The claim: The Earth is flat because cities can’t be upside down
The flat Earth theory, the misconception that the Earth is flat, continues to persist online despite overwhelming evidence to the contrary.
Some proponents of this model believe that the Earth cannot be a globe because that would mean that some areas of the Earth are upside down.
Fact check:Plenty of evidence that the Earth is round and rotating, contrary to persistent social media claims
This group includes the user behind a November 22 Facebook post (direct link, archive link) that features a photo of an upside-down city. It has been shared over 100 times in less than three weeks.
“It’s Scientifically Impossiball,” reads the text included in the post.
This argument is wrong.
There is no real “up” or “down” in space. Gravity pulls objects toward the Earth’s core, creating the sensation of standing, physicists say. The photo in the message has been distorted.
USA TODAY has reached out to social media users who shared the post for comment.
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Space has no ‘up’ and ‘down’
There is no real up or down in space, North Carolina State University physics professor David Brown said in an email to USA TODAY.
“Near Earth – or any other planet or star – ‘true’ is always the opposite direction of gravitational force,” he said. “That is, ‘true down’ is always towards the center of the Earth.”
This means that the Earth, like any sphere, has no fixed top or bottom. Instead, people feel the “up” and “down” sensations with reference to the Earth’s core.
“Gravity pulls us toward the Earth’s surface,” Brown said. “So wherever you are on the spherical Earth, you are pulled towards the center of the Earth. This is just as true in Antarctica, or Australia, as it is in North America.”
That’s why no matter where the Earth is during the rotation, buildings stay on the ground and water stays in the oceans, said Jason Steffen, a mathematician and physicist at the University of Nevada.
If the Earth were flat, Brown said, people would also feel a gravitational pull toward the center of this disk. This would mean that people on the “edge” of the flat Earth would fall sideways.
“It’s one of the many, many ways we know the Earth isn’t flat,” Brown said.
The photo in the message was also manipulated, said Siwei Lyu, a digital forensics expert at the University at Buffalo. It shows the Earth curving steeply to the sides of the image even though the scale only includes one city.
“We shouldn’t see the early warping for that effect with that altitude,” he said.
Our opinion: False
Based on our research, we rate FALSE the statement that the Earth is flat because cities cannot be upside down. Gravity pulls objects towards the center, no matter where people or cities are on Earth. There is no real “up” or “down” in space.
Our fact-checking sources:
- David Brown, December 5-6, email exchange with USA TODAY
- Jason Steffen, December 5, email exchange with USA TODAY
- Siwei Lyu, December 6, email exchange with USA TODAY
- NASA, January 29, 2004, Sleeping in Space
- NASA, December 17, 2020, What is gravity?
- NASA, October 8, 2015, What happens when your brain doesn’t know which direction is up?
- CNBC, October 7, 2016, Here’s why hurricanes spin counterclockwise in the North
- NASA, December 24, 1968, Earthrise
- Space, April 22, 2013, Earth From Space: Classic NASA Photos (Gallery)
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