How does the dome of St. Paul’s Cathedral support itself? The dome of St Paul’s Cathedral in London looks like one massive dome, but it is actually two domes with a cone of bricks between them to give it strength and structural support. St Paul’s Cathedral is one of the main landmarks in London. It
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Why is looking at the sun dangerous? Because the UV light can burn a hole in the retinal tissue. If you look at the sun for even a few seconds, you can badly damage your eyes, something called solar retinopathy. It is also called eclipse retinopathy because it is very common during solar eclipses. People
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On the Shoulders of Giants #1 Euclid was an ancient Greek mathematician. He is most famous for his book “The Elements”. He probably lived in the City of Alexandria in about 300 BC, but there is not much reliable historical evidence for his existence. All of the records about him were written several centuries later.
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How do noise cancelling headphones work? They play the sound from around you, but reversed, which cancels out the noise. Sound is a pressure wave that is created by an energy source that makes the molecules of the medium it is travelling through vibrate. Sound can travel through any medium and it travels through some
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What is a Luddite? A Luddite is someone who is against new technology, but Luddites were a group of people who followed Ned Ludd, a person who was probably made up to support their cause. These days, we refer to anyone who is against new forms of technology or even new ways of doing things
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Will we ever end up with just one language? We will lose more languages, but it is very unlikely that we would all end up speaking the same language. There is no way of knowing when language appeared. Humans evolved about 300,000 years ago and they probably started by grunting and gesturing at each other.
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Why can mantis shrimp see so many colors? It turns out that they can’t see more colors than we can. They just process the way they see colors differently. Manis shrimp have twelve to sixteen different types of photoreceptors in their eyes, which lead people to believe that they could see many colors, or shades
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What are druids? Druids were members of a priestly class in ancient Celtic cultures. There is not a lot of evidence for druids because they don’t come from a people with a written culture. Most of the records about them were written down by the Roman invaders Gaul and Britain. The Romans suppressed the local
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How does mortar keep the bricks together? It holds the bricks together in a similar way to how glue holds wood together. It also acts as a waterproof sealant. Mortars are not always made of the same material. They are any material that holds together the bricks or stones used to make buildings. Mortars have
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What is forensic facial reconstruction? It is the attempt to recreate the face of someone from just their skull. There are several reasons why it might be necessary to try to work out what a person might have looked like from just their skull. One obvious reason is in criminal cases. If an unknown skeleton
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