It’s Professor Dave, and I wanna show you the world. Throughout this astronomy series, we’ve
learned quite a bit about every object you could hope to see in the night sky, as well
as many others that you can’t. So how does all of this fit in with the understanding
held by the common public? For one thing, just the way that an understanding
of chemistry and biochemistry makes it easy to refute things like alternative medicine,
the understanding of astronomy we have just gained will make it easy to refute similarly
alternative cosmological models, most notably the present fad that is the flat-earth model. There exists a community of folks who believe
that contrary to everything the human species has learned over the past few centuries, the
world is not spherical, but is instead flat, and is also the center of the universe. A knee-jerk reaction to this is often one
of disbelief and even mockery, but rather than go that route, let’s consider this
model in a rigidly academic way. Whether the earth is flat or round, we should
be able to demonstrate it, and show how all astronomical phenomena make sense in one model
versus the other. Let’s go through some of these phenomena
now, and put them into context. First, let’s just look at the celestial sphere. We look up and we see stars and planets going around. The flat earth model says we stay still while
everything goes around us, and the round earth model says we rotate, which is what causes
the apparent motion of objects in the sky. At face value, with no further investigation,
these are two completely valid hypotheses. Either of them could feasibly explain what
we see in the sky. Now let’s dig a little deeper. What are some details we notice about the
celestial sphere and certain earthly phenomena? We experience night and day, alternating periods
of light and dark that change over time. We see the ecliptic. This is the part of the sky that traces the
sun’s path throughout the year, as well as the paths of all the planets. The path of the sun follows a slowly tilting
pattern that lasts one year. This length of time also outlines other cycles
observed on earth, which we call the seasons. These seasons go a particular way in the northern
hemisphere, and the opposite way in the southern hemisphere. There exists a phenomenon called the Coriolis
effect, whereby rotating masses like storms rotate in one direction in the northern hemisphere
and the other direction in the southern hemisphere. Each hemisphere also sees an entirely different
collection of stars. These are just a handful of the observations
we can make that beg to be explained. Here is where the round earth becomes obvious. All we have to do is understand that the earth
is roughly spherical, spinning on an axis tilted somewhat from the vertical, and going
around the sun just like all the other planets. This singular assumption makes all of the
observations fall into place. As earth rotates, it’s daytime when facing
the sun and nighttime when facing away from the sun. The apparent motion of all these celestial
objects utilizes elliptical paths, and can therefore be predicted. The seasons occur because of the amount of
sunlight hitting one hemisphere versus the other at any given time in earth’s orbit. One year is also no longer an arbitrary amount
of time, it’s equal to one revolution of the earth around the sun, and the differing
lengths of night and day are also explained by the tilt in the rotational axis. The Coriolis effect is just the result of
simple physics related to rotating bodies like the earth. The hemispheres have different skies because
they point out at different regions of space. Everything we see makes perfect sense with
one simple, unifying assumption. That’s what science is all about. In the flat earth model, all of these observations
require their own separate explanations. What is night and day? If you try to place a luminous object like
the sun above a plane like the flat earth, how does light reach half the plane and not
the other half? Say you come up with a mechanism whereby light
dissipates appropriately. How does this then fit with other observations? What are the seasons? If you try to explain them by pulling the
sun closer and farther from the earth, how can it be winter in the north and summer in the south? What is the Coriolis effect? If earth is a plane, what magically alters
the rotation of a storm in one half of the plane compared to the other? Shouldn’t we also all be seeing the same
night sky, since our lines of sight all face the same direction? Flat earth subscribers do actually attempt
to answer all of these questions, but beyond the fact that the explanations are never mathematically
or logically sound, the sheer fact that each phenomenon requires its own independent explanation
makes it unscientific. If we invent a luminous sun-like object, and
start tracing elaborate paths through the sky, this is just the epicycles from the geocentric
model all over again. It’s assumption upon assumption, adjustment
upon adjustment, all of which are totally ad hoc, based in nothing but an attempt to
fit observation. This is very poor science. When we say the earth is round and put the
sun at the center of all this motion, not only are all of these phenomena easy to explain,
even to a layperson, but predictions can be made. In 2017, a total solar eclipse occurred over
the United States. Using a modern understanding of astronomy,
we can do math to predict any such event, like eclipses, the return of Halley’s comet,
or anything else. This is done very simply, with the sun at
the center, and using Kepler’s laws regarding elliptical orbits, which involves basic algebra
accessible to anyone. Only in this model is the math so easy. So when we operate under this framework and
say that a solar eclipse is going to happen at this time, on this day, in this place,
and then it does match our prediction with extreme precision, there can be no clearer
vindication for this model of the solar system. Game, set, match. The flat earth model can never make such predictions,
not just because the notion of an eclipse has no logical basis, but also as there is
no unifying mathematical system. It’s a bunch of separate phenomena with
separate explanations, if such explanations even exist. It doesn’t end there. The flat earth model has a huge laundry list
of other things to explain besides what we have mentioned so far. Everything we see in space is a sphere. Why is earth the only thing that isn’t? Things fall to the earth because of gravity,
which attracts things to earth’s center of mass. If earth is not a sphere, why do things fall
to the earth? What is gravity? The implications run so much deeper than just
what rotates around what. Ad hoc solutions are offered, like the idea
that the flat earth is accelerating upwards which an acceleration of 9.8 meters per second
squared, and that’s why we all stick to the ground. But this doesn’t help, it actually makes
things worse. What is up? What is causing the acceleration? If it is constantly accelerating, we should
be traveling the speed of light by now. What is meant to be a simple explanation actually
complicates things so much further. Then there is the matter of the geometrical implications. How do we slice up the globe to make it flat? What places are far away that we thought were close? How is it possible to fly or sail around the
world, which has indeed been done by so many people? Where is the edge of the earth? Why hasn’t anyone seen it? What about all the pictures we have of the
earth from space? Again, ad hoc solutions are required for all
of these questions. It is proposed that a huge ice wall surrounds
the earth, which we call Antarctica. No one can go there, because NASA is guarding it. How? Where is the personnel? Where is the budget for such an operation? NASA also fabricates all of the photos we see. Why? What is the motivation? And how? We have had photos of the earth from space
since the 60s, which predates computer editing software by several decades. The logical hole gets deeper and deeper. Because it is impossible to form a consistent
framework for these observations, the model must turn to conspiracy. Now to be clear, I am a firm believer that
outside-the-box thinking should be encouraged, and we should always be ready to challenge
institutions and governments, but the validity of a conspiracy theory depends largely on
how many people have to be in on it. The notion that all the governments and all
the scientists and all the airline pilots and flight attendants and communication technology
operators and thousands of others are all in on it… it starts to get pretty absurd. The manufacturing of a holographic sphere
playing a movie of the heavens, which is operated by unknown entities oppressing mankind into
deception and slavery is really what we are left with for the flat-earth model, and perhaps
that realization makes the whole thing make sense. It is the desire to live in a science fiction
movie and feel like the hero leading the fight against evil forces that may be the best explanation
for the motivations involved with those who insist on this model. So that’s all there is to it. We do not say the earth is round because we’ve
been told it’s round, or because we are repeating scientific dogma. We say it is round because it is the simplest
explanation for what we see. The earth is round because the round earth
model makes perfect sense of every observation we can make. No ad hoc reasoning, just a bunch of puzzle
pieces that fit together to form a coherent view of the universe and everything in it. This is the same reason that the heliocentric
model replaced the geocentric model when Copernicus and Kepler came around. It just works better. The orbits of the planets don’t have to
be explained by epicycles upon epicycles. If the sun is at the center of the solar system,
the planets follow very simple ellipses, and Kepler’s laws predict the positions of planets
with much better accuracy and precision than any previous model. When the world is round, everything fits. In contrast, the flat earth model has to come
up with ad hoc modifications to explain each and every observation in a different way. All of these problems simply vanish with a
round earth. The earth is round, and what we see makes perfect sense. The precise position of every celestial object
can be predicted with great accuracy, far into the future. We can say that an eclipse will happen at
a particular time on a particular day in a particular place, and that’s exactly what we see. This is the essence of good science. A model or theory that correlates mountains
of data to form a simple and cohesive explanation for observations, and makes falsifiable predictions
regarding phenomena. If a model can’t do that, it’s not scientific,
and the flat-earth model simply does not hold up to scrutiny, so it must be discarded, as
it was for the majority of the human race a few thousand years ago. Now that we’ve caught back up to what we
already knew, let’s move forward and see what else we can say about the public’s
perception of space.
