As Spinal Tap once taught us, there’s a fine line between stupid and clever.
For the past few years, the centuries-old—and disproven—theory that the Earth is flat has been making a comeback.
A self-professed flat-Earther, “realist,” and YouTuber known as D Marble has attempted to prove the planet is shaped like a hockey puck by taken a spirit level (also known as a bubble level, or just, a level) on a flight to prove his crazy theory.
D Marble flew from North Carolina to Seattle with the level positioned on his plane seat arm rest for 23 minutes. He theorized that if the bubble moved when the pilot dipped the nose of the aircraft to “compensate for (the Earth’s) curvature,” it would mean the Earth was indeed round. (Why hadn’t Neil deGrasse Tyson thought of this before?)
It didn’t budge—and that was enough to further convince D Marble that he hadn’t lost any of his… well, you know.
Like any good scientist, he posted the results of his research to YouTube and social media. He said of the experiment, “I recorded a 23 minute and 45 seconds time-lapse, which by those measurements means the plane traveled a little over 203 miles. According to curvature math given to explain the globe model, this should have resulted in the compensation of 5 miles of curvature. As you’ll see there was no measurable compensation for curvature.”
While the video has been shared by several flat Earth societies, including Flat Earth Activism, God’s Flat Earth, and various other globe-deniers, it’s gone viral for other reasons. While some viewers were left scratching their heads, others quickly took D Marble to task. One man, Matty Young, tweeted, “You think he would have looked out the window at the curve in the horizon like at least one time.” Another, Brian Levinson wrote, “Remarkable how the plane stayed completely 100% level during take-off and landing, I’m beginning to question whether air travel exists.” Ouch!
So, why didn’t the level move? Simple—airplanes generate a constant “lift” from their wings. In this way, they counteract gravity to maintain a consistent altitude. They do not need to regularly adjust their flight angle for the curvature of the Earth. It’s the same idea behind that of a car driving along a road that has a slight curve—instead of using several jerking movements to meet the curve, the driver turns the steering wheel just a little and leaves it there. Planes compensate for the curvature of the Earth using a similar maneuver. An aircraft’s controls are adjusted to maintain a constant altitude with movements so small that you would need a sensitive gyroscope to read them. In other words, a store-bought level won’t cut it.