How to prove to everybody that the Earth is round

We live in an amazing time. Most of the celestial bodies of the solar system was studied NASA's probes, above the Earth circling the GPS satellites, ISS crews stable fly into orbit and returned the rocket landing on a barge in the Atlantic Ocean.

Nevertheless, there is still a whole community people who are confident that the earth is flat. Reading their statements and comments, sincerely hope that all of them are just trolls.

Here are some simple evidence that our planet is round.

Ships and horizon

If you visit in any port, take a look at the horizon and watch the ships. When the ship is moving away, it is not just getting smaller and smaller. It gradually disappears over the horizon: first, the body disappears, then the mast. Conversely, approaching the ships do not appear on the horizon (as they would have if the world was flat), but rather to go out of the sea.

But no ships emerges from the waves (with the exception of "The Flying Dutchman" from "Pirates of the Caribbean»). The reason that approaching ships look like they rise slowly over the horizon, is that the Earth is not flat, but round.

varying constellations

Of the various latitudes seen various constellations. This Greek philosopher Aristotle observed more in 350 BC. e. Returning from a trip to Egypt, Aristotle wrote that "in Egypt and <...> Cyprus have stars that are not visible in the northern regions."

The most striking examples are the Big Dipper and the Southern Cross. Big Dipper, the constellation of the seven stars, like a bucket, 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 reaching 20 ° north latitude. And the further south you go, the higher above the horizon is the Southern Cross.

If the world was flat, we could observe the same constellations from anywhere in the world. But this is not the case.

Aristotle can repeat the experiment, when going on a trip. Find constellations in the sky you will help these apps for Android and iOS.

lunar eclipses

Another proof of the sphericity of the Earth, found Aristotle, - a form of the earth's shadow on the moon during the eclipse. When the eclipse, the Earth is between the Moon and the Sun, the Moon covering the sunlight.

Form the shadow of the Earth, which falls on the moon during eclipses, perfectly round. That is why the moon becomes a crescent.

The length of the shadows

The first who calculated the circumference of the earth, was a Greek mathematician named Eratosthenes, who was born in 276 BC. e. He compared the length of the shadow at the summer solstice in Siena (this Egyptian town now called Aswan) and located north of Alexandria.

At noon, when the sun was directly above Siena, it was shadows. In Alexandria, a stick mounted on the ground, casts a shadow. Eratosfen understood that, if he knows the angle of the shadow and the distance between the cities, it can calculate the circumference of the globe.

On the 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 planets explain why the different position of the sun in two cities at a distance of several hundred kilometers apart.

Observations from a height

Another obvious proof of the sphericity of the Earth: the higher you climb, the further you can see. If the Earth was flat, you would have had the same review, regardless of your elevation. Curvature of the Earth limits the range of our review to about five kilometers.

world tour

The first trip around the world has made the Spaniard Ferdinand Magellan. Voyage lasted three years, from 1519 till 1522-th. To circumnavigate the globe, Magellan took five vessels (of which returned two) and 260 crew members (of which 18 returned). Fortunately, in our time, in order to ensure that the Earth is round, just enough to buy a plane ticket.

If you've ever traveled by plane, you can see the curvature of the Earth's horizon. Best of all it can be seen in flight over the oceans.

according to the article,Visually discerning the curvature of the EarthPublished 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 review of at least 60 °. Passenger airliner windows overview of still smaller.

The curvature of the horizon more clearly visible if soar above 15 kilometers. Best of all it noticeably the photographs from the "Concorde", but unfortunately, this supersonic aircraft no longer makes flights. However, high-altitude aircraft reborn in the passenger rocket planes of Virgin Galactic - Space Ship Two. So in the near future we will see new pictures of the Earth, made suborbital flight.

The plane could easily circumnavigate the globe non-stop. Trip around the world on airplanes carried out repeatedly. In this case, the aircraft did not show any "edge" of the Earth.

Observations from weather balloons

Conventional passenger airliners flying is not so high: at an altitude of 8-10 kilometers. Weather balloons rise substantially higher.

In January 2017 students of the University of Leicester strapped multiple cameras to a balloon and launched it into the sky. He rose to a height of 23.6 km above the surface, much higher than fly passenger airliners. The images captured by cameras clearly visible curve of the horizon.

The shape of other planets

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

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

Flat Planet (our or any other) would have been an incredible discovery, which would be contrary to everything we know about the formation of planets and orbital mechanics.

Time Zones

When in Moscow, seven in the evening in New York midday and midnight in Beijing. In Australia, at the same time, 1:30 am. You can lookHow much time anywhere in the world, and make sure that all times of the day their own.

This has only one explanation: the Earth is round and revolves around its axis. On the other side of the planet where the sun shines, at present day. The opposite side of the Earth's dark, and the night there. This forces us to use time zones.

Even if we imagine that the sun - directional spotlight, which runs over a flat Earth, then we would not have had a clear day or night. We still would have seen the sun, even in the shadows, as we can see in the theater spotlights shining on the stage, while being in a dark room. The only explanation for the change of the time of day - sphericity of the Earth.

The center of gravity

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

Our Earth is spherical shape. The center of mass of the sphere is that it is logical, in her heart. Gravity pulls all objects on the surface in the direction of the Earth's core (ie, straight down) regardless of their location, we always observe.

If we imagine that the Earth is flat, then gravity would have to attract all that is on the surface, the center of the plane. That is, if you find yourself at the edge of a flat earth, gravity will pull you down are not, and the center of the disk. One can hardly find a place in the world where things are not falling down, and sideways.

Images from space

first the photo Earth from space made in 1946. Since then, we have started to get a lot of satellites, probes and astronauts (or astronauts, or taikonaut - depending on the country). Some satellites and probes have returned, some remain in Earth orbit or flying through the solar system. And in all the photos and videos transferred to the spacecraft, the Earth is round.

Earth curvature is clearly visible on the ISS photos. Also, you can see Photo Earth, which makes at intervals of 10 minutes, the Japan Meteorological Agency satellite "Himawari-8." He is constantly on the geostationary orbit. or here Photo in real time from DSCOVR satellite, NASA.

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Now, if you suddenly find yourself in a community of supporters a flat earth, you will have multiple arguments in a dispute with them.