Neil Tyson Demonstrates Absurdity of "Flat Earth"
Summary
TLDRIn 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
🌐 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.
📏 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.
Mindmap
Keywords
💡Flat Earth
💡Spherical Earth
💡Astronomy
💡Lunar Eclipse
💡Physics
💡Eratosthenes
💡Horizon
💡Brilliant
💡Education System
💡Experimental Evidence
💡Peer-Reviewed Studies
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
[Music]
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
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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
[Music]
you
[Music]
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How the Ancient Greeks Proved that the Earth was Round
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