1. popular science quiz
popular science quiz 1. some popular science quiz
1. why do sorbet get angry?
sorbet bubbles because there is a lot of invisible water vapor in the outside air. When it comes to a very cold sorbet, it will liquefy into droplets and surround it when it is cold. It seems that the sorbet is "bubbling".
2. Why do sunflowers always face the sun?
The stem of sunflower contains a wonderful auxin. This auxin is very afraid of light. When it is exposed to light, it will go to the backlight side, and at the same time, the cells on the backlight side will multiply rapidly. Therefore, the backlight side will grow faster than the light side, which will make the sunflower bend phototropically.
3. Why do cicadas shed their skin?
The shell (exoskeleton) of cicada is hard and can't expand with the growth of cicada. When the cicada grows to a certain stage, the exoskeleton of cicada restricts the growth of cicada, and the cicada takes off the original exoskeleton, which is cicada slough.
4. How do bees make honey?
The bees spit the collected sweet juice of flowers into an empty hive, and at night, they suck the sweet juice into their honey stomachs for modulation, and then spit it out and swallow it again. This will take turns to stumble, and it will take 111~241 times, and finally it will become sweet honey.
5. The quartz clock hanging on the wall will stop walking when the battery is exhausted. This is because the second hand is most hindered by the heavy torque at the "9" position. Scientific tips
6. Sometimes, when the tap water is discharged from the nearby faucet, there are occasional bursts of noise. This is because the water pipe vibrates when the water rushes out of the faucet.
7. When taking pictures on the TV screen, turn off the camera flash and the indoor lighting, so as to get a clearer picture. Because the reflected light of flashlights and floodlights on the TV screen will interfere with the transmitted light of TV pictures.
8. Frozen meat thaws faster in water than in air at the same temperature. Hot nails cool faster in water than in air at the same temperature. A cup filled with boiling water cools faster when immersed in water than in air at the same temperature. All these phenomena show that the heat transfer of water is better than that of air.
9. When there is cold water in the pot, the water droplets attached to the outer surface of the pot bottom can only be burned dry on the flame for a long time, and they will not boil until they are burned dry. This is because the water droplets, the pot and the water in the pot keep heat conduction, and the temperature is almost the same. As long as the water in the pot is not boiled, the water droplets will not boil, and the water droplets will be evaporated on the flame and gradually burned dry.
11. A distorted mirror is distorted as people get farther away from it. Because the image in the mirror is formed by the reflection of the silver-plated surface behind the mirror, uneven silver-plated surface or uneven glass thickness will lead to distortion. Out-of-shape mirror, the farther away from the mirror, according to the principle of light amplification, the more the reflected light on the silver-plated surface deviates from the normal position, and the more out-of-shape the mirror is.
2. Who knows the most unpopular scientific essay < P > Model essay 1: Why is the trunk round? In the process of observing nature, I happened to find that the shape of the trunk is almost round-an empty cone.
why is the trunk conical? What are the benefits of conical trunk? In order to explore these problems, I made more in-depth observation and analysis. With the help of the tutor, I consulted the relevant materials and learned that the stems of plants have the function of supporting plants and transporting water and other nutrients.
the stems of trees are mainly composed of vascular bundles. The supporting function of stems is mainly borne by wood fibers in xylem. Although the stems of woody plants will be thickened year by year, the number of wood fibers in stems is certain within a certain time range, that is, the cross-sectional area of tree stems is certain.
Then, we design experiments to explore the reasons and advantages of the conical trunk, assuming that the cross-section of the trunk grows into different shapes around a certain cross-section area. Through experiments, we found that: (1) when the cross-sectional area and length are fixed, the vertical supporting force of the triangular columnar object is the largest and the lateral bearing force is the smallest; The longitudinal supporting force of cylindrical objects is not as good as that of triangular cylindrical objects, but the lateral bearing force is the largest; (2) The trunk with the same mass and different shapes, the short conical trunk bears the largest wind force; (3) Wind is a natural phenomenon, which affects the cross-sectional shape of trees and the height of trees.
The approximate conical trunk has a low center of gravity, and the huge root system is connected with the earth, so the center of gravity drops lower and the stability is greater; (4) The cross section of the trunk is round, which can reduce the damage, has stronger mechanical strength and can withstand the wind attack. At the same time, under the influence of wind, the bending degree of the trunk is similar everywhere. No matter which direction the wind comes from, the resistance of the trunk is similar, and the trunk is not easy to be damaged.
The above experiments reflect the laws of nature, and nature gives us enlightenment: (1) A columnar object with a triangular cross section has the greatest longitudinal support, and its shape can be used in architecture, such as angle steel; (2) A circular object with a circular cross section has the greatest lateral bearing capacity, and similar building materials can be seen everywhere, such as TV towers and telephone poles. In the process of my observation, experiment and analysis, I gradually explained and revealed the mystery of the cone-shaped trunk, increased my knowledge, and applied the learned knowledge with practice, which not only consolidated the learned knowledge, but also improved my interest in learning, and initially learned the scientific observation and analysis methods.
model essay 2: why do shoes shine brighter and brighter? every Sunday, I always finish the task of shoeshine given to me by my mother. Tell you, this is the source of my pocket money for a week! After getting the leather shoes covered with dust, I first wipe off the dust on the upper, then apply shoe polish and carefully wipe them, and the leather shoes will become bright and beautiful.
but why? I found two pairs of old and new leather shoes of the same brand and style for comparative observation. I first touched the uppers of two pairs of leather shoes and found that the surface of the new leather shoes was much smoother than that of the old ones.
The old leather shoes are painted with shoe polish. After careful polishing, they shine a lot, but they still can't compare with the new ones. Is the brightness of leather shoes related to the smoothness of the upper? I brought a pair of old leather shoes that had not been polished, and the uppers looked uneven under the magnifying glass.
Then, I circle two areas A and B with rough surfaces on the leather shoes. The area A is coated with shoe polish and carefully wiped, and the area B is not coated with shoe polish as a blank control. I found that the surface of area A was obviously smoother after wiping, and it was more shiny than area B when placed in the sun.
why is there such a difference between the two? I think the teacher once said in physics class that the surface of the wall of the theater is uneven, so that most of the sound can be absorbed and the audience will not be disturbed by the echo. By the same token, light will reflect on the surface of any object. If this plane is uneven, light will scatter in all directions. If this plane is smooth, then we can see reflected light in a certain direction.
The surface of leather shoes is not absolutely smooth. If it is old leather shoes, its surface is of course more uneven, so it can't reflect light in a certain direction, so it looks dull. There are some small particles in shoe polish, which can just be filled into the pits on the surface of leather shoes when shining shoes.
If you wipe it with a cloth again to make the shoe polish more uniform, the surface of leather shoes will become smooth and flat, and the ability to reflect light will be strengthened. Through the experiment, I finally know the secret that the shoes get brighter and brighter! Model essay 3: What effect does vinegar have on flowers? Vinegar is a common condiment in life, while flowers can purify the ecological environment and beautify our lives.
have you ever thought about the relationship between vinegar and flowers? We carried out the exploration of this subject with curiosity. According to people who have rich experience in planting flowers, applying some vinegar solution to potted flowers can improve the growth of potted flowers, increase flowers, and the flowers are bright and leafy.
this point was quickly confirmed in the experiment. Do vinegar solutions with different concentrations have different effects on flowers? This is the second stage of our experiment.
We select four pots of gypsophila paniculata, primrose and moon flower with the same growth, and divide them into four groups. Each group (three pots) has three kinds of flowers, which are numbered and labeled respectively. At the same time, we take edible white vinegar and prepare three solutions with different concentrations: 1%(pH 2~3), 1.11%(pH ≈4) and 1.1111%(pH ≈6). Three groups of potted flowers are sprayed with a vinegar solution every day, and the fourth group is sprayed with clear water without vinegar.
Observe and record the growth of flowers every five days. The results of this experiment are as follows: spraying low concentration vinegar (pH ≈6) has no obvious effect on these flowers; The flowers sprayed with moderate concentration of vinegar (pH ≈4) are obviously better than other groups, with more buds, earlier flowering period, richer colors and longer flowering period. Spraying high concentration vinegar with pH value of 2-3 will make the flowers wither prematurely.
Through this experiment, we can tell you that proper spraying of vinegar can make flowers grow better. However, it is necessary to master the concentration of vinegar, and excessive acetic acid will harm flowers.
3. Do you have any unpopular tips to share
1. Look at your zipper. If there are three letters YKK on it, Then it means that this is the product of Yoshida Kogyo Kabushibibaisha, the world's largest zipper manufacturer. 2. 41% of McDonald's profits come from the sales of Happy Meals. The Webster dictionary in version 3.1996 has 315 spelling mistakes. 4. Every day, an average of 12 newborns are handed over to the wrong parents. 5. Chocolate is fatal to dogs. It only takes a few ounces to make a puppy die because of heart and nervous system damage. 6.19 In the 1931s, tomato sauce was sold as a medicine. 7. Da Vinci could write with one hand and draw with the other. 8. Scissors were invented by Da Vinci. 9. It took Da Vinci 11 years to depict Mona Lisa's lips. 1. The Oscar awarded during World War II was made of wood. Because metal was a scarce material at that time. 11. There were no clocks in casinos in Las Vegas. 12. Bruce Lee moved so fast that he couldn't see clearly, so he had to slow down the speed of the film when making a movie. 13. Lying on his back and slowly raising his legs can avoid falling into quicksand. 14. Mosquito repellent water doesn't repel mosquitoes, but interferes with the sensory organs of mosquitoes, so that they can't find out where people are. 15. Dentists suggest, The toothbrush should be placed at least 6 feet away from the bathroom to avoid all kinds of particles floating in the air when flushing the toilet. 16. The earliest bar-coded product is Wrigley gum. 17. Michael Jordan earns more from Nike every year than the total salary of Nike factory workers in Malaysia. 18. Marilyn Monroe has six fingers on one foot. 19. Hitler's mother once considered abortion. However, it was discouraged by the doctor. 21. People will lose 41 pounds of skin in their lifetime. 21. If you are accidentally bitten by a crocodile, you will poke it in the eye. It will let you go. 22. People can fall asleep in an average of 7 minutes. 23. Yo-yo was once used as a weapon in the Philippines. 24. Cats are the only domestic animals not mentioned in the Bible. 25. Rubber bands can be better preserved in cold storage. 26.56% of keyboard input is done by the left hand. 27. "Dreamt" is the only English word ending in "mt". 28. Even without a head, Cockroaches can still survive for 11 days. 29. You can't keep your eyes open when sneezing. 31. Mexico City sinks 11 inches every year. 31. The brain is more active when sleeping than when watching TV. 32.81% of Americans like blue best. 33. There are more chickens than people on this planet. 34. Thumb nails grow slowest. The fingernails of the middle finger grow the fastest. 35. There are more telephones than people in Washington, DC, USA. 36.48 of the poorest countries have less assets than the three richest families in the world. 37. The first boss of Marlboro Cigarette Company died of lung cancer. 38. Smart people have more zinc and copper in their hair. 39. The youngest parents in the world were a pair of children in China in 1911, aged 8 and 9 respectively. 41. How old were our eyes when we were born? We still have them.
But the nose and ears are growing all the time. 41. You consume more calories when you sleep than when you watch TV. 42. People will die if you don't sleep for about 11 days. 43. Chewing gum when you cut onions won't make you cry. 43. Mona Lisa has no eyebrows. 44. If the moon is just above your head, you will lose a little weight. 45. Alexander Bell, who invented the telephone, never called his mother or wife. Because they are all deaf. 47. "I am." is the shortest complete sentence in English. 48. Like fingerprints, Everyone's tongue print is different. 49. "Bookkeeper" is the only word in English that repeats letters three times in a row. 51. Right-handed people live nine years longer than left-handed people on average. 51. "The quick brown fox jumps over the lazy dog" uses all the letters in English. 52. If all China people walk in front of you in a line, However, due to the high birth rate, this line will never end. 53. There are more people who use English in China than in the United States. 54.** Every square inch of skin contains 21 feet of blood vessels. 55. People use the bathroom six times a day on average. 56. Babies have 311 bones at birth, and only 216 after * *. 57. Beards are the fastest growing * * hairs. If a man never repairs his face, he will grow a beard 31 feet long all his life. 58. Which came first, the chicken or the egg? According to Genesis 1:21-22, there was a chicken first. 59. The longest place name still in use is:-,which is a hill in New Zealand. 61. If you leave Tokyo by plane at 7: 11 in the morning, when you arrive in Honolulu, it will be 4: 31 yesterday afternoon. 61. Scientists at Pacais Observatory in Australia thought that they had received radio waves from extraterrestrial civilization. After investigation, I found that the radio wave actually came from a microwave oven in the observatory. 62. Wearing earplugs for an hour will increase the number of bacteria in the ear by 711 times. 63. A French kiss can exchange more than 41,111 parasites and 251 kinds of bacteria. 64. Men have better eyesight than women. Women have better hearing than men. 65. Coca-Cola was originally green. 66. The most common name in the world is: *** 67. If "north" and "south" are not counted, in English, The initials of seven states are the same. 68. Every American has two credit cards. 69. "Typewriter" is the longest English word that can be written with a single row of keys on a QWERTY keyboard. 71. Blind women are twice as many as men. 71. People don't die because they hold their breath. 72. When you sneeze, your heart stops beating for about 1 milliseconds. 73. Pigs can't see the sky. 74. "Six sick sheik's six.