radioactivity
US /ˌredioækˈtɪvɪti/
・UK /ˌreɪdɪəʊæk'tɪvətɪ/
B2 中高級
n. (u.)不可數名詞放射能；放射現象
The radioactivity of uranium makes it a potential source of nuclear energy
影片字幕
中國為何能成為「清潔能源」的龍頭？ (China Is Outspending the U.S. to Achieve the ‘Holy Grail’ of Clean Energy | WSJ U.S. vs. China)
- Fusion has the potential to create nearly limitless energy with no carbon emissions and very limited radioactivity.
核聚變有可能產生幾乎無限的能源，而且沒有碳排放，放射性也非常有限。
- Fusion has the potential to create nearly limitless energy with no carbon emissions and very limited radioactivity.
為了使原子碰撞和融合，需要將它們加熱到極高的溫度，形成等離子體，它基本上是帶正電和負電的粒子的混合體。
專家打臉時刻TOP 10！沒想到他們也會錯？ (Top 10 Times Experts Were Proven WRONG)
- why not change to camels for the next 30 days and see what a difference it makes in your smoking enjoyment welcome to watch mojo and today we're counting down our picks for the wrongest experts in the game the model t was the game changer of the car world and the way it was put together changed the game for the manufacturing world too number 10 communication satellites silly sci-fi then came sputnik and telstar tunis augustus mcdonough craven wasn't some cranky luddite he was a navy communications officer turned chief engineer and then commissioner for the fcc the man lived his life with a front row seat to the future of technology he even saw sputnik sparked the space age until two days ago that sound had never been heard on this earth suddenly it has become as much a part of 20th century life as the whir of your vacuum cleaner it's a report from man's farthest frontier the radio signal transmitted by the soviet sputnik yet in 1961 craven confidently dismissed the idea of communication satellites he said quote there is practically no chance that communication space satellites will be used to provide better telephone telegraph television or radio service end quote at the time it sounded reasonable rockets were still experimental and space was mostly the stuff of pulp novels just a few years later telstar bounced the first live tv signal across the atlantic owned by at&t telstar was also the first privately sponsored space launch and produced the first transatlantic television signals it turns out satellites were the future of communication after all number nine high speed rail is impossible now it's global in 1823 science writer dionysius lardner had a grave warning for the world trains going faster than 30 miles per hour would asphyxiate passengers some people thought that you know the steam engines would scare the cows and they'd all drop dead or that the sheep would kind of turn black or that if you traveled at more than 30 hours an hour your lungs would blow up king william the first of prussia reportedly scoffed no one will pay good money to get from berlin to potsdam in one hour when he can ride his horse there in one day for free for some of educated minds relatively high speed rail sounded like reckless science fiction in the end though they discovered that they weren't going to suffocate and the sheer practicality of going from a to b quickly and safely trumped anything else but trains would soon shrink continents and fuel the industrial revolution transportation would never be the same again fast forward and railroads reshaped the planet modern high-speed trains run faster than lardner ever imagined today the only choking involved with trains tends to involve bureaucratic red tape california governor gavin newsom is touted high-speed rail but in a march interview with bill maher he blamed the slow-moving process in part on imminent domain which requires the government to reach compensation agreements with private landowners to buy and repurpose their land for public use number eight television won't last said radio hosts and film producers when tv arrived some folks thought it was just a noisy lamp in the 1940s major radio industry experts dismissed it as a passing novelty in 1946 20th century fox head daryl zanuck is said to have predicted quote people will soon get tired of staring at a plywood box every night spoiler they didn't over the next few decades television spread faster than a cold television unified the world in a way that it never had before for the first time instead of just hearing of what was going on someplace else you could now see live what was going on half a world away tv didn't kill radio or the movies but it sure stole the spotlight television reshaped politics culture and entertainment in ways no one on the airwaves ever saw coming the medium they wrote off as a fad is now something we binge stream and carry in our pockets it isn't long before television takes over as the most popular form of entertainment in america number seven the smartphone a niche toy until it changed everything in 2007 microsoft ceo steve ballmer laughed off apple's new iphone there's no chance he scoffed that the iphone is going to get any significant market share the most expensive phone in the world and it doesn't appeal to business customers because it doesn't have a keyboard which makes it not a very good email machine his reasons no keyboard no business appeal and a whopping 500 price tag some experts thought it was a flashy luxury a toy for apple fans with money to burn every argument aged like milk within a few years smartphones didn't just go mainstream we think what we've done is to is to reinvent the phone and completely change what your expectations are going to be for what you can carry in your pocket alien observers could honestly say the smartphone conquered humanity from american classrooms to remote villages in sub-saharan africa these miniature computers are everywhere for many they've replaced cameras maps alarm clocks landlines even computers and tv it's a pocket sized device more powerful than the computer that put man on the moon intelligent powerful innovative from the inside out this is iphone 16 pro number six nuclear power is pure fantasy until it wasn't in the late 1920s nobel laureate robert millikin dismissed atomic energy as a childish bugaboo you might think that it was always inevitable that we would be able to harness the inside the nucleus of atoms but that was far from the case he told the chemist club in new york that expecting usable energy from the atom was a completely unscientific utopian dream fast forward to 1933 and ernest rutherford who had just split the nucleus laughed at the notion he insisted that anyone expecting power from atoms quote is talking moonshine there was good reason for their pessimism when beck were all first observed radioactivity he thought it was a similar to phosphorescence even albert einstein weighed in stating in 1934 that there is not the slightest indication that nuclear energy will ever be obtainable a decade later america dropped nuclear bombs on hiroshima and nagasaki the age of the atom forced all the naysayers to recant instead they had to shift their criticisms and focus on the potential of a nuclear armageddon first time in human history we now were capable of our own destruction as a species number five surgeons laughed at antiseptic methods then infections killed thousands in the mid 1800s joseph lister suggested something wild maybe surgeons should stop waving pus covered tools around like party favors he thought that sterilization which means getting rid of germs could save lives after reading about germ theory lister began sterilizing instruments and spraying carbolic acid in operating rooms but many of his peers weren't impressed some mocked his ideas people would say there's absolutely no way that a tiny microscopic organism could possibly kill an organism as big as we are others flat out refused to believe invisible germs could kill one critic sneered that lister's methods turned surgery into a quote rainstorm yet hospitals that adopted antiseptics saw mortality drop dramatically today we scrub sterilize glove up and mask in every operating room on earth the guy they laughed at saved more lives than most of them could ever imagine lister had a huge impact on reducing deaths in surgery that's why he's known to this day as the father of modern surgery number four who would want a computer in their home misjudging the pc boom in 1977 ken olsen ran one of the world's top tech companies there's a place for everything the pcs will pay cart part of it terminal is another part of it the workstation is another part of it medium computers and large ones other parts there's a place for all of it then he face planted there was no reason anyone would want a computer in their home he declared back in the 40s ibm's thomas watson reportedly said five computers would be enough for the whole planet spoiler he was off by a few billion there were two experts decades apart who couldn't have been more wrong if they tried you're looking at a small portable computer called the ibm 5100 it's helping a lot of different people do their work more productively by the 90s computers were ubiquitous and the internet was bringing the world together that's when newsweek columnist clifford stole dunked on it the 90s he said were the pinnacle of hardware and software it would never get any more portable or user-friendly today he laughs at his own howler of a bad prediction is there a lesson to be learned yeah probably number three lord kelvin said flight was impossible weeks before the wright brothers flew lord kelvin wasn't just a brilliant scientist and scholar he was the scientist of his time president of the british royal society during his lifetime thompson made an enormous contribution to the study and understanding of thermodynamics electrodynamics hydrodynamics and geophysics a mathematical genius the man literally helped define the absolute temperature scale so when he declared in 1895 that quote heavier than air flying machines are impossible people listened the problem of course was that he'd been proven wrong before a decade had passed the 12 second flight proved that sustained controlled powered flight was in fact possible just eight years later the wright brothers lifted off at kitty hawk sadly for lord kelvin's legacy that wasn't his only whiff in 1896 he also dismissed x-rays as a hoax right before they medicine discovered x-rays and changed the world just a short time later our engineers developed the first x-ray tubes specifically designed for medical use as it turns out even the hottest of hot shots can get scorched by technological revolutions number two the stock market has hit a permanent high right before the 1929 crash economist irving fisher was one of the most respected minds in america he was a brilliant yale professor when he spoke policymakers listened intently his name and economic theory still show up in textbooks so when he said that stock prices had reached a permanently high plateau people believed him all across the country not just new york city but in cities in small towns all across america people were in love with the stock market sadly for fisher this prediction came in the fall of 1929 mere days before the utter collapse of the u.s stock market black tuesday wiped out billions in wealth by the end of the crash some stocks had lost over 90 percent of their value fisher himself lost both his own fortune and his credibility he will go down in history as delivering one of the most spectacularly absurd predictions of all time the lessons from the crash of 1929 are that history repeats itself that human folly and greed are much stronger forces in financial affairs than reason and restraint before we unveil our top pick here are a few honorable mentions online shopping will flop time magazine predicted online shopping back in 1966 they said it wouldn't catch on long ago in cyberspace bold predictions were being made by the end of the millennium they said electronic commerce would be worth billions of pounds and we'd all be doing our shopping via computers but that was way back when the internet was young power poses are real even one of the authors of the original power posing study thinks she was probably wrong power poses are postures that we adopt when we feel really confident in power powerful so we expand we take up a lot of space just like other animals do there will never be a bigger plane than the 247 a boeing engineer said in 1933 that the 10-seater 247 would be the largest plane ever the boeing 247 its top speed of 200 miles per hour will be 50 miles per hour faster than any other commercial airliner on earth the machine gun will end all war hero maxim believed his deadly invention would make war impossible not more terrible you are now gazing upon three of the most unusual inventions of the 90s the flicker films the first machine gun and the squared derby we can't learn anything further about astronomy in 1888 astronomer simon newcomb said we'd learned all there was to know of the stars this was owned by simon newcomb an astronomer who later became one of the most prominent scientists in the united states before we continue be sure to subscribe to our channel and ring the to get notified about our latest videos you have the option to be notified for occasional videos or all of them if you're on your phone make sure you go into settings and switch on your notifications number one smoking doesn't cause cancer doctors once said smoking was safe or even healthy for decades the smartest people in the room said cigarettes were fine luckies taste better and good reasons first lucky strike means fine tobacco and then this fine good tasting tobacco is toasted to taste even better cleaner fresher smoother in the 1930s and 40s tobacco companies ran ads claiming doctors actually recommended their brands some even brag that their cigarettes were physician tested and less irritating to the throat medical journals ran cigarette ads health professionals endorsed them one campaign had doctors choosing camels quote by a wide margin more doctors smoke camels than any other cigarette meanwhile lung cancer rates were quickly exploding by the time the truth caught up it was too late for millions today it's hard to imagine anyone not knowing the risks but back then your doctor would have lit one up right there in your hospital room because they know what a pleasure it is to smoke a mild good tasting cigarette they're particular about the brand they choose who do you think was the wrongest genius in history let us know in the comments below we've got great windows mobile devices in the market today we you can get a motorola q phone now for 99 it's a very capable machine
為什麼不在接下來的 30 天裡換成駱駝，看看它能給你的吸菸樂趣帶來什麼不同呢？ 歡迎收看 Mojo，今天我們將評選出遊戲中最錯誤的專家，T 型車改變了汽車世界的遊戲規則，它的組裝方式也改變了製造世界的遊戲規則。然後是人造衛星和突尼西亞電信星 奧古斯都-麥克唐納-克雷文並不是什麼暴躁的魯德主義者 他曾是一名海軍通信軍官，後來轉任總工程師和聯邦通信委員會委員他甚至親眼目睹了人造衛星引發的太空時代 直到兩天前 那聲音還從未在地球上出現過 突然間，它就像吸塵器的嗚嗚聲一樣 成為了 20 世紀生活的一部分然而，19
- When Becquerel first observed radioactivity, he thought it was a phenomenon similar to phosphorescence.
WM 發布最終結果！ (WM발표 최종)
- By mastering all three disposal methods, Cavern, surface and trench, Karad optimizes disposal efficiency based on the specific radioactivity levels and characteristics of the waste.
透過掌握地下儲存、地面儲存和掩埋溝這三種處理方式，Karad 能根據廢棄物的特定放射性等級和特性，優化處理效率。
- trench—KORAD optimizes disposal efficiency based on the specific radioactivity levels and characteristics of the waste.
除了基礎設施，我們也精進了技術能力。
