How would our lives change if the Earth was flat?
Paul Tinkler
Send your questions to nq@theguardian.com
Readers respond
What does it mean? Chriskiy
Terry Pratchett could have won the Nobel Prize for Physics. Alan Williams-Key, Sudbury
The invitation to join the disc-ussion in this tiny box is the most charmingly appropriate Guardian comment ever made. ThereisnoOwl
There would be a lot of conspiracy theorists out there trying to convince people that there is a globular Earth. lexicon_mistress
I am fairly certain that the rotational forces required to flatten/form matter into a disk, rather than an ovoid, are so strong that they will inevitably cause the disk to fall apart before it can stabilize completely. The Earth would not be here if it was flat. Thomas1178
After the cats had flung everything off of it, there wouldn't be much left. Bokalok
Mountaineering would be safer if the Earth were flat. Jerry144
Plate tectonics could not exist, so there would be no mountain ranges. You would see a thin sea that covers the entire disc, and all land would be eventually eroded. RogerMusson
The obvious differences are:
Gravity would behave very differently. It would not pull down if it assumed uniform density. Instead, it would pull more strongly towards the centre. You would be pulled back towards the centre if you tried to move towards the edge. (Unless, of course the flat disc rotates at such a speed as centripetal acceleration cancels the effect.
As the sun rises and sets simultaneously across the globe, there would be no time zones.
There would not be any difference in climate between poles and equator.
Coriolis forces work in a different way, so weather systems in southern hemisphere would not rotate in the other direction.
You would not have a horizon. If you could reach high enough to see beyond any hills or waves, you could see the entire world.
It is unlikely that the Earth has a magnetic field. The Earth rotating and a liquid core that conducts electric current are the two main ingredients of our magnetic field. It would also mean that we all would be immune to cosmic or solar radiation. Shasarak
Is there a flat Earth? No. No. A planet's large body and internal heating by radioactive elements makes it behave like a fluid and succumbs to the gravity pull from its centre. To get as much mass as possible close to the planet's centre of gravity, you must form a sphere. This is called isostatic adjustment.
The gravitational pull of smaller bodies, like the 20km asteroids seen in recent spacecraft imagery, is too weak for the asteroids' mechanical strength. These bodies don't form spheres. They are instead irregular and fragmentary.
If the object is sufficiently heavy and mass, gravity will eventually crush it into a spherical shape. Flat objects with the Earth's mass would invariably break apart due to gravity. The Sun's gravity will then cause them to accrete and become spherical objects. A flat Earth could only exist in a universe without gravity. However, there is no gravity. This means that neither matter nor energy cannot exist. So, no life, no planets, no stars. Nothing. We were stuck with spherical universes regardless of what. Tiberius123
If the Earth was flat, but had three spatial dimensions, it is likely that this conversation would have been between bacteria living on top of a piece wombat dung (which is well-known for being cuboid). This explanation is more plausible than any other I've seen for why the UK elected Boris Johnson to be its PM. BlueThird
Christopher Columbus would not have ever returned. Leif Erikson would also not have returned. MyOtherNameIsReal
It would need to be able to rest on four elephants, who are also standing on the backs a giant turtle. Sir Terry Pratchett would still live. Skydancer1
Brexit would have been a brilliant idea. Styggron
Let's assume that gravity, magnetism and daylight are all the same (perhaps this flat Earth was fabricated by aliens who love to watch us scurrying around in our playpen). Perhaps life would remain the same for many, particularly those living near the centre.
One thing that is unmistakeable is the edge. It could be a cliff edge or a wall or invisible force field and have profound consequences for society. Maybe religion would intervene to stop people from approaching it. Maybe we'd throw criminals or our garbage over it. Maybe explorers would try to scale it. paulreilly
If the Earth were flat, it would be impossible to account for everything we see in the sky, including the sun, moon, and planets. These luminaries are just that, they are unknowable to us. This unknowing would make us happy, as it is clearly God's will.
We didn't see the moon until we took out the telescopes and took a good look. We would then see that the moon, Jupiter, Saturn, Venus, and Saturn are all globes. We would see that Jupiter has its moons, which are happily orbiting around. Sunspots would be visible and we could see their movement across the sun's surface, which would show that the sun is also a rotating globe. Sorry God.
Some clever clogs will soon discover how the force that causes apples from trees to fall would also cause the movement of planets. Not long afterwards, another person would find out that objects larger than a certain size are more likely to become globe shapes due to this force.
It is only a matter time before people realize that an object as large as the Earth can only be one shape, and that it isn't flat.
Of course, I could be wrong. Perhaps an earlier, more intelligent clog experimented with the lengths of shadows cast at midday by sticks and noticed that they were longer if you travel further north. Someone that smart might have been able to see the Earth's shape long before telescopes.
It can only be flat Earth until we start to think about it. ThatBlokeBruce
14:23 Flat Earth Rising: Meet the People who are putting aside 2,500 years worth of science video
The sun is the centre of our solar system. We have measured the motions of planets and observed how sunlight hits them. If the Earth were flat and didn't spin, then it would either have sunlight on its top or below it, which would cause it to have water that is too hot or too cold to drink. Or, it would spin horizontally on an axis. In this case, we would have days, nights, but all of the water would be displaced from the axis by Coriolis forces. We would not have evolved. It is highly unlikely that any kind of life could have started. This is just the beginning. EdgarCarpenter
Many of these answers approach this question from a physics standpoint. I enjoyed looking at it from a mathematical perspective: How to map points on a surface of a sphere in 3D to those on a plane?
One option is to map the points to an annulus planar (the region that has been defined in 2D space using two concentric circles). Although it might work, it can produce very strange results for large circles. It could take 1000 times longer to walk around the annulus world if you start from due west than if you started from due north. AlCramer
It is worth asking what an Earther flat would think of the M25 orbital. The road appears to follow a straight line while driving on it, but after many roadblocks and long queues, you still reach the same point. We can extrapolate the data to the third dimension if we get a reasonable answer to this question, which I doubt. Wishful thinking? I'm sure. Cycling_uk
We would be in complete contact with billionaire space tourists if the world were flat. Richard Simmons
We wouldn't have to climb hills if the Earth were flat. This is something I've thought about a lot. Dae Pandy, Wales
Signs such as "The end is near", "Dead end ahead" and "The end of the line" sound even more alarming. Richard Orlando, Quebec
We would have to face the unbearable smugness that comes with flat Earthers being right Dave Smith
