字幕表 動画を再生する 英語字幕をプリント It's AumSum Time Hi guys. Can you guess the title of my next video? Shush. Somebody's talking. It's the trees. Hurry up. Write your guess in the comments section below. Oh no. I'm gonna die. Just kidding. Bananas contain a radioactive isotope of potassium called K-40. But it doesn't lead to radiation poisoning. How do I know? Unit to measure radiation exposure is sievert. According to research, radiation exposure should not exceed 50,000 millisieverts annually. Eating a banana exposes us to only 0.1 microsieverts. So, bananas won't cause radiation poisoning unless you eat millions of them at the same time. Why do snakes have forked tongue? Just for fashion. Nope. Even though snakes have noses, they smell odors of their prey. Mate or surroundings with the help of their tongue and vomeronasal organ. Each time a snake flicks its tongue in air, it collects odor particles. Then when the tongue is brought back, the particles are transferred to the vomeronasal organ. This organ detects the odors and sends signals to the brain, helping the snake smell. That's interesting. Now, we know that when we see with our two separate eyes. Our brain combines the two different perspectives. And makes a detailed image of our surrounding. Similarly, because the tongue of a snake is forked. It collects odor particles from two different locations. Helping the snake understand in which direction the odor is coming from. And thus, making it easier to locate the prey. Topic: Archimedes' principle. Why do ships float? Good question. Give me minimum five years to unravel its mystery. Alright. Don't bother. To answer this question, we need to understand Archimedes' principle. Archimedes' principle states that, An object partly or fully immersed in a liquid experiences an upward force called buoyant force. Which is equal to the weight of the liquid displaced by it. Oh man. It is too complicated. Okay. Wait, I'll explain. A ship has a long and wide base due to which the amount. And the weight of water displaced by it increases. Now according to Archimedes' principle, the buoyant force is equal to the weight of displaced liquid. Hence, as the weight of displaced water increases. The buoyant force that is the upward force exerted by the water increases, making the ship float. Topic: Forced vibrations. Why does a guitar have a hollow box? To keep clothes while traveling. Not at all. Wait, I'll explain. Whenever we strike an object, it vibrates. Sometimes, these vibrations influence other objects to vibrate. The vibrations which take place under the influence of an external periodic force are called forced vibrations. So, whenever I see delicious food, my stomach starts to vibrate. Is this a type of forced vibration? Please concentrate. A guitar has a hollow box which holds quite a huge volume of air. Now, when we strike its string, it starts to vibrate. These vibrations influence the air in the hollow box, producing forced vibrations in them. Now we know that vibrations in air produce sound. Hence, as a huge volume of air is vibrating, the sound produced is louder. Are Einstein's gravitational waves real? No. They are waves created by Titanic. As always, you are wrong. Gravity is the attractive force with which two objects pull each other. However, Albert Einstein imagined gravity as well as space and time a little differently. His theory of general relativity unified two separate entities space. And time into a single entity called spacetime. Spacetime can be considered as the fabric of universe. Now, just like a heavy ball creates a curve or distorts the trampoline. Mass of an object creates a curve in spacetime. According to Einstein, this curve is gravity. This trampoline is amazing. First listen. Just like our hands create ripples in water, moving objects create ripples in spacetime. These ripples are termed as gravitational waves. Gravitational waves were directly observed for the first time on September 14, 2015. By Laser Interferometer Gravitational Observatory in the US.