Flat Earthers say footage from David Blaine's Ascension stunt proves their conspiracy theory.
The illusionist flew 24,000 feet above the Arizona desert on Wednesday as he gripped a rig of around 50 helium balloons.
It was originally due to take place in Blaine's hometown of New York City on August 31, but was moved to Page due to windy conditions.
The 47-year-old performer took to the skies in a stunt reminiscent of a scene from the movie Up .
His live stream of the stunt allowed viewers to see the stunt from his perspective.
This led Flat Earthers to claim the vision from his chest-cam proved Earth is not round in YouTube comments.
"EARTH IS FLAT," one user wrote as others disagreed.
"CURLY EARTH," one said, while another wrote: "Earth is round."
One hit back at conspiracy theorists, posting: "Studies place the threshold altitude for seeing Earth's curvature at about 35,000 feet."
Blaine's footage was shot at a peak height of 24,000 feet.
Flat Earthers are adamant that satellite photos of Earth as a sphere are fake.
They believe that a 'round Earth conspiracy' has been orchestrated by NASA and others.
Blaine's flew for around an hour before letting go of the balloons and falling thousands of feet. He then pulled his parachute and coasted back to the ground.