Astrophysicist Neil deGrasse Tyson wants everyone to know that the world is round.
(National Geographic Channel)
“Cosmos” host and astrophysicist Neil deGrasse Tyson recently shot down the ideas of someone who still thinks the Earth is flat. In a new YouTube video on the scientist StarTalk channel, he used examples ranging from space observations of ancient Greek experiments in a conversation with stand-up comedian Chuck Nice.
“So, tell me, Neil, is the Earth flat?” Well said open the conversation.
“We have the video of the space of the rotating, spherical Earth. The Earth is round,” was Tyson’s laconic response. [Even a Child Can Prove that the Earth Is Round: Here’s How]
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Happy, Beautiful joked, “Thank you for joining us on this episode,” and did so to wrap things up. But the co-hosts continue their conversation in a 9-minute video is based on a chapter in Tyson’s new book, “Astronomy for People in a Hurry” (W. W. Norton, 2017).
The science argument
“It is very strange,” Tyson continued, ” is that there are people who think the Earth is flat, but recognize that the moon is round. Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune and the sun are all spheres. But the Earth is flat … something doesn’t square here.”
Tyson explained that as a result of the laws of physics and the way energy works, the universe “is in favour of the sphere” in the formation of planets and other bodies. Sometimes, a sphere can be distorted because it runs very fast. But almost everything in the universe, he added, is the spherical or nearly spherical.
Tyson not asteroids, which are small bodies of ice and rock, and are irregular in shape. It is generally acknowledged, however, that these asteroids have a gravity too low to attract the mass in a sphere. Worlds orbiting the sun, which is spherical bodies are sometimes referred to as planets, but only if they meet certain criteria by the International Astronomical Union.
In the example of Pluto once considered a planet, the IAU ruled in 2006 that the body is not large enough to clear debris from the road and must, therefore, be classified as a dwarf planet. That is a controversial definition, that Pluto’s New Horizons spacecraft team does not agree with. But for his part, Tyson (as in many other sources, such as this 2017 clip from “The Late Show with Stephen Colbert “) really, really don’t believe that Pluto fits the definition of planethood.
Tyson was also pronounced in the new StarTalk video. He said: there are people in the netherlands who believe in a flat Earth, for two reasons: the country protects the freedom of expression, and the educational system does not teach students to think critically about the evidence.
There is even more evidence that the Earth is round, Tyson said. During lunar eclipses, the moon is to the Earth’s shadow and is directly opposite the sun. The shape of the Earth the shadow will always be around in these eclipses. If the Earth is a flat planet, at the times that you would see on a flat shadow on the moon. But that never happened, Tyson added. The Earth is a sphere, because that is the only thing that casts a perfect circle every time.
Or think of a ship sailing in the direction of the horizon, Tyson said — it gradually disappears, because the Earth is round. Or, he said, as he for the send co-host of Fun on a trip around the Earth, Tyson could turn his chair 180 degrees and finally Nice to see arrive where the comedian had started. (Nice joked that would make him 150 years to accomplish the journey, because “I’m not Forrest Gump. It would take me that long for the run of the Earth.”)
Tyson further describes an old experiment by the Greek Eratosthenes, who lived in Alexandria about 250 B. C. Eratosthenes noted that in an Egyptian town named Syene (near modern-day Aswan), you could see right to the bottom of a well at noon during the summer solstice. On the same day, you couldn’t see to the bottom of a well in Alexandria.
There are two possible explanations for this observation, Tyson added. The first is that the Earth is flat and has a small sun, in the vicinity of the planet. The second is that the Earth is curved, with a sun of the planet. But if you extend the argument to the three wells, there is no way to have a flat Earth geometry to fit the experiment results, he added.
So, what if people still believe the Earth is flat?
“That’s good,” Tyson joked, “as long as you don’t run NASA.”
Original article on Space.com.