"The horizon looks flat, therefore the Earth
is flat."
This seems to be the governing idea behind
the flat Earth movement.
However, the globe-busters world also appears
to have experimental scientists.
"Hi, I'm Darryle, and I'm a realist, also
known as a flat earther."
"One thing that we deal with as being flat
earthers is the scientific community."
"What I'd like to do is submit a new experiment
to the scientific community, and one thing"
"that anybody can do is a simple experiment
that anybody can conduct to determine definitely"
"that the Earth is flat."
"Grab a spirit level and take it on a plane
with you."
So Darryle here made a video to provide the
scientific community, as he says, with FACTS
to support the flat Earth model.
He takes a quick flight from Savannah, Georgia
to Charlotte, North Carolina and, at cruising
altitude he tries to measure the curvature
compensation of the plane with a spirit level.
"If we're living on a spinning ball, or a
globe, then the plane should constantly be"
"dipping its nose forward in order to compensate
for the curvature regularly during flight,"
"but I don't know anybody who's actually reported
that happening, and thus far has just been"
"speculation."
No it hasn't, or at least it shouldn't be,
but we'll get back to that!
"And while that bubble's staying perfectly
centred, it's gonna be rather anticlimactic,"
"but that's proof that the Earth is flat."
So I suppose the bubble didn't move enough
here for you to consider it valid.
Ah, I think I get it now.
So the further you go, the more curvature,
the more the bubble should move...
Why, because your spirit level thinks it's
still in Savannah?
Or, since you bought it there, it will measure
as if it's still home?
When you said the pilot would have to compensate
for curvature, how did you envision that happening?
Or better yet, how often, like once every
minute, or...?
Maybe something like this?
Or, like this?
So let's see if we can understand his scientific
experiment.
If the Earth was flat, then the situation
is pretty straightforward, the plane flies
parallel to the ground, so the spirit level
or the bubble doesn't move.
For the round Earth, the plane flies like
this, and the bubble still doesn't move.
Now why is that?
If you think about it, if the plane constantly
adjusts for the curvature, then it is always
parallel to the horizon line, and that's what
the spirit level measures.
Then how should the plane fly to make the
bubble move?
On the flat Earth, the plane would have to
fly like this, such as when it's taking off.
The situation is quite similar on the globe.
The bubble will only move if the plane (or
the spirit level) is not parallel to the horizon
line, i.e. during takeoff or landing.
But why does the plane follow the Earth's
curvature at cruising altitude?
Is it because the pilot keeps adjusting it
so it doesn't fly into space?
Well, not really, it follows the curve because
the air density is also altitude, but more
importantly, curvature dependent, and so we
can imagine we have these layers of roughly
constant air density.
Now if the pilot doesn't change any flight
parameters, the plane will follow nicely along
these lines.
Well, not according to your experiment...
