How can you prove the world is round?

Question

An eccentric billionaire has stated that he does not believe the world to be round. He has offered you a prize worth millions of dollars if you can prove him wrong. You have an unlimited amount of time and budget.

How would you prove to the billionaire the world is round?

Answer 1

When you change an image from globe to a map, you get distortion.

And if he still doesn't believe it he could send a satilite into space and look at thoses images.

Answer 2

Just fly in a line all the way around the world without stoping. When we come back to the place we started from he'll have his proof.

Answer 3

I would take him up in an air plane or out on a boat to see the curvature of the Earth. If he still doesn't believe me than I'd spend some money getting the Russians to take him up on the Soyuz. If he doesn't want to go into space than here the most interesting plan...

Level out a huge piece of land and mark out three points as far as you can get them. Draw a line from each point to the next until you have a triangle. Now, measure the angle at each point. If the triangle had been drawn on a perfectly flat surface the angles would add up to be 180 degrees. If the triangle was on a curved surface than the sum of the angles would not be 180 degrees. The sum would be more than 180 degrees.

If the billionaire still doesn't believe it than let him... hes a billionaire what does it matter to him.

Answer 4

If you go to a high elevation, lets say 500ft, you can see the curvature of the Earth, proving its round, right before your eyes.

Answer 5

I think this guy is just supposing there was a prize.  The questioner is the stupid one, not the imaginary billionaire.

But, yes, you do not need to go into space.  As you rise up in a plane, you see more and more over the horizon, and of course, anyone who has looked has seen ships with their superstructure hidden over the horizon, and that’s from the beach.  

I have been in an airliner taking off after sunset, and as it gains altitude the sun seems to rise again, which of course is just the fact that as you go higher you see over the horizon.  

Hey, try and ask any airline pilot how he knows the earth is round – he’d probably think you were crazy; well no crazier than the guy who walked up to Buzz Aldrin and told him he didn’t believe he walked on the moon.

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If you wanted to do it mathematically – easy.  You place a powerful light at a known height on the high rigging of a ship.  In another ship, you sail away until the light just disappears over the horizon.  You record the distance between the two ships.

You then repeat this all around the world, and discover that the distance between ships at the point the light disappears is constant.  This can only happen on a spherical world.  

Also, knowing the height of the light and the distance when it vanishes, the math is easy for calculating the size of the Earth.

Answer 6

Give me his name and email.  We'll go talk to him together.  I'll give him the proof, and we can split the money.

Answer 7

Did he miss science class or something? How did he ever get to be a billionaire with a brain like that?

Solar and lunar eclipses, satellite images, observation of spherical planets of lower masses, study of hydrostatic equilibrium, and if you get high enough, and have a clear view, you can see the curvature of the Earth.

MILLION DOLLARS PLEASE! :)

Actually, I'd have to give that the numerous other qualified scientists (who actually read at least the preface to a geology book) that have shown numerous times that the world is round. But the very first scientists died... more for me!

Answer 8

I'd put him on board a Soyuz and send him up into space. If he thinks it's fake, he's more than welcome to step out of the air lock and take off his helmet.

This guy is either a crackpot or an attention-w***e. In either case, he should be dealt with in an identical fashion: disregard.

If he really believes what he says, then there can be no proof. Someone once said, "Don't confuse me with facts, my mind's made up." Another quote I like along the same vein: "A doubter is one who will accept no proof, and a believer is one who needs none."

I hope you're not expecting to claim the prize. If you want practice, try to convince one of these nut-jobs that the Apollo landings were not faked. They wouldn't believe it if you took them to the Moon itself and let them examine all 6 landing sites personally. They'd find a way of dismissing even this.

Answer 9

show him a picture from space.

or look at the earths shadow during a lunar eclipse

Answer 10

these days the fastest way would be to just buy a ticket to the international space station and point out the window.  it was a little more difficult to prove a couple hundred years ago.

Answer 11

Wait for a lunar eclipse & point out the shadow on the moon...  

Answer 12

I was going to suggest the eclipse also, but heres one more.

Take him to the beach (his cost) and watch ships come in. They are not just springing up out of the water now are they? We can do this all year at  every beach in the world for all I care. :))

Answer 13

we can sail (or these days fly) right round the world and come back to where we started without ever falling off the edge or going over any sharp corners.