Watch on YouTube Why are deserts cold at night? The sand reflects the heat up and the air cannot hold the heat in. Deserts have very high temperature extremes. The Sahara Desert, for example, has an average daytime high of 38 ˚C and an average nighttime low of 4 ˚C. If you are stuck in […]
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Watch on YouTube How quickly do bones biodegrade? It depends on what kind of soil they are buried in, but from 6 years to thousands of years. The bones we have of dinosaurs are not actually bones but fossils. If a dinosaur dies in the right conditions, minerals can replace the calcium in the bones,
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Watch on YouTube How does an iron remove wrinkles from clothes? The heat forces the cellulose chains to lie straight. People started wearing clothes about 170,000 years ago. Scientists worked this out by looking at the evolution of lice that live on humans. Lice that live on clothes are different from the lice that live
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Watch on YouTube What makes things sticky? When the molecules in two substances are attracted to each other things become sticky. The stickiness of an adhesive and the stickiness of something like maple syrup are a little bit different from each other. Let’s look at the stickiness of glue, adhesive tape, and maple syrup. There
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Watch on YouTube When did people start wearing wedding rings? Wedding rings have been found dating back as far as 4000 BC. Rings were first used in Egypt by the pharaohs to represent eternity. A ring has no beginning and no end. It also reflects the circular shape of the sun and the moon, both
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Watch on YouTube Why is carbon-based life common? Because carbon can bond with many different elements to allow chemical reactions to happen. On our planet all living things contain carbon. There may be lifeforms on other planets that are made of different elements but on Earth, everything uses carbon in one way or another. Plants,
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Watch this on YouTube How do spiders make webs? By producing silk from their bodies and weaving it into a strong web. There are two parts to this question: how do spiders produce silk and how do they make their webs. Let’s look at how they make silk first. Spiders are able to produce silk
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Watch this on YouTube What is the difference between a moth and a butterfly? Amongst other things, their wings, their bodies, how they behave, and how they pupate. Butterflies and moths both belong to the Lepidoptera family. Lepidoptera is a huge insect family and it contains 180,000 insects, which is approximately 10% of all living
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What are the Dead Sea Scrolls? They are a series of ancient Jewish manuscripts discovered between 1946 and 1956 on the northern shore of the Dead Sea. The first of the scrolls were found in 1946 by Bedouin shepherds. They were discovered in a cave near to the Dead Sea. The story is that a
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How does cacao become chocolate? Through fermentation, drying, roasting, grinding, and adding milk and sugar. Cacao beans grow on a cacao tree, which is native to the Amazon basin in South America. The tree is called “Theobroma cacao.” “Theobroma” means “food of the gods” in Greek and “cacao” is the Spanish form of “kakaw” and
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