What shape is the planet earth?
Most of us are convinced by the evidence showing
that the earth is a sphere,
but there are a few people that believe that
the earth is flat.
Sure, some flat earthers are just trolls,
but no matter how strange an idea,
if enough people say they believe it, chances
are, not all of them are trolling.
If you met someone that believes in the flat
earth model, how would you show that it is
incorrect?
Think about it.
Most of us accept that the earth is round
as common knowledge,
but how would you go about convincing someone?
Show them footage from space?
Oh, That's just CGI.
GPS Satellites?
There are no satellites, just cell phone towers.
Besides waiting for Elon Musk to take us all
to space,
how can we show someone that the earth is
not flat?
By looking at the sun.
Let me explain.
In the flat earth model, the earth is a disk.
The sun travels clockwise, in a circle, about
3000 miles above the surface,
shining at different parts of it like a flashlight,
to make day and night.
To show why this is incorrect we will first
have to start on common ground,
and one thing that is not disputed, is when
it's solar noon.
Solar noon is when the sun is at its highest
point in the sky.
For example.
On March 1st 2017 at 11:30AM UTC, it will
be noon anywhere along this longitude line.
Including this point.
At this time, on this day, this place is different
than any other point on earth in one specific
way.
Just off the coast of Angola, the sun is directly
overhead.
In the united states, Hawaii is the only place
that experiences this phenomenon.
They call it Lahaina Noon.
At any time, there is only one point on earth
where the sun is directly overhead.
Let's plot it on a map.
The flat earth model uses an Azimuthal Equidistant
map.
On this type of map projection,
all points are the right relative distance,
and direction from the center.
There is, however, a problem with maps.
Since maps are flat, no map can accurately
represent a spherical planet.
We have to make tradeoffs.
No map can accurately show size, shape, and
direction all in the same map.
Azimuthal maps preserve directions from the
center, but distort size and shape.
The further from the center, the more distorted
everything is.
Whatever is on the opposite side gets completely
distorted and makes a ring around the map.
The flat earth map is an Azimuthal map centered
on the North Pole.
On this map, Antarctica is distorted and looks
as though it is surrounding all the other
continents.
If we rotate this map and start to center
it on Manila, in the Philippines.
South America starts to become distorted.
Eventually, it looks like it is surrounding
everything else.
This is what flat earthers think the earth
actually looks like.
And if the earth was actually flat, you would
be able to accurately model it on a map.
Preserving size, shape, and direction.
To say that this is what the earth looks like
is a positive claim.
If we can show that some of the features on
this map don't correlate with what we see
in the world,
then we can also show that the flat earth
model is wrong.
First, we're going to need a second map.
Another azimuthal map.
I chose one centered on New York City, but
you can use one centered on anywhere you want.
It's also zoomed in a little so that we can
get more accuracy.
On March 1st 2017, when the sun is directly
overhead just off the coast of Angola,
it will be sunrise in New York City.
6:30AM Eastern Time.
Light travels in a straight line.
Since this map preserves direction from the
center,
connecting these two points will tell us the
direction of the sun at sunrise.
If you are in New York on this day, and at
this time, you will see the sun rise in the
east, and about 9 degrees south.
Looking at the Polar map, also zoomed in for
accuracy, we can make a different prediction.
Connecting New York to the point off the coast
of Angola, we get another line.
If this map is an accurate representation
of reality, we can use a compass to determine
where on the horizon we should expect the
sun.
Using this map as though it retains directions
not just from the north pole,
tells us that the sun would rise in the east,
but also 10 degrees north.
That's a difference of 19 degrees.
You don’t need fancy equipment or to travel
the globe to know that the earth isn’t flat.
You can do it at home, with a map, and a basic
compass,
By measuring where the sun is on the horizon.
If you want to do this experiment at home
you can find all the tools I used, in the
description.
Links to make your own maps, maps showing
where the sun is directly overhead, and the
direction that the sun will be relative to
you.
Thanks for watching!
Leave a like if you enjoyed, and leave a comment
on what other topics you would like to see
explained.
