What do you guys think about this phenomenon? Here are some experiments done on this subject, since it is very easy and cheap to do, hopefully we can recreate some here ond "bring into light" what is going on here.. pun intended.. :D


    So what we see here is.. this guy used 2 glasses of water, both on the same table, at the same starting temperature, one was exposed to moon light and other was in moon shade.. he was constantly measuring the temperature of water in both cups, and end result showed that the one exposed to moon light was much cooler.. no pun intended.. :D

    so you can see the entire video here if you want..

    there are also many more like this one that show the same results.. can someone recreate this experiment, or a similar one?
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  2. Mick West

    Mick West Administrator Staff Member

    He moves the moon glass to another area of the table, this cools it down because now it's on cold table.
  3. Trailblazer

    Trailblazer Moderator Staff Member

    He's also leaning a big metal heat sink (the magnifying glass) up against the "moonlight glass".
  4. Abishua

    Abishua Member

    oohh.. yes.. that makes sense.. it's quite possible..
  5. Mick West

    Mick West Administrator Staff Member

    That too, although the contact area there is quite small.
  6. Mick West

    Mick West Administrator Staff Member

    A much better way of doing this experiment would be to use a FLIR thermal camera. I might give it a go.
  7. Abishua

    Abishua Member

    there are also 2 other videos I saw on this subject.. in one of them.. a guy was measuring copper temperature.. with that infrared gauge.. so if you are interested to see it type into youtube "Moon Light Magnification Test". I would link it but dunno if I may..
  8. Abishua

    Abishua Member

    please do.. I am interested in objective results.. I might try it myself..
  9. Mick West

    Mick West Administrator Staff Member

  10. Abishua

    Abishua Member

    Dont have it.. I have one of these... it should work nicley.. very precise readings I get from it..

  11. Mick West

    Mick West Administrator Staff Member

    Don't move the glasses. Cover the moonlight first (at the window), then ensure the temperature remains the same in both glasses for five minutes (i.e. it decreases at the same rate), then uncover the window.
  12. Bfahome

    Bfahome Member

    I remember someone calling in to The Atheist Experience with this claim several weeks ago. The setup for their claimed experiment was different (put two thermometers outside, one covered, one uncovered; this setup has its own numerous flaws) but the claim was the same.

    In this case, I'm not sure what the magnifying glass is expected to do. I expect it's there because "magnifying glass + light" conjures the image of setting ants ablaze on a hot summer day. In this case, though, it looks like the magnifier would do absolutely nothing for the temperature of the water. All it's doing is collecting the light that would have gone into the glass anyway and concentrating it into a slightly smaller area. And it's only affecting the very bottom of the glass.

    So whether or not it was the intention, it seems as if the only thing the magnifier does is make the experiment seem more visually impressive.

    (As an aside, here's a cool xkcd "What If?" about moonlight and magnifying glasses. "Can you use a magnifying glass and moonlight to light a fire?" The answer is no, you can't, essentially because a magnifier cannot make something hotter than the surface of the light source it is magnifying from.)
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  13. Trailspotter

    Trailspotter Senior Member

    This thread is in a wrong forum.
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  14. Mick West

    Mick West Administrator Staff Member

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  15. Rory

    Rory Active Member

    I'm aware there are lots of these "moonlight is cold" videos and experiments around, generally showing the results as above.

    The usual explanation is that either something is wrong in the performing of the measurement, or that the experimenter has only shared the results that match their hypothesis, and discarded all those that contradict it.

    What doesn't much seem to happen is that a sceptic takes the measurement for themselves, which is what I'd be interested in seeing.

    Also, I do believe that the temperature should probably be measured on at least a hundred occasions before any kind of proclamation be made. One measurement is proof of nothing: I once worked in gambling statistics and was told that even if something occurred 500 times, it may not necessarily be significant. In our tests we ran scenarios tens of thousands of times before getting behind it.

    All that said, I think this is an interesting idea that I, for one, haven't yet seen debunked.

    PS Does anyone know where the idea for the moon's cooling light comes from? I know Rowbotham wrote about it, and that he also cited an article in the Lancet (March 14th, 1856) in which "several experiments proved the Moon’s rays when concentrated can actually reduce the temperature upon a thermometer more than eight degrees."

    Interestingly, at the moment I live in the desert and we have clear, cloudless nights and I haven't noticed any sort of dampness, chill, or drop in temperature from being out under the full moon.

    If the hypothesis that moonlight can decrease temperature by several degrees is true, would it also follow that places which normally have clear skies at night would show a marked change in average temperature the more moonlight there was? I.e., that it would dip around the full moon?
  16. Abishua

    Abishua Member

    well put a glass of water outside on the moonlite and put the other one next to it in the shade.. then measure.. simple..
  17. Bfahome

    Bfahome Member

    Not quite so simple, actually. There are several factors to control.

    1. You'd probably want the glasses to be right next to each other to control for any ambient temperature differences.
    2. You'd need to make sure that only one is in the light, and the other is in the dark, for the entire duration.
    3. You can't simply put one in an opaque box, because the box would block the glass from radiating its own energy to its surroundings. This can lead to a false positive result; if the open-air moonlight glass is free to radiate but the shaded, boxed glass isn't, the result can appear to support the "cooling moonlight" effect.

    In order to make any sort of determination as to the cause, you could to the covered/uncovered experiment during both a full moon and a new moon. The new moon test should show you any differences caused by the covering itself, independent of the moon. You could test for other things too, such as putting a glass in a transparent box.

    So, it's not really hard to do, but there are several factors that the basic "put two glasses outside" test wouldn't account for.
  18. Rory

    Rory Active Member

    I won't be able to do that, but here's a video by a fellow who goes by the name of John le Bon, who I've come across before. I think he's a conspiracy theorist and globe-sceptic, who also doesn't believe in the flat earth, interestingly enough.

    In any case, he carries out an experiment with three thermometers - one as control, one under magnified moonlight, and one under direct moonlight - and finds "no evidence that moonlight lowers the temperature of the thermometers" (quoted at 16.01):

    Also, here's a long discussion between two opposing sides of this idea, with lots of references to sources for the "moonlight is cold" notion. It makes a pretty nice summary for those who want to get up to speed:

  19. Hevach

    Hevach Senior Member

    You're failing to control a lot of variables.

    Let's say you do the above, and the one in moonlight is cooler.

    Now, to eliminate variables you also put glasses in the same two locations on an equally clear but moonless night. What does it tell you if you get the same results?

    Something the above posters have missed is Radiative Cooling. Out of the sun on Earth (or any body surface, for that matter), the rate that an object cools is heavily influenced by how exposed it is to the sky. Overhead cover greatly reduces this - clouds have a good effect but trees or canopies are much better. The link describes a simple test you can do on a moonless night with just a sheet of paper and only exposed skin for testing aparatus.

    Moonlight actually slows this, measurably (with very high quality instruments at least) but not significantly - photons cannot carry negative energy, because thermodynamics hates fun and whimsy and crushes all the joy out of life.
    Last edited: Nov 17, 2016
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  20. Mick West

    Mick West Administrator Staff Member

    I just made this video showing magnifying sunlight:

    Source: https://www.youtube.com/watch?v=M-gCvkqcs-8

    Now if moonlight had any effect, either warming or cooling, then there would be a difference in the ground temperature light vs shadow, in a thermal image.

    If I remember I'll try to take a photo of moonlight and moonshadow areas of the ground with my FLIR camera tonight. I expect no difference between the two areas.
  21. Clouds Givemethewillies

    Clouds Givemethewillies Active Member

    A dash of vodka in one glass should do the trick.
  22. Z.W. Wolf

    Z.W. Wolf Active Member

    I've seen quite a few of these experiments. Putting a shade over one glass and leaving the other open to the sky is supposed to measure the cooling effect of moonlight. But there is a confound in the experiment. What you are really measuring is differences in temperature due to differing rates of radiative cooling.


    Backpackers know about this too. Even a simple canvas "roof" on some sticks keeps you warmer at night because the IR you lose bounces back instead of being lost into the sky.

    Some of these videos measure the temperature in a set up experiment, some measure temps in unshaded and shaded areas of their backyard. They both share this problem with radiative cooling. Surfaces in the shade will be warmer because they have lost less energy through radiative cooling.

    I've suggested to more than one of the authors of these YT videos that they should also try the experiment on a night with no moon in the sky. My prediction is that they will get the same result: in other words the differences in temp have got nothing to do with the moon. It's a false correlation.

    I haven't gotten a sensible reply.

    Edit: I just saw that Hevach made a similar post.
    Last edited: Nov 17, 2016
  23. Z.W. Wolf

    Z.W. Wolf Active Member

    As for the cooling effect of moonlight being intensified by optics... I've observed the moon through an 18 inch telescope. I don't remember my eye getting frostbite.
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  24. Z.W. Wolf

    Z.W. Wolf Active Member

    The author of this video has propped a small magnifying glass up against a glass of water. Moonlight is supposedly concentrated on the water and is cooling it more rapidly than the water in the glass that doesn't have a magnifying glass propped against its surface.

    Problem: The magnifying glass in no larger than the width of the glass, and is much shorter. (Not to mention the total volume of the water inside.) A magnifying glass this size would not heat the water as a whole in sunlight. Why should it cool the water in the "cooling" moonlight?

    Problem: He has the magnifying glass just propped up against the side of the glass. How would that focus the moonlight?

    The psychological problem I see here is that the author of this video associates a magnifying glass with heating (or concentrating light), but he does not have any analytical grasp of why it does so.*

    A magnifying glass collects light and (when at the right distance) focuses it on a smaller spot. It takes the energy of light hitting its surface and concentrates it on a smaller spot. The total energy (heat) is the same, only the temperature is different. A magnifying glass cannot raise a flat surface as large or larger than itself to a higher temperature than it would already be under the light striking it. We're just multiplying the problem by trying to change the temperature of a container of liquid.

    I really suspect that he would not be able to define the difference between heat and temperature.

    Everyone has used a magnifying glass in the sun. Think back. The hot spot it produced was only a tiny fraction of the size of the magnifying glass itself.

    So why would "cooling light" behave any differently? You would need a magnifying glass much bigger than the container of water... and you would need to focus it. Not just prop it up against the container.

    * I can once again point to a favorite book. Quite apropos because it deals with the difference between intuitive thought and analytical thought. Intuitive people think in associations and categories.

    In this case the author of this video associates a magnifying glass with heating something under it, (and by extension, cooling something beneath it). But he doesn't have any real idea of how it does so.

    I'll give another example of what I mean. People associate fans with cooling, so they want to leave the ceiling fan running when they leave the house so that the room will be nice and cool when they get home.
    Last edited: Nov 17, 2016
  25. Abishua

    Abishua Member

    Why make things complicated? You can put a peace of carboard as obstruction of moonlight 2 feet away from the object you are measuring.. that way only moonlight is blocked.. and rest of the factors are not affected..

    Why not use 2 coins next to eachother? One with obstructed moonlight and one with a magnifieng glass focusing the moonlight on it? I think this guy used something like that..

  26. Trailblazer

    Trailblazer Moderator Staff Member

    I suspect it all started from the simple observation that nights tend to be colder when you can see the moon. That is simply down to the fact that when you can see the moon it means the sky is at least partially clear, and clear nights are generally colder than cloudy ones, because clouds trap heat.
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  27. Hevach

    Hevach Senior Member

    Still not controlling for radiative cooling. Cardboard is more than enough to create a tangible difference on a moonless night, let alone under moonlight.

    You need to do this in multiple nights under multiple conditions, the two most important being moonlit and moonless with clear skies.
  28. Abishua

    Abishua Member

    you don't cover the coin with carboard.. you put an obsticle to moons light further away.. lets say moon is at 45 degree angle.. you put a small obsticle between the moon and coin as far as possible.. 2 feet lets say.. so nothing directly above the coin will be blocked.. therefore radiative cooling is not blocked.. sky is clean above both coins.. only difference is one is lit by moonlight.. and the other one is not.. let's not complicate this too much.. think about it as if you did this experiment with the sun.. one in the shade.. other one in the sun.. the difference would be obvious.. not much philosophy there.. it eather works or it doesen't..
  29. mm1145

    mm1145 Member

    if it is the light that is cooling put one in a clear plastic box and the other next to it in a non clear box?

    or set them up side by side and then put a piece of card somewhere about a meter away so that it's shadow blocks the moon to only 1 of them
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  30. Henk001

    Henk001 Active Member

    Flat earthers NEED to show that the moonlight isn't reflected sunlight, because if it IS, the moon phases show it is a sphere, and the lunar eclipses show that the Earth's shadow is always circular, which means that the Earth must be a sphere as well.
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  31. Mick West

    Mick West Administrator Staff Member

  32. Mick West

    Mick West Administrator Staff Member

    Yes, it's similar to the need they feel to disprove gravity, and instead replace it with something that looks just like gravity.

    It's the ultimate destination of any flat earth theory where the participants are willing to do a little math and science. We end up with some force that simulates gravity just like in the solar system, some mechanism of moving the planets that simulates universal gravitation, some way of getting quick flights from Australia to South America, Some way the sun and moon appear the same size as the traverse the sky and set, some way mountains are hidden by the horizon in a way that first the size of the globe, incredibly detailed images from space that show a round earth, and some mechanism that bends light to make the solar system model SEEM perfectly correct.

    Ultimately for a flat Earth theorist the earth is not round, it only looks and acts round.
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  33. Abishua

    Abishua Member

    well this is kinda offtopic.. but same can be said about ball earthers.. like you just put my video to "terminator illusion".. I don"t agree with that at the moment.. I think it is what we see.. this is why there is such debate at the moment.. and we truly need to put our opinions and theories aside more than ever.. and look at the pure evidence..
  34. Mick West

    Mick West Administrator Staff Member

    Well if you want to refute the terminator illusion, do so in that thread. But you will find, as you have with everything so far, that regular science explains all the observations very well and the "flat Earth" model just leaves you with a pile of ever increasing "somehows" to shoehorn in.

    Take a step back. Do you really think if that if Moonlight cooled water then this had somehow gone unnoticed by science? Or that such a trivially easy thing to test was somehow being covered up? No, what's going to happen here is that eventually you'll accept that moonlight is in fact NOT cooling (or measurably warming). You might even do the math and find out that the brightness of the full Moon (1/400000th the brightness of the Sun) is exactly what you'd expect for sunlight reflected off a rocky object the size of the moon at those distances.
  35. Rory

    Rory Active Member

    Did it happen, Mick?
  36. Mick West

    Mick West Administrator Staff Member

    No, the Moon wasn't full enough to really cast shadows, and it was darn cold out (for Californian). I'll wait for the next full moon.

    Just looking at the ground with the thermal camera in daytime showed a lot of variation. Somewhat counterintuitively in one spot the areas that we in shade were warmer than the areas right next to them that were in the sun. This is because the shaded areas had previously been warmed for hours by a high sun, and the sunlit areas (in this case) had been in the shade until recently. That's only true in the evening though.
  37. Mick West

    Mick West Administrator Staff Member

    9:25AM, some grass and concrete, illustrating the thermal camera's ability to detect temperature differences

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  38. Abishua

    Abishua Member

    and what if you find that it is cooling? would you post it here or find a way to explain it before you do?
  39. Mick West

    Mick West Administrator Staff Member

    Of course I'd post there, and also get ready for my nobel prize. I'm pretty sure it won't though.
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  40. Abishua

    Abishua Member

    No bell prize :D Does it ring a bell.. well.. what are we waiting for.. lets test.. lemme check where the moon is ^^