字幕表 動画を再生する 英語字幕をプリント It's AumSum Time Can you guess the title of my next video? Hurry up. Write your guess in the comments section below. What causes tides? Tides are the periodic rise and fall of sea level at a particular place. When the sea level rises to its greatest height. It is known as a high tide and when the sea level drops to its lowest height, it is known as a low tide. Tides are primarily caused due to the gravitational force of the moon. But how? Part of the earth facing the moon experiences a stronger gravitational pull towards the moon as compared to the earth's center. So, the part facing the moon is pulled away from the center, creating a bulge. Thus increasing the sea level and causing a high tide. Now, the earth's center experiences a stronger gravitational force towards the moon. Than the part facing away from the moon. Hence, this part is pulled away from the center, resulting in high tide on the opposite side as well. In addition to this, the places in between the two high tides, where the sea level drops, experience low tides. Why do dogs wag their tails? Coz they are happy!! A dog's wagging tail doesn't always mean that it is happy or excited. So, what does it mean?? Popular researches and studies over the years, suggest that the tail position. Wagging direction represent different feelings or moods of dogs. When the tail is hung down in its natural position, it means that the dog is calm, and is not worried. If the tail is curled in between its legs, it indicates that the dog is scared or anxious. When the tail is straight up. It indicates that the dog is curious or wants to show other smaller dogs that it is bigger and dominant. Moreover, if the tail wags towards right. The dog is expressing positive emotions such as joy, excitement, etc. However, if it wags towards left, it conveys negative emotions such as anxiety, stress, etc. Why do birds need gravity to swallow food? Maybe because they are fans of Newton!! Nooo!!! When humans eat food, it enters into a muscular organ called food pipe or esophagus. In the esophagus, a series of contraction and relaxation take place that pushes. Moves food towards the stomach. This movement is called peristalsis. Dude!! Why do you use such complicated names?? Oh!! Just listen!! In most birds, such peristaltic movement doesn't take place in their esophagus. Hence, they need to depend on gravity to push their food through the esophagus. When a bird eats its food. The bird lifts or tilts its head up and with the help of it directs the food towards the throat. Then the gravitational force of earth causes the food to slide down into a pouch called crop. Thus helping it to swallow its food. Why do animals' eyes glow in the dark? Coz they have hidden torches!! Naahhh!! Wait I'll explain!! Our eyes have a layer called retina which is made up of photoreceptors. When light enters our eyes, it hits the photoreceptors. Photoreceptors detect light, thus making it possible to see. However, the light which doesn't hit the photoreceptors remains undetected. Ohh!! Poor undetected light!! Now, nocturnal animals like owls, need to see better during the night. Hence, their eyes have another layer below the retina called tapetum lucidum. Now, when light doesn't hit the photoreceptors, it reaches the tapetum lucidum. This layer acts like a mirror. It reflects light back onto the photoreceptors, thus giving them a second chance to detect light. Some of this reflected light also comes out of the animal's eyes. Thus, making it seem that its eyes are glowing. Topic: Nerves Why don't we feel pain when we cut our hair? Well duh!! Coz if it would, then we would have got angry on our hair dressers!! Oh!! You are just impossible!! Wait!! I will explain it to you. Inside our body, there is a network of nerves. These nerves help us to sense our surroundings and feel pain, touch, etc. By sending messages to the brain. So, do the nerves of my hair not know how to send a message?? Noo!! Generally, the part of our hair above the skin is made up of dead cells. It does not have any nerves. Hence, when we cut our hair, due to the absence of nerves, our brain does not receive any messages of pain. As a result, we don't feel any pain.