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

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 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.

The Cambrian Explosion and Fossil Records (541 – 245 million years ago)

The Cambrian explosion was the largest diversification of life in Earth’s history. Everything before this era was Precambrian. We couldn’t identify life because we didn’t have fossilized shells or animals. This is when hard-shelled invertebrates originated in the oceans. The Cambrian explosion started with the Age of Invertebrates. And life got more diverse from there.

Next came the Age of Fish when thousands of fish species arose. Then, the first vertebrate land animal made its leap ashore. Amphibians took a breath of fresh air and colonized the empty continent of Gondwana. This was the start of the Age of Amphibians. We share similar characteristics to our vertebrate ancestors. For example, humans have spines, jaws, and mouths originating from fish.

In the Paleozoic Era, lush rainforests flourished on land. But due to an abrupt shift in global warming, a major marine and terrestrial extinction event began. This event was the Carboniferous Rainforest Collapse. Plants and swamps were buried, compacted, and cooked into underground coal deposits. It left behind vast deserts for reptiles to eventually dominate the continental interior.

The Paleozoic Era ended with the largest extinction in Earth’s history. The Permian-Triassic Extinction vanquished 96% of all marine species. About 70% of terrestrial vertebrate species were wiped out. Opinions vary about the Permian-Triassic Extinction cause. But the consensus is that it was from a major asteroid impact event.

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.

Waar moet je op letten met het kopen van zonnebrandcrème?

• Factor: De factor van je zonnebrandcrème is heel belangrijk. Met een te lage factor loop je het risico om te verbranden. Het is aan te raden om minimaal factor 30 te gebruiken. Verbrand jij snel? Kies dan voor een zonnebrand met factor 50.
• Gebruik: Waarvoor ga je de zonnebrandcrème gebruiken? Voor je gezicht, voor je lichaam of specifiek voor kinderen? Kies een zonnebrand die aansluit bij je behoeften, zo weet jij zeker dat jij het best beschermd bent.
• Substantie: Zonnebrand is te verkrijgen in verschillende substanties zoals olie, crème of lotion. Bedenk wat bij jouw huidtype past en wat jij fijn vindt smeren.
• Aanbrengen: Zonnebrand, flessen komen als een spray, spuitbus of knijpfles. Afhankelijk van het merk en type zonnebrand bepaalt dit het gebruiksgemak van de fles.
• Extra’s: Sommige zonnebrand merken bevatten bronzer, teint of extra hydratatie. Kies een zonnebrandcrème die aansluit bij jouw behoeften. Daarnaast kunnen sommige zonnebrandcrèmes slecht zijn voor het koraal. Zo heeft Hawaï een wet aangenomen welke alleen crèmes toelaat welke niet slecht zijn voor het koraal. Wij hebben hier op gelet.

De straling van de zon bestaat bijna geheel uit UVA-straling. Deze straling zorgt er niet voor dat je huid verbrand, maar het dringt wel heel diep door in je huid. De UVA-straling recht schade aan in je DNA en versnelt huidveroudering. 2 De UVB-straling is de variant die zorgt voor een verbrande huid als jij je niet goed beschermt met zonnebrandcrème. Daarnaast zorgt deze straling ook voor de aanmaak van vitamine D, en dat is goed voor je botten en tanden.

Hoe lang blijft zonnebrandcrème goed?

Gemiddeld is zonnebrand na het openen 12 maanden houdbaar. Na een jaar is de SPF dusdanig minder dat de crème niet meer goed beschermt. Koop daarom jaarlijks nieuwe zonnebrand zodat jij altijd goed beschermd bent.

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.