How I Proved the Earth is Round (with my Bike and Two Sticks)

Share this video on

What's Hot

What's New

Top Grossing

Top of the Chart


Rich Jarvis : Yeah that actually doesn't prove the Earth is round. If the Sun was smaller and closer at a distance equal to Earths diameter it would produce the same exact shadows on a flat surface.

Requiem4aDr3Am : Good work. Not many people would be willing to bike 138km one way just to figure this out. Flat earthers certainly haven't:P

Domain of Science : This was awesome! Love the big diagram in the car park with the chalk, that was a great way to show the calculation.

Red Pill Philosophy : 2:39 - you presupposed the sun's distance. That is the same mistake Eratosthenes made. Good effort but you've clearly not done your research or stuck to the science. #MaybeNextTime

Massimo O'Kissed : I noticed you used a compass to find North, and wondered if the difference between magnetic & axial Norths may have led to errors, but in Saskatchewan axial North is kinda due North of magnetic North, so it wouldn't make much difference.

Vegtam : I can prove it is flat right now, with the same test he did. Stand two pens up on a table, place one in the centre, and one anyplace else, perhaps nearer the edge. Let's pretend this is the flat earth. Use a lamp to represent the sun. Now you will find that both shadows are different in length, depending on how near they are to the source of the light. This entire test is null and void. The question remains. WHY IS THERE NO PHOTO OF THE EARTH? If there were real photos of earth, there wouldn't be any flat earthers.

QuestForTruth : The stupidity of this experiment is beyond any form of good science! you automatically assume that the sun is 93 million miles away which automatically flaws the outcome of the experiment! There is absolutely zero way to prove the sun is 93 million miles away. The sun is a lot smaller than mainstream science says it is and a lot closer which is what gives the results of the stick having shorter Shadow when farther away from the other stick. If the Sun is closer to one stick it'll give the closest stick is shorter shadow on a flat surface so this experiment does not prove the Earth to be round because you are going on the assumption that the sun is a mind-blowing 93 million miles away which is physically impossible! Anymore on can look up at the sun on a cloudy day and see the disc of the Sun just above the highest clouds and know that there is no way it could be 93 million miles away! Crepuscular rays and anticrepuscular Rays prove the Sun to be close because it is not giving off parallel rays as you would expect from a sun at 93 million miles away! only people who are one track mind and not able to think outside the box will fall for this dumb trick

QuestForTruth : The simple fact that it's perfectly flat for 138 kilometers is proof that there is no curvature 🤣🤣🤣

cristi p : 99.99 of the flat earthers will not understand a word from what are you saying :)

Steven Baumann : The time thing. You need to use UTC not local time and you need to go to suncalc but that’s only in even minutes. So you need your longitude and latitude as best as possible. Great biking job. 33,000. Not that far off from the 40,000.

Tippycanoe 117 : I’m pretty certain that test works on a heliocentric and a geocentric model the same ... 🐇⚫️...

WKD : They are right. Earth is not round, it's an oblate spheroid.

One smart girl : I was the girl in the bubble! Subscribed and liked and my mom is sharing it!

FE Diplomats : Did he just recreate a 2000 year old test that would work the same if the sun were closer and a flat plane. And people say flat earthers are stupid. It amazes me that people dont know how to think and fall for anything. First you have to prove the distance of the sun. The light is not parallel since we have crepuscular rays.

Gary Ryan : Dude .This works on a globe and flat earth . Just change how far the sun is away and .. There it is . The same .. Come on . Research .

So Woke : This math works exactly the same with a close moving sun. It did not prove curvature.

H N : you forget that they dont believe the sun is that far away to have parallel rays. now you need to prove the distance of the sun from the earth and how rays are not in different angles and are all parallel. please do this!

Vortexpuppy : Ignoratio Elenchi - Logical Fallacies. I can't believe that people still fall for this drivel and base sophistry. If you assume that the Sun is far, far away and that its light rays are parallel, then you can use these premises to come to the conclusion (via simple trigonometry) in this video that the surface of Earth is curved. If you assume that the Sun is NOT far away and light rays are NOT parallel, then you can use these premises to come to the conclusion (via the same simple geometry) that the Earth is flat and level with a local sun. Discerning whether the Sun is far, far away is geometrically IMPOSSIBLE due to the Size.-Distance Invariance problem. Only if you assume certain properties of light and composition of stars (aka certain substances) can you "apparently determine" distance and size. This is also nothing but unproven assumptions. This experiment proves NOTHING either way. It only shows how easily people have been sucked in the Globe Cult Religion and how desperately they will cling to an absurd belief that is incapable of distinguishing natural science from mathematical sophistry. Do some real critical thinking for yourself ffs. Large bodies of standing Water cannot conform to the exterior of shapes. So absurd theories that contradict the known properties of fluids as experienced by every person of rude health and good judgement. If the Earth is a space ball and covered in water, how is this remotely possible. FFS, engage your brain and stop repeating nonsense. It's alright to argue from facts against a hypothesis; but it's not real science, to come w/ a hypothesis, & argue against the facts. That's not even science.

cowcar87 : Amazing video as always. Keep making science tangible! Great work!

Mitchel Tan : EPIC FAIL @ 2:40 you say: "since the sun is really far away". This is an assumption and therefore you are not using the scientific method. First proof the sun is that far it creates parralel lightrays... Earth is flat my friend.

James Doherty : even more balltard nonsense

Donald James : ball earthers BTFO thinking this proves anything lmao !! all the dingleberries who have no concept of flat earth eating up this trash lol


Andreas Mueller : Absolutely great way to perform this classic experiment, thank you! One little "but..." though, knowing that flerfs will debate the result by saying that the sun is close, and therefore the rays not coming in parallel. So if you ever going to do that experiment again, I suggest you take a third person along, who doe a measurement in the middle of the whole distance. The lenght of the shadows then will only make sense on a sphere, no matter how close or far "they" claim the sun to be. :-)

Sian : Hi Kurtis, could Express Newspapers use part of your video in a story with a credit to yourself? Thanks

Stk1bronx Stk1bronx : I did the same math on my dining table, & now it's a sphere! Thanks a lot.

Andre Prilianto : Thank you for this experiment, I hope people out there who believe the earth is flat now believe that earth is not flat anymore... What you guys did is really something and inspiring and great work.. and.. don't forget to erase what you drew at that parking lot dude :lol

Jason Clements : You put a meter stick at point zero "regina", then put another meter stick in stoughton to acurately measure a sphere without taking into account the altitude difference between both points as earth isnt perfectly round and has its bumps "hills".With a little search it shows Stoughton at almost 50m higher then regina. If i were to say regina is point zero with a 1m stick then stoughton stick would resemble a almost 51m stick to point zero. A highly inaccurate way to measure shadows and or curves. Eratosthenes made the same mistake and hence why he was a mathematician and not a scientist. Today's scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality. "Nikola Tesla"

blake bauer : You deserve more subs.

Pudar Sandi : Yang kesini dari Indozone siapa aja?

michael rud : Great, great work. There's a really depressing behaviour of name calling and childishness in these comment sections.

daniel reza : Coins, tortillas, and pancakes all round. Globers dont know they mean spherical.

ashley vdpk : Amazing! Loved it when you were showing the shadows from the sticks in the orange. Made it so bite-sized and understandable!

Howitzer : I love your enthusiasm around what youre doing its contagious

The Robot 13 - Flat Earth Videos : You do realize that the sun is close and small, right?

Batuhan İnalkaç : Nice!

MisterB : So you measured 138 km / 1.5°; Eratosthenes measurement was 800 km / 7.2°. Flat-earthers can now plug both these angles into their flat-earth models and, once and for all, confirm the size of Flatardia! I can't wait.

recentlyhatched : Enjoyed.

Kasia Stepien : Wow, what an epic undertaking!!! You certainly go to extreme lengths to do cool experiments! (Get it? Extreme lengths? You biked a long way? Lol.) I am wondering, though, why the time of day mattered. As long as the sticks were lined up, couldn't you take the measurement at whatever time of day the shadow fell across them?

Nur Ahmad : 😘. From INDONESIA 💕

Jesse Brydle : The selfie stick on the bike worked out so well! It looks so stable and well framed... awesome film making, like a new take on the Veritasium walk & talk videos. I hope we see more of it in future videos, even if just as a way to make exposition more interesting to look at.

Dana Stout : I just have to point out the extremely obvious point that most are not catching......bicycle tires are round! These people are constantly saying the earth is round, but they are using the wrong word, purposely no doubt, they should be saying spherical. But hey I actually think so I am a minority for sure :) lol lol

Nor Cal : Earth is flat

Facts and Things : As someone said already, good try but they say the sun is 3,000 miles above earth, so this doesn't disprove their claim. If you measured atleast 3 points though then you could show that the angular change is consistent, then you prove the globe

Zooming in on stuff : Ok... Now you just have to prove that the sun is 93 million miles away and you have a serious scientific experiment! .. (Assuming you know the distance of the sun from the Earth is not good science).

fmt_ 45 : greetings adherents earth teach box Lol v:

rafmazza : OMG this is amazing! Keeping up with greek philosophers!!! Congrats on your enthusiasm and making things happen. You truly are an inspiration for this generation!

mhkelsey : Great experiment! It reminds me a lot of the guy who took his kids and an atomic clock up to the top of Mount Hood to measure time dilation. It's too bad the Earth is so large that I can't easily do this over distances less than hundreds of kilometers (I'd love to have my daughter's fifth grade science class do this). I think there's a problem in your analysis, however. Highway 33 runs almost due southeast (bearing S 45 deg E) from Regina to Stoughton, which means the two sundials are offset in longitude, as well as latitude. Taking Hwy 6 due south to... (thanks, Google Maps!) Pangman would have given better north-south alignment. The direction reduces your north-south distance (which is what you need for the angle-to-circumference computation) by 1/sqrt(2), increasing the computed circumference by the same amount (46 Mm instead of 33 Mm). The longitudinal shift means the two measurements weren't simultaneously at local noon. The Stoughton measurement was "later" (i.e., local noon in Stoughton occurs _before_ local noon in Regina), by about 6.4 minutes (1.6 degrees of longitude). That angular difference corresponds to a ~4 mm difference in shadow length, which is quite small compared to your other uncertainties.

Fates Paladin : Hello from Alberta just want to say Awesome video! And you've gained a share and a new subscriber

Bora Bora : I'd say get on your bike and pedal 93 million miles to prove the Sun is that total distance away... but then again the deepest anyone has ever drilled into the Earth is 8 Miles..... so in light of that fact only our handlers have inside know-how of where we live