$10,000 Cold Moonlight Challenge

Does the moon actually put out cold light? Of course not, that would violate the first law of thermodynamics, or it would require photons to have a negative frequency, or maybe time travel. It’s absolutely ridiculous. But flat earthers regularity make the claim that is does.


Because they are incapable of doing a good experiment. They have something directly over the shaded part which has an insulating effect. They either are not intelligent enough to realize this or they intentionally lie. We all know #GoittaLieToFlerf

To embarrass flat earthers I am offering $10,000 for them to do a proper experiment testing the hypothesis that moonlight has a cooling effect. They will either NEVER attempt the challenge or discover that they were wrong.

This is a proper science experiment and the procedure outlined in the challenge has very specific parameters to control for confounding variables. To have a good experiment, one must prevent things other than the moonlight from affecting the measurements.

The challenge is not live yet, the version on this page is a work in progress. When the final version is done there will be a video announcing it and the video will include the SHA256 has of the official rules text file which will be linked on this page.

Overview of the setup. Courtesy of Tommy Grønvold.

Legit Challenge Framework v0.9b


Flat earthers often claim that the moon produces its own light.  They claim that moonlight cools things when it shines on them, the opposite of sunlight which warms things up.

Radiative cooling is the cause of many temperature differentials in cold moonlight experiments.  This is where a structure overhangs a region and insulates an area, keeping it warmer.  This challenge specifies techniques to reduce the impact of radiative cooling.

[NOT YET OFFICIAL] Definitions:

Flat earth: the idea that the earth as a whole, excluding topography, is generally a flat plane.  This includes these ideas: the earth is an infinite plane, all horizontals are parallel, the surface of undisturbed water is flat, and other ideas that have similar implications.

Flat plane: see definition for “flat earth”.

Flat earther: a person that posits Flat Earth idea as defined above.

[NOT YET OFFICIAL] Challenge: Test the hypothesis that moonlight has a cooling effect while controlling for variables that may affect the results.  There is a very specific setup outlined in this challenge that must be followed.  This is to remove as much possibility of extraneous factors affecting the test as well as prevent people from trying to fake the results.


Moonlight is the presumed cause of the cooling so there shall be one test measurement and one control measurement.  The presence of moonlight is varied.  The test measurement is with the moon present, the control measurement is with the moon not present.  Each measurement shall have two basins.  The test measurement when the moon is present measures the temperature difference between the moonlit basin and the shaded basin.  The control measurement when the moon is not present has an identical setup and the temperature between the two basins is measured.


The moonlit test measurement can be performed any night when the moon is present, provided it is not within 2 days of a new moon.  This might be at or near full moon, however, testing the difference between waning and waxing may also be desirable so there is no need for the test to be performed exactly during full moon.


The moonless control measurement must be performed on the day of the new moon, the day before, or the day after a new moon.


The test material shall be placed into identical basins.  These basins must be the same color, the same material, the same dimensions, made by the same manufacturer.  The basins must be as identical as possible to prevent differences in the basins from influencing the results.


The basins shall be on a table at least 0.7 meters high.  Only one table is allowed.  The table must be uniform in color and material.  There must not be anything under the basins, in the basins, or near the basins.  Nothing shall be on the table other than the basins.  The basins shall be no more than 1.0 meter away from each other on the table.


The moon shade shall be a vertical panel.  No part of the panel shall be over the table.  The panel shall be tall enough and wide enough to block the moonlight from hitting one of the basins.


Look up the moon’s highest position using moon position resources such as timeanddate.com to obtain the angular range the moon will be in during the test.  Use this knowledge along with the table height and the distance from the table to determine how tall the panel must be.


The panel should be easy to move to ease positioning.  Yet it should be stable enough to accept any wind that may be present during the test.  A PVC frame with an opaque panel affixed to it is an example.  Heavy objects could be placed on the base to resist movement.


The moon shade shall be at least 2.0 meters away from the table.


Nothing shall be directly over the basins, they must have a completely unobstructed path from the basins to the sky.  There shall be no structures, trees, buildings, vehicles, or large objects within 10.0 meters of the table.  The only allowed structure closer than 10.0 meters is the vertical panel.


When measuring the temperature of the contents of the basins the experimenter must approach from the side of the table opposite the vertical shade.  This removes the possibility of the experimenter casting a shadow on the experiment.


The entire test shall be sent via livestream to YouTube on two different cameras simultaneously.  There is a specific arrangement of the test equipment and camera set up to document the process and prevent fraudulent results.


Camera 1 shall be in line with the table positioned high enough to see the top of the table and the top of the contents of each basin.  This camera shall have the vertical pane appearing either to the right or left of the table in the frame.  When the experimenter approaches to record the temperatures, this shall be completely in frame.


Camera 2 shall be on the same side as the vertical shade, potentially attached to the shade, positioned high enough to see the top of the table and the top of the contents of each basin.  When the experimenter approaches to record the temperatures the front of the experimenter’s body shall be in the camera’s frame.  The measuring process shall be completely visible from camera 2.


Once the experiment starts nothing shall touch or disturb the table or the basins.


For the test measurement, the two basins shall begin the experiment completely in shade.  The temperature of the two must be at the same temperature within 0.5 degrees for 30 minutes while both basins are in the shade.  Once the temperatures have stabilized the vertical shade shall be moved to expose only one basin to the moonlight.  


When the vertical shade is moved the experimenter shall not get closer than 2.0 meters from the table.  A remote movement system may be employed, such as a rope attached to the base of the vertical panel.  Moving the vertical panel shall not disturb the table or basins.  Moving the panel must not move the panel any closer than 2.0 meters from the table.


Control measurement

The control measurement setup is identical to the test measurement.  Including the vertical panel.

[NOT YET OFFICIAL] Acceptance parameters:

The test measurement temperature differential must be more than 5 degrees for at least 30 contiguous minutes and the control measurement temperature differential must be less than 0.5 degrees at all times.

[NOT YET OFFICIAL] Submission method:

Email the links to the two videos and spreadsheet of the temperature measurements to mctoon@mctoon.net.


A confirmation of receipt via email will be sent back to the winning submitter.  The submission is not complete until a confirmation of receipt has been received via email to the submitter.


$10,000 US Dollars.  Payment will be via Bitcoin using the most favorable to the submitter conversion rate from coinbase.com on the day the submission is first sent in UTC time zone.  If the escrowed funds are less than $10,000 in value, the full balance of the escrowed funds shall be awarded.  If a previous prize has been awarded for a different competition and the escrowed value is less than $10,000, the remaining balance will be awarded.

[NOT YET OFFICIAL] Timing and Number of solutions: 

The challenge opens on XXXX, 2022, at Midnight UTC.  At most one single winner shall be awarded.


0.4BTC is held in escrow by Brainy Beaver.  Brainy Beaver will transfer funds to the winner in the event of a successful solution.  See escrow documentation on mctoon.net/escrow


MCToon is the primary judge.

[NOT YET OFFICIAL] Arbitration:

Should an entry be submitted but rejected by the judge, and this rejection not accepted by the submitter, a panel of three experts shall be named in accordance with the Legit Challenge Framework specification version 0.9b section 5.1. See https://mctoon.net/legit-challenge-framework/

Each judge must be qualified in one of the following ways:


-Professional [credential] with at least 5 years experience and currently working in the field.


-[credential] professor at the university level or higher with at least 5 years experience and currently teaching at that level.


-Physics teacher with at least 5 years experience teaching physics at high school or university level and currently teaching at that level.


Judges must provide verification of their qualifications.

[NOT YET OFFICIAL] Expiration:

The challenge automatically expires 10 years from the date and time of issuing.  At MCToon’s discretion, the challenge can be withdrawn.  This will be announced on MCToon’s YouTube channel with at least 30 days prior notice.

If a winner is ever declared and prizes are awarded, the challenge expires.


Units must use the International System of Units.  Referred to as “SI Units”.  Temperatures shall all be measured and recorded in Celcius.


Measurements shall be done with only one temperature measuring device.  This is to reduce the possibility of different devices being calibrated differently.