How large would an object in the sky have to be for the entire world to see it at one time? Also what shape?

Question

I am trying to figure out if something in the sky could actually be viewed by the entire earth at one time.

Answer 1

nothing could be viewed all over the world at the same time unless it is toroidally shaped and wrapped around the world.

Answer 2

It would have to be a circle and it would have to cover the earth. Or only a section (hemisphere) would be able to see it. Think of the shape of the earth (a ball). If one side could see something by looking up, the other side would have to look down to see it. Since the earth is not see through, that would be out of the question. So you would need to envelope the earth for something to be seen all over the earth. Of course, you could put it on the web or on tv, then everyone could see it at the same time. In which case, it could be as small as an atom.

Answer 3

Well, for everyone on the Earth to see it at the same time, it would have to be wrapped around the entire Earth, since the Earth is round. I really do not believe there is anything out there that is possible of being seen everywhere. No matter how large it is, one side of the Earth will always be facing another direction. If you could find something that is large enough to wrap around the entire Earth, then there is your object.

Answer 4

OK. I am having a little trouble visualizing this. The world is basically a sphere. I'm not sure that everyone in the world would ever be able to see something at the same time unless it enveloped the entire planet. Maybe dough-nut shaped? The object would need to have a concave surface of some type that the world could nestle into.

Answer 5

No, the reason being, the Earth is a spheroid and the people in southern China are looking off in an entirely different direction than the people on North America.

Answer 6

Look at all the people (except one) that think it would be impossible. The angle involved is so slight , but mathematically it's there. If your eye is 5 feet off the ground then the earth would block slightly less than 180 degrees of sight. if you have two lines 10,000 miles apart that are parallel and you concave one a millionth of a degree they would eventually intersect.It might be billions of miles away where they meet , BUT ITS THERE.

Answer 7

If the earth were perfectly round and you head is six feet off the ground with the object being exactly on the other side of the earth. your line of sight would be about180.2 * or less so your object would need to be 160,000 times the widith of the earth.

Answer 8

impossible! think about it! The earth is not transparent so the people underneath the earth could not see it. The object would have to completely encompass the earth.

Answer 9

well, the whole world sees the sun, just not at the same time, and the sun is kinda circular, so either it would have to be 4times bigger, wraping around the earth or 4 times closer wraping around the earth, it would have to completeley surrond the earth for the entire world to see it

Answer 10

I dont think that anything could be viewed be everyone at the same time on earth because we are on a sphere.

Answer 11

I assume you understand the earth is a ball? Hence, no one will be able to see the complete object at the same time..but an example could be a telephone cable you get...no reason why this can't run completely around the earth in zig zags to make sure it covers all areas...also high enough that at any point you can see the telephone cable...