視頻版權：Seeker；
字幕翻譯：天文志願字幕組（有錯誤的地方望各位指出）
翻譯：@棠棣
解說詞
（字幕翻譯：天文志願字幕組，若有錯誤，歡迎指出）\N【視頻版權：Seeker】
我了解的宇宙有兩點最主要的特點：它很大，\NIf there’s two things I know about the universe it’s that it’s big and there’s a lot
並且包含許多物質。\Nof it.
實際上，由於宇宙裡包含的物質實在太多，\N直到最近我們才知曉總物質量的一半是多少。\NSo much in fact, that we didn’t know where half of it was until recently.
在你們重拾希望前，我現在先不聊暗物質和暗能量，\NNow before you get your hopes up, I’m not talking about dark matter or dark energy,
雖然它們加一起佔宇宙95％的物質總量\Nwhich combined make up over 95% of the universe.
我知道大家都和我一樣，\N焦急地想要弄清楚暗物質和暗能量究竟是什麼，\NI know you’re all as antsy as I am to find out what dark matter and dark energy really
但是這個謎團至今仍未解開。\Nare, but that mystery remains unsolved.
現在我想聊聊像我們和我們所知道的所有物質，這些普通的重子物質。\NNow I’m talking about plain old baryonic matter like you and me and everything we know.
這類物質在宇宙中所佔比重不到5%。\NThe stuff that makes up less than 5% of the universe.
實際上我們甚至連這部分物質的量的半數是多少都還不清楚。\NTurns out we couldn’t even track half of THAT stuff down.
並不是說我們沒有完全了解它在哪兒。\NThat’s not to say we didn’t have a pretty good idea of where it was.
你能想到的物質就是那些我們可以來計數在5%內的東西，\N物質的半數點或許在裡面，被裹藏在\NSee the matter we could account for was where you』d expect it to be, bundled up in two
平均每個擁有數億顆星星的兩萬億個星系的\Ntrillion galaxies each with an average of hundreds of billions of stars across the observable
整個可觀察的宇宙中。\Nuniverse.
在這些星系之間我們認為是暗物質組成的框架，將星系等構建成\NIn between those galaxies we think are filaments of dark matter, linking them together in a
我們所無法想像的一個宇宙大網。\Nmind-breakingly huge cosmic web.
我們懷疑暗物質的引力同樣吸引普通的物質。\NWe suspected the gravity of that dark matter also attracted regular matter too,
受早期恆星演化時分散原子中電離出來的電子的紫外輻射影響\Nwhich had been turned into plasma after ultraviolet radiation from early stars separated atoms
而形成的等離子體\Nfrom their electrons.
這種等離子體也就是WHIM，或者說是暖星際介質。\NThis plasma is what’s known as the WHIM, or Warm-Hot Intergalactic Medium.
在很長的一段時間我們無法觀測到暖星際介質，它太難被探測到了。\NFor a long time the problem was we couldn’t see the WHIM, it was just too hard to detect.
直到兩個獨立的團隊利用蘇尼亞耶夫-澤爾多維奇效應成功搜尋到它。\NUntil two separate teams found it using the Sunyaev-Zel'dovich effect.
當光子穿過等離子體，它們的能量水平會發生輕微的變化，\N升到一個較高一點的能級。\NWhen photons pass through a plasma, they get shifted to a slightly higher energy level.
這種變化並不明顯，因此這兩個團隊從成千上萬組\NThe effect is very tiny though, so the teams took data from hundreds of thousands to a
他們認為之間可能存在暖星際介質連接的星系中收集數據，\N並把這些數據進行堆棧，\Nmillion pairs of galaxies they figured would be connected by the WHIM and stacked them
直到變化明顯到可以被察覺。\Nup until the effect was noticeable.
利用這種方法，他們找到了宇宙中重子物質的半數點，\N還有越來越多能揭示\NJust like that, they found half the baryonic matter in the universe, and more evidence
暗物質網存在的證據。\Nof a dark matter web.
所以我們完成了目標的5%，還有95%等著去完成。\NSo 5% down, 95% to go.
朋友們，我們離目標更近了！\NWe’re getting closer, guys!
如果你喜歡這個視頻那就訂閱吧，\N這樣你就不會錯過更多有趣的科學事件。\NIf you liked this video subscribe so you don’t miss more cool science matters.
我們一直在想新的方法去尋找暗物質，比如說藉助黑洞或者\NWe keep coming up with new ways to look for dark matter, like with black holes and gravitational
引力波！\Nwaves!
點擊確認一下這個地方。\NCheck out the deets here.
順便說一下，我們說到的重子物質，嚴格意義上是沒有算電子的。\N因為電子屬於輕子，\NBy the way when we say baryonic matter, technically electrons don’t count because they’re
然而天文學家將電子和光子、中子算在一起，來使事情簡單化。\Nleptons, but astronomers lump them in with protons and neutrons to make things simpler.
感謝大家觀看搜索者！\N翻譯：@棠棣\NThanks for watching Seeker!\N（觀看更多中文天文視頻歡迎關注weibo天文在線）\N【也歡迎您加入我們字幕組，私信koukou零度星系（南充）】
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