Yes Jan, but you can also imagine that person on horse for that distance. No need to just walk these 800 kilometers. But the point is the same. The data was important.
Honestly, the precision & consistency in the walker's steps, taking such even steps of a known, fixed, repeating distance over what could be extrapolated to some 800 000 steps, is what impresses me the most.
The funny thing is that Eratosthenes did this with his eyes and a couple of sticks, but on present days when we're launching rockets into space and flying around the world, flat earthers still can't figure out
Flat Earthers don't want to figure it out, that's why. They feel they have the inside track on the issue... it makes them feel special. Low information people like to delude themselves that they're somehow smarter then the majority of the population. It's part of the Dunning Kruger effect.
Who is more annoying? The couple dozen mentally ill people who unironically believe the Earth is flat, or the millions of people like you who constantly bring it up? Answer: people like you, because I constantly have to read it. Give it a rest, feeling superior to mentally ill people is not an accomplishment and it's just tiresome.
Of course not. Sagan's "TDHW" explains this exceptionally well. Too many humans rely entirely on their opinions and beliefs. They hoist those high upon pedestals, way, way above facts and science. 🐲✨🐲✨🐲✨
Well they fully embody confirmation bias and dunning Kruger, the billions of evidence to show the earth is fake/wrong/bad, but random nonsense diagrams a flat RU-vidr posts becomes doctrine and immediately believed hahah. They're a cult at this point, facts, reality and objective truth no longer applies
Between having a naturally soothing voice and pleasing cadence, a lot of us have the nostalgia from watching him as kids. Cosmos was one of my favorite shows.
I legit get chills when Sagan says "that's the right answer". It's such a simple feat but what a thing to work out so long ago with the most basic of tools.
We all carry incredible machines with the ability to do incredible scientific feats in our pockets and a percentage of ppl doubt the science of these great men through chosen ignorance. Crazy time to be alive, we could do with Sagan now.
Eratosthones calculated the Earth's circumference to be 40 000 km, with modern technology we can calculate the circumference, from pole to pole to be 39 940,7 km. Around the equator the circumference is 40 075 km so on average, the circumference of the earth is 40 008 km, insanely close to the calculation over 2000 years ago.
Well, dude, the very reason it's a 'simple feat' is because dudes like Eratosthenes took the pains of doing such experiments and discovering such things. Had he not done this particular experiment and a certain bunch of other people had also been dormant in this area, it would have been a 'great feat'. What I basically mean is that once we know something, it always appears to be trivial.
A guy 2200 years ago hears a story about the shadow of a pillar, thinks for a little while on the implications, devises an experiment to confirm those implications, and successfully carries out that experiment. Now, 2200 years later, there are people handed all this information on a silver platter, and at literally 100+ times the precision and evidence, and somehow still fall far short.
@@geraldfrost4710 no one sees steam and immediately goes "hey that looks like a good way to power a 2 ton long metal rod with a hollow inside that moves faster than 10 horses that can get people to far away places quickly"
@Raffle Yer right. It was probably some crazy drunken Scotsman who blew the roof off the distillery. His boss came round and was about to fire him. Suddenly, seeing how far away the lid landed (and seeing free whiskey disappearing into the tall grass), said, "If we make it blow horizontal, and add some lever, wheels, and rails, this will move people safely and rapidly across the continent!"
Not only that but they try to prove that the earth is flat. Sailors like Christpoher Columbus of course also knew that the earth is round. Thats why they thought that they could sail west instead of East and still land in India. Problem was the Americas were in the way. 😅
@@helenamcginty4920Most medieval people believed the Earth was round, especially those who opposed Colombus' voyage. Since they didn't know a landmass was in between, their distance calculations that he'd run out of food long before reaching India were otherwise correct.
If every school in the world had a science teacher like Carl Sagan, the human race would have explored the whole solar system by now, and we would be reaching for the galaxies. We will never make up for his loss.
I placed some secret homages to both Carl Sagan and also, to Eratosthenes in my series of books. It will be interesting if anyone ever detects these enigmatic gems, because they're hidden bloody daemn well. Meant solely for the truly intelligent to recognize. 🐲✨🐲✨🐲✨
The earth is flat and this proves it. Why would u go off of something someone said in ancient times rather than do it in modern times...he said the distance from the two points was 800km ..thats on 497 miles . We know have pics at high attitudes. The earth doesn't curve at only 500 miles even if it does curve. This is ridiculous and stop repeating some weirdo from ancient civilization...also same thing can happen with a local sun. Hes assuming the sun is far away...thats an assumption, And a wrong one at that. Its flat
@@erikdeeNOSPELLSNO And he inspired me to learn. Learn, ask questions, think, explore and perform experiments. I love that man almost as much as I loved my own father.
@@davelister6632 Now, sadly, all those things are being forced out of the School Systems, by insane leftist progressive shills. Damn, children in schools nowadays are not taught math, science, spelling, reading- but instead victimhood, hatred, perverse sexual ideologies- you know what i am saying if you've been paying attention. Stay sane!
I prefer to contextualize his passing in this way: how lucky are we to have been alive at the same time, as the GREAT, Carl Sagan. And that his thirst for knowledge and reverence for historical thinking could have been implanted in our spirits to live on!!
@@ThePeej Not just that. You and I are old enough that our timelines of our lives overlap that of Carl Sagan. But I have never met the man. To the best of my knowledge I have never been within 50 miles of him. But his WORKS... His TV Series. His recorded lectures. His books. Those is how I know him. And those are for the ages - and for all ages! Our children’s children’s children with any luck will know Carl Sagan and his teachings as well as you or I!!
I guess back then, documentaries, movies & video games were made by more passionate people (as it was more of a niche back then). Everyone just wants to cash in nowadays...
I remember my Earth Science teacher telling my classmates and I about Erastothenes back when I was in the ninth grade. This was in 1978. More than anything else, this lesson stayed with me through the years. Mr. Prewitt, thank you sir.
@@colinjava8447 I first read the name in Sagan's book, Cosmos, but I was very young. For the longest time, I read it as "ee-rat-oh-ss-theeens". lmao It took me a solid year or so to break that habit once I finally heard it spoken as a teenager.
His genius gets me too. It reminds me of the old Sherlock stories, where the solutions were so simple and elegant that I felt like a doofus for knowing how unlikely it is that I could have done it.
The follow-up with Neil deGrasse Tyson is also good, but not quite the same as the original with Carl Sagan. I was 14 when that aired on Norwegian TV in 1981.
@@fromnorway643 Sadly I think Poet is right. There is a vast difference in the available media now vs then. Back then it was good enough that a large swath of the population saw it. It would have to be 10 times as good to compete in a world that has 20 times as many choices (numbers made up for examples sake). I agree though that the Myers/Tyson joint was very good.
Although as a teenager I didn't like documentaries, as I found them boring, I was fascinated by Carl Sagan. This man made me understand that all the things that my teachers were teaching me in different subjects were connected , that everything had to do with everything. And that was when learning became meaningful.
I liked it too, but I stopped liking it the 5th time my dad made me watch the whole thing, and now I'm revisiting it because its neat and easy to digest in small video format on youtube.
My dad watched this as a teenager in 1980 and I watched it a teenager in the 2010's. I was completely captivated. Sagan’s storytelling, the ideas is explored, and the beautiful music from Vangelis come together perfectly to make a true masterpiece. Carl Sagan has been my hero ever since and I enjoy coming back to rewatch the series from time to time. It just goes to show that you don't need a big budget and fancy graphics to create a truly captivating series.
Keeping an accurate pace count over a vast distance in a more or less featureless desert, is quite an achievement in its own right. I have a lot of experience in land navigation from my time in the Army, and even with a compass, protractor, and pace beads, keeping an accurate pace count whilst navigating is not an easy task. Kudos to that unsung man!
They were called "bematists" from wiki: "human paces, although deviating from each other, sometimes larger and sometimes smaller, obey statistics and quickly converge on the average pace of the bematist and thereby provide a much more accurate read of distance. For this reason a human pace counter, a bematist, is superior to a mechanical device especially over longer distances."
I've done thousands of kilometers traveling. It's hard to deduce the actual number even with a compass and a topographical map. I wonder what his assistant used to pace out that distance. It certainly couldn't have been easy. One thing is for sure... he was either a loyal assistant, or shared a curiosity with Erotosthenes. Or both.
I wouldn't be surprised if some rhythmic device was also employed, even if nothing more than to calibrate the pacing.. We have such a strong sense of rhythm that we can detect a difference of a couple of beats per minute.. so, as someone else mentioned, if you had a wheel with a 'clicker' you would very easily establish a good, consistent rhythm (and hence, a regular walking pace distance) fairly quickly. O'course, all these theories go out the window once you're walking a meandering path.. and you're walking up 'n down hills, walking on sand, scrambling over rocks, etc... 😁
@@aniket385 That there makes all kinds of sense. We do that today, but instead of dropping a stone we have geared readouts counting the revolutions of the wheel. (Or lasers).
MsMsmaryam I doubt he paid someone to measure the length as the water well was a well known area and there would have been many records and people who already knew the distance between Alexandria and the well.
And this is what Carl want. And keep in mind he did not care what education that was. If you're a plumber, Carl would think it was cool he inspired you to be a plumber.
I remember watching this as a kid. I can can think of no other show in my childhood that had such a profound impact on me. I recorded it (on Betamax) and watched it over and over again.
I've watched this many times over the past years. 6:00 "That's the right answer" always gets me. This is what I turn to, whenever feel I need to regain my hope for humanity. It's very bitter sweet to know, that even though all the world is crazy, there is still hope for vindication far beyond my lifetime.
We can only see progress in the World if we see our ancestors as barbarians. Hopefully by the year 3,000 humanity has progressed enough to see flat earthers as barbarians and they are non-existent by then.
if you think a little bit harder than sagan did here, you will realize this experiment coudnt prove curvature of the earth in the time of ancient greece
It doesn't matter what happens. Humans will always strive to understand their environment because that is human nature. Even if all scientific knowledge were forgotten, it would eventually be rediscovered.
Eratosthenes estimated the distance from Alexandria to Syene as 5,000 stadia, or about 500 miles (800 kilometers). He made this estimation from the time it took walkers, who were trained to measure distances by taking regular strides, to trek between the cities. -Khan Academy
A guy 2200 years ago figured this out with almost nothing and yet in the age of information and technology we still have people that think it's flat 🙄. No, I've never seen it with my own eyes, beyond just equations and satellite photos, but I trust the scientific community with this one.
I went to borrow my neighbors weed eater last night. He handed it over and asked me immediately if I believe we can travel to space. Very randomly and out of the blue. I said of course! I thought we were about to have a conversation about colonizing space someday, a favorite subject of mine. He continued "no man, we can't go to space, it says in all the ancient religions that the sky is a firmament" 😳 "Go on." Said I, stunned. "The earth is flat. What you see on a map of the world as Antarctica is actually a mountain range that goes all around the world" he said, dead serious. He seemed excited that I was willing to listen "and the North Pole is the center of the world, but it's not a pole. It's actually a hole that leads to the center of the earth!" I said "Thanks for the weed eater, I'll bring it back in a few." I had so many questions but since I already knew that ultimately the answers all boiled down to "he's nuts" I chose to just go cut my grass and have a good laugh with the wife about it. I had heard of these people but this is the first time anyone has ever told me that this is what they believe in person. I used to ask myself, where the hell do they find these people? Two doors down apparently! 🤣😂
@@misterwilde1251 oh man! I had honestly forgotten about it! Had me cracking a smile myself until I read your follow up, at which point I was cracking up. I tell ya, I just don't get how anyone buys into that stuff lol 😆 Thank you for the laugh! 😁
And Christians hated him. People complain of Islam terrorists, Christian terrorists are aish present. They bombed many planned parenthood buildings, seventh death threats to people like Carl Sagan, int guy even shot a doctor in tht church of all places because the Ductor was Pro Choice.
This is a very appropriate segment in terms of speaking to the main reason that Carl Sagan created this series. In spite of vast technological advance, he always, always was a proponent of the capacity and capability of the human intellect. He spoke several times during the series referencing Alexandria, the intellectual powerhouse that it was, and the focal point of that ancient city being the wealth of knowledge contained in its great library. Carl recognized the fundamental and absolute importance and necessity of human intellect, and the collection and collaboration of its constituents. He also recognized the implications of its demise. Here, he is so happy to relate and relish in one of mankind’s finer moments. Carl Sagan’s incite into the human condition and intellect are unmatched. He was a treasure to us all.
The destruction of the library of Alexandria was an attack on human culture and learning. It made the "Dark Age" in the west take longer after the fall of Rome. There were other dark ages before that as western civilization collapsed around 1100 BC to 750 BC during the Bronze Age. One of Carl's messages is that the scientific method and the findings of science need to be distributed to the people if they are to keep supporting science, and if we wish to avoid another collapse or Dark Age.
This is clearly one of the most brilliant moments ever shared with the public. Sagan's natural television presence made the heady topic of science easier to understand. In re-visiting this from my childhood, I am reminded of why I entered teaching. Watching Sagan share history like a story (such as his tale about Eratosthenes employing someone to pace out steps) makes it more appealing to youth, and inspires me to teach history in the same manner.
Always enjoyed this tidbit of history. That is to say, tidbit, yes, but a one of monumental proportions! Loved Sagan in this era, never missed his shows or guest-appearances. He was right for his times, striking a chord with the public more than any other astrophysicist before or since. I mourned this "Star of the Stars" upon his passing & have never forgotten him.
I remember Carl Sagan very well from when I was a youngster, he certainly helped to fire up my interest in astronomy, and his television series, Cosmos, was not only fascinating, beautiful, and educational, but groundbreaking. He was one of our greatest science communicators, speaking very wisely too, and he is sorely missed in these very uncertain times.
Just love this! I remember watching Cosmos back in 1980--in my mid-teens then. Absolutely glued to it--the content, Sagan's presentational style, including the fiction of him being a cosmic traveler, the soundtrack (esp. Vangelis). A masterpiece of a series.
I remember weeping at the beauty of his opening monologue about imagination. "Perfect as a snowflake, organic as a dandelion seed, it will carry us to worlds of dreams and worlds of facts. Come with me."
Having seen this episode when it was originally broadcast I asked myself "why didn't any of my teachers through elementary and high school ever tell this story?". That would have made science and/or history more real.
A story that should have been told earlier was about the lead industry and putting lead in gasoline and lobbying for all pipes to be lead. Then, a man tried to create a clean room, but was finding lead everywhere. By the time I was a boy, the government was phasing lead out of everything: gas, pipes, paint. That story was in one of the _Cosmos_ episodes by Neil deGrasse Tyson.
I love this series….Before Carl Sagan, the only real exposure to the cosmos came from occasional family trips to the Griffith Park Observatory when I was a child. Those trips created a fascination and thirst for more knowledge. I read encyclopedias, but the television series Cosmos really opened things up for me. Carl Sagan brought the Cosmos to myself and so many others, just ordinary people. I’m forever grateful.
Eratosthenes provided a highly accurate diameter of the Earth in 300 BC and then 1700 or so years later Christopher Columbus got it wrong by a gigantic amount thereby mistaking the islands of the Caribbean for India. Eratosthenes was an genius. Columbus was a buffoon.
Columbus went out sailing towards India, but when he found the new world he knew he did not hit India. Also he died not knowing he had discovered two new continents.
Columbus was a genius. Had he revealed how far he really believed India was from Spain, he could not have recruited any sailors for a voyage that long. There would have been no way to outfit his ships with sufficient provisions for a journey that long, and no known source of resupply along the way. He gambled and it paid off.
He knew he wasn't in India. And it didn't really have anything to do with how big the entire globe was, but more so with the precise locations of the continents which nobody knew at that time.
Eratosthenes - Chief Librarian of the greatest libraries in ancient times that contained knowledge now since lost to us. Yet -- I had never heard of him. What a shame. He should be just as well know as Socrates, Plato and other such giants of the ancient world.
There's also a connection between Eratosthenes and that little tower mentioned by Sagan. Communications tower, or a lighthouse. More likely a lighthouse, if I had to choose. The square base, an octagonal shape above that, and the cylindrical top makes the tower almost certainly one of many ancient lighthouses that mimicked the design of one of the 7 wonders of the ancient world, in this case the 110 meter tall lighthouse, _Pharos of Alexandria,_ 280 BCE. Both that Great Library of Alexandria _and_ the Pharos of Alexandria existed at the same time. Surprised to see this mini-Pharos turn up in this particular video. A nice surprise!😄
I have read Cosmos 4 times over 30 years and just devour it every time. Dr. Sagan, just as Eratosthenes gave the world gifts of such incredible value. Humans will one day live for centuries, but how I wish that ability would have been available for people like these two.
Apparently some of them claim that the sun's rays aren't actually parallel and the sun is closer, hence why the shadows are different lengths. Obviously horseshit, but what do you expect from people so willing to ignore reality?
@@greatorder They'll insist on proving shit with flashlights. Ignoring the fact, that the sun isn't a dam flashlight. Note how Carl sagan actually put the cardboard in the sun and didn't have to use flashlights to make his point
@@greatorder Exactly. To them the sun is extremely small and close so Sagan's example here proves nothing to them. Shifting location of a directional light source varies the shadows the same way.
@@greatorder that's the frustrating part. Any generally accepted facts you use to prove that the earth is indeed round, they can just say those facts are false and negate your whole argument. There has to be a common ground of science for scientific proofs.
One of the cool parts about living in a tropical region is seeing a Lahaina noon (time of no shadows). which by definition only happens in tropical regions. Therefore, we live on a round earth.
They did a Cosmos update series around 1990 I believe. Then Neil deGrasse Tyson did a couple seasons of a new _Cosmos_ series with Carl Sagan's widow in the 2000s or 2010s.
At 1:05, this honorable champion is demonstrating, ~2300 years later, why you shouldn't burden yourself with the petty judgments of others. Sound logic stands the test of time.
These educational miniseries from 40, 50, 60+ years ago seem so much more effective to me than current ones. Cosmos with Carl Sagan, Civilisation with Kenneth Clark, Connections with James Burke. I have a college degree and each one of them has still taught me so many fascinating things in an easy to understand manner.
@@hammalammadingdong6244 That scene where James Burke explains rocket fuel for like a full minute and times it perfectly so that his monologue ends precisely when a rocket ignites like a mile in the background is masterful. No special effects or slick editing there.
I saw this show when I was a little kid, and I still remember this segment vividly. This one and the one on Champollion and his decipherment of the hieroglyphics.
From what ive heard he used a camel or something as they ride at a steady pace. They can apparently also travel about 80-120 miles per day, so we could have done it within a week. I seriously doubt he walked :P
We did something like this in the early days of the United States to measure the Land and Map it. We used simple chains and rocks, with teams of men. Starting at the East Coast and working our way West.
Totally love with this man he filled my mind with such Wonder. My mom got me a record of the soundtrack that I used to play as I drifted off to sleep such a wonderous world
Astounding story and retelling, but what I'm most impressed by is Sagan's voice and accent. Does anyone speak like this anymore? The drawn out language, the phrasing ... it's from some place and time lost to us now except in recordings like this from the past.
@@woopert7 I bet she didn't see the inflation coming that this sack of potato brains in the White House has caused. Affectation doesn't mean intelligence, wisdom, or character.
@@woopert7 thanks for mentioning that. Very similar, but Sagan is really something else. You listen intently, sensing his genius, regardless of what he is actually saying.
Sagan glossed over a point that is intriguing and important. Eratosthenes recognized that the difference in the length of shadows cast, at a simultaneous moment, in Alexandria and Syene (Aswan) meant that the Earth’s surface was curved, not flat. But he knew that the differences in shadows cast at noon in different places •had• to mean that the Earth’s surface was curved, •because• the light source casting the shadows, the sun, was so immensely far from earth that its distance was, for purposes of these measurements, infinite. Put another way, the difference between the shadows in Alexandria and Syene •could• have been present on a flat Earth, if the sun were only some 4,000 miles away. And if you think about it, it wouldn’t be immediately obvious to a person in Classical Antiquity - who, like most humans through our species’ existence, knows of the world (and all existence) only what he observes immediately around him - that the sun is •not• just something like 4,000 miles away. Figuring out that the sun must be much, much farther away takes a rigorous, sustained contemplation of disparate pieces of evidence, a disciplined analysis of the (not immediately obvious) ways in which those strands of evidence must be related. I think Sagan omitted that piece of the puzzle to keep the narrative as simple as possible. But it is an interesting element of Eratosthenes’ work, and his grasp that the sun is so far from Earth was both an essential part of his work, and much to his credit.
I'm kinda disappointed by his prodigy, Neil deGrasse Tyson. He's incredibly knowledgeable but his planet-sized ego stands in stark contrast to Sagan's humble charm.
@@Parpyduck Look up Brian Cox. He's a British astrophysicist. If you haven't heard of him, you're in for a treat. He cites Sagan as one of his heroes and inspirations.
When the Voyager probes were being built and supplied, someone at NASA suggested putting some Bach on the disc of music and voices - Carl Sagan allegedly replied "No, I think that would just be showing off!"
Just started watching Carl Sagan. I heard of him a long time ago , if I knew he w as so interesting to listen to I would have been watching sooner. Good stuff.
- Seeing the top of landmasses/mountains appearing first from ships approaching them. - Seeing stars from Egypt that aren't visible from Europe. - The never changing apparent size of the Sun and Moon and the shape of the constellations. (within the accuracy that our eyes can detect) - The curved shadow on the Moon during a lunar eclipse.
The seventh is the best one. Everyone knows that. It was the first one he wrote after going completely deaf and he said IDGAF. Every little trick he learned was compressed into that last movement.
Our schools really desperately need to be teaching the history of science and technology. I'm so thankful I got brought up on programming like this that instilled in me the truth that our understanding of the world changes with each new day we spend on it!
The logic Eratosthenes used is so simple, so obvious--once it is explained by a brilliant communicator like Sagan. And Sagan points out two wonderful ancillary facts: 1) None but the most curious (and literate) souls like Eratosthenes would even wonder why the two shadows were different. 2) Ordinarily Eratosthenes is described as "proving" the Earth's circumference, as though that quantity was already proposed. But no--Eratosthenes was the first to measure, or even consider, the size of the sphere upon which we stand; in addition, he was proving the already standing speculation that the Earth is spherical. Interestingly, Eratosthenes friend--Archimedes--arrived at a very close approximation for how many grains of sand comprise the Cosmos. Responding to a request from the King of Syracuse, the greatest mathematician of Antiquity indeed produced that number in a work lyrically titled "The Sand Reckoner." And his number is astonishingly close to Arthur Eddington's number of protons in the universe, the famous "Eddington Number," calculated 22 centuries later, 10 to the 80th. Archimedes sand grains? 10 to the 63rd.
Dylon, Yeah, sure, every single person from history and all scientist are liars, and only flattards speak truth. This is truly the only way to 'convince' someone that Earth might be flat...
Dylon, How am I 'contradicting myself'?! Who are the 'people that came before us'?! Even old Greeks knew that Earth is not flat, although they were not aware of Earth's rotation and mutual position of celestial objects. If you want to 'screw my science', then please turn off your computer and go away from internet because you have all this thanks to this science. You 'read' anger in my sentences?! You are more delusional than I thought...
God Bless Carl Sagan (and Bill Nye, the Science Guy!). Because of great men like Carl I have a son who is a Mechanical Engineer and a daughter who is an Elementary School Teacher. I enjoyed watching all these shows back in the 1980's when my kids were small. Literally Millions of kids eyes were opened to Science by Carl Sagan. From the smallest child to the old folks in the house we sat absorbed with interest and curiosity when Sagan spoke to us through the TV...
Those credentials won't mean shit when there dead ....all just here to occupy us , hobbies , jobs , sports...... and keep us from focusing on our true meaning....we are special....and this earth is for us ,and us for it....we are not just here by accident...as this pseudo science bum (like Bill Nye The actor lie guy) wants so bad for you to believe .... every generation gets their own pseudo science actor lie bum guy to indoctrinate them at a young age(the key) on the sewage spewing television/radio.....sad ..but #theawakeningisunstoppable #goldenratio the paradigm is shifting.....fast
@@BCPRODUCTIONS19 you're so right. That dude can lay down and die and the world would be a more knowledgeable place. I was just about to comment the same thing lol
