I learned this today. Why is Wall Street called “Wall Street” and why has it become a financial center? There are two theories as to why Wall Street is called Wall Street. Nobody knows which one is true. The first theory is that it was a street for a people called Walloon. At that time, […]
#25 Why is Wall Street called Wall Street? Read More »
I learned this today. What causes water mirages and heat hazes? Water mirages and heat hazes are caused because light travels at different speeds through warm air and cold air. Light travels at 299792458 m / s in a vacuum. When the light from the sun hits our atmosphere, the density of the air causes
#24 What causes water mirages and heat hazes? Read More »
I learned this today. An electric eel produces electricity in the same way that a battery does. Electric eels usually grow to be about 2m long and they have three organs that they use to make electricity. These are called the main organ, Hunter’s organ, and Sach’s organ. These three organs take up most of
#23 How do electric eels make electricity Read More »
I learned this today. The piano is only 300 years old and many famous composers that we know composed for the harpsichord, not the piano. The piano was invented by Bartolomeo Cristofori in about 1698. He worked for the house of Medici. He called his invention, “un cimbalo di cipresso di piano e forte,” which
#22 Why was the piano invented? Read More »
I learned this today. Most TV remote controls operate by sending binary signals to the TV using infrared light. The remote controller in your house has an LED fitted to the end of it. This LED emits a wavelength of 940 nm, which is infrared. The human eye can only detect wavelengths between 380 and
#21 How do TV remote controllers work? Read More »
I learned this today. Cats appear never to blink, but they actually blink with a third eyelid, a nictitating membrane, which is difficult for us to see. Most animals that have eyes blink. Insects with compound eyes can’t blink, and fish, snakes, ghekos, slinks, and some lizards don’t need to blink. Apart from these, blinking
#20 Do cats blink? Read More »
I learned this today. Hurricanes and tornados are not the same thing. Hurricanes, typhoons. and cyclones always form over the sea. Incidentally, hurricanes, typhoons, and cyclones are all different names for the same thing, except they form in different places. Hurricanes are tropical storms that form over the North Atlantic Ocean and the Northeast Pacific.
#19 Are hurricanes and tornados the same thing? Read More »
I learned this today. Pluto has been classified as a dwarf planet instead of a planet because it only meets two out the of the three criteria required of a planet. The International Astronomical Union came up with the definition of a planet in August 2006. They said that an object is a planet if:
#18 Why isn’t Pluto a planet? Read More »
I learned this today. Hibernation is not the same as sleeping. Animals sometimes have to come out of hibernation to be able to sleep. Hibernation is basically an energy-saving technique. During the winter, the temperature obviously drops, which means that endothermic animals (animals that generate their own heat internally) need more energy to keep themselves
#17 What happens when animals hibernate? Is it the same as sleeping? Read More »
I learned this today. The mathematical symbols + plus, – minus, x multiply, ÷ divide, and = equal are not as old as we think. Mathematics itself goes back a very long way. The idea of counting began with hunter-gatherer tribes. Presumably, they would have known how to talk about adding and subtracting parts of
#16 Where do the plus, minus, multiplication, and division symbols come from? Read More »
