'The Earth's curvature explains this phenomenon, as described in the diagram accompanying the photograph. 'The Andes Mountains, 287 miles away, and although taller than the plane's altitude, lay below the sensible horizon, marked by the white horizontal line in the photograph,' NASA officials wrote in a description of the flight. In December 1930, for example, Stevens snapped a photo looking westward while flying at an altitude of 21,000 feet (6,400 meters) above Villa Mercedes, Argentina. Similarly, from a great distance, the tops of tall objects like mountains are visible well before their bases.Īnd Earth's curvature is clearly apparent from high altitudes, as Capt. If you've ever watched a ship on the horizon, you've seen this for yourself.

There are so many experiments, observations and demonstrations that have, time and time again, revealed the curve of the Earth.Īs objects recede from you, they begin to look smaller and slowly disappear in a very unique way: first their bottoms become hidden, and then their tops. The fact that social media recommendations sometimes encourage conspiracy theories and radicalization is also well known.To put it bluntly, we know more about the curvature of Earth than almost any other topic in the realm of physical science. So, too, have the problems that arise when advertisers make Facebook users uncomfortable by knowing too much about them. The issues that emerge when advertisers target political campaigns or misinformation at a specific group on Facebook have been well documented. The particular ad is simply removed from a person’s feed. But under the company’s ad system, even if many people flag an ad, the account is not disabled, Facebook said. “This error still had nothing to do with the content of the ad campaign nor any user reports.”įacebook declined to elaborate. “Our systems are not perfect and we made a mistake by accidentally disabling the account,” the statement said. But though it’s possible that flat earthers and conspiracy theorists flagged the ad, this was not why the ad came down, the company said. Facebook also confirmed that the account was later disabled repeatedly. “No ads were ever rejected from this page,” Facebook said in a statement. Redgrove had said, all the ads were originally approved.

On Thursday, after the publication of this article, a representative for the company said it had investigated the issue and had confirmed that, as Mr. Facebook said it could not immediately comment on what had gone wrong.

Flat earth conspiracy theory