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  • Earth LOOKS flat. It FEELS flat. The logical explanation is: the earth is flat! Right?

  • #facepalm. But like, once you get past the crazytalkHow do we know the Earth IS round?

  • Welcome back my woke friends, Trace here for DNews. If you follow the pervasive yellow

  • journalism online and elsewhere, you've probably heard of Rapper B.o.B.'s beef with NASA, science

  • and specifically Dr. Neil deGrasse Tyson, astrophysicist and science celeb. In short,

  • some pop culture peeps think the Earth is Flat. Proving them wrong is simple, though

  • it took hundreds of years for science to figure it out in the first place.

  • how do we know otherwise? We know the Earth is round by observing it

  • closely. If you watch a ship as it disappears over the horizon, the bottom vanishes first

  • and then the top disappears later. It looks like it's sinking. That's because the Earth

  • is curved. Using a stopwatch you can do your own experiment to prove it. Watch the sun

  • set over the ocean or a open plain with a friend. If you stand, while they lay down,

  • each will see the sun cross the horizon at a slightly different time!

  • how did we first realize the earth was round? The Greeks first realized this 2500 years

  • ago, and spent hundreds of years attempting to explain it. First, mathematician Pythagoras

  • looked at the moon and discovered a curve in the line dividing light from shadow on

  • its surface -- called the terminator. A flat moon would have a straight line! The only

  • explanation? The moon must be a sphere! Sometime later, Anaxagoras, while watching the moon

  • during an eclipse, realized the shadow covering the moon must be from the Earth! As that shadow

  • is definitely curved, the Earth must be round! And still later in about 350 BC, Aristotle

  • noted that star constellations, visible in Greece were hidden beyond the horizon in Egypt.

  • His conclusion, yet again, was the Earth must be a sphere, just like the moon! Sidebar:

  • Notice, humanity knew the Earth was round 1800 years before 1492 when Columbus Sailed

  • the Ocean Blue. Just debunking some grade school crap.

  • how curved is the earth? Once these great thinkers realized the Earth

  • was curved, they wanted to PROVE IT. A Greek astronomer named Eratosthenes figured it out.

  • On the summer solstice, the sun reaches a peak at the top of the sky. Eratosthenes went

  • to two distant locations in Egypt on the Solstice and measured the angles cast by the shadows

  • in each place. Then, using some geometry he could calculate the curvature of the Earth

  • between those places! From there, he could extrapolate how many degrees around the circle

  • of the Earth he had moved -- ultimately, revealing the circumference and diameter of the EARTH!!

  • Dang.

  • Thanks to all these ancient humans we know Earth is just a bit over 40 thousand km around

  • the poles (about 24,860 miles) (which is supported by modern observations), and knowing that

  • we can determine how far the horizon is from you -- which changes depending on how high

  • above sea level you are. The Earth is curved, and we know it.

  • Why do these people think this? In the end, the problem is Flat Earthers just

  • don't trust science. When the Flat Earth Society was founded in the mid-1920s, the idea was

  • observation trumps all. This is called the Zetetic philosophy. Many skeptics believe

  • the same. If the Earth looks flat it must be flat. Often they cry "Prove me wrong!"

  • "Only trust your own observations!" The funny thing about that argument is that it was observation

  • that showed us the Earth’s curvature in the first place! Pythagoras observed that

  • shadow line across the moon. Countless people have observed ships sailing underneath the

  • horizon. NOT TO MENTION the fact that weve gone to space and observed a very spherical

  • Earth from above.

  • And if you don’t believe all those people for some reason, make your own observation.

  • Climb a mountain, watch a ship sail away, or watch the sun set with a friend. And behold

  • an inarguably spherical Earth.

  • Your move, B.o.B.

  • Conspiracy theories are just, the best, aren't they? Have you ever wondered why people love

  • 9/11 conspiracies? Why are we so obsessed with the Illuminati or which conspiracy theories

  • might be actually true? TestTube Plus is the podcast/show for you! We cover

  • Do y'all know anyone that we should make a video debunking? Comments. Do it.

Earth LOOKS flat. It FEELS flat. The logical explanation is: the earth is flat! Right?

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B1 earth flat moon curved horizon shadow

How We Know The Earth Isn’t Flat

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    陳美妤 posted on 2016/01/30
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