字幕列表 影片播放 列印英文字幕 when you look up at the stars in the night sky to the stars stare back at you. I don't know about that, but I can tell you what makes them twinkle, what a bucket of water can do to them, why they have five points and what you have in common with a star. How many stars can you see in the night sky? Every love song and poems ever written will tell you millions. Romantic as it is, it's just not true on Lee. If you have great eyesight and there are no clouds or any sources of light, including the mo nearby, you'll be able to spot around 2000 stars at a time. Dark of the sky, the more stars you'll notice during the full moon or in a big city with tons of light, you'll only get to see a dozen or so of the brightest stars. Do stars really twinkle? Nope. It only seems so, especially when they're near the horizon, because the Earth's atmosphere is to blame. It has layers of different Dan sitting, so when the light from a star is traveling through these layers, it gets deflected and changes its color and intensity. So what you see is a star that looks as if it's twinkling when it's not. If you pour a giant bucket of water on a star, will you extinguish it? Well, Even if you found a way to get a bucket of water that big into space, you wouldn't put out a star quite the opposite. You'd make it shine brighter. What makes a star burns is a high temperature and pressure in its core. If you added all that extra hydrogen and oxygen water consists of, you know on Lee make the star more massive and its core pressure higher. Are all stars the same color? Well, it seems so when you look at them from Earth, but in fact they come in different colors. Any heated object changes color as it gets hotter, so a stars Hugh depends on how hot it is. The hottest ones air, blue, white, yellow and orange are a bit less scorching, and the coolest ones are red and brown ish. Okay, let's take a little break. I challenge you to draw star. If you don't have a piece of paper and a pencil, use your imagination. So what's the result of five armed thinking. That's how stars appear to us, but they're actually spherical like planets. So the question is, why do they seem to have five points? Distant stars look pointing not only to humans but even to super advanced telescopes. It has to do with the nature of line. It's a unique thing that can travel both in straight paths, like a particle and like a wave. When light comes across something on the way, its waves bounce and bend around that object, creating patterns. That's why when you squint your eyes, any source of light seems to have appointed corners. Why five of them? Well, your eyes have so called suitor lines on them. Thes lines are at the juncture of islands fibers. When the lights going through the lens, it meets thes suitor lines and appears to you like a sphere with five arms, by the way, because your eyes are unique to you, stars look slightly different, depending on the person waiting. Stars seem to be the same size. Look at the night sky through a telescope, and you'll see that stars don't have the same color and brightness. But the real size is hard to tell because you can only judge a faraway objects by how much space it appears to take up in the sky. Some stars may indeed be equally large, and the same distance from Earth or the biggest one can be further away from us than the smaller one. We would know because they look identical from our reference point. Okay, so how can you calculate the distance to a star? A short answer. The Parallax method. No, it's not too laxatives toe. Understand how it works. Stretch your arm out in front of you now. Closure right eye. And put your thumb over something in the distance. Okay. Open your right eye and close the left one. Now notice how your thumb moved a bit. If you know the distance between your eyes and can measure the distance your thumb moved. You can calculate how far away the object is. Astronomers do something similar with stars when they look at them from different positions and measure the distance. How do stars get their names? Altair, Aldebaran, Sirius, The Dog Star. The brightest stars were named thousands of years ago when they were first discovered. The biggest stars and constellations also get Greek letter names in alphabetical order. Alfa Beta, Gamma and so on. These days, thanks to telescopes, people discover more and more stars. Now most of them go toe a systematic catalog and have names consisting of numbers that represent the star's position in the sky. Plus, some stars can't have names consisting of Onley letters. Can you name a star after your loved one? You can buy a certificate from an agency, but it won't be officially recognized by astronomers. That's why one in the same star can be named after you and a whole bunch of other people. If you really want to go through with this plan, try naming a star on the dome of a planetarium for a donation. By the way, if you discover a comet asteroid or a Keiper belt object, you can officially give it any name you want, like wack a doodle or something. What's the most common type of star Rid Doors are the most typical stars in the Milky Way. They're not quite cool. Remember the color and temperature thing and not bright enough for you to see with your own eyes. They burn slowly and can sit at their star fuel for trillions of years. The older they get, the dimmer they become. There are also two times smaller than the sun, which is a yellow dwarf. How do scientists know the age of stars? They asked them What stars tend to lie about their age is seriously, since they can't tell the age of a single star, astronomers look at groups of them, their brightness and movement through space. Then they compare this data with a diagram that tells them how a star should look in this or that stage of life. In astronomy. A star born two million years ago is still a teenager. The average age of a Milky Way star is around 13.5 1,000,000,000 years. Yes, almost as old as the universe itself. I wasn't around them. Smaller stars live longer. Giants are bright, but not long live police. In star terms, they simply burn their star fuel faster. How do people use the stars to navigate? Polaris, also known as the North Star, will always show you where the north ISS and Orion, which looks like a bent hourglass, will guide you to the South for more advanced navigation. You'll need to have a journal and keep track of time. Then the height of a star passing across a certain meridian will show you your latitude. Of course, a compass or GPS device might make things easier. Hand more precise, but you can still try to figure out where you are the same way they did centuries ago. Our stars always alone. Around half of all the stars in our galaxy are binary. They come in pairs that share one center of gravity. There can also be systems of three or four stars or even Maur. So short answer. They usually have a friend or two. Are humans made of stardust? Sure are. When the universe was forming, there was just hydrogen, a little helium and tiny amounts of everything else. Stars were working like power stations converting hydrogen into helium. And when those stars went supernova, that event turned helium into carbon, nitrogen, oxygen, iron and sulphur. Everything you and I are made off. So you can honestly say there are elements in you that are as old as the universe. Boy blows my mind every time. 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