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  • BILL NYE: Is the earth flat or round?

  • It's round, okay.

  • Now, let's see.

  • How do we go about proving that?

  • MICHELLE THALLER: That's a hard thing for me to even start talking about because there

  • are so many proofs that the earth is round it's difficult to know where to start.

  • NEIL DEGRASSE TYSON: B.o.B., the rapper, I have a video letter to him the transcript

  • of which is in ""Letters From An Astrophysicist.""

  • That rose to that level of attention because he started saying 'I'm using laws of math

  • and physics to show Earth is flat.'

  • Those are fighting words.

  • You're going to say using math and physics?

  • That is an alarm to the Geekoverse that we must rise up and counteract these forces from

  • the dark side that are out there.

  • THALLER: There are proofs all around you.

  • It is not difficult to know that the earth is round.

  • So let's start from the simple to the slightly more complicated.

  • One of the things you can see yourself with a pair of binoculars is if you actually go

  • out to a lake and there are boats on that lake the farther away a boat is, the more

  • the bottom of the boat will disappear and you'll basically just see the mast of the

  • boat.

  • And as a boat goes farther and farther away, the last thing you will see is the very top

  • of the mast of that boat, and that's because the boat is actually going over the horizon

  • that's curved.

  • And that means that as it goes farther and farther away you see less and less of the

  • bottom of it and more of the top of that.

  • You can see that with binoculars by an ocean, by a lake.

  • It's really easy.

  • That wouldn't happen if the earth were flat.

  • You would simply see the boat getting smaller and smaller and smaller as it went farther

  • away, but you'd be able to see the whole thing with the same proportions.

  • NYE: Go to the seashore.

  • Go to a seashore and figure out if you live on the East Coast figure out why you can't

  • see Spain from the East Coast of North America.

  • Just go to the middle of the Mississippi River and look south.

  • Why can't you see Louisiana.

  • Why can't you see New Orleans.

  • What's the problem there?

  • Or the climb a tower or go to the top of a hill or a mountain and you'll see a little

  • farther, but you will not see to the other side of the earth, places we know to exist.

  • For example, I've been to London.

  • I can tell you other people have.

  • I've been to Vancouver, British Columbia and you cannot see Vancouver, British Columbia

  • from Boise, Idaho let alone from New York City or Toronto or what have you.

  • THALLER: Then there's some other proofs that are a little more obscure but they're actually

  • really lovely and one is to observe What happens during a lunar eclipse.

  • Now a lunar eclipse happens when the earth casts a shadow on the moon.

  • The moon actually goes dark.

  • In fact if you've seen one you could actually see the earth's shadow go across the moon.

  • And when the moon is entirely in the earth's shadow the moon looks like of dark and even

  • kind of red colored.

  • It's really, really beautiful.

  • What's happening in that case is that the sun is on one side of the earth.

  • The earth is in the middle and it's casting a shadow.

  • The earth is casting a shadow on the moon.

  • And as the shadow moves across the moon you'll notice that the shadow is curved, it's round.

  • So something like the Sun that's bigger than the earth and is able to cast a shadow of

  • the earth on the moon can actually show you the shape of the earth.

  • Aha, you might say, but could the earth be a disk?

  • Could it be flat but it's actually still shaped like a disc, not like a sphere.

  • There was a Greek scientist called Aristarchus and what he noticed was that you can get a

  • lunar eclipse at many different angles where the sun is.

  • Sometimes the shadow goes straight across the moon.

  • Sometimes it just kind of glances the moon just a little bit is in shadow just on the

  • top or on the bottom.

  • From every different vantage point, every different angle that the sun is casting a

  • shadow you always get a perfectly curved shadow.

  • The only shape that can cast a shadow that's curved from any direction you put the light

  • is a sphere.

  • So people have known that the earth is spherical for thousands of years.

  • NYE: Look at pictures from space where you see the earth as a sphere.

  • Those pictures are not faked and I'll tell you just if nothing else here's why you can

  • tell they're not faked.

  • Just to create the paperwork that NASA had created, NASA in this one case.

  • Just the paperwork to send anything out in space.

  • To send people into orbit or to send them to the moon, that amount of paperwork would

  • make faking it prohibitively expensive.

  • No one could afford to generate that much documentation.

  • Then the other thing if you want to get into this, if your friends are really serious,

  • have them get on a boat or a ship and go out at sea and you'll notice you can't see infinitely

  • far.

  • Furthermore if you get into it enough pick up a book about navigation or go online and

  • learn about navigation.

  • A very, very important thing you have to take into account when you try to navigate the

  • ocean from a ship or a boat is how high you are off the sea surface.

  • The higher you are off the sea surface, the farther you can see, the farther away the

  • horizon is.

  • THALLER: I actually said this to somebody and I couldn't believe they'd never thought

  • of it, but with binoculars you can see planets.

  • You can see Saturn and Jupiter.

  • You can see Mars with a telescope.

  • The sun, the moon, everything else you see in the solar system is a sphere.

  • So we're the one thing that is different?

  • And that actually made somebody who was more interested in actually hearing information,

  • that got them to think like you're right.

  • Everything else we take a picture of is a sphere.

  • NYE: And you guys, come on.

  • Everybody watches newscasts.

  • You all use mobile phones.

  • You all see airplanes fly around.

  • You all go to see Ed Sheeran in concert one day in London, another day in Melbourne, Australia.

  • This all depends on our fundamental understanding of the size of the earth and its shape with

  • extraordinary precision.

  • And if you want to get into it the earth isn't quite a sphere.

  • It's a little wuhh.

  • Its spin is a little wuhh, stretched it, made it slightly oblate as the saying goes.

  • THALLER: And it's not okay to think that the earth is flat.

  • This is not a viable argument.

  • I have friends who have been on the international space station.

  • They have orbited the earth once every 90 minutes.

  • I have had personal experience with people that have been up in space and can see with

  • their own eyes that the earth is round.

  • And, of course, we've taken all these amazing pictures from space.

  • They're so beautiful all those pictures of the earth.

  • So I don't really know what's going on right now with this earth is flat thing.

  • TYSON: In a debate what is the construct?

  • It's typically two people and there's an audience and you debate some opposite sides of some

  • issue and then there's a winner of the debate.

  • And everyone walks away reflecting on the winner.

  • So who wins a debate?

  • It's often the person who's charismatic, who may be charming that's related to charisma

  • of course.

  • Who had a good way with words, good vocabulary.

  • And you can have someone who doesn't have any of that who is speaking objective truths

  • who could lose a debate.

  • So then what is the point of the debate if one of these points of view is objectively

  • true?

  • I will not enter a debate where I have the objectively true side of an argument and the

  • other person does not.

  • That is something that should not be debated, does not belong in front of an audience getting

  • debated.

  • You want to debate something?

  • Debate political policy of what to do in the face of climate change.

  • Do you have carbon tax?

  • Do you have solar panels?

  • Do you subsidize them?

  • Debate that.

  • Don't debate something that is or is not objectively true in this world.

  • NYE: This is all susceptible to analysis, but spend some time learning about navigation,

  • tell your friends to spend some time learning about navigation.

  • Ahh.

  • Navigation has changed the world by the way.

  • What are you wearing?

  • You're wearing stuff that came from another part of the world on a ship.

  • It didn't get here by magic.

  • It got here through science.

  • TYSON: I think it's important to combat people who are claiming that they are using math,

  • science, evidence and physics behind their cause when, in fact, they either aren't or

  • they're using it badly.

  • That needs to be called out.

  • Otherwise, if you just have a belief system I don't really care.

  • We live in a country that protects free speech which usually also means free thought.

  • You want to think Earth is flat, go right ahead.

  • But if you start influencing other people who have power over other people and you have

  • no foundation in objective reality it can be dangerous.

  • If you influence people or you yourself become someone who has influence over legislation,

  • laws, rules by which we all abide in society, that's an unhealthy situation for civilization

  • to be in.

  • If your personal belief system which does not have correspondence in objective reality

  • starts becoming predominant in the thoughts and hearts and minds of civilization.

  • THALLER: It's not okay to say that the earth is flat.

  • This is some sort of strange denial.

  • I don't know where it comes from and it's something where I keep getting this question.

  • We really need to put this question to bed because we've known the earth is a sphere

  • for a long time.

BILL NYE: Is the earth flat or round?

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B1 US earth shadow moon debate nye boat

3 scientists school flat Earthers on the evidence | Neil deGrasse Tyson, Bill Nye, Michelle Thaller

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    joey joey posted on 2021/05/13
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