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 […]
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What happens if you drink too much water? Your brain can swell up and you can have seizures and possibly even die. Overhydration is the opposite of dehydration, and just like dehydration can be fatal, overhydration can be as well. However, it is much harder to be overhydrated than it is to be dehydrated. To
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What causes acid rain? Acid rain happens when water molecules in the atmosphere encounter sulfur dioxide or nitrogen oxide. Acid rain was a big problem in the USA and European countries during the 1980s and 1990s, but we don’t hear so much about it anymore. Has the problem been solved, or has it just shifted
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How does carbon dating work? Carbon dating allows scientists to estimate the age of something by counting the number of carbon-14 atoms that are left. Carbon-14 is created in our atmosphere and is absorbed by all living organisms. It is created when cosmic rays impact nitrogen atoms in our atmosphere. A cosmic ray is a
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Why was the Cold War called a “cold” war? It was called a “cold” war because there were no direct military confrontations between the United States on one side and the USSR on the other side. This is compared to World Wars 1 and 2 which had gone before and were hot wars because there
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Why don’t army ants make nests? Army ants can clear an area of insects and food in a few days, so they have to keep on the mood to find more food. Most species of ants build complex nests that have interlocking tunnels and chambers for different purposes. They have places to keep their larvae,
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How quickly does your blood regenerate after you donate it? The blood volume will be back in 48 hours, but it will take four to eight weeks for the red blood cells to regrow. When people donate blood, they usually give about 450 ml, which is about a pint. Depending on your size, that is
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How long can a cable car be? The longest cable car in the world is the Norsjö ropeway in Sweden and it is 13.2 km long. This is probably close to the upper limit of how long a cable car cable can be. The 13.2 km part is just one section of the Norsjö ropeway,
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Why does Canada have two official languages? Canada has ended up with two official languages because of European colonialism. Canada is not the only country in the world to have more than one official language. There are over 30 altogether. Not all of them, but with many you can see in the impact of European
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Why are so many arrowheads made of flint? Flint wasn’t the only material, but it is a fairly common rock, easy to break into flakes and it can be sharpened fairly easily. The oldest arrowhead that has been found has been dated to 74,000 years ago. They were found in the lowlands of where northwest
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