Science Notes (26) 썸네일형 리스트형 How red eyes are caused - the science behind it(눈 충혈이 일어나는 이유) Red eyes(bloodshot eyes) happen by various reasons - from allergies to even exposure to sunlight. A list of these causes are: allergies dry air/dust too much exposure to sunlight gas substance in the air (gasoline, etc) chemical substances smoke/flue gas All of these can be harmful to your eyes and cause inflammation. In order to prevent or stop inflamation, your body causes vasodilation of bloo.. Why lightning strikes the highest places(번개가 잘 떨어지는 곳) Lightning strikes have been a mystery to mankind since the appearance of thought. In the long past, people were afraid of it, and imagined it as a weapon of Zeus. We are still unearthing the mysteries of lightning, and there are still a few unsolved ones, but that's not the point. One of the most interesting facts about lightning strikes is that they seem to hit only high places. Then how come l.. Why doesn't the atmosphere vanish into space?(대기가 날아가버리지 않는 이유) The space is very close to a vacuum. It has nearly nothing that's not a part of a celestial object, like Earth. Imagine a vacuum cleaner, which works by sucking dust from the floor. That's right! Vacuums have a characteristic in common: sucking objects. But actually, a vacuum doesn't 'suck' objects. It is just an extreme case when the density of matter in and outside a container is different. So.. Why do you shiver when you're cold?(추울 때 왜 몸을 떨까?) When you are cold, you body just starts to shiver. What is the reason that our bodies do so? When your body's temperature starts to drop, the brain orders muscles all around your body to repeat contraction and relaxation. Contraction is when a muscle tightens, and relaxation is the opposite. When muscles contract and relax, they produce heat. The brain orders the body to shiver to get this heat... Why is there more matter than antimatter?(세상에 물질이 존재하는 이유) At the moment of the Big Bang, space was filled with energy. In the middest of that, pair production and pair annihilation of matter and antimatter happened everywhere. But then, a question comes into our minds. How come only matter survived, when matter-antimatter pairs were created and destructed as pairs? According to CERN, about one out of a billion particles survived, and they were matter, .. Diving Reflex - What is it?(잠수 반사) When you suddenly go into a pool of cold water, your breath becomes rapid. Same is when you are sprayed with cold water. This kind of reaction seems useless. But then, why does this happen? This phenomenon is called a 'diving reflex'. Every species in the class Mammalia(mammals) have this reflex, occuring stronger in sea mammals than those living on the land. This diving reflex leads to some eff.. Why does the moon look bigger near the horizon?(달에 대한 착시현상) In 2017, when I was on a trip with my family, I noticed that the moon looked way much bigger than it usually was. I wondered why and decided to research more about the phenomenon when I got home. There is no proven reason to why the moon looks bigger near the horizon. However, one thing is for sure: that it has something to do with our brain's functions. The current most widely accepted theory i.. What is Piezoelectricity?(피에조 전기) Piezoelectricity is the electric charge created when mechanical force is applied to certain solid materials such as crystals, some types of ceramic, DNA, bones, etc. In this text I am going to explain how piezoelectricity in crystals work. Let's say that the crystal has a tetrahedron structure. In normal situations, it will have a neutral charge of 0, since all of it's dipole moments cross out e.. 이전 1 2 3 4 다음
