字幕列表 影片播放 列印英文字幕 It's AumSum Time. Can you guess the title of my next video? Hurry up. Write your guess in the comments section below. Are dolphins smart? Not smarter than me. I'm the smartest of them all. You wish. Dolphins belong to the family of cetaceans which includes aquatic animals like whales and porpoises. Cetaceans have gradually evolved over millions of years to become the present-day dolphins which have large, complex brains. Now, coming back to the question, are dolphins smart? The answer is yes. The large complex brains of the dolphins help them perform various functions which are usually not seen in other animals. One of these functions is human like socializing. Which can be seen when bottlenose dolphins form a group to hunt. By beating its tail. A bottlenose dolphin from the group stirs up the seabed and starts to make a circular ring of mud around a shoal of fish. Then, by making the ring smaller and smaller, it traps the shoal of fish. Now, another bottlenose dolphin in the group signals the remaining dolphins to line up around the circle. So, when the confused and trapped fishes try to escape by jumping out of the mud ring. They end up in the dolphins' mouths. In addition to this, although dolphins have eyes to see. They even have the ability to echolocate which can help them navigate better especially in murky water. To echolocate, dolphins produce high frequency sound waves which travel through water. Get reflected from obstacles as echoes. When these echoes return to the dolphins, they are able to identify the location, shape, etc. of the obstacles. Hence, using this method, they easily avoid the obstacles and navigate in murky water. Moreover, it is also observed that using low frequency sounds, dolphins communicate with each other. They even have signature whistles, like names, which they use to call each other. According to a study, it is also believed that dolphins can recognize themselves in the mirror. This quality of physical self-awareness is not usually present in other animals. Topic: Vaccines. How do vaccines work? By giving extreme pain. Not at all. Vaccines train our body to fight against the dangerous disease causing pathogens. Oh really. Do they have a training academy? You are just unbelievable. Vaccines often contain weakened or dead pathogens. When they are injected into our body, they just trigger the immune response but do not cause fully-fledged diseases. Our immune cells recognize these pathogens as foreign invaders and thus, produce antibodies. These antibodies kill the pathogens. Also, the immune cells record the information about the pathogens and the way they were killed. Hence, in case in the future, a similar strong pathogen enters our body. Our immune cells remember and easily identify that pathogen. They produce the required antibodies to fight it back. Thus, we remain healthy. Why pop rocks pop? Because they have springs in their legs. No. Pop rocks are tiny candy crystals. Candies are usually made using sugar, water, corn syrup, various flavorings, etc. Initially, all these ingredients are mixed together. The resulting solution is heated until most of the water boils off and we are left with a thick sticky syrup. Usually, this syrup is poured in moulds and allowed to cool and harden to make candies. However, to make pop rocks, highly pressurized carbon dioxide gas is added to the syrup. Then, it is cooled to subsequently form a hard candy. This results in the formation of small bubbles of pressurized carbon dioxide trapped inside the candy. Now, when we put this candy in our mouth, our saliva dissolves the candy. As a result, the highly pressurized carbon dioxide escapes from the bubbles with a pop. Why are sunsets red? Because sunsets are romantic. No. It is basically because of scattering of light in the atmosphere. Our atmosphere is primarily composed of tiny nitrogen and oxygen particles. Now usually, when sunlight comprising of seven colors passes through the atmosphere. It hits the nitrogen and oxygen particles. These particles scatter blue and violet light more as compared to red, orange and other colored lights. Hence, mostly bluish light enters our eyes, thus making the sky to usually appear blue. However, during sunset, the sunlight must pass through a greater distance in the earth's atmosphere. Causing it to pass through more particles. As a result, most of the blue and violet light get scattered before they reach our eyes. Due to this, the less scattered light like red or orange reaches our eyes, making the sunset appear red. Topic: Heat transfer. Why do we use a black umbrella in summer? Hey. Looks like you are heading out today. But it is so hot outside. Why don't you take a dark colored umbrella, preferably black? See, I warned you. At least now use the black umbrella. Now, do you notice the heat? No, right? Do you know why? This is because in summer season, the temperatures are quite high. Now, as compared to other colors, a black colored umbrella, being dark, absorbs most of the light. Ultraviolet radiations coming from the sun and gets heated. It then radiates the heat back into the air. Thus, making a black umbrella, a good choice to use in summers.
B2 中高級 美國腔 海豚聰明嗎?| 我的天啊!我的天啊!我的天啊!我的天啊!我的天啊!我的天啊 (Are Dolphins Smart? | #aumsum) 39 4 AumSum 發佈於 2021 年 01 月 14 日 更多分享 分享 收藏 回報 影片單字