WHY are Japanese suicide bombers called kamikazes?
The Mongol khan Kublai twice planned an invasion of Japan, and both times he was prevented by violent typhoons.
The Japanese saw this as help from above and called them “kamikaze,” which means “divine wind.” And in World War II they used the term to describe suicide pilots.
WHY do calculators start at the bottom and the phone starts at the top?
The calculator is the successor of cash registers and mechanical counting machines. That’s why the numbers on the calculator from zero to nine are from the bottom to the top.
Until the 1960s, dialing on the telephone was done with a dial. Then tone dialing became possible, and the familiar dial was replaced by buttons.
There were many different attempts: they were arranged in a circle, or in two rows… But as a result, the familiar option was chosen, where the numbers are arranged in three rows in ascending order (from top to bottom).
WHY are sweet foods sticky?
It’s due to the chemical bonding that occurs between sugar and water molecules. The water molecules envelop the sucrose and create a shell. Thus, at high concentrations (like honey, jam, and syrup) they form hydrogen bonds with each other, this bonding is what gives the sticky feeling.
WHY is everything colored green in night vision devices?
In traditional night vision devices (not thermal imagers), light entering the lens is converted into shades of black and white, and only when it hits the phosphor screen does it take on a greenish hue.
The green gamut is chosen for two reasons:
✔️ the human eye is most susceptible to waves of this length.
✔️ it is the least tiring to the eye for prolonged exposure.
WHY are the ribs of coins notched?
Coins used to be valued according to the amount of metal they contained. Fraudsters used to cut the metal off the edges, pocketing the gold and silver. It was incredibly difficult to catch them.
A solution to this problem was suggested by Isaac Newton, who was an employee of the British Royal Mint. He suggested making fine notches on the edges of the coin, which made the worn edges immediately visible.