Watt is watching grandma cook in the kitchen. There is a pot of boiling water on the stove. The boiling water is boiling. The lid of the pot smacked and kept jumping up. Watt observed it for a long time and felt very strange. He wanted to know what the reason was, so he asked his grandmother. What makes the lid jump? "
Grandma replied, "The water is boiling, that's all." Watt asked discontentedly, "Why does the water jump as soon as the lid is opened?" ? Is something pushing it? Maybe my grandmother was too busy to answer him correctly, so she said impatiently, "I don't know." What's the point of children asking these questions? "
For several days in a row, whenever cooking, he squatted by the fire and observed carefully. At first, the lid was very stable. After a while, the water will boil and make a loud noise. On the ground, the steam in the pot came out and pushed the lid to jump. The steam kept rising, and the lid kept beating, as if a magician was hiding inside, doing tricks.
Watt almost cried out for joy. He opened the lid, closed it again and again, and verified it again and again. He also covered the cup and spoon that sprayed steam. Watt finally figured out that steam pushed the lid to jump, and the power of this steam was not small.
1769, watt changed the steam engine into a single-acting engine with great power. Later, after many studies, the trial production of the new steam engine was completed in 1782. Through the linkage device on the machine, the single model is turned into a rotating motion and a perfect steam.
2, Newton-the law of universal gravitation
From 1665 to 1667, Newton was already thinking about gravity. One night, he was sitting under an apple tree to enjoy the cool, and an apple fell from the tree. It suddenly occurred to him: Why do apples only fall to the ground and not fly to the sky?
He analyzed the three laws of Copernicus' Heliocentrism and Kepler, and then thought: Why do planets go around the sun without leaving? Why are planets fast when they are near the sun and slow when they are far away from the sun? Why does the farther a planet is from the sun, the longer it runs?
Newton believed that their fundamental reason was that the sun was very attractive. After a series of experiments, observations and calculations, Newton found that the gravity of the sun is closely related to its huge mass.
Newton put forward and showed the universal law of the universe: all objects are attractive; The greater the quality, the greater the attraction; The greater the spacing, the less attractive it is. This is the famous law of universal gravitation in classical mechanics.
3. roentgen x-rays
1895165438+1October 8th, Roentgen did experiments in the laboratory as usual. He first wrapped a crookes discharge tube in black paper, blackened the room, connected the induction coil, and let the high voltage discharge pass through the discharger. There is no light leakage on the black paper, and everything is normal. He cut off the current and prepared to do experiments every day, but in the blink of an eye, there seemed to be a flash of green fluorescence in front of him, and then it turned black.
The discharge tube was wrapped in black paper just now, and the screen didn't stand up. How can there be fluorescence? He thought he must have observed this mysterious fluorescent fire in a dark room all day, formed a habit and had hallucinations, so he repeated the discharge experiment. But the mysterious fluorescence appeared again. With the ups and downs of the induction coil, a small pale green cloud suddenly floated deep in the night sky and moved evasively.
It turned out that a small platinum barium cyanide screen stood nearly one meter away from the workbench, and the fluorescence was emitted from here. But cathode rays cannot pass through the air more than a few centimeters. How can they make this surface flicker on the screen nearly one meter away? Is it an undiscovered new ray?
Roentgen took out a playing card to block the ray, and the light still appeared on the screen. He changed to another book. Although the screen is not as bright as it was just now, it is still very bright. He changed another thin aluminum sheet, and the effect was the same as that of a thick book. He replaced it with a thin piece of lead, but there was no light-lead could actually cut off the light.
Roentgen was so excited that he kept changing bomb shelters. He tried almost everything he could touch. At this time, the workmates came in to urge him to eat. He promised casually, but didn't do it. Although the experiment in hand stopped, he was still staring at the screen. Now it is certain that this is a new kind of ray, but what is its use?
What shall we call it for the time being? It is really an unknown number. Ok, let's call it "x-ray" for the time being.
From that day on, Roentgen lived in the laboratory, conducted research and experiments day and night, and finally published a research report on February 28th, 1895. 1896 65438+1On October 5th, Vienna Daily published a major report on X-rays, which immediately attracted the attention of the whole world.
Four days after the United States reported the incident, someone found the bullet on the patient's foot with X-rays. X-rays soon entered the medical field. At that time, Thomas Henry, a famous British surgeon, called it "the biggest milestone in the history of diagnosis".
190 1 year, roentgen won the nobel prize in physics for his discovery of x-rays.
4. Hans Justus von Liebig-Look at the glasses.
/kloc-One day at the beginning of the 7th century, Justus von Liebig, the owner of an optical shop in a small Dutch town, lined up a convex lens and a concave lens to check the quality of the polished lenses. Looking through the lens, he found that the church spire in the distance seemed to be getting closer and closer, so he accidentally discovered the secret of the telescope.
1608, he applied for a patent for his telescope, and made a binoculars according to the requirements of the authorities. It is said that dozens of opticians in the town claimed to have invented the telescope.
Legend has it that a shepherd happened to find his sheep skipping when he was herding sheep. When he looked carefully, it turned out that the sheep had eaten a red fruit, which led to their funny behavior. He tried to pick some red fruits to cook. Unexpectedly, the room is full of fragrance. After drinking the cooked juice, it is more refreshing and refreshing. Since then, this fruit has been regarded as a refreshing drink and has been well received.
5. Fleming-penicillin
From 65438 to 0928, Fleming worked as a doctor at Melly Hospital in London. The 47-year-old middle-aged man is actively studying ways to deal with staphylococcus. One of the reasons why people's wounds fester after injury is that staphylococci are making trouble. Fleming cultivated staphylococci in Petri dishes and then tried to kill them with various drugs.
This job took him several years, and so far nothing has been achieved-this staphylococcus is really a tough guy!
One morning in September, Fleming found blue-green mold growing on one of the Petri dishes. Obviously, this is caused by some kind of natural mold falling in. This made him feel depressed because the culture in this Petri dish was useless. Fleming was about to dump the moldy culture when he suddenly had an idea: put it under a microscope.
"ah!" As soon as Fleming saw the microscope, his mood immediately stirred up: Staphylococcus died near the mildew spot! Is this the staphylococcal nemesis that he has dreamed of and pursued for several years? Fleming immediately began to cultivate this turquoise mold in large quantities, filtered the culture solution and dropped it into Staphylococcus.
As a result, all the staphylococci died within a few hours. Dilute the filtrate 800 times, and then drop staphylococcus, which can still kill staphylococcus!
Fleming called this culture medium penicillin. Next, he did a pathological test and injected the mouse with penicillin. The results showed that penicillin was harmless to animals. He dripped the liquid into the rabbit's eyes again and found nothing unusual.