• Question: why does the world seem flat when i know it's round????????????

    Asked by thegingerninja123 on 24 Apr 2020.
    • Photo: Anabel Martinez Lyons

      Anabel Martinez Lyons answered on 24 Apr 2020:


      It’s because 1) you can’t see very much of the Earth at one time and 2) the degree of curvature of the Earth isn’t very steep! The curvature of the Earth’s surface is about 20 centimetres (8 inches) for every mile on flat ground. This website has worked out all the maths for how far it is possible to see from different heights, and explains why the horizon looks flat when we are at ground level: http://www.davidsenesac.com/Information/line_of_sight.html. Only when you start getting really high up can you start to see the curvature of the Earth (like astronauts can in space). Hope that helps!

    • Photo: Ozge Ozkaya

      Ozge Ozkaya answered on 24 Apr 2020:


      Because it’s very big. You can actually see the curvature when you are on a plane and travelling at dawn or dusk 🙂

    • Photo: Kim Liu

      Kim Liu answered on 24 Apr 2020: last edited 24 Apr 2020 5:20 pm


      These are already great answers! I’ve just found it’s possible to see the roundness of the earth by searching photos of ships approaching beyond the horizon – you see the top of the ship before the bottom because it is blocked by the curved earth, e.g. https://www.youtube.com/watch?v=NmmFDlErF1M

    • Photo: Jamie McGinn

      Jamie McGinn answered on 24 Apr 2020:


      This is a brilliant question! The Earth is so amazingly big it is almost impossible to tell just looking from the ground.
      Imagine holding a football close to your eyes and looking at the top, you suddenly cant see that it is round at all – it all depends on your perspective. That is why photos from space are so fantastic to see.

    • Photo: Philip Denniff

      Philip Denniff answered on 25 Apr 2020:


      Now that a really good question as it brings together so many ideas. The short answer is it’s all a matter of scale. First it depends where you are looking. Looking across the Derbyshire hills the horizon is all up and down due to the hills and valleys. Flat / round you can’t tell. The variation in hill height is experimental variability; it stops you seeing the true picture. Lookout across the English Chanel, we have removed the experimental variability now, and the horizon is a line. But its looks a straight line and not a curve. This is where a branch of mathematics comes in called calculus of infinitesimals, if you take small enough slices of something you can make it into a straight line. Thus you can draw a circle by just using straight lines, OK you may need millions of lines. Try this, draw a triangle, a square, a pentagon. Which looks most like a circle. Now draw a hexagon and an octagon. Same question. The horizon you see is just one of those straight lines that make up a circle. In order to see the curve of the earth you need to get further away from it, like a really high aircraft or better still a space rocket. Its questions like yours that drive science. Stay curious and ask why.

    • Photo: Alex Fower

      Alex Fower answered on 25 Apr 2020:


      A few people have already answered this question well, but I will also agree with them that the world seems flat to us because of scale. By scale I mean, how big or small things appear to be compared to us. Imagine you are an ant on the surface of a big beach ball. To you, your surface seems flat because that is all you can see. But zoom out, and you can see that it is round. Just like we can by using ships and satellites that are sent into space.

    • Photo: Sreejith Radhakrishnan

      Sreejith Radhakrishnan answered on 25 Apr 2020:


      Many good answers. You can also think of it like this – if an A-level student and a two-year old baby were standing on a really big round ball, the baby might think that she’s sitting on a completly flat surface because she’s small and really close to the ball’s surface. The A-level student will be taller and can see how the ball’s surface starts to curve at the edges, so she would know that she’s actually standing on a round object. Because we are all so small, compared to the size of the earth, we actually need to be high up in the air, like on a plane, to see how the surface of the earth starts to curve at the edges.

    • Photo: Patricia Brown

      Patricia Brown answered on 25 Apr 2020:


      That’s a wonderful question. Although I don’t know exactly how to explain it, I know that the horizon appears flat because the Earth is a very big sphere compared to us, and we’re very close to it. For example, when you look at a small ball or a marble, you can definitely see that they are spheres. If you take a bigger ball and look at it from a distance, you can see that it is a sphere… but if you are very very close to it, you will only be able to see a part of the surface and it will look curved. It’s the same with the Earth, but it is so big that we can’t really see the curve! If you go further away from it, say when you’re inside an aeroplane, you start to see that the horizon is curved! And if you were in a rocket in space, you might be able to see the whole world if you get far enough!

    • Photo: Nina Rzechorzek

      Nina Rzechorzek answered on 25 Apr 2020:


      Thanks for the question – yep, as others have said, it’s all about how small you are compared to the planet, and how close you are to its surface. If you go really high up, it’s possible for a human to see the curvature of Earth. Check it out here:

    • Photo: Catriona Aitken

      Catriona Aitken answered on 27 Apr 2020:


      Everyone else is exactly correct, I just wanted to add in the best demonstration I’ve seen of this. I’ll put the link below (it’s from an anti-flat Earth website, I’m sorry for that…). Basically they took a basketball, which we all know is round, and zoomed in really really closely on the surface of it. From that perspective, the surface of the basketball looks totally flat. This is the kind of view we have of the Earth because we’re so tiny and it’s so huge. Hope this helps!

      How to “Prove” a Basketball (or any Spherical Object) is Flat

    • Photo: Shenghong He

      Shenghong He answered on 28 Apr 2020:


      Because we human beings are too small and the distance we can see on the earth is too short compared with the earth itself. If you put a tiny ant on a huge ball probably Mr ant will never know the ball isn’t flat 😉

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