The theory that the earth is round. When you found out the earth is round

People have known for a long time that the Earth is round, and they are finding new and new ways to show that our world is not flat. And yet, even in 2016, there are quite a few people on the planet who firmly believe that the Earth is not round. These are scary people, they tend to believe in conspiracy theories and it's hard to argue with them. But they exist. So does the Flat Earth Society. It becomes ridiculous at the mere thought of their possible arguments. But the history of our species has been interesting and quirky, disproving even well-established truths. You don't have to resort to complicated formulas to dispel the flat earth conspiracy theory.

It is enough to look around and check ten times: the Earth is definitely, inevitably, completely and absolutely not 100% flat.

Moon

Today, people already know that the Moon is not a piece of cheese and not a playful deity, but the phenomena of our satellite explains well modern science. But the ancient Greeks had no idea what it was, and in search of an answer, they made some astute observations that allowed people to determine the shape of our planet.

Aristotle (who made quite a few observations about the spherical nature of the Earth) noticed that during lunar eclipses (when the Earth's orbit places the planet exactly between the Sun and the Moon, producing a shadow) the shadow on the lunar surface is round. This shadow is the Earth, and the shadow cast by it directly indicates the spherical shape of the planet.

Because the Earth rotates (look up Foucault's pendulum experiment if you're not sure), the oval shadow that is produced during every lunar eclipse tells us not only that the Earth is round, but also not flat.

Ships and horizon

If you have recently been to the port or just strolled along the beach, peering at the horizon, you may have noticed a very interesting phenomenon: Approaching ships don't just "appear" from the horizon (as they should if the world were flat), but rather emerge from the sea. The reason that ships literally "come out of the waves" is that our world is not flat, but round.

Imagine an ant walking on the surface of an orange. If you look at an orange from a close distance, nose to the fruit, you will see how the body of the ant slowly rises above the horizon due to the curvature of the surface of the orange. If you do this experiment with a long road, the effect is different: the ant will slowly "materialize" into your field of vision, depending on how sharp your eyesight is.

constellation change

This observation was first made by Aristotle, who declared the Earth round, observing the change of constellations when crossing the equator.

Returning from a trip to Egypt, Aristotle noted that "stars are observed in Egypt and Cyprus, which were not seen in the northern regions." This phenomenon can only be explained by the fact that people look at the stars from a round surface. Aristotle went on to say that the sphere of the earth was "small in size, otherwise the effect of such a slight change of terrain would not have manifested itself so soon."

Shadows and sticks

If you stick a stick in the ground, it will cast a shadow. The shadow moves with the passage of time (based on this principle, the ancient people invented the sundial). If the world were flat, two sticks in different places would produce the same shadow.

But that doesn't happen. Because the earth is round, not flat.

Eratosthenes (276-194 BC) used this principle to calculate the circumference of the earth with good accuracy.

The higher, the farther you can see

Standing on a flat plateau, you look towards the horizon away from you. You strain your eyes, then take out your favorite binoculars and look through them as far as your eyes can see (using binocular lenses).

Then you climb the nearest tree - the higher the better, the main thing is not to drop the binoculars. And again look, straining your eyes, through binoculars beyond the horizon.

The higher you climb, the further you can see. Usually we tend to associate this with obstacles on Earth, when you can’t see the forest behind the trees, and freedom behind the stone jungle. But if you stand on a perfectly clear plateau, with no obstructions between you and the horizon, you will see much more from above than from the ground.

It's all about the curvature of the Earth, of course, and this would not be the case if the Earth were flat.

Airplane flight

If you've ever flown out of a country, especially far away, you must have noticed two interesting facts about airplanes and the Earth:

Planes can fly in a relatively straight line for a very long time and do not fall over the edge of the world. They can also fly around the Earth non-stop.

If you look out the window on a transatlantic flight, you will in most cases see the curvature of the earth on the horizon. best view curvature was on the Concorde, but this aircraft has long been gone. From the new Virgin Galactic plane, the horizon should be absolutely curved.

Look at other planets!

The earth is different from others, and this is indisputable. After all, we have life, and we haven't found any planets with life yet. However, all planets have similar characteristics, and it would be logical to assume that if all planets behave in a certain way or exhibit certain properties - especially if the planets are separated by distance or formed under different circumstances - then our planet is similar.

In other words, if there are so many planets that formed in different places and under different conditions, but have similar properties, most likely our planet will be one. From our observations, it became clear that the planets are round (and since we knew how they formed, we know why they have such a shape). There is no reason to think that our planet will not be the same.

In 1610, Galileo Galilei observed the rotation of the moons of Jupiter. He described them as small planets revolving around a large planet - a description (and observation) that the church did not like, as it challenged the geocentric model in which everything revolved around the Earth. This observation also showed that the planets (Jupiter, Neptune, and later Venus) are spherical and revolve around the Sun.

A flat planet (ours or any other) would be so incredible to observe that it would overturn virtually everything we know about planet formation and behavior. This will not only change everything we know about planet formation, but also about star formation (because our Sun should behave differently to accommodate the flat earth theory), speed and movement of celestial bodies. In short, we don't just suspect that our Earth is round - we know it.

The existence of time zones

It's 12 midnight in Beijing now, no sun. It's 12 noon in New York. The sun is at its zenith, although it is difficult to see it under the clouds. In Adelaide, Australia, one thirty in the morning. The sun will rise very soon.

This could be explained only by the fact that the Earth is round and rotates around its own axis. At a certain moment, when the sun is shining on one part of the Earth, it is dark at the other end, and vice versa. This is where time zones come from.

Another moment. If the sun were a "spotlight" (its light fell directly on a specific area), and the world was flat, we would see the sun even if it did not shine above us. In much the same way, you can see the spotlight on the stage of the theater, while remaining in the shadows yourself. The only way to create two completely separate time zones, one of which will always be in the dark and the other in the light, is to acquire a spherical world.

Center of gravity

There is interesting fact about our mass: it attracts things. The force of attraction (gravity) between two objects depends on their mass and the distance between them. Simply put, gravity will pull towards the center of mass of objects. To find the center of mass, you need to study the object.

Imagine a sphere. Due to the shape of the sphere, wherever you stand, there will be the same amount of sphere under you. (Imagine an ant walking on a glass ball. From the ant's point of view, the only sign of movement will be the movement of the ant's legs. The shape of the surface will not change at all.) The center of mass of a sphere is at the center of the sphere, meaning gravity pulls everything on the surface towards the center of the sphere (straight down), regardless of the object's location.

Consider a plane. The center of mass of the plane is at the center, so the force of gravity will pull everything on the surface towards the center of the plane. This means that if you are on the edge of the plane, gravity will pull you towards the center, and not down, as we are used to.

And even in Australia, apples fall from top to bottom, not from side to side.

Pictures from space

In the last 60 years of space exploration, we have launched many satellites, probes and people into space. Some of them have returned, some continue to stay in orbit and transmit beautiful images to Earth. And in all the photographs, the Earth (attention) is round.

If your child asks how we know the earth is round, take the trouble to explain.

People have known for a long time that the Earth is round, and they are finding new and new ways to show that our world is not flat. And yet, even in 2016, there are quite a few people on the planet who firmly believe that the Earth is not round. These are scary people, they tend to believe in conspiracy theories and it's hard to argue with them. But they exist. So does the Flat Earth Society. It becomes ridiculous at the mere thought of their possible arguments. But the history of our species has been interesting and quirky, disproving even well-established truths. You don't have to resort to complicated formulas to dispel the flat earth conspiracy theory.

It is enough to look around and check ten times: the Earth is definitely, inevitably, completely and absolutely not 100% flat.

Today, people already know that the Moon is not a piece of cheese and not a playful deity, but the phenomena of our satellite are well explained by modern science. But the ancient Greeks had no idea what it was, and in search of an answer, they made some astute observations that allowed people to determine the shape of our planet.

Aristotle (who made quite a few observations about the spherical nature of the Earth) noticed that during lunar eclipses (when the Earth's orbit places the planet exactly between the Sun and the Moon, producing a shadow) the shadow on the lunar surface is round. This shadow is the Earth, and the shadow cast by it directly indicates the spherical shape of the planet.

Because the Earth rotates (look up Foucault's pendulum experiment if you're not sure), the oval shadow that is produced during every lunar eclipse tells us not only that the Earth is round, but also not flat.

Ships and horizon

If you have recently been to the port or just strolled along the beach, peering into the horizon, you may have noticed a very interesting phenomenon: approaching ships do not just “appear” from the horizon (as they should if the world were flat), but rather come out of the sea. The reason that ships literally "come out of the waves" is that our world is not flat, but round.

Imagine an ant walking on the surface of an orange. If you look at an orange from a close distance, nose to the fruit, you will see how the body of the ant slowly rises above the horizon due to the curvature of the surface of the orange. If you do this experiment with a long road, the effect is different: the ant will slowly "materialize" into your field of vision, depending on how sharp your eyesight is.

constellation change

This observation was first made by Aristotle, who declared the Earth round, observing the change of constellations when crossing the equator.

Returning from a trip to Egypt, Aristotle noted that "stars are observed in Egypt and Cyprus, which were not seen in the northern regions." This phenomenon can only be explained by the fact that people look at the stars from a round surface. Aristotle went on to say that the sphere of the earth was "small in size, otherwise the effect of such a slight change of terrain would not have manifested itself so soon."

Shadows and sticks

If you stick a stick in the ground, it will cast a shadow. The shadow moves with the passage of time (based on this principle, the ancient people invented the sundial). If the world were flat, two sticks in different places would produce the same shadow.

But that doesn't happen. Because the earth is round, not flat.

Eratosthenes (276-194 BC) used this principle to calculate the circumference of the earth with good accuracy.

The higher, the farther you can see

Standing on a flat plateau, you look towards the horizon away from you. You strain your eyes, then take out your favorite binoculars and look through them as far as your eyes can see (using binocular lenses).

Then you climb the nearest tree - the higher the better, the main thing is not to drop the binoculars. And again look, straining your eyes, through binoculars beyond the horizon.

The higher you climb, the further you can see. Usually we tend to associate this with obstacles on Earth, when you can’t see the forest behind the trees, and freedom behind the stone jungle. But if you stand on a perfectly clear plateau, with no obstructions between you and the horizon, you will see much more from above than from the ground.

It's all about the curvature of the Earth, of course, and this would not be the case if the Earth were flat.

Airplane flight

If you've ever flown out of a country, especially far away, you must have noticed two interesting facts about airplanes and the Earth:

Planes can fly in a relatively straight line for a very long time and do not fall over the edge of the world. They can also fly around the Earth non-stop.

If you look out the window on a transatlantic flight, you will in most cases see the curvature of the earth on the horizon. The best kind of curvature was on the Concorde, but that plane is long gone. From the new Virgin Galactic plane, the horizon should be absolutely curved.

Look at other planets!

The earth is different from others, and this is indisputable. After all, we have life, and we haven't found any planets with life yet. However, all planets have similar characteristics, and it would be logical to assume that if all planets behave in a certain way or exhibit certain properties - especially if the planets are separated by distance or formed under different circumstances - then our planet is similar.

In other words, if there are so many planets that formed in different places and under different conditions, but have similar properties, most likely our planet will be one. From our observations, it became clear that the planets are round (and since we knew how they formed, we know why they have such a shape). There is no reason to think that our planet will not be the same.

In 1610, Galileo Galilei observed the rotation of the moons of Jupiter. He described them as small planets revolving around a large planet - a description (and observation) that the church did not like, as it challenged the geocentric model in which everything revolved around the Earth. This observation also showed that the planets (Jupiter, Neptune, and later Venus) are spherical and revolve around the Sun.

A flat planet (ours or any other) would be so incredible to observe that it would overturn virtually everything we know about planet formation and behavior. This will not only change everything we know about planet formation, but also about star formation (because our Sun should behave differently to accommodate the flat earth theory), speed and movement of celestial bodies. In short, we don't just suspect that our Earth is round - we know it.

The existence of time zones

It's 12 midnight in Beijing now, no sun. It's 12 noon in New York. The sun is at its zenith, although it is difficult to see it under the clouds. In Adelaide, Australia, one thirty in the morning. The sun will rise very soon.

This could be explained only by the fact that the Earth is round and rotates around its own axis. At a certain moment, when the sun is shining on one part of the Earth, it is dark at the other end, and vice versa. This is where time zones come from.

Another moment. If the sun were a "spotlight" (its light fell directly on a specific area), and the world was flat, we would see the sun even if it did not shine above us. In much the same way, you can see the spotlight on the stage of the theater, while remaining in the shadows yourself. The only way to create two completely separate time zones, one of which will always be in the dark and the other in the light, is to acquire a spherical world.

Center of gravity

There is an interesting fact about our mass: it attracts things. The force of attraction (gravity) between two objects depends on their mass and the distance between them. Simply put, gravity will pull towards the center of mass of objects. To find the center of mass, you need to study the object.

Imagine a sphere. Due to the shape of the sphere, wherever you stand, there will be the same amount of sphere under you. (Imagine an ant walking on a glass ball. From the ant's point of view, the only sign of movement will be the movement of the ant's legs. The shape of the surface will not change at all.) The center of mass of a sphere is at the center of the sphere, meaning gravity pulls everything on the surface towards the center of the sphere (straight down), regardless of the object's location.

Consider a plane. The center of mass of the plane is at the center, so the force of gravity will pull everything on the surface towards the center of the plane. This means that if you are on the edge of the plane, gravity will pull you towards the center, and not down, as we are used to.

And even in Australia, apples fall from top to bottom, not from side to side.

Pictures from space

In the last 60 years of space exploration, we have launched many satellites, probes and people into space. Some of them have returned, some continue to stay in orbit and transmit beautiful images to Earth. And in all the photographs, the Earth (attention) is round.

If your child asks how we know the earth is round, take the trouble to explain.

Today it is well known that the planet Earth is a ball or very close to it (a bulge at the equator due to the rotation of the Earth).

When Christopher Columbus suggested reaching India by sailing west from Spain, he assumed the Earth was round. India was a source of precious spices and other rare goods, but it was difficult to reach it by sailing to the East, because Africa blocked the journey. Guessing that the Earth is round, Columbus wanted to reach India.

Even in ancient times, sailors knew that the Earth was round, and the ancients not only suspected a sphere, but even estimated its size.

If you stand on the shore and look at the ship, it will gradually disappear from view. But the reason is not the distance: if there is a hill or a tower nearby, and climb to the top after the ship has completely disappeared, it becomes visible again. In addition, if you watch carefully on the shore as the ship disappears from view, it is noticed that the hull disappears first, while the masts and sails (chimney) disappear last.

Ancient philosophers about the shape and size of the Earth

Greek philosopher Aristotle(384-322 BC) argued in his writings that the earth was spherical. This he suggested thanks to the circular shadow on the moon, during a lunar eclipse. Another reason was that some stars are visible from Egypt and are not visible further north.

Alexandrian philosopher Eratosthenes went one step further and actually determined the size of the earth. On the day of the summer solstice (June 21) in the city of Siena in southern Egypt (now Aswan, near the huge dam on the Nile River), at noon the sun passed into a deep well. Eratosthenes himself lived in Alexandria, near the mouth of the river, north of Syene, about 5,000 stadiums north of Syene (stadium (stadium), the size of a sports arena, was a unit of distance used by the Greeks - about 180 m). In Alexandria, the sun did not reach the zenith at all on the corresponding date, and vertical objects still cast short shadows. Eratosthenes established that the direction of the zenith of the sun differed from the zenith by an angle that was equal to 1/50 of a circle, 7.2 degrees, and he estimated the circumference of the Earth to be 250,000 stadiums (stadia).

Eratosthenes also headed the Royal Library of Alexandria, the greatest and most famous library in classical antiquity. Officially, it was called the "Temple of the Muses" or "museion", a derivative of which is our modern "museum".

Greek Posidonius received a similar value, a little less. The Arab Caliph El-Mamun, who ruled in Baghdad from 813 to 833, sent out two teams of surveyors to measure and from them also received the radius of the Earth. Compared to the value known today, these estimates were very close.

All these results were known to Columbus' team, who were sent by King Ferdinand to study with Columbus.

We will never know whether Columbus knowingly justified an expedition to explore the unknown or whether it was actually believed that India was not too far west of Spain.

One of the definitions of a meter

As for the size of the earth, it has been accurately measured many times since then and many times.

Most notably: the French Academy of Sciences at the end of the 18th century. Their goal was to develop a new unit of distance equal to one part in 10,000,000 of the distance from the pole to the equator (Paris meridian). Today this distance is known even more precisely, but the unit introduced by the French Academy is still used as the standard in all distance measurements. This unit of measure is called the meter..

At the end of September, the domestic program “The Most Shocking Hypotheses” was released on REN-TV, which excited the public.

For a whole 45 minutes, in all seriousness, specialists, experts and even a whole former NASA employee prove to the viewer that the planet Earth really flat.

If you don't believe me, here's the show, enjoy:

Ask any schoolchild what shape our planet is. Average answer: spherical. And all why?

Yes, that's what they teach us in school.

Stop brainwashing us! With the light hand of REN-TV, everything more people begin to believe in a flat earth.

earth figure

Any child will say that the earth is round. Almost. Officially, our planet has the shape of a geoid, that is, a ball slightly flattened at the poles.

Revolutionary theorists deny this. Among them, it is believed that we live on a flat disk with upturned edges, which is covered with a dome from above. The North Pole is located in the center of the disk, and there is no South Pole as such. This is a kind of ice wall that protects us.

Doesn't it remind you of anything?

In Game of Thrones, for example, the world is also flat. And the border is a huge wall, beyond which the wildlings live, and white walkers rule the ball. Who knows, maybe it's not fiction, but real story.

Why don't we know anything

There is an opinion that NASA constantly misleads us, ordinary people.

In the program "The Most Shocking Hypotheses", ex-NASA employee Matthew Boylan himself claims that the Earth is flat and its real appearance can be seen on the UN flag.

For several years he painted a blue round planet and passed it off as reality. So, in his opinion, the department exists only to promote the theory of the sphericity of the planet.

The only way to check is to get a job in the department.

Curvature

The curvature parameter was invented by scientists. In fact, neither architects, nor the military, nor designers ignore the fact that the planet is spherical. When calculating, it is assumed that the Earth is motionless and flat. And everything works out: the shells fall where they should, the buildings are not destroyed. If we live on a geoid, then why does this fact not count?

In practice I can give an example: The city of Chicago is visible across the bay from a distance of 140 km, which is contrary to science.

If the Earth were a sphere, the city would drop about 1.5 km down relative to the observer.

Check it out for yourself

In May 2017, the American Darryl Marble was able to simply and easily prove the flat-earth hypothesis while flying in an airplane.

If the Earth is spherical, then the ship must fly along a curved path; thus, at certain intervals, the pilot needs to lower the nose of the aircraft so that it does not fly into space or into the upper atmosphere.

Darryl took a building level with him on the flight. However, for 23 minutes, or 326 kilometers, the plane never lowered its nose. Means, it flies in a straight line and the earth is flat.

Try it too. Launch the building level on your phone during your next flight.

What about space flights?

Everything is set up! Filming is mounted, the benefit of technology allows. In fact, humanity has never left the near-Earth dome.

Pictures are taken with a Fisheye lens. So any straight object in the photo will become spherical. The videos are all edited using chroma key technology. Attentive observers notice air bubbles, studio lighting, reflections in spacesuits.

Is everything we know a myth?

You will say that ships sooner or later disappear on the horizon. Yes, but it's not because the surface is curved. We simply cease to clearly distinguish objects due to the density of the atmosphere.

They say gravity doesn't exist either. Our disk simply flies upward with an acceleration of 9.8 m/s 2 and thus keeps us on the surface. True, it is not yet entirely clear why the birds remain in the air, for example.

Admit it, you did not hold a “candle” in space. There is no 100% proof of the sphericity of the Earth. This year we are celebrating the 60th anniversary of the launch of the first artificial Earth satellite. Was it really? Was a satellite really launched into space? Or is everything mounted and we are being deceived?

To believe in long-proven truths or to become supporters of a shocking hypothesis, it's up to you. As the saying goes, "trust but verify"! Whose side are you on?

We live in an amazing time. Most of the celestial bodies in the solar system have been explored by NASA probes, GPS satellites are circling the Earth, ISS crews are flying steadily into orbit, and returning rockets are landing on barges in the Atlantic Ocean.

Nevertheless, there is still a whole community of people who are sure that the Earth is flat. Reading their statements and comments, you sincerely hope that they are all just trolls.

Here are some simple proofs that our planet is round.

Ships and horizon

If you visit any port, look at the horizon and watch the ships. As a ship moves away, it doesn't just get smaller and smaller. It gradually disappears behind the horizon: first the hull disappears, then the mast. Conversely, approaching ships do not appear on the horizon (as they should if the world were flat), but rather come out of the sea.

But the ships do not emerge from the waves (with the exception of the "Flying Dutchman" from ""). The reason why approaching ships look like they're slowly rising from the horizon is because the Earth isn't flat, it's round.

Varying constellations

Different constellations can be seen from different latitudes. This was noticed by the Greek philosopher Aristotle as early as 350 BC. e. Returning from a trip to Egypt, Aristotle wrote that "in Egypt and<…>there are stars in Cyprus that are not visible in the northern regions.

The most striking examples are the constellations Ursa Major and the Southern Cross. Ursa Major, a bucket-like constellation of seven stars, is always visible at latitudes above 41° north latitude. Below 25° south latitude you will not see it.

Meanwhile, the Southern Cross, a small constellation of five stars, you will find only when you get to 20 ° north latitude. And the further south you move, the higher the Southern Cross will be above the horizon.

If the world were flat, we could observe the same constellations from anywhere on the planet. But it's not.

You can repeat Aristotle's experiment when you travel. Find the constellations in the sky will help you these for Android and iOS.

Lunar eclipses

Another proof of the sphericity of the Earth, found by Aristotle, is the shape of the earth's shadow on the moon during an eclipse. During an eclipse, the Earth is between the Moon and the Sun, blocking the Moon from sunlight.

The shape of the Earth's shadow that falls on the Moon during an eclipse is perfectly round. That is why the moon becomes a crescent.

Shadow length

The first to calculate the circumference of the earth was a Greek mathematician named Eratosthenes, who was born in 276 BC. e. He compared the length of the shadows on the day of the summer solstice in Syene (this Egyptian city is today called Aswan) and Alexandria located north.

At noon, when the sun was directly over Siena, there were no shadows. In Alexandria, a stick placed on the ground cast a shadow. Eratosthenes realized that if he knew the angle of the shadow and the distance between cities, he could calculate the circumference of the globe.

On a flat earth, there would be no difference between the length of the shadows. The position of the Sun would be the same everywhere. Only the sphericity of the planet explains why the position of the Sun is different in two cities at a distance of several hundred kilometers from each other.

Observations from above

Another obvious proof of the sphericity of the Earth: the higher you go, the farther you can see. If the earth were flat, you would have the same view regardless of your elevation. The curvature of the Earth limits the range of our view to about five kilometers.

World travel

The first circumnavigation of the world was made by the Spaniard Ferdinand Magellan. The voyage lasted three years, from 1519 to 1522. It took Magellan five ships (of which two returned) and 260 crew members (of which 18 returned) to circumnavigate the globe. Fortunately, in our time, in order to make sure that the Earth is round, it is enough just to buy a plane ticket.

If you've ever traveled by plane, you may have noticed the curvature of the Earth's horizon. It is best seen in flight over the oceans.

According to article Visually discerning the curvature of the Earth, published in the journal Applied Optics, the curve of the Earth becomes visible at an altitude of about 10 kilometers, provided that the observer has a view of at least 60 °. From the window of a passenger airliner, the view is still less.

More clearly, the curvature of the horizon is visible if you fly above 15 kilometers. It is best seen in photographs from the Concorde, but, unfortunately, this supersonic aircraft has not flown for a long time. However, high-altitude aviation is reviving in the passenger rocket plane from Virgin Galactic - Space Ship Two. So in the near future we will see new photos of the Earth taken in suborbital flight.

An airplane can easily circle the globe without stopping. World travel have been carried out on aircraft several times. At the same time, the planes did not detect any "edges" of the Earth.

Weather balloon observations

Ordinary passenger airliners fly not so high: at an altitude of 8-10 kilometers. Weather balloons rise much higher.

In January 2017, students at the University of Leicester tied some cameras to a hot air balloon and launched it into the sky. It rose to a height of 23.6 kilometers above the surface, significantly higher than passenger airliners fly. In the pictures taken by the cameras, the curve of the horizon is clearly visible.

Shape of other planets

Our planet is pretty ordinary. Of course, there is life on it, but otherwise it is no different from many other planets.

All our observations show that the planets are spherical. Since we have no good reason to think otherwise, our planet is also spherical.

A flat planet (ours or any other) would be an incredible discovery that would contradict everything we know about planet formation and orbital mechanics.

Time Zones

When it's seven in the evening in Moscow, it's noon in New York, and it's midnight in Beijing. In Australia at the same time, 1:30 am. You can see what time it is anywhere in the world, and make sure that the time of day is different everywhere.

There is only one explanation for this: the Earth is round and rotates around its axis. On the side of the planet where the Sun shines, it is currently day. The opposite side of the Earth is dark, and there is night. This forces us to use time zones.

Even if we imagine that the Sun is a directional searchlight that cruises over a flat Earth, then we would not have a clear day and night. We would still observe the Sun, even if we were in the shade, as we can see the spotlights shining on the stage in the theater, while being in a dark hall. The only explanation for the change in time of day is the sphericity of the Earth.

Center of gravity

It is known that gravity always pulls everything towards the center of mass.

Our Earth is spherical. The center of mass of the sphere is located, which is logical, in its center. Gravity pulls all objects on the surface in the direction of the Earth's core (that is, straight down) regardless of their location, which is what we always observe.

If we imagine that the Earth is flat, then gravity will have to attract everything on the surface to the center of the plane. That is, if you find yourself at the edge of a flat Earth, gravity will not pull you down, but towards the center of the disk. It is hardly possible to find a place on the planet where things fall not down, but sideways.

Images from space

The first photograph of the Earth from space was taken in 1946. Since then, we have launched many satellites, probes and astronauts (or astronauts or taikonauts - depending on the country) there. Some satellites and probes have returned, some remain in Earth orbit or fly through the solar system. And in all the photographs and videos transmitted by spacecraft, the Earth is round.

The curvature of the Earth is clearly visible in photographs from the ISS. In addition, you can see photographs of the Earth taken every 10 minutes by the Himawari-8 satellite of the Japan Meteorological Agency. It is constantly in geostationary orbit. Or here are real-time photos from the DSCOVR satellite, NASA.

Now, if you suddenly find yourself in a flat earth society, you will have several arguments in arguing with them.