While it is strange (and disturbing) that some religious conservatives dispute the scientific consensus on the age of the Earth and the universe, another Space.com article this past week (3-10-2018) — Yep, the Earth Is Still Round, Neil deGrasse Tyson Says — reminded me that there’s an even stranger group, namely, those who still play with the notion that the Earth is flat (hopefully not just as performance art or for publicity).
The fact that an astrophysicist like Tyson found it necessary to address the notion of a flat Earth is telling. In the 21st century no less. But his answer provides a useful historical context and overview of scientific reasoning.
“Cosmos” host and astrophysicist Neil deGrasse Tyson recently shot down the ideas of anyone who still thinks the Earth is flat. In a new YouTube video on the scientist’s StarTalk channel, he used examples ranging from space observations to ancient Greek experiments in a conversation with stand-up comedian Chuck Nice.
“What’s odd,” Tyson continued, “is there are people who think that Earth is flat but recognize that the moon is round. Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune and the sun are all spheres. But Earth is flat … something doesn’t square here.”
- The science argument
- The geometry argument
Is that the end of the story? No more flat-earthers?1
So, what if people still believe the Earth is flat?
“That’s OK,” Tyson quipped, “as long as you don’t run NASA.”
 Another Space.com article: “8 Times Flat-Earthers Tried to Challenge Science (and Failed) in 2017.”
UPDATE 6-25-2018: This Space.com article from June 22, 2018, “How Fast Is Earth Moving?” references NASA Goddard’s 2016 YouTube video “One Year on Earth – Seen From 1 Million Miles” which was composited from images taken by the space agency’s EPIC camera on NOAA’s DSCOVR satellite.
[Spin] If you estimate that a day is 24 hours long, you divide the circumference by the length of the day. This produces a speed at the equator of about 1,037 mph (1,670 km/h).
[Orbital speed around the Sun] So, Earth travels about 1.6 million miles (2.6 million km) a day, or 66,627 mph (107,226 km/h).
[Galactic motion] The sun and the solar system appear to be moving at 200 kilometers per second, or at an average speed of 448,000 mph (720,000 km/h). Even at this rapid speed, the solar system would take about 230 million years to travel all the way around the Milky Way.
In about 4 billion years, the Milky Way will collide with its nearest neighbor, the Andromeda Galaxy. The two are rushing toward each other at about 70 miles per second (112 km per second).