Why are rubies red, emeralds green, and sapphires blue? Rubies and sapphires are varieties of the mineral corundum. Emeralds are a variety of the mineral beryl. They all have impurities that give them their color. Rubies are obviously red. Their name comes from the Latin ruber, which means red. They come in many different shades […]
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How does a Geiger counter work? By using radiation to create an electrical signal. There are four types of radiation and they all have different mass and energy. The types are alpha, beta, neutrons, and electromagnetic waves. Alpha particles are the heaviest. They have two protons and two neutrons. They are made by many of
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Why is the Dead Sea so salty? Because the sea evaporates very quickly and there is only one source of freshwater coming in. The Dead Sea is not actually a sea. A sea is defined as “a body of water that is partly surrounded by land”. There are about fifty seas in the world, but
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What is the tallest a mountain can be? It depends on the strength of the surface gravity, the amount of volcanic activity, the movement of tectonic plates, and the weather. The highest mountain on Earth is Mount Everest at 8,848 meters high. Technically Mauna Kea in Hawaii is the tallest mountain if you measure from
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Why do we get jet lag? We get jet lag because rapid travel puts our circadian rhythm out of sync with the local time. Jet lag is a fairly recent problem. In fact, the expression “jet lag” was only coined in 1966. The reason for this is that you have to be able to jump
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How quickly are the continents moving apart? Our continents are moving apart at a rate of 2.5 cm every year. The surface of Earth is divided up into 15 tectonic plates. There are seven major plates and eight minor ones. The major plates are named after the continents that are on them: African, Antarctic, Eurasian,
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Why is New York called New York? New York is called New York because it was named in honor of the British Duke of York. Before European people colonized the Americas, the Algonquian speaking Native Americans lived in the area where New York is now. The Algonquian speaking people were the largest indigenous group in North
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When were latitude and longitude invented? Latitude in about 600 BC and longitude in AD 1736. Latitude are the horizontal lines that measure your distance to the north or the south of the equator. Longitude are the vertical lines that measure your distance to the east or west of 0, which has been set as
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Why do we say north, east, south, and west? The cardinal directions north, east, south, and west came about because of the position of the sun in the sky. Nobody has any idea when the idea of cardinal directions came about. Early civilizations would have had no need for directions such as north and south
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How did the Polynesians navigate? They used star compasses, maps of waves made using sticks, clouds, the color of the sky, and birds. From about 5,000 years ago, groups of people started to spread out from Taiwan into South East Asia. These were the people we call Polynesians. By 1200 AD, they had spread across
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