It's AumSum Time. Can you guess the title of my next video? Hurry up. Write your guess in the comments section below. How do microwave ovens work? They work with the help of Iron Man lasers. No. A microwave oven is basically a metal box containing a magnetron. It heats or cooks food much faster and more evenly as compared to a conventional oven. When switched on, the magnetron converts electricity into microwaves. Microwaves penetrate the food and excite water, fat and sugar molecules, generating heat. Thus, helping us to heat up or cook the food. Also note that, conventional ovens heat the food from outside in. Hence, the outer surface of the food is exposed to heat for a longer time, thus causing the food to cook unevenly. However, in microwave ovens, as microwaves penetrate the food, the food is cooked more evenly in less time. Thus, nutrient loss is less as it is exposed to heat for less amount of time. How do igloos keep you warm? I’m a little busy. So, I'll tell you about it later. Alright. I'll explain. Heat is a form of energy present in our body. When the temperatures around us are low, we begin to lose heat. The more we lose heat, the colder we feel. Now, although igloos are made up of blocks of compressed snow, they keep us warm. Stop bluffing. How's that possible? Compressed snow has air trapped in it and air is a bad conductor of heat. Hence, the heat given off by our body does not get lost from the igloo. It stays in the igloo, thus keeping us warm. Besides this, we know that warm air rises up and cold air sinks to the bottom. Hence, during night, eskimos, i.e., people living in igloos sleep at the uppermost part of the igloo to stay warm. How do painkillers work? They act like a sponge and absorb the pain. No. When something is causing us damage, such as tip of a needle or pencil, special cells called nociceptors send signals to the brain. The brain then perceives it as pain. However, when cells of our body are severely damaged or injured, they release chemicals like arachidonic acid. Now, just like a key fits in a lock, the arachidonic acid fits perfectly in enzymes called COX-1 and COX-2. Forming prostaglandin and other compounds. These compounds increase the sensitivity of nociceptors due to which it pains or hurts more. Now, the most common painkillers are aspirin and ibuprofen. These painkillers work by attaching themselves to COX-1 and COX-2. Thus blocking them and not allowing arachidonic acid to bind to them. As a result, prostaglandin is not produced and the sensitivity of nociceptors decreases. Hence, the pain begins to subside. Why are planets round? Because I commanded them. You wish. Planets are round because of the force of gravity. Gravity acts as if it originates from the center of a planet and pulls each point of the planet towards it. Hence, the only way for everything on the surface to be equally close to its center is to form a round shape. However, planets are not exactly round. They are roughly spherical. This is because planets spin on their axes. Just like a spinning top, right? Absolutely. When planets spin, things near the equator tend to move away from the center due to centrifugal force. Resulting in formation of an equatorial
bulge. Because of this bulge, the equator of a planet becomes farther from its center than its poles. Creating a roughly spherical planet. Topic: Osmosis. Why is grass killed if salt is sprinkled on
it? Hey. What are you doing? Don't eat the grass. Fine. As always, ignore me. See, I warned you earlier. Hey, Wait. You are making it worse. Don't do that. Look. You spoiled it totally. Alright. Don't cry. I will tell you why this happened. This happened because of a concept called osmosis. Osmosis is the diffusion or movement of water molecules from a region of higher concentration of water. Through a semi-permeable membrane to a region of lower concentration of water. Do you think osmosis took place when we sprinkled salt on the grass? You are right. Normally, osmosis does not take place on a day to day basis. Because the grass tries to keep the concentration of water same inside. Outside its cells through the process of transpiration. However, when we sprinkled salt on the grass, the concentration of salt outside the grass increased. The concentration of water decreased. As a result, the water present inside the
plant started flowing outside due to osmosis. Since most of the water flowed out, the grass drooped down and eventually, it died.
