How did humans spread across the world? Generally, early humans moved around the world using land bridges or ice bridges. Occasionally, they may have used boats. The first migration happened before home sapiens had even evolved. Homo erectus evolved in central Africa at least three million years ago. This can be attested to by the […]
#1076 How did humans spread across the world? Read More »
Why did people think Australia was there? They believed that the continents in the northern hemisphere and the southern hemisphere should balance each other out. In this question, I am talking about Europeans, particularly the British people, who would go on to colonize the island and subjugate the people that lived there. The aboriginal people
#1064 Why did people think Australia was there? Read More »
Why do volcanoes become dormant? Volcanoes become dormant because the magma in the Earth’s mantle can no longer reach the volcano. There are roughly 1,500 active volcanoes on Earth at the moment and 70 of them erupt every year. Most of those eruptions are small, but some are much bigger and have more of an
#1062 Why do volcanoes become dormant? Read More »
Why is Lake Titicaca so high up? It was formed in a hollow in the mountain and is replenished by melting glaciers. Lake Titicaca is located in the Andes mountains, on the border of Bolivia and Peru. Its surface is 3,812 m above sea level. It if often thought to be the highest lake in
#1058 Why is Lake Titicaca so high up? Read More »
What causes the monsoon? The monsoons are caused by a wind change between the seasons. When we picture a monsoon, many of us think of the monsoon season that comes to India every year, but India isn’t the only country to get a monsoon. Monsoons occur across most of Southern Asia and Northern Australia. Across
#1056 What causes the monsoon? Read More »
Why is Mexico City sinking? Mexico City is sinking because they are pumping more water out of the underground aquifer than can be replaced. Mexico City is the capital of Mexico, and it has a population of almost 22 million people, which is over 17% of the population of Mexico. Since the beginning of the
#1045 Why is Mexico City sinking? Read More »
What is the Mercator projection? It is a map projection that tries to put the countries from a sphere onto a rectangle. Almost all world maps you see, and all of the ones we learned about at school, use the Mercator projection. Because of this, we all have a distorted view of how big countries
#1029 What is the Mercator projection? Read More »
How do animals sense earthquakes? No one actually knows how animals can sense earthquakes. They might be able to hear them. Possibly they can smell them. It could be that they sense the changing pressure. The surface of our planet is constantly moving and there are several hundred earthquakes a day. Many of them are
#1027 How do animals sense earthquakes? Read More »
What are the doldrums? They are an area of windless ocean where sailing ships used to get stuck. The doldrums are not a problem for modern shipping because they don’t rely on wind power. They are a problem for yachts and other types of sailing boats. A Salvadoran fisherman called Jose Salvador Alvarenga spent 14
#1023 What are the doldrums? Read More »
How quickly does a river cut through rock? It depends on the type of rock, the material the water is carrying, the amount of water, the speed of the water, and the acidity of the water. This is not a simple question. When we think about the erosive power of water we often think of
#1007 How quickly does a river cut through rock? Read More »
