Details of the story of Eratosthenes' calculation of the Earth's circumference are debatable, particularly in how he measured the distance between Syene and Alexandria, however my favoured version is that he used a unit of distance known as a "camel train" - the distance that a camel can travel in one day.

IF you want to earn Residual/Passive Income IF you want to have more time for family and kids IF you wish to quit your JOB soon IF you still have DREAMS! -> goo.gl\3oaVB REMEMBER, you deserve a better tommorrow.

oh... every teacher should be like him :D

"And I thought that was an idea worth sharing." fixed.

How simple ideas lead to scientific discoveries

These people that rather mess with their smartphones than paying attention , these tired looking girls that rather want to be in the mall shopping with their friends ..... the western and especially american youth has almost no scientific interest and sadly no mind for global and technoligical events.

This is BY FAR the best T.E.D. speeches I've seen yet. I HATE T.E.D. WITH A PASION !! You can't get a ticket or make a speech unless you are an elitist millionaire mother **** er. Mr. Savage is an "honorary guest" - but he's still one.

11 ppl still think columbus proved the world was round

How did Eratosthenes knew that when one looks down a well, the sun cast a perfect zero degree angle, while on the same time - but miles away - the sun cast a shade of 7.2 degree.. My question is how did he know that on the same time different angles were casted?

I knew half the stuff he said from a professor I had; he always went on interesting tangents and explained things really simply. xD Oh, and I hate Chris Columbus. So very overrated.

☺☻<--- WE ARE ALL EQUAL! <--Me playing with "alt" functions

I hate looking at those kids, look how bored they look. I would kill to see a TED talk.

Brilliant! Just.. f*ckin brilliant!!!

Man, can physics be taught like that? Seriously, I have never had a professor that can explain stuff like him and in a simple way like him. Oh and mythbusters rock. I LUV TROLLIN!

I find this so much more beautiful and imaginative than a religious sermon. I LUV TROLLIN!

**** ing Adam Savage! I Love Him...when he gets hurt!

mythbusters dont believe in chemtrails lol

Adam Savage is BRILLIANT :D

Congratulations to TED for finally getting rid of loud noise at the beginning of every talk. Thanks...!!

And I thought he was only good for blowing stuff up. Good job Adam!

so engaging.

Wonderful speech! Thank you, Adam! Long live science, long live curiosity and the desire to expand our knowledge!

i didnt realize until 0:52 that it was adam from mythbusters!!!! this show just got ten times better :D

YAY FOR ADAM

:|

mith busted !

0:56 Why would no one know that the ball would be in back of the wagon when you move the wagon forward??? I know why. Because you didn't move the ball. You moved the wagon - so of course it will be in the back of the wagon. If it moved with the wagon then I would not know why because that would not make any sense to me. Why does the audience stay that whole time?? They should have left right then and there knowing that this guy doesn't know what he's talking about.

Ok... I'll admit the rest of the video is stuff I'd like people to see, but the wagon thing was stupid. He shouldn't have said "noone knows" because it was a child's problem. It's like saying that noone knows why a taller glass can hold less water than a shorter, wider glass. Only young children should have problems with things like this. If an adult has the problem, I won't judge them, but please do not say that noone knows if people do know the answer. I think that's just wrong.

He wasn't saying that no one knows, he was quoting the conversation. Relax people aren't perfect and the father could have honestly thought that no one knew.

i like being so young and watching this and understanding it

Amazing!! 

Really? Is someone trolling right now? I do so hope so.

ya myth busters 

Inertia wasn't common knowledge. You have to understand that when people don't know a concept, they don't know it. its not someone claiming they made and naming it, it was actually discovered and then broadcaster through out the masses, to the point its common knowledge WHY.

dude, are you really **** ing about that like its a big deal? its what the dude said, deal with it.

Adam <3 :D

i feel smart

MYTHBUSTERS! WHAT HOW!!!

what else is left to discover? that doesn't require a higgs accelarator time warp machine. Something I can do with my mind and a pen.

That was so engaging I was about to clap at the end until I realized I was alone in my room.

It starts with a simple idea and ends with something worth sharing. 

I'm sure they said that 10 years ago, and 100 years ago, and 1000 years ago. How do we know what we don't know?

he's such a screamer... no- really this is one of the best talks i've heard in a long, long time. It shows how, if, you can find order in your thinking, you can see a real answer to problems other people have simply not bothered enough to think about..

short sweet an punchy- one of the best teds.. ever

omg stop screaming at me!! D=

hahaha i feel like he screaming at me XD