This Was GENIUS!!!

[@crimsondragon2677]

And he was off by less than 2%. Well done, man with stick.

[@LePookieBear00]

No he wasn’t

[@karuki5791]

He was off by 75km. Also his guess was 40,000 not 41,134, the real figure is 40,075km by the way.

[@DidiTheCoolio]

@@LePookieBear00yeah, 0.2 percent off

[@romanbundy921]

​@@karuki5791I searched it up, and it was true

[@niknik6718]

Yay

[@neiljoshualerin9108]

ancient greek with stick > Flat earthers

[@momaizgamer]

wdym HE WAS EGYPTIAN

[@clown_wubtasticbox03]

"But how can he prove it, it's just a stick, earth is flat" 🗣️🗣️ *nasa use satelite to take a picture of earth* "THAT'S CGI, WE CAN PROVE IT WITH ONLY CAMERA" 🗣️🗣️🗣️🗣️ Flat earthers☕

[@neiljoshualerin9108]

@@momaizgamer dude his name is eratosthenes, greek, better use internet for something

[@neiljoshualerin9108]

@@clown_wubtasticbox03 how can you prove its cgi?

[@avantgarde04]

​@@clown_wubtasticbox03 man don't get me wrong but you are painfully unfunny

[@Manueltion15]

We underestimate ancient people

[@ClydeAlb]

Yeah when there are really naive peoples like u around who thing this is true than yh they were smarter😂

[@The_Green_Man_OAP]

We underestimate sticks and stones 🏒 🗿, then go to our _safe places_ 🛐 to hide 🙈 from the nasty barbarian _PAGANS_ 🐍👺 who discovered & taught us _everything_ 👨‍🏫👩‍🏫🧙‍♂️.

[@notjeff7833]

You mean the ones that hindered scientific process by killing/imprisoning scientists for saying something they didn't like? You overestimate them

[@Ghost_Cube]

My boss told me aliens created the pyramids with their sophisticated technology. I said, if their technology was so advanced, why did they make a pile of rocks? And why did they follow Egyptian tradition?

[@SerunaXI]

Ancient people had a lot of time on their hands, and far less youtube to occupy that time.

[@Xenomnipotent]

People take for granted how much our modern numeral system makes math calculations easier. For example, try using Roman numerals to solve XIV times XXV, it’s completely unintuitive. It just makes all ancient mathematicians so much more amazing.

[@brindur]

You’ll be happy to hear that it’s quite a bit more complex. Using symbols and arabic numerals in mathematics in europe only became a thing during the renaissance, before this they were using actual geometrics and they kept doing that after the 14th and 15th century, only in the 1600’s with isaac newton did we really transfer to using mathmatics the way we do today. The ancient mathematicians were using actual triangles, squares and rectangles to represent amounts, symmertries and multiplications.

[@railx2005]

Actually its proven that if we counted to 12 instead of 10 math would be infinitively easier

[@Xx_Sunny0mor1_xX]

CCCL?

[@Kishblockpro]

It’s unintuitive because we’ve grown up without using that… you can’t say it’s just objectively harder, why does this have likes bruh

[@Amit_Pirate]

​@@railx2005 can you explain how?

[@55Quirll]

With a very small % of error. The sad part is there are people who believe the Earth is flat even when it was shown to be Spherical over 2,000 years ago.

[@chocolateneko9912]

How is that sad? Doesn't change your life. We should be skeptical of fundamental claims like where we live.

[@55Quirll]

@@chocolateneko9912 Living on a disk with a dome over head? That is sad. Even with all the evidence to the contrary it is.

[@junghunt8645]

People with mental illness or shattered reality who are prone to grifting and radical ideologies are sad and bad for everyone. Radical idiocy is damaging.

[@gyrow1684]

​@@chocolateneko9912 We should be sceptical of something according to evidence. If you simply deny the evidence, it's called delusion.

[@_apsis]

@@chocolateneko9912skeptical, yes. but it is easily verifiable that the earth is round, and if you still deny it after that, that is not skepticism. that’s ignorance.

[@Milexodus]

Bro drew a backwards checkmark

[@GenesisRasphotos]

"BuT tHe EaRtH iS fLaT" 😂

[@SacralSource]

No doubt

[@shelly8563]

Well in a Flat Model the Sun revolves around the Flat Earth surface in a Disc like motion, similar to a CD/Record player.

[@alexisalbertoza]

​@@shelly8563still, in a flat earth the sun would light all the planet at once, as everything is flat, there's no face of the planet that's hidden from sunlight

[@chocolateneko9912]

​@@alexisalbertozaFail. flat earth doesn't claim the earth is a planet. It also doesn't claim that the sun is the same as commonly thought, rather it's a local, smaller light that doesn't brighten up ALL of however large the plane of earth is.

[@alexisalbertoza]

@@chocolateneko9912 still a flat earth doesn't make any sense. I mean, if there were a flat earth, you wouldn't be able to see the horizon and it'd be covered by buildings. This effect is explained by how far we can see things (e.g. you can watch objects millions of light years away with your bare eyes because their light reaches your eyeballs).

[@SyDatNguyen-r4j]

To calculate the circumference of earth, the circumference of any circles is 2 pi times the radius. Just take 2 pi multiply it by earth’s radius

[@hyoominoid01]

Gosh your not thinking straight, to know the earths radius you must know it's diameter or circumference. You can get it in many other ways and god knows who would walk at a steady pace around the entire earth and in a straight line.

[@robertzappe9747]

6×6350=38100+3141=41241km

[@MadHEX369]

How did they communicate when exactly to take the measurements simultaneously? Sun Dial?

[@jimgreekgamerYT]

I believe so because they were in the same time zone then the time was the same so the sun dial would work

[@ivantxic7870]

Eratosthenes used a sundial to measure the angle of the Sun's rays. He noted that at noon, in the city of Syene, the Sun was directly overhead and objects cast no shadows. By comparing this with the angle of the Sun's rays at noon in Alexandria, where he was located, he could estimate the Earth's circumference.

[@DerDrako]

That is something, we learned in school in Germany. I was honestly amazed when our teacher told us this story.

[@gaethriramesh4670]

While, a Greek philosopher used two stones and some math to calculate the circumference of the Earth. We complain about putting milk before our cereal it's just in plain sight of how much of potential we have.😮😮😮

[@kakyoindonut3213]

Y'all underestimate just how fucking smart people was back in the day

[@Universe4-U]

We still are but something died, curiosity of how everything works, in comfort that we can know a search in a engine search bar away.

[@JailbreakMoments]

Human have always remained intelligent. I feel that we today, completely underestimate the power of the human mind thousands of years ago.

[@jernej7660]

How did they measure distance between the two cities and how did they measure it at the same time? 800km back then was days worth of traveling and it''s not like they mechanical clocks to sync the time to measure

[@Amit_Pirate]

You might want to see the detailed video, it's an interesting watch.

[@CharlesBAJD]

There ar. e any number of explanations of how Eratosthenes did this. Try the first chapter of "Cosmos" by Carl Sagan

[@carultch]

He hired someone to manually pace the distance. Also he didn't get simultaneous shadows. His shadow measurements were done on the same day of the year, in two separate years. I.e. the summer solstice.

[@SyDatNguyen-r4j]

Earth’s circumference is 40 075 km at the equator and 40 008 km at poles

[@DrDrOp55]

Little did he know that over 2000 years into the future, people will try to prove that earth is flat.

[@nathanpfirman625]

We as a species need to start thinking like we did back then were we questioned everything and tested it all. Nowadays we’re to comfortable and prideful to question. Cause we think we understand the inner workings of the universe but in reality it’s probably a billionth of the truth.

[@RahulSharma_45]

On hearing stick, I thought that he measured the whole earth with his stick as a measurement scale.😂😂😂

[@mohamednuur3887]

To even think about that was brilliant

[@SerunaXI]

The stick was one of the controls for the experiment. Using the same stick meant he could ensure the shadow cast from the same height in both locations. He also knew that the shadow in one location at a certain time was significantly different than another location, and used the stick to confirm. Likely also, also helped, that he was able to get the information from both locations and factor any differences caused by how many days between data collection. The rough knowledge of distance and how many days it took to travel likely resulted in the small discrepancy in the calculation.

[@akdb]

Uhm so ☝️🤓 the world is actually 47262973 sticks circumferencs

[@juliavixen176]

​@@SerunaXIAll his measurements were taken at noon on the summer solstice.

[@uddiptabhowmick2403]

Man I have this in my geography book but couldn't understand. Thanks a lot

[@agni0001]

Genius

[@JimSmith-u5g]

Greeks are Amazing; always

[@tiskbubbles4688]

Some omitted details: The orange arrows are rays of sunlight. You know that there is a ray of sunlight going just above the stick and landing just above the shadow, so you know the hypotenuse of the stick-shadow right triangle lies on a ray of sunlight. You can also treat the rays of sunlight as approximately parallel since the sun is very far from the earth. You get the angle as arctan(shadow/stick). You can find the angle inside the earth to be the same by the transversal theorem. Then the video covers the rest.

[@Faizan-Shafaqat]

But how they now when to measure, or the exact time to take reading.

[@CalinColdea]

Question is, how were them able to look at the stick in the exact same time???

[@juliavixen176]

The measurements were made at noon on the summer solstice. It's really easy to know the date and time. If you look into a deep water well in Syene -- which is on the equator -- you will see the sun reflect off the water in the bottom of the well at exactly noon.

[@AddyGoesPlaces]

What’s interesting is that he believed Earth was round at all.

[@50srefugee]

"At this time of the day." I've always wondered, though, how old 'Tos knew it was the same time in both locations? Am I missing something?

[@leonghwashin74]

But how to synchronize the time?

[@dross4207]

They use local solar noon which is when the Sun is at its highest point(zenith) in the arc it traces across the sky, and thus, it’s a geometrical reference, and not a time reference. Local solar noon is also the time when shadows are the shortest and point directly north.

[@carultch]

He didn't synchronize the time. He used solar noon on the summer solstice in two separate years.

[@willjackson5885]

That’s assuming rays from the sun are parallel. Alternatively if the sun was a nearby point of light and Earth was flat, then sun would be (800 km) * sin(83) / sin(7) = ~6515 km above the Earth’s surface.

[@elhartzer1639]

Sure, but the rays are parallel and the sun is about 150mio km away.

[@andrewsad1]

Yep. There are so many proofs that the earth is round, and I don't like people using this as proof because all it proves that that ancient people were extremely good at math

[@willjackson5885]

@@elhartzer1639 How would an ancient person know that the rays were parallel?

[@actually5004]

@@willjackson5885 The illusion of a vertical object having no shadow would not work at all anywhere.

[@willjackson5885]

@@actually5004 I understand what you’re saying, the sun might never cross directly over the vertical stick. But if it did, then the stick would have no shadow

[@Dgbxse]

It is actually just 40000 kilometers. Because 1 meter is 1/10,000,000 of the distance between North pole and equator, so it is 1 million meters or 10000 kilometers so the circumference is 40000 km

[@AnAverageItalian]

The meter isn't defined like that anymore, and even if it was, Earth isn't a perfect sphere, so depending on where you are, the distance between the North Pole and the Equator can be a bit different

[@babaskarma1981]

​@@AnAverageItaliangrazie fra

[@syncradar]

​@@AnAverageItalianthe difference between the circumference of the North Pole and the Equator are negligible, only off by about ~70km.

[@Jester343]

Flat earthers: Nuh uh

[@YoBoiHrcky]

Okay, but how do we know that the ratios of the degrees and distances are the same?

[@pixelhy]

That's how a circle works.

[@Literallytheplanetsaturn]

greek mathematicians were goated

[@aezurefx]

The egyptians did this first.

[@Literallytheplanetsaturn]

@@aezurefx honestly bro i do NOT care

[@aezurefx]

@@Literallytheplanetsaturn Don't worry you can live in ignorance

[@joecommenter1332]

Did he post his findings on tiktok or Instagram?

[@sotofpv]

Did he use some sort of clock to be able to get the measurement in both locations at the same time? Unless he can immediately travel 800 km or shout really loud to someone else 800 km away how did he do it?

[@hujjjhjnbb1017]

they did it on the same day in separate years

[@Andy_Mark]

I dont understand how he kept the time in sync. Did they have mechanical clocks?

[@bia8367]

No they used cell phones

[@andrewsad1]

You can agree to take the measurements on a given day at high noon

[@Andy_Mark]

@@andrewsad1 Oh wow. Ofcoarse. 🤯

[@waynebro7828]

how did he synchronized the time ??

[@andrewsad1]

You and a friend agree to go to two different cities, and take your measurements at high noon on the summer solstice.

[@tux1968]

It's really annoying that we don't know how Eratosthenes measured time. Somehow he knew the exact moment it was noon in Syene, even though he was 800km away in Alexandria.

[@pixelhy]

I'm *guessing* he probably measured a specific time from sunrise in both places

[@tux1968]

@@pixelhy You might be on to something there, but we have no idea how he would measure that specific time. How did he keep track of the length of time since sunrise. He had no mechanical clocks, and I don't see a way to make a sundial work, since it's the thing you're trying to measure.

[@γνῶσῐς-6]

Simple, logic. Shadows are shortest at noon, so one must assume that it's noon when the shadow doesn't grow.

[@tux1968]

@@γνῶσῐς-6 It's not so simple. The issue is not determining noon in Alexandria, where he was. It was knowing the exact moment it was noon 800km away in Syene. They didn't have a telephone, or any other method to communicate this information quickly.

[@toheli1071]

They did all that instead of just multiplying the radius by 2pi 🙄

[@carultch]

The radius wasn't known at the time either, until his experiment happened.

[@toheli1071]

@@carultchIk it was a joke

[@ohwow512]

Let's be honest. Are you even suprised that this was done by a Greek mathematician?

[@trinityy-7]

the polar circumference is ~40,000km. why? because we said so. that's the original definition of the meter

[@darkshot-2495]

What's a kilometer?

[@cubingwithdev5761]

10^13 armstrong

[@JailbreakMoments]

About 11,236 McDonald’s cheeseburgers laid down next to each other

[@denysberezovskyi1113]

How did he time the event? This experiment requires that he knows the difference in shadow at exact moment in different place.

[@ivantxic7870]

Eratosthenes used a sundial to measure the angle of the Sun's rays. He noted that at noon, in the city of Syene, the Sun was directly overhead and objects cast no shadows. By comparing this with the angle of the Sun's rays at noon in Alexandria, where he was located, he could estimate the Earth's circumference.

[@realbrickbread]

But how did he know when to exactly measure the angles?

[@JailbreakMoments]

If i recall correctly, he did it in 2 different years during the summer solstice?

[@hikikomorihachiman7491]

M o T h e r f u k!!! I will be damned man🤯🤯🤯🤯🤯🤯

[@yournerdiness3135]

I mean, it's actually just the definition of a kilometre, a 10,000th of a quarter of the earth's circumference, but it was off a bit

[@The_Green_Man_OAP]

Assumptions: 1. R= _Sphere_ 🌍 _Radius_ , 2. C= _Great circle circumference on_ 🌍 _Sphere._ 3. R≈ _Actual mean radius for_ 🌍 4. C≈ _Actual mean Great Circle_ ⭕ _on_ 🌍 Arc segment "⌒" ≈ Opposite side to angle in "∇". 800{km}≈2Rsin(7*π/360), using trig. 800{km}≈2R(7π/360), due to small ∡ in ∇ . 2R(7π/360)=C(7/360), C=circle circumference. Therefore: C≈(360/7)*800{km}.

[@branwhite4973]

I knew the flats would be here. Its like i say to EVERY FLAT EARTHER... DOOOOOOO MATTHHHHHH

[@shadowstrike3724]

Everyone : "Wow, this guy was Genius" Le* Me : "But earth is spherica-"

[@purplrshadowyay]

He said just that

[@OverWims]

But isnt the earth not a proper sphere, being squashed at one part? Meaning depending on which circumference you measure you could get an entirely different result. It's like measuring a rugby ball and saying its the same circumference everywhere. The earth isn't as squashed as a rugby ball but you get my point.

[@alakazam482]

Tje earth is only 14 miles wider at the equator so it's really not that big a deal

[@uddiptabhowmick2403]

Equatorial circumference is about 40076km but the polar circumference is about 40008km.

[@Ben-p2l6q]

One problem with that the french descueres the circumference of the earth

[@KM-tv2zf]

How did they know what time it was tho?

[@freakingannonymouspanda1766]

I knew the story, but how exactly did they pinpoint what was going on in a city 800 km away in real time?

[@CharlesBAJD]

That's explained. He knew that at solar noon in Syene on that day. the sols, the Sun was directly overhead. Syene is on the Tropic of Cancer and it was the summer solstice.

[@bia8367]

He we called his mate who lived a few time zone away and asked if the sun was casting a shadow or not?

[@purplrshadowyay]

Or he just did it the next day/a few days later.

[@andrewsad1]

It's easy when you agree to take the measurements at high noon on the summer solstice

[@shariifjakes4290]

He said “basic algebra” while explaining the circumstance of the earths surface 😂

[@420sakura1]

Most problem come under basic algebra...if you break the solution down.

[@Evan490BC]

Yes, where is the problem? It's not an algebra over matrices, but over a field (that of the real numbers).

[@miladmirgv2259]

It's crazy to beleive that people thousands of years ago

[@yablock7346]

He used a big mesureing tape

[@osifox8119]

He could have stayed in Greece and got the same result!??? The Egyptians knew that is how the story involves Egypt, but the details changed over 2000 years 😅

[@EndietheEnderman]

What? Egypt was Greek around 2000 yrs ago and many Greeks lived there

[@osifox8119]

@EndietheEnderman we're not talking about that. Egypt was on the decline by millenia before Alexander went on his conquest but the Trigonometry it took to build the pyramids was already known much less rudimentary time measurement. They knew Pythagoras theorm before Pythagoras was born lol.

[@aezurefx]

Exactly. Most ancient greeks travelled to Egypt to study and develop their own "knowledge" on particular fields. If you know history this is no surprise.

[@MoyuGuy]

i thought of sending a boat past the horizon but this is much easier.

[@abdelazizkara2352]

There something not clear for me. How he would know it is exactly the same time at 2 different cities 800 km a part. They don't have clocks at the time, they used the same sun for the time?

[@1994mrmysteryman]

They had sun dials which allowed them to measure the sun at it's highest point. However, even at its highest point, the sun sometimes cast a shadow. And sometimes it didn't. That's what he used.

[@The_Green_Man_OAP]

Mirror relays, sun dials and sand timers.

[@Deboned_butter]

If the two cities are on the same longitude, it doesn’t matter!

[@AdamPruett]

But how did they measure how far the cities were from each other?🤔

[@BrandonBDN]

He likely didn’t, maps existed back then

[@syedrafiqkazim448]

Yes flat earthers are annoying but another annoying argument is "there's no way they could've done that without aliens"

[@roniloanub8991]

If earth's circumfurence is approximately 41,143 km, we move at 41,143 km/24hr = 172.625 km/hr.

[@alexanderananyev3271]

You calculations are a bit off. 41143/24≈ 1714.29

[@bpivr]

@@alexanderananyev3271That’s just the rotational motion. We’re also moving around the Sun and the whole solar system is moving around the Milky Way. I suppose the Milky Way is moving too, at least relative to some other point.

[@Harry-bd6pb]

​​@@bpivrwell there is a thing known as refrence frame which can sort out all confusion,, if you take ground as reference frame , your velocity is zero , if you are viewing earth from space (considering you are stationery)you will fing that the persons velocity is 1714 km/h approx

[@xd0895]

This guy kinda sounds like Sheldon Cooper

[@kduty236]

More likely similar first name Nicho Felich. I almost can't tell the difference

[@kduty236]

Searc "Nicho Felich" and u Will shock

[@Greeneon6073]

Who will win: 20,000 Flat earthers with access to modern science and thousands of dollars of hi-tech equipment Man with primal tools

[@andrewsad1]

In this case? The flat earthers can easily say that the sun is 6,500 km above the earth

[@Josh.V]

And it also confirms that the earth is round

[@torfley]

should mention, he didn't actually use meters

[@kaustubhpandey1395]

Great minds Considering all the prevailing flat earthers back then

[@muazalli8999]

Where is 7° coming from?

[@Shrektus]

shadow relative to stick relative to sun. It forms a right triangle

[@jamesmcardle1494]

2000 years ago they did not have the metric system, so no he did not . he did measure it but not in kilometres.

[@LaserTractor]

People today: "Yeaa I will become anime isekai protagonist powerful with all my knowledge if I am to be teleported back in time hahaha" People back then: [this video] You, when teleported back in time: "uh so we have those laptops and electricity and it comes from things in our house...with wires and cables you know..."

[@420sakura1]

Yeah. I love isekai but hate that part. People back in the day lacked the knowledge we have but they weren't less intelligent than us. We know what works and what doesn't. The knowledge we have is due to centrists of trial and error, necessity, sharing of knowledge etc.

[@RealKidNamedFinger]

nahhh they just walked

[@mindyourownbastardbu]

How did he know 2,000 years ago to measure the shadow at the exact correct time in each place

[@ADuxk]

Measured at exactly noon at the summer solstice

[@DrDeuteron]

The original definition of the km was that 10,000 km spans the equator to the pole. So, it’s tautological.

[@amirul3233]

But isn't the Earth egg shaped? So doesn't that mean the Earth doesn't have a fixed circumference?

[@IMMORTALSHADOW-nh3si]

Bruh it s not 41000 km it's approximately 40100 km(40075)measured

[@JailbreakMoments]

Yes, and we got that figure with advanced satellites, he got a very close number with a stick, Millenia before us.

[@akrambereriche4742]

I wonder how he figured the time of the day in a city 8000km far from him ... :), since the only watch at that time is a stick on the ground :)

[@juliavixen176]

The two cities are about 800km apart, and he made several measurements over a couple of years. The thing about Syene is that being on the equator, the sun will shine directly down a deep water well exactly at noon on the summer solstice, which you can easily observe just by looking into the well. Anyway, it's not hard to figure out when it's noon, and it's not hard to figure out when the summer solstice is. The year was already known to be 365.25 days long, and that part of Egypt had been surveyed already for agriculture (so distances and directions between cities was already known).

[@lauroneto3360]

Doesn't this experiment also mean the sun might be 41.000Km away from a flat earth?

[@andrewsad1]

No, it means the sun could be 6,500 km above a flat earth. There are a multitude of reasons we know that the earth isn't flat, though. For example, astronomers then were aware of the distance to the moon through a similar method of triangulation-they moved a known distance away from each other, and noted the position of the moon during a known time, typically a lunar eclipse.

[@lauroneto3360]

@@andrewsad1 oh I know the earth isn't flat bro. I'm just saying based on this experiment. Back in the day.

[@forfun6273]

But how do he know the time when they didn’t have clocks? They used a sun dial?

[@dross4207]

They use local solar noon, when the Sun is at its highest point(zenith) in the arc it traces above the sky. That(local solar noon) is also the time when shadows are at their shortest and point due north. That way it’s a geometrical reference, and not a time reference, so no need to coordinate time.

[@cosmorito961]

How did he knew that syene has no shadows casted As he was 800km away?

[@alexisalbertoza]

Because in the full story, he asked for help from someone in Alexandria

[@spewter]

Asking the right questions! Then we must ask how accurate their time keeping was

[@mayank.semwal]

​@@spewterThere is no way of confirming the accuracy but let's assume that they must've communicated through letters and would have fixed a date and time for the experiment. And since that is a guy who calculated the circumference of a planet about 2000 years ago with just shadows and math, you must not question his ability to coordinate and calculate.

[@carultch]

@@spewterIt's pretty easy to coordinate the time. You simply look for solar noon in both places on the summer solstice. The sundial was a mature technology, and plenty of people knew how to identify solar noon. If you were to do a modern reproduction of this experiment, you would coordinate with your friend using a cell phone, and you could use an odometer to keep track of the distance. Here is a modern reproduction of this experiment, doing exactly that. kzbin.info/www/bejne/j5KzkmebqK99rpY

[@The_Green_Man_OAP]

Mirrors? _Archimedes_ allegedly used them to burn 🔥 Roman ships ⛵, so it's possible they were used to communicate 🗣️ over extremely long distances between elevated areas 🏔️.

[@opufy]

without a calculator

[@MarcColten73]

How did they know they were measuring at the same time?

[@ClydeAlb]

Its bullshit😂

[@MarcColten73]

@@ClydeAlb In what way?

[@carultch]

@@MarcColten73They weren't measuring at the same time. They were measured at equivalent times in separate years. Same day of the year (summer solstice), and at solar noon in both places. This will work as long as Earth's precession doesn't change, which it won't change by a significant amount in a human lifetime.

[@dross4207]

They use local solar noon, when the Sun is at its highest point(zenith) in the arc it traces above the sky. That(local solar noon) is also the time when shadows are at their shortest and point due north. That way it’s a geometrical reference, and not a time reference, so no need to coordinate time.

[@dross4207]

@@ClydeAlbIt’s bullshit, huh?? It’s been repeated thousands of times, idiot. What’s it like being a reality denier? How’s that working out for you? Have you chased away all your friends and family yet?

[@charlesmurray3255]

So, he phoned his friend and said , where's the shadow now?

[@wilsonarno]

Eratosthenes knew that at noon on the first day of summer no shadows are cast in the town of Syene (noon being the time with the shortest shadow). Eratosthenes only needed to measure the shortest shadow in a different city along the same longitude at noon on that day. This is the genius of his experiment. No time "synchronization" was required; he merely observed the length of the shortest shadow!

[@neiloppa2620]

​@@wilsonarnohow did he know when noon was?

[@_apsis]

@@neiloppa2620sundial

[@wilsonarno]

@@neiloppa2620noon was the time with the shortest shadow, which for cities on the same longitude happens simultaneously.

[@neiloppa2620]

@@wilsonarno ohhh that's smart. ❤️

[@effyleven]

(Sigh) He didn't use sticks. He used the reflection of the local noon sun at the bottom of deep wells.

[@Sp4rk3d_GD]

I cant believe a greek is more smarter than most of us today

[@phxen1x128]

Not most but a few, but that's not because of the fact if they or smart or not, it's because they, idk why, just won't believe that the earth is round

[@GoofyAhOklahoma]

​@@phxen1x128Nah people are dumb as bricks today

[@methrod]

hey i thought of that

[@basiccoder2166]

Km was first Introduced on 17th century just after French revolution and there were no clocks 2000 years ago

[@Alden_Redstoner]

true

[@ClydeAlb]

Exactly its all bullshit ,"smart greek" propaganda to get more tourism and history in europe ,greeks didnt even knew how to wipe their ass back than in reality

[@gyrow1684]

How gullible you have to be to assume that Eratosthenes used kilometers? He measured it in stadions and they were converted into kilometers for us...

[@basiccoder2166]

@@gyrow1684 and what about time how someone can measure exact time on 2 spots at the same moment? When there were no clocks or any way to communicate over the range of 800km

[@gyrow1684]

@@basiccoder2166 Eratosthenes knew that during summer solstice on June 21st the sun in Syene would be directly overhead and that it wouldn't cast shadows unlike Alexandria. Do you really think that all of modern well-researched fundamentals of physics, astronomy, geography, and geology would be incorrect even with incontrovertible evidence, and that you're right without any proof? This is delusion.

[@EdOeuna]

A short video about the earth still brings flat earth sufferers out of their basements to comment.

[@TheSolidheroes]

Hahaha whose the fool? You actually believe a 2000 year old fairytale about a Greek guy with a stick??? Lmao and that unicorn story about the magic spinning ball shooting through space?😂 man another spinning ball buffoon

[@TheSolidheroes]

@@leeperkillz5397 Show me the scientific proof other then a story about a Greek guy with a stick man it’s So obvious its ridiculous. Your one of those Guys who claim there’s science behind this nonsense but fail to show the evidence.

[@kushansulochana3459]

But how the fuck he exactly knew that theres no shadow in a city that is 800 km away?

[@totallynotpaul6211]

He could send a letter to someone and tell them to put a pole in the ground and mark what time of day it has no shadow, then send the results back to him to calculate.

[@andrewsad1]

You and a friend both agree to go to different cities and measure shadows on a given day. You know when the solstice is, and you know when high noon is, so you agree to take your measurements at high noon on the solstice. You meet up later and compare notes.

[@JailbreakMoments]

He did it during the summer solstice at solar noon during 2 different years

[@stevenwilliams7549]

42,000

[@oofmynugs5923]

How did he know they were 800km apart?

[@ittrallion2685]

He used anthor system it's obviously not km Like he used a long stick/rope and pure dedication

[@BrandonBDN]

@@ittrallion2685no.. no no he did not… why would you just comment this without actually looking it up or knowing it

[@BrandonBDN]

They had maps back then you know

[@niknik6718]

Cool

[@Maxime_K-G]

It's so easy. You just need to not be a religious small minded dork and anyone could do this.

[@16a128]

Greek people are so smart like they discovered the first language they discovered math physics biology took a big part on history astronomy literature iliad and Odyssey have a great mythology like greece is so underated

[@ItsWazzza]

How did the numerous civilisations around long before the Greeks, such as the Babylonians, Sumerians, Hittites, Egyptians, Chinese, Indus, etc. speak to each other if the Greeks somehow “discovered” the “first language. You don’t discover language, you create it, and Greek language was not the first

[@16a128]

@@ItsWazzza it was the Phoenician alphabet was the first language and then it became greek before any other language like thousands of years ago

[@MarcColten73]

Also nude Olympics

[@junghunt8645]

We can all rejoice in the Greeks discovery of the first language. Myself, I’m grateful for the discovery of the English language b/c I don’t speak Greek.

[@ItsWazzza]

@@junghunt8645 truly commendable by the Greeks

[@EZMawloc]

How did he know both measurements were taken at the same time?

[@Somebodyherefornow]

solar clocks?

[@EZMawloc]

@@Somebodyherefornow that doesn't work to synchronize time unless you already know the distance between the two clocks and the radius of the earth

[@thomasvogel1696]

No it'd work. You just tell your friend "measure when the sun dial hits 12 midday exactly."

[@EZMawloc]

@@thomasvogel1696 is that sarcasm?

[@thomasvogel1696]

@@EZMawloc No. Sun dials were used all over the world so I think that's how they'd coordinate

[@dovishsharma]

Ever heard about Indians?

[@kwamepi1]

Wowowow

[@rk-fb5hw]

But now we all know the earth is flat so what do the Greeks know

[@BrandonBDN]

Good joke

[@melihugurlu291]

WOW

[@JeremyBoss-hi3mf]

Is absolutely incorrect and in many ways the angle that he drew was approximately 28.8 degrees not the 7 degrees witch makes the earth in that diagram around 1,789.98 km which is 38,632 km off and the "circle" he drew the a shape of 1485 sides and the earth is a perfect ball witch makes the equation wrong in two ways but there is more there are only certain places of the world that have a shadowless figure on straight up facing polls and were he said in most likely not one of them and it only happens once a year witch and Egypt in just barely one of them

[@elhartzer1639]

And now in english. Or at least some grammar and structure, so anyone can read this incoherent mess.

[@totallynotpaul6211]

Punctuation, grammar, and spelling please 🙏🙏🙏

[@andrewsad1]

There is a wide area on earth where poles cast no shadow once or twice a year. Every point within about 23° of the equator is in that range.

[@Bullevue]

Eratosthesenuts

[@purplrshadowyay]

Unfunny

[@Bullevue]

@@purplrshadowyay opinion

[@purplrshadowyay]

@@Bullevue Bruh that joke is really really unfunny

[@Bullevue]

@@purplrshadowyay Ur opinion

[@moodman6426]

He doesn't explain how he got the 7 degree angle 😂

[@carultch]

He did this experiment on two days that were the same day of the year (i.e. the summer solstice). In Syene (now Aswan Egypt), he observed the sun shining straight down a well. About 800 km north in Alexandria (both the modern and ancient name), he measured the shadow length of an obelisk of a known height. This gives enough information to use inverse tangent to find the angle. While he didn't have modern trig functions on calculators, he could draw it to scale, and work out what fraction of a circle that was. Knowing the distance, you could scale that by inverse of the circle fraction, to find the circumference.

[@jonathanpena5972]

​@@carultch So are you saying he had to do this over the span of two years, or is there another method of getting such accurate results? I've always wondered about this. Thanks!

[@carultch]

@@jonathanpena5972 I don't know how many years apart he did his trials in both locations. But if you were doing this in the days before the telephone or its predecessor the telegraph was invented, you'd have to either coordinate extremely well with a partner to observe it at the same time, or do it on two equivalent days of separate years. If you do a modern reproduction of this experiment, it's trivial to coordinate it with your partner, just by calling each other.

[@carultch]

​@@jonathanpena5972 Historians dispute how accurate Eratosthenes was. We know he used a distance unit called a stade (plural stadia), but we don't know which stade unit he used, of the ones that have a known conversion factor to modern units. If he used one of the plausible stade unit, his results could be within 2% of the modern accepted value, which is an extremely impressive accuracy. If he had used the other plausible stade unit, he'd be off as much as 17% the modern accepted value. So it's the right order of magnitude, but not a measure I would rely upon for any modern application of knowing the radius of Earth. Either way, it is still a great experiment of indirectly determining how big your world is, using very simple clues around you, that took a genius mind to realize how to use them.

[@shaneh1003]

@@jonathanpena5972traveling north and south, it could be in the same year, as long as he made the trip in only several days time. No need for any communication with anyone else. Simple tilt of Earth, and depending on time of year, the angle doesn’t change that quickly per day/week.