How do they know Earth’s circumference?

To accurately measure the Earth, you have to accept one maddening fact.

WELCOME TO HOWTOWN! Our small but mighty team of two (Joss Fong and Adam Cole) digs into the evidence behind commonly held facts and claims in the news.

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SOURCE LIST:

BOOKS!
“The Measure of All Things” by Ken Alder chronicles the process of creating the meter.

“The Measure of the Earth” by Larrie D. Ferreiro follows the bizarre and hapless French Geodesic Mission to the equator

Chapters:
00:00 Simone’s question
00:51 Eratosthenes measures the earth
02:57 our experiment
04:19 results
05:34 enlightenment punks
07:05 the ellipsoid visualized
07:46 proving the ellipsoid
08:59 geodesy
11:44 the satellite era
13:37 awkward corrections
14:06 credits

[bhs]

Love your new channel! Keep it up! One question though- you mentioned that gravity is weaker farther from the center of the earth when talking about the pendulum, but then in your gravity map, you mention that gravity is weaker when you are closer to the center.

[veronicamcghie]

Clicking this video and absolutely hyped to hear about those Greek dudes and their trigonometry

[VishnuPadmanabhan]

The research, the visuals and the explanation, absolutely wonderful! Brilliant!

[tomato]

You explained this without making it complex, and you were able to keep me curious throughout the video. You guys are fantastic storytellers. Thankyou.
It is crazy that you two are perfectly situated to perform that experiment.

[TS-cspe]

0:45 flat earthers got excited for a while

[sebastiantovarmarquez]

Imagine my surprise when I found out that you're living in my home city Bogotá, awesome experiment, awesome channel, subscribed from day 1

[joshsatterwhite]

Wait, you've already had Cleo, Hank, and now Simone on your channel in the first month? Impressive connections you must have. Much more impressive than the algorithm taking this long to let me know you existed.

Awesome video! I like the pacing, the info, and the presentation style. It's not everyday my ADHD-addled brain will sit through 14 minutes of things I (mostly) already know just because I enjoy the way it's shown. I look forward to whatever - and whoever - you bring to the table next!

[leahvashevko]

Love the visuals! One thing: maybe hold for one more beat after an explainer animation finishes playing before cutting away. Like at 7:38, give a second to look at the different lengths before cutting to Adam.

[vinny]

"Why is it so close to exactly 40k"

The answer in this case is "because that's what we based the meter on", but otherwise it does raise the very interesting question of "why _do_ people care about these coincidences?" Why is it that we think we rolling two sixes with dice is much harder than to roll a 3 and a 4?

[kw]

The visual effects in your videos are incredible!!

[revealist]

These animations, sound, writing...dang. Great explanations created with words and images

[jeouxgentry]

Super-impressed with the artful effects. The overlapping text to illustrate a face particularly caught my eye.

[abhkr]

You mentioned that gravity is weaker in some places and stronger in others. Why and how is this possible?

[powerverwirrt]

I loved this video but I noticed that the official captions are off a lot of the time, so the automatically transcribed ones ended up being much more accurate. Maybe something to look into?

[geekgee]

Noticed a thumbnail with Simone in my recommendations, watched, liked and subscribed. 👍👍

[katjarozantseva]

Quick note before watching, new thumbnail “how do they know the Earth circumference” is way better than old one. I do know that Earth is not a sphere, that doesn’t make to have a thought about clicking

[WaitWhat]

Stumbled across this channel from shorts. Immediately subscribed 😁 Loving it, cant wait for more!

[oblivious_waffle]

10:29 cat cat cat cat cat cat cat cat cat

[needamuffin]

I clicked because of Simone, disappointed that she's in the video for all of 9 seconds.

[ChristopherYeeMon]

You and the other Vox alumni are keeping the Vox video heritage alive