Louis Braille was born in France in 1809. Sadly when he was a little boy, he had an accident. By the time he was four years old, he was completely blind. However, at the age of ten, Louis was lucky enough to go to one of the first schools for blind children in Paris. At this particular school they had special books. They were written in ordinary French but the letters raised up off the page, so that the students could feel the shape of the words and read them. But there were two problems with this system. First, the letters were huge and difficult to read. Second, the books were very expensive so the school library only had fourteen altogether.

In 1821, when Louis was twelve years old, a soldier came to his school. This man had invented a system for soldiers to send and receive messages in the dark. Although this idea had not worked very well, Louis became very excited and began experiments with it. By the time he was fifteen, he had invented a perfect system which used only six dots. And by 1827 the first book using his system was published.

It still took a long time before people realized what a wonderful invention Braille’s system was. In fact, Louis died in 1852 and did not live to see the success of his system, which has been adapted to almost every language in the world. Thanks to him, blind or weak-sighted people are able to read or write as well as any sighted person.

Scientists said this week that they used a high-powered laser (激光) to change the direction of lightning strikes for the first time. The laser was aimed at the sky atop Mount Santis in northeastern Switzerland.

Lightning is a powerful electrical discharge between a cloud and the ground, within a cloud or between clouds. It kills thousands of people and causes billions of dollars of damage to communication systems, power lines, and equipment each year.

American inventor Benjamin Franklin first invented the lightning rod (避雷针) in the 1750s. That technology is still used today but can protect only a small area.

Scientists say the new device, called Laser Lightning Rod (LLR), could increase protection by extending the height of rods hundreds of meters. With further development, LLR could improve protection for important places such as power stations and airports.

Workers brought the equipment to the top of Mount Santis at 2, 500 meters by helicopter. The laser is the size of a large car and weighs more than 2, 700 kilograms. It was aimed at the sky above a 124-meter Swisscom telecommunications tower, one of Europe’s structures most affected by lightning.

The laser works by creating a beam of electrically charged particles called ions (离子). The ions attract lightning, just as a metal lightning rod does.

In experiments during the summer of 2021, the LLR sent strong laser pulses 1000 times per second. The laser redirected all four lightning strikes that happened during the laser’s operation.

Scientists said that 10 to 15 years more work would be needed before the Laser Lightning Rod can enter common use. One worry is avoiding airplanes in flight. In fact, air traffic in the area was stopped when the researchers used the laser.

“Indeed, there is a potential problem using the system with air traffic in the area because the laser could harm the eyes of the pilot if he crosses the laser beam and looks down, ” scientists said.

What happened: In its salad days, nitrous oxide was strictly a party toy, since it made people howl like hyenas (鬣狗). But a friend of the dentist took too much of the stuff at a laughing-gas stage show and cut his leg.

Big Discovery: The friend didn't realize that he'd hurt himself.

As a Result: Nitrous oxide became an early form of anesthesia.

What happened: He was experimenting with chicle (树胶)as a substitute for rubber. After mounting failures, the depressed inventor popped a piece into his mouth.

Big Discovery: He liked it!

As a Result: “Adams New York No.1” became the first mass-produced chewing gum in the world.

What Happened: During the war years, the General Electric engineer combined silicone oil and boric acid in an attempt to find a cheap alternative to rubber for tank, boots, etc. It didn't work.

Big Discovery: He tossed a gob of the compound from the test tube onto the floor. To his surprise, the gob bounced right back at him. And the compound was very bouncy and could be stretched and pulled.

As a Result: Plastic eggs containing silly putty became popular among kids.

What Happened: With the end of World War II, the Raytheon engineer was looking for other uses for the magnetron, which generated microwaves for radar systems during the war. While Spencer was standing next to the magnetron device one day, a chocolate bar in his pocket melted.

Big Discovery: The magnetron worked even better on popcorn.

As a Result: Orville Redenbacher became very rich.