
America’s flat-Earth movement appears to be growing – Daily chart - kercker
https://www.economist.com/blogs/graphicdetail/2017/11/daily-chart-21
======
xelxebar
In all fairness though, I don't have good reasons to believe most of consensus
science other than appeals to authoritative sources.

It gets me wondering how I could emperically test the things I supposedly
know.

~~~
Spooky23
You can trivially deomonatrate that the earth is round using basic tools
available 2000 years ago.

You of course have to trust the math isn’t some conspiracy theory, but the
ancient Greeks were able to measure the earth’s circumference.

~~~
xelxebar
> You can trivially deomonatrate that the earth is round using basic tools
> available 2000 years ago.

It's not actually so trivial. There are simple observations that are
_consistent_ with a Round Earth model, but it's pretty difficult to nail
things down rigorously and precisely.

Anyway, it's sort of interesting to me that you even bring that up. My comment
didn't really claim anything about Flat Earth at all; it was more an open
statement about the epistimics of scientific knowledge among non-experts.

The fact that you and one other commenter come to defend Round Earth, seems to
suggest a sort of belief tribalism in our current science-oriented zeitgeist.

~~~
eesmith
Questions about rigor and precision are a function of your goal.

The goal is to determine if a Round Earth model is a more useful model than a
Square or Disk Earth model.

I've demonstrated it empirically to my own satisfaction.

I've seen the Southern Cross right at the horizon from the Florida Keys, but
not visible father north. I've seen that the North Star rises higher in the
sky as I've gone north. And in summer I've seen that the daytime is much
longer in Michigan than Florida, and how the sunlight in the evening goes
through the windows of the north side of buildings, which it doesn't really do
in Miami.

I've driven across the US and seen that the sun rises a couple of hours later
in the West than the East.

I've been below the Equator, and seen Orion cross the sky upside down, while
the Southern Cross and the Magellanic Clouds were high in the sky. I also got
confused when driving because it turns out my sense of direction was based on
the expectation that the Sun should be in the south at midday, not in the
north.

I was once at about 55 degrees north latitude, in early December, and the sun
was low in the sky at noon. By measuring the shadow length I calculated the
latitude to within a couple of degrees. (This calculation does require knowing
the axial tilt, which I have not independently measured.)

These are all consistent with a Round Earth model, and not at all consistent
with any description of a Flat Earth model that I've come across.

Now of course it's possible to say that I've not measured the radius of the
Earth to sufficient precision, or demonstrated that the diameter between the
poles is shorter than the equatorial bulge.

But that's changing the goalposts. I did not have to appeal to any authorities
to confirm that the round earth model is a much better fit to my observations
than a flat earth one.

Why are you not able to make similar empirical tests? If you are able to carry
them out, why are they not enough for you?

The TV series "Ring of Truth" from the 1980s tried to address the question of
how you can test things out for yourself. One of the things they did, in such
a way that you could reproduce their work, was to drive along a long north-
south road and measure the elevation change in a star. From this they could
estimate the size of the Earth. They call it the "Van of Eratosthenes." You
can see it at
[https://www.youtube.com/watch?v=yRY2SkMTafc](https://www.youtube.com/watch?v=yRY2SkMTafc)
.

Again, there's no reason to trust what the said. Rather, you can use it to
reproduce their methods yourself, which is the sort of empirical test you
asked about.

~~~
xelxebar
Thanks for sharing those stories. It sounds like you pay quite a bit of
attention to the sky and stars!

> Why are you not able to make similar empirical tests? If you are able to
> carry them out, why are they not enough for you?

I'm guessing you meant these as rhetorical questions. They're indeed good for
introspection. For clarity though, I'm perfectly satisfied with a globe Earth.
Seems to be a pretty good model for my needs.

I was actually hoping sidestep discussions of Flat Earth vs Round Earth since,
as you point out, the empirical observations aren't to hard to think up as a
lay person. They're not quite trivial enough to be done in your backyard
though.

What I'm more interested in, personally, are questions like "What is the
structure of the Earth's interior?" I learned an answer from a textbook and am
vaguely aware of how seismic data has been used to extrapolate this, but I'm
not quite sure how to come up with a Core + Mantle + Crust model myself.

Instead of brute forcing these things, I'd really like to hear some clever
reasoning and Fermi estimation capable of rederiving these standard results.

Perhaps easier to answer would be "Does the moon have an atmosphere?" One idea
I had was to point a telescope on a line of site tangent to the lunar surface
and look for abberations in starlight compared to stars a large angular
distance away. This seems doable in your backyard with relatively cheap
hardware.

~~~
eesmith
I was responding to your statement "It's not actually so trivial. There are
simple observations that are consistent with a Round Earth model, but it's
pretty difficult to nail things down rigorously and precisely."

I object to the idea that additional rigor and precision is needed for the
specific case you were responding to.

As to your overall topic, one step is to watch that miniseries I mentioned
earlier, "The Ring of Truth: An Inquiry into How We Know What We Know". It
gives several examples of working things out from scratch. For example, drop a
measured and small amount of olive oil onto a still pond. It produces an oil
patch. The volume of the oil divided by the size of the patch gives an upper
bound for the size of the molecules in olive oil.

What you might not know is that there is a large amount of literature in
repeating some of the classic experiments. For example, physics undergraduate
lab courses may have the students measure the strength of the Earth's local
magnetic field, or the value of the gravitational constant G (not g, which is
the acceleration due to gravity), and do so using basic equipment you can
gather or make yourself.

Detecting the Earth's structure on your own is difficult. You will need a
seismometer, and learn how to interpret it. A quick search shows there are
many hobby plans for building your own seismometer, or you can buy ones made
for schools. The harder part is to come to trust that P-waves and S-waves are
different, that they have different speeds, that one cannot go through liquid,
and that observations of many earthquakes from around the world can be
combined with an understanding of material science and thermodynamics to
produce a model of the interior of the Earth.

If your purpose is to avoid what you consider to be appeals to authoritative
sources, you will have to redo from scratch what took others several lifetimes
to develop. One of these is Francis Birch,
[https://en.wikipedia.org/wiki/Francis_Birch_(geophysicist)](https://en.wikipedia.org/wiki/Francis_Birch_\(geophysicist\))
. Quoting that Wikipedia page, "In 1952 he demonstrated that Earth's mantle is
chiefly composed of silicate minerals, with an inner and outer core of molten
iron."

Concerning the round earth model, what you can do given limited travel is to
create a Foucault pendulum, or visit somewhere which has one set up. In
principle this can be done in a backyard, but it required a long pendulum wire
and still air - do you have an empty corn silo in your backyard? The time it
takes to go around can be used to calculate your latitude.

However, this only shows that you are in a rotating reference frame. You then
need to repeat what the ancient Greeks did, and look at lunar eclipses to see
that the shadow of the earth is always a circle, no matter where the Moon is
in the sky.

These together mean that from your backyard you could (in principle) determine
that the Earth is a rotating round object.

Concerning your question "Does the moon have an atmosphere?", the problem is,
the Moon does have an atmosphere. It's very thin -
[https://en.wikipedia.org/wiki/Atmosphere_of_the_Moon](https://en.wikipedia.org/wiki/Atmosphere_of_the_Moon)
. A naked eye view of the Moon is enough to determine that it does not have an
extremely thick atmosphere. So with a backyard telescope all you can do is set
an upper bound for the thickness of the atmosphere.

But to do that, you need some way to predict what those aberrations might look
like. For example, if it had a CO2 atmosphere that was 0.1 bar at the surface,
would you be able to detect it? Have you measured the index of refraction of
different gasses, or are you willing to trust the measurements of others.

I'm not saying it's impossible, but rather that you have to decide at some
point where you can trust the results of others.

~~~
xelxebar
Wow. Thank you for you thoughtful and long replies.

> ...you have to decide at some point where you can trust the results of
> others.

Exactly. My personal attitude in asking is very much in the "hacker spirit";
mainly I point out appeals to authority as an identification of an opportunity
to dig deeper.

> Foucault pendulum

Oh! That's a thing I had forgotten. Back in the day, I remeber using several
of these and correlating their positions against rotation rates to estimate
the Earth's radius. Not quite a backyard experiment though.

> "The Ring of Truth" miniseries

It seems this is on YouTube. Thanks for the pointer! The oil drop experiment
sounds really cool.

> Moon does have an atmosphere... all you can do is set an upper bound for the
> thickness of the atmosphere.

Fair enough. You're speaking more precisely than I. I'm also wondering at what
point the variance drops beneath the noise from Earth's atmosphere. This is
something that's worth taking a top-down approach by initially trusting our
Handbook of Physics and Chemistry and slowly working our way back.

Anyway, thanks again for your in-depth replies. You must be an amazing
conversation partner!

~~~
dwaltrip
I really like everything eesmith wrote. I'm all about understanding on a
deeper level how things work and how pieces of the world fit together. I also
think re-proving fundamental knowledge with simple experiments is awesome.

For the general question of knowing how we can trust modern knowledge, there
is another useful angle. We can look at the technological devices and items in
the world, and try to imagine how they work so reliably and precisely.

For example, things like digital cameras, microwaves, mcat machines, gps
devices, weather predictions, infrared goggles, sunblock, pneumatic machinery,
one-way mirrors, miniature electronics, etc... the list goes on

Why are these things so reliable? How do they work? It's very hard to imagine
a world in which these countless devices exist, and yet the corresponding
science is not very well-understood or robust, at least without jumping too
far off the deep end.

Of course, it's a fantastic exercise to try to research and understand which
individual bits of scientific knowledge are required for the various modern
technological devices that we encounter.

I know you don't think that the foundations of modern knowledge are shaky. I
just thought that your questions were considerate and genuine, and that you
might appreciate this additional way of analyzing things.

Edit: Watching the Ring of Truth right now... very cool program. Makes me want
to do some observations myself.

~~~
eesmith
Thanks to both of you for the praise.

You might also be interested in "The Secret Life of Machines".
[https://en.wikipedia.org/wiki/The_Secret_Life_of_Machines](https://en.wikipedia.org/wiki/The_Secret_Life_of_Machines)
and
[https://www.youtube.com/watch?v=KDpNQQqdSh8&list=PLByTa5duIo...](https://www.youtube.com/watch?v=KDpNQQqdSh8&list=PLByTa5duIolYRtq45Cz_GmtzfWJyA4bik)
.

Philip Morrison (from Ring of Truth) is perhaps best known for his powers-
of-10 movie.
[https://en.wikipedia.org/wiki/Powers_of_Ten_(film)](https://en.wikipedia.org/wiki/Powers_of_Ten_\(film\))
.

He was also a columnist for Scientific American. The only column I remember is
when he decided to make bread from scratch. Really from scratch. They grew
wheat in a small plot of land near his home in Cambridge, Mass.

He's part of the generation that developed the first atomic bomb. He carried
the first core to the Trinity test site in the back seat of his car, and
helped load the weapons on the planes that went to Japan.

~~~
dwaltrip
Ah yeah, I remember the powers of ten video. Great way to visualize the
concept of scale, and to get a broad look at the universe as we understand it.

Thanks for the other links, I'll have to check them out!

------
joshbaptiste
Flat earthers have an answer for every scientific question posed. Now suppose
NASA Is faking every video etc.. There's no way Americas rivals Soviets, North
Korea etc.. who have been or have satellites in space would collude with
America to hide such information.

~~~
derekp7
But then they come back and try to say that the Russians are trying to tell
them the truth, but the information is getting suppressed before it gets to
them (after all, how many of them have personally spoke with a leader in a
foreign government, and if so, how do they know that the person they spoke to
wasn't a fake planted by the "establishment"?)

I still think that this movement is a big gag, that 99% of the members are in
on (something like the Church of the SubGenius).

------
em3rgent0rdr
> "If schools were better at teaching analytical thinking, that might reduce
> the appeal of conspiracy theories. And it would not hurt if governments were
> more open and trustworthy."

Two big if's.

------
akuji1993
Site that I haven't visited in two months immediately hits me with a pay wall
because I've "reached my article limit". Nice.

The issue itself is, of course, ridiculous. I'd really like to read the actual
article, but apparently, I'm not.

~~~
eesmith
You would like to read the article ... and the writers at the Economist would
to get paid to write articles.

------
exlurker
Neil deGrasse Tyson weighs in on this:
[https://twitter.com/neiltyson/status/934906611088359426](https://twitter.com/neiltyson/status/934906611088359426)

------
miiiiiike
There’s very little content or context in this article.

~~~
nerbert
It's just a comment of trends on google search.

------
smashu
America’s flat-Earth movement will soon become a global movement (LOL)

------
lawlessone
I blame facebook. Theres hundreds of these flat earth groups and other junk
about vaccines and "gang stalking" . It's all completely unchecked filter
bubbles.

~~~
dragonwriter
Filter bubbles alone cannot explain an expanding movement (they can explain
solidifying and radicalizing within a fixed-size movement, but not growth of
the movement.)

