Neil Tyson Demonstrates Absurdity of "Flat Earth"

Summary

In this enlightening episode, the host refutes the flat Earth theory by presenting scientific evidence and historical insights. The discussion highlights the spherical nature of celestial bodies, the significance of lunar eclipses in revealing Earth's round shadow, and Eratosthenes' experiment that measured Earth's circumference. The video also touches on the importance of critical thinking and education in discerning truth from misconceptions, promoting a scientific mindset for understanding our universe.

Takeaways

• 🌐 The Earth is round, supported by video evidence from space showing the rotating spherical Earth.
• 🤔 Despite evidence, some people believe the Earth is flat but recognize other celestial bodies as spheres.
• 📚 The speaker's latest book, 'Astrophysics for People in a Hurry,' discusses why the universe favors spherical shapes.
• 🌌 The laws of physics and energy processes in the universe contribute to the formation of spherical bodies, including Earth.
• 🌀 Fast rotation can cause slight flattening, which is why Earth is not a perfect sphere but close to it.
• 📖 Historically, the idea of a flat Earth was prevalent before the scientific method was established for verifying ideas.
• 🌑 Lunar eclipses provide evidence for a spherical Earth, as the shadow cast on the Moon is always round, indicating a spherical body.
• 📏 Eratosthenes' experiment using the angles of shadows in different wells at noon supports the spherical model of Earth.
• 🚢 Ships disappearing over the horizon and the curvature of the Earth's surface are observable phenomena contradicting a flat Earth model.
• 🏃 Traveling continuously in one direction on a spherical Earth would eventually lead you back to your starting point.
• 🤓 The rise of flat Earth beliefs may indicate issues with education systems and the importance of critical thinking skills.
• 🌟 The script promotes the use of 'brilliant.org' for learning more about science and math, offering a discount for Startalk viewers.

Q & A

What is the main argument against the flat Earth theory presented in the script?

The script argues that the Earth cannot be flat because all celestial bodies in the universe, including the Earth, tend to be spherical due to the laws of physics and the way energy processes unfold in the universe.

Why do celestial bodies tend to form spheres?

Celestial bodies form spheres because the laws of physics and the accounting of energy as processes unfold in the universe favor the spherical shape, which is the most stable and energy-efficient form.

What is the significance of lunar eclipses in disproving the flat Earth theory?

Lunar eclipses are significant because the Earth's shadow on the Moon during an eclipse is always round, which indicates that the Earth is a perfect sphere, as only a sphere can cast a perfectly circular shadow.

What is the historical context of the flat Earth theory mentioned in the script?

The script refers to the time of Columbus, where there was a flat Earth contingent due to the lack of experimental checking of ideas and peer-reviewed studies, which only began in earnest during the 1600s with figures like Francis Bacon and Galileo.

What experiment conducted by Eratosthenes is mentioned in the script, and what does it demonstrate?

The script mentions Eratosthenes' experiment, which used the angles of shadows in different wells at the same time to demonstrate the Earth's curvature. The experiment showed that a spherical model could explain the observed angles better than a flat Earth model.

How does the disappearance of ships over the horizon support the spherical Earth theory?

The disappearance of ships over the horizon supports the spherical Earth theory because if the Earth were flat, ships would not vanish from view as they sail away, but the curvature of the Earth causes them to eventually drop below the horizon.

What is the title of the book mentioned in the script, and what does it explore?

The book mentioned in the script is titled 'Astrophysics for People in a Hurry.' It explores how the laws of physics and the accounting of energy in the universe conspire to make things round, including the Earth.

What is the role of peer-reviewed studies in the advancement of scientific knowledge according to the script?

According to the script, peer-reviewed studies play a crucial role in the advancement of scientific knowledge by ensuring that ideas are tested and verified, rather than simply accepted based on personal beliefs.

What is the significance of the Greeks' understanding of lunar eclipses in relation to the shape of the Earth?

The Greeks' understanding of lunar eclipses was significant because they recognized that the round shadow of the Earth on the Moon indicated a spherical Earth, which was a correct scientific observation thousands of years before modern science confirmed it.

What does the script suggest about the rise of flat Earthers in modern times?

The script suggests that the rise of flat Earthers in modern times is evidence of two things: the protection of free speech in the country and a failure in the education system to train people not only on what to know but how to think about information, knowledge, and evidence.

What is the promotional offer for the 'Brilliant' platform mentioned in the script, and how can viewers take advantage of it?

The script mentions a promotional offer for the 'Brilliant' platform, where viewers can sign up for free to access weekly challenges. Additionally, the first 19 prime numbers of viewers who go to brilliant.org/Startalk will receive a 20% discount on the annual subscription.

Outlines

00:00

🌐 Debunking Flat Earth Theory

This paragraph discusses the concept of a spherical Earth, supported by evidence from space and the laws of physics. The speaker emphasizes that all celestial bodies, including the Sun, planets, and even the Earth itself, are spherical due to the natural tendency of energy processes in the universe. The paragraph also touches on the historical perspective, mentioning that while there were flat Earth proponents in Columbus's time, the scientific method developed later by figures like Francis Bacon and Galileo has since debunked such beliefs. The speaker uses the example of lunar eclipses, which consistently cast a round shadow, as evidence of Earth's spherical shape. Additionally, the paragraph mentions the Greek understanding of Earth's roundness, thousands of years before Columbus, based on observations of lunar eclipses.

05:01

📏 Eratosthenes' Experiment and Earth's Curvature

The second paragraph delves into the historical experiment conducted by Eratosthenes to measure the Earth's circumference. The experiment involved observing the angles of sunlight at different wells in two cities and deducing the curvature of the Earth based on the varying angles of shadows cast by the Sun. The speaker explains that while two wells might allow for ambiguity in the Earth's shape, a third well would definitively prove the Earth's curvature, as no flat Earth model could account for the angles of three different shadows. The paragraph also discusses the observable phenomenon of ships disappearing over the horizon, which further supports the Earth's roundness. The speaker concludes by commenting on the importance of critical thinking and education in discerning truth from falsehood, and ends with a promotion for the platform 'brilliant', which offers challenges and learning opportunities in math, science, and engineering.

Keywords

💡Flat Earth

The concept of 'Flat Earth' refers to a belief that the Earth is not a sphere but a flat plane. This idea is central to the video's theme, which discusses the scientific evidence against this belief. The script mentions people who think the Earth is flat despite evidence to the contrary, such as the spherical shape of other celestial bodies and the laws of physics that favor spherical shapes.

💡Spherical Earth

A 'Spherical Earth' is the widely accepted scientific understanding that the Earth is round, shaped like a sphere. The video emphasizes this concept by explaining how the laws of physics and energy processes in the universe tend to create spherical shapes, and how the Earth's roundness is evidenced by phenomena like lunar eclipses and the disappearance of ships over the horizon.

💡Astronomy

Astronomy is the scientific study of celestial objects, space, and the physical universe as a whole. The video script touches on astronomy when discussing the round shape of the Earth and other celestial bodies, and how understanding astronomy can help debunk the flat Earth theory.

💡Lunar Eclipse

A 'Lunar Eclipse' is an event where the Earth comes between the Sun and the Moon, casting its shadow on the Moon. The script uses the example of lunar eclipses to argue against the flat Earth theory, pointing out that the Earth's shadow on the Moon is always round, which would only be possible if the Earth were a sphere.

💡Physics

Physics is the natural science that studies matter, its motion, and behavior through space and time. The video script discusses how the laws of physics and the accounting of energy in the universe favor the formation of spherical shapes, which supports the idea of a spherical Earth.

💡Eratosthenes

Eratosthenes was an ancient Greek scholar who is known for calculating the Earth's circumference. The script mentions his experiment using the angles of shadows in different cities to demonstrate the Earth's curvature, which is a key piece of evidence supporting the spherical Earth model.

💡Horizon

The 'Horizon' is the line at which the Earth's surface and the sky appear to meet. The video uses the concept of the horizon to illustrate the Earth's curvature, explaining that ships disappear over the horizon due to the Earth's round shape.

💡Brilliant

In the context of the video, 'Brilliant' is a platform that helps users master concepts of math, science, and engineering through problem-solving. The script promotes Brilliant as a resource for those interested in learning more about the Earth, the Sun, and related scientific concepts.

💡Education System

The 'Education System' is the organized institution responsible for the teaching and learning of knowledge and skills. The script criticizes the education system for failing to teach critical thinking skills, which is implied to be a reason for the persistence of the flat Earth belief.

💡Experimental Evidence

Experimental evidence refers to the empirical data gathered through scientific experiments that support or refute a hypothesis. The video script emphasizes the importance of experimental evidence in disproving the flat Earth theory, such as the round shadow during a lunar eclipse.

💡Peer-Reviewed Studies

Peer-reviewed studies are scholarly works that have been evaluated and approved by experts in the same field before publication. The script mentions the historical shift from unverified beliefs to the scientific method, where ideas are tested through peer-reviewed studies, as a way to establish truth.

Highlights

The Earth is round, as evidenced by videos from space showing its rotating spherical shape.

People who believe in a flat Earth recognize other celestial bodies as spheres but not Earth, which is inconsistent.

The laws of physics and energy processes in the universe favor the formation of spherical objects.

Fast-rotating objects like Earth can become slightly flattened due to their rotation.

Lunar eclipses provide evidence for Earth's round shape, as the shadow cast on the Moon is always round.

The Greeks knew Earth was round based on lunar eclipses thousands of years before Columbus.

Eratosthenes' experiment using the angles of shadows from different wells supports the spherical Earth model.

A flat Earth model cannot explain the angles of shadows from three different wells simultaneously.

Ships disappearing over the horizon indicate a curved surface, not a flat one.

Traveling due east without stopping would eventually bring you back to your starting point on a spherical Earth.

The rise of flat Earthers reflects both the protection of free speech and failures in the education system.

Education should train individuals not only on what to know but also how to think critically about information.

Brilliant.org offers a platform to master concepts in math, science, and engineering through problem-solving.

StarTalk viewers can get a 20% discount on Brilliant's annual subscription with a special link.

The importance of keeping an open mind and continuing to explore the universe is emphasized.

Ancient Greek philosophers would encourage the pursuit of knowledge and understanding of the Earth's shape.

Transcripts

so tell me Mele is the earth flat we

have video from space of the rotating

spherical earth the earth is round thank

you for joining us on this episode

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but what's what's odd is there are

people who think earth is flat right but

recognize that the moon is round Mercury

Venus Mars Jupiter Saturn Uranus Neptune

and the Sun are all spheres but earth is

flat

that's not something doesn't square

that's a job right okay plus in my

latest book hmm your latest book is

called astrophysics for people in a

hurry well we just happen I swear we

didn't plant the book I have an entire

chapter titled on being round and it's

an exploration of how all the laws of

physics and the accounting of energy as

processes unfold in the universe how

that conspire to make things round so it

favors the sphere favors a sphere yes

and if something is not a sphere it's a

little bit flattened you can ask what's

landed and you find out oh it's rotating

real fast right so then it gets a little

flattened because of that right and so

almost everything in the universe is

either spheres or slight distortions of

a sphere for some other thing that's

happening to it I mean we can just see

how the the universe favor spheres so

its nature right basic maneuver it is

fairness to the people who want a

flatter yes let's be fair to those in

Columbus's day there was surely a flat

earth contingent yes

columbus predates the era of

experimental checking of any idea you

might have not a lot of peer-reviewed

studies on just let just say whatever

you felt you know what I believe that

elephant poop will cure cancer there you

go that's right

wrote a paper about it like to read it

here it is right right so it was until

till Francis Bacon Galileo 1600s where

the idea that if you're going to say

something and you think what you're

saying is true then no matter how

obvious you think it is that it's true

you should still test it

gotcha there could be something fooling

you in one way or another so if you want

to say earth is flat then for example

lunar eclipses what's a lunar eclipse if

your face is the brilliant Sun thank you

and this is Earth and the moon is over

here the Sun is always casting Earth's

shadow into space it's always there no

matter what right obviously okay it's

such a shadow it's a channel the moon

shining on blackness yeah a shadow in

darkest shadow and so so the moon

occasionally passes through that shadow

and if you see the shape of Earth shadow

on the moon it is always round always

round if earth were flat sometimes you

get like a flat shadow right and we've

never seen a flat shadow right in fact

it is a segment of a arc of a circle

no matter the orientation of the moon

and the Sun and the only thing that

makes a perfectly circular shadow would

be something that's perfectly circular

perfectly spherical yes so the only

thing that makes a perfect circle shadow

every single time is a perfect sphere

right okay no matter what angle and

where as a disc it would only make a

perfect circle if you lined it that way

right and then they have to look at the

face of the disc in order to get the

circle Greeks knew this right all the

lunar eclipses had a set oh my gosh we

must be in a round or this is thousands

of years before Columbus exactly so now

if the earth is round how big is Earth

you might want to check for that there's

a famous experiment conducted by

Eratosthenes Bethany ever touched the

knees there the two cities in the old

world and one of them they knew that at

12:00 noon on a particular day of the

year that the Sun was directly overhead

and you can see the bottom of a well

okay you don't run around looking at the

bottoms of wells no you net because the

light doesn't take it's just doesn't get

down it doesn't get down it how can we

use this observation to see if Earth's

surface is curved we needed another well

turns out we can't see the bottom of

both wells at the same time what might

explain this

well they're two possible explanations

first we could have a flat earth with

the Sun that's small and close by so

that the light hits the second well at

an angle or a second we could have a

curved earth with a Sun that's big and

far away so that all the light comes in

parallel but only one well at a time is

lit all the way to the bottom turns out

with just two Wells there's enough

wiggle room for both explanations to fit

our observations Eratosthenes only had

two wells but what if he had added a

third with a third well it doesn't

matter where the Sun is no flat earth

model can explain the angles of all

three shadows but the spherical model

explains it all all three angles with

ease and to do this experiment you got

to measure the angles Greeks had the

angles yeah okay in fact geometry

translates to earth measurement so one

last thing which should be obvious okay

if you pay attention and think about it

if you send a ship straight to the

horizon eventually it begins to

disappear until it's no longer visible

beyond your horizon right and you should

ask yourself what kind of surface would

produce that result if it's con ocean

has a ramp they just like going down

seafarers knew this right and so what

however flat they would have imagined

the earth to be they couldn't they

couldn't have accepted to be completely

flat because otherwise you would never

not see the ship okay also if I just

tell you chuck walk due east okay right

and don't ever stop right I just turn

around my chair and face this way and

eventually you gonna come back right and

you'll probably be about a hundred and

fifty years old I am no Forrest Gump

that is how long it would take me to run

the earth for me the fact that there's a

rise of flat earthers there's evidence

of two things okay long one we live in a

country that protects free speech that's

actually kind of Awesome and two we live

in a country where they failed education

system ooh that one hurt our system

needs to train you not only what to know

but how to think about information and

knowledge and and and and evidence if we

don't have that kind of training you'd

run around believe anything anything

anything and if you're interested in

learning more about the earth the Sun

and how the fact that we're rolling

through space at what do I what is this

17,000 miles per hour is that what we're

going to pull that number out of your

you know what I pulled it from so you

should consider all of this and consider

chucking out brilliant whether you are

an adamant defender of the Earth's

curves mmm-hmm or a professional

scientist or a lifelong learner

brilliant helps you master concepts of

math science and engineering through

solving fun challenging problems and you

can sign up for free to get access to

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Startalk viewers anyone up to the 19th

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will get 20% off the annual subscription

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through god of course material and the

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click the little button that gets you

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comment below with the topic of your own

that you've been dying to get to the

bottom of all right so hey for those of

you who are flat earthers we say it's

okay as long as you don't run NASA and

for those of you who are Greek

philosophers and mathematicians Neil

will tell you what they would tell you

which would be I don't know Greek but if

you could translate ancient Greek into

English they would say keep looking up

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you

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