Alles over Earth Line Zonnebrandcrème - Bescherming en Verzorging voor de Zomer

Is this Earth curvature calculator accurate?

You might find that if you were to test our calculator vs. a real-life scenario, our calculator might be slightly wrong in some cases. Why does this happen? Does it mean the Earth is flat and doesn't curve at all?

Of course not! It just means that our calculator doesn't account for the phenomenon of refraction. When light travels through a medium that is not perfectly uniform, such as air, it bends or refracts. For example, refraction can happen when light hits a pocket of cold air or a hot draft of rising air.

As the ray of light bends slightly, it changes direction. That means that some photons from the object that would usually hit the ground can bend around the Earth's surface and reach your eye, so the heights and distances as shown in the picture above may seem to be different. That's why, when you are calculating the obstructed height of an object, the distances you see maybe a bit different from the observed ones!

If you are interested in reading more about snell's law of refraction, you should check out our Snell's law calculator here.

How far is the horizon at sea level?

1. Assume the height of your eyes to be h = 1.6 m .
2. Build a right triangle with hypotenuse r + h (where r is Earth's radius) and a cathetus r .
3. Calculate the last cathetus with Pythagora's theorem: the result is the distance to the horizon: a = √[(r + h)² - r²]
4. Substitute the values in the formula above: a = √[(6,371,000 + 1.6)² - 6,371,000²] = 4,515 m

How do I calculate the distance of the horizon?

To calculate the theoretical distance of the horizon from your point of view, imagine building a right triangle with sides equal to:

• Earth's radius plus the height of your eyes above sea level, r + h ,
• Earth's radius r , and
• The line tangent to the surface of the Earth starting in your eyes. That's the distance of the horizon.

The Age of Mammals and Homo Sapiens (66 million years ago – now)

Mammals existed long before the Cenozoic Era. But they kept a low profile because dinosaurs dominated the land. The extinction of the dinosaurs marked the Age of Mammals. When dinosaurs roamed the Earth, mammals remained small and furry. And because dinosaurs went extinct, mammals emerged as the largest land animals at this time.

Apes remained in trees for their primary food source. Eventually, grass began to spread in places like the African Savannah and there were fewer trees. This forced apes to walk to new food sources. With their heads above the grass to see predators, apes evolved by walking on two legs. It also helped to have their hands available when they were traveling.

As the timeline to modern human evolution begins, hominids were the early proto-humans. They were known for sharpening objects with silicon rocks. They began to master the use of their hands and fingers. In the Stone Age, early humans had fire under control. This enabled them to cook their food giving them more calories. Modern humans learned to make more complex sounds and share information in groups. So humans have only existed for about 0.004% of the age of the Earth.

What is the Earth's curvature?

Suddenly, you begin to see a point that is getting larger and larger. First, it is a top of a white sail, when it moves closer, you can also notice the shape of a ship. Where was this ship before? It was hidden behind the horizon.

The reason for this is obvious: as Earth's shape is very similar to a sphere – the surface between you and the ship is not entirely flat but "bulges" up a bit. That is why it has obstructed your view. The curvature of Earth is simply the measure of this "bulge". It is expressed as the height of the "bulge" per kilometer or mile.

💡 Note that if the Earth were flat, you would see the whole ship even from afar. Expect it would start out very small whole ship (a dot) and then get larger as it got closer. However, by observing just the top of the sail from afar first, you've seen for yourself that the Earth is not flat. If you are interested in exploring this further, you should check out our flat vs. round earth calculator.

The Age of Reptiles and Dinosaurs (245 – 66 million years ago)

When Earth’s climate became hotter and drier, rainforests collapsed triggering the Age of Reptiles. Reptiles are different from amphibians because they lay their hard-shelled eggs on land. They essentially adapted to the land by cutting all ties with the ocean. Because reptiles evolved to dryland conditions, they gained a unique ecological advantage.

As conditions changed, dinosaurs (also known as terrible lizards) began to evolve. These reptile-like mammals had scaly skin and hatched eggs like reptiles. Some dinosaurs adapted as herbivores and some as carnivores. For the next 160 million years, dinosaurs were the dominant land vertebrates on Earth.

The Age of Conifers in the Mesozoic Era provided the spread of seeded plants. Conifers store vast amounts of carbon. As a result, oxygen content in the atmosphere jumped to 35% compared to 21% today. In addition, they provided habitat, shelter, and a source of food for specific animal species to survive.

Also notable is that Pangea existed as one supercontinent in this era. Dinosaurs lived on one supercontinent. Plate tectonics was the mechanism that eventually tore continents apart. Don’t forget that dinosaurs existed for 160 million years. So continental drift gradually rifted dinosaurs apart. We know this because we can find the same fossils on separate continents.