Placeholder Image

字幕列表 影片播放

  • About once every century,

    大約一個世紀會有一次,

  • a massive star somewhere in our galaxy

    我們的銀河某處, 有一個大質量的星體

  • runs out of fuel.

    把燃料用光了。

  • This happens after millions of years of heat and pressure

    會有這種情況,是因為 數百萬年來,高熱和壓力

  • have fused the star's hydrogen

    將該星體的氫氣融入到 更重的元素當中,

  • into heavier elements like helium, carbon, and nitrogenall the way to iron.

    如氦、碳、氮,一直到鐵,

  • No longer able to produce sufficient energy to maintain its structure,

    無法再產生出足夠的能量 來維持星體的結構,

  • it collapses under its own gravitational pressure and explodes in a supernova.

    它的引力壓力會讓它自己垮掉, 發生爆炸,成為超級新星。

  • The star shoots most of its innards into space,

    這個星體會把它的 內容物都射入太空,

  • seeding the galaxy with heavy elements.

    在銀河中播下重元素的種子。

  • But what this cataclysmic eruption leaves behind might be even more remarkable:

    但這種劇烈爆發 留下的東西或許更驚人:

  • a ball of matter so dense that atomic electrons

    一個球形物質,密度非常高, 以致於原子的電子

  • collapse from their quantum orbits into the depths of atomic nuclei.

    會從它們的量子軌道 落到原子核的深處。

  • The death of that star is the birth of a neutron star:

    那個星體的死亡, 成了一個中子星的誕生:

  • one of the densest known objects in the universe,

    中子星是全宇宙 最高密度的已知物體之一,

  • and a laboratory for the strange physics of supercondensed matter.

    它也是超級壓縮物質的 奇異物理實驗室。

  • But what is a neutron star?

    但,中子星是什麼?

  • Think of a compact ball inside of which protons and electrons fuse into neutrons

    想像一個緊實的球體,

  • and form a frictionless liquid called a superfluid

    它裡面的質子和電子融入中子,

  • surrounded by a crust.

    形成一種沒有摩擦力的液體, 叫做超流體,

  • This material is incredibly dense

    被外殼包起來。

  • the equivalent of the mass of a fully-loaded container ship

    這種材料非常緊密,

  • squeezed into a human hair,

    等同於將滿載的貨櫃船的質量

  • or the mass of Mount Everest in a space of a sugar cube.

    擠壓到一根人類頭髮中,

  • Deeper in the crust, the neutron superfluid forms different phases

    或是將聖母峰的質量 擠壓到方糖的大小中。

  • that physicists callnuclear pasta,”

    在殼的深處, 中子超流體形成不同的相,

  • as it's squeezed from lasagna to spaghetti-like shapes.

    物理學家稱之為「核麵條」,

  • The massive precursors to neutron stars often spin.

    因為它被從扁麵平擠壓成 義大利麵條的形狀。

  • When they collapse,

    中子星的大質量前身通常會旋轉。

  • stars that are typically millions of kilometers wide

    當它們崩垮時,通常 有數百萬公里寬的星體

  • compress down to neutron stars that are only about 25 kilometers across.

    會被壓縮到只有 二十五公里寬的中子星。

  • But the original star's angular momentum is preserved.

    但原始星體的角動量還被保存著。

  • So for the same reason that a figure skater's spin accelerates

    和花式滑冰選手把手臂收進來 就能加速旋轉是相同的道理,

  • when they bring in their arms,

    中子星的旋轉速度 會比它的母體更快。

  • the neutron star spins much more rapidly than its parent.

    紀錄中最快的中子星

  • The fastest neutron star on record rotates over 700 times every second,

    每秒鐘能轉七百次,

  • which means that a point on its surface whirls through space

    這就表示,它表面上的點 在太空中的轉動速度

  • at more than a fifth of the speed of light.

    比光速的五分之一還要快。

  • Neutron stars also have the strongest magnetic field of any known object.

    中子星的磁場也是目前 所知物體中最強的。

  • This magnetic concentration forms vortexes

    這種磁力的集中,會形成旋渦,

  • that radiate beams from the magnetic poles.

    從磁極放射出光束。

  • Since the poles aren't always aligned with the rotational axis of the star,

    因為磁極未必一定對齊星體的轉軸,

  • the beams spin like lighthouse beacons,

    光束就會像燈塔指引信號一樣旋轉,

  • which appear to blink when viewed from Earth.

    從地球來看就像是閃爍。

  • We call those pulsars.

    我們稱之為脈衝星。

  • The detection of one of these tantalizing flashing signals

    1967 年,天體物理學家約瑟琳貝爾

  • by astrophysicist Jocelyn Bell in 1967

    偵測到這些誘人的閃爍訊號,

  • was in fact the way we indirectly discovered neutron stars

    事實上,這就是我們一開始

  • in the first place.

    間接發現中子星的方式。

  • An aging neutron star's furious rotation slows over a period of billions of years

    經過數十億年的時間,

  • as it radiates away its energy in the form of electromagnetic and gravity waves.

    年邁中子星的猛烈轉動會慢下來,

  • But not all neutron stars disappear so quietly.

    因為它以電磁波 和重力波的形式耗掉能量。

  • For example, we've observed binary systems

    但並不是所有的中子星 都會如此安靜地消失。

  • where a neutron star co-orbits another star.

    比如,我們曾經觀察到雙星系統,

  • A neutron star can feed on a lighter companion,

    就是一個中子星 和另一個星體共用軌道。

  • gorging on its more loosely bound atmosphere

    中子星能以這個 比較輕的伙伴為食,

  • before eventually collapsing cataclysmically into a black hole.

    吞食它比較沒有緊密結合的大氣,

  • While many stars exist as binary systems,

    直到最後劇烈崩垮成為黑洞。

  • only a small percentage of those end up as neutron-star binaries,

    許多星體以雙星系統的方式存在,

  • where two neutron stars circle each other in a waltz doomed to end as a merger.

    但當中只有一小部分 最後會變成中子星雙星,

  • When they finally collide, they send gravity waves through space-time

    也就是兩個雙子星 像跳華爾滋一樣繞著彼此,

  • like ripples from a stone thrown into a calm lake.

    最後注定會合併起來。

  • Einstein's theory of General Relativity

    當它們終於相撞時, 會透過時空發出重力波,

  • predicted this phenomenon over 100 years ago, but it wasn't directly verified

    就像把一顆石頭丟入 平靜的湖中會產生漣漪。

  • until 2017,

    愛因斯坦的廣義相對論

  • when gravitational-wave observatories LIGO and VIRGO

    在至少一百年前 就預測了這個現象,

  • observed a neutron star collision.

    但它一直到 2017 年 才被直接驗證,

  • Other telescopes picked up a burst of gamma rays and a flash of light,

    那年重力波天文台 LIGO 和 VIRGO

  • and, later, x-rays and radio signals, all from the same impact.

    觀察到中子星相撞。

  • That became the most studied event in the history of astronomy.

    其他望遠鏡發現 伽瑪射線爆發,還有閃光,

  • It yielded a treasure trove of data

    後來還有 X 光和無線電訊號, 通通來自同一次撞擊。

  • that's helped pin down the speed of gravity,

    那事件成為天文學史上 最被拿來研究的事件。

  • bolster important theories in astrophysics,

    它衍生出了珍貴的資料,

  • and provide evidence for the origin of heavy elements like gold and platinum.

    協助確定了引力的速度,

  • Neutron stars haven't given up all their secrets yet.

    支持重要的天體物理學理論,

  • LIGO and VIRGO are being upgraded to detect more collisions.

    並為金和鉑這類重元素的 來源提供了證據。

  • That'll help us learn what else

    中子星還有未知的秘密。

  • the spectacular demise of these dense, pulsating, spinning magnets

    LIGO 和 VIRGO 已經被升級, 可以偵測到更多的撞擊。

  • can tell us about the universe.

    那能夠協助我們了解,這些高密度

About once every century,

大約一個世紀會有一次,

字幕與單字

單字即點即查 點擊單字可以查詢單字解釋

B2 中高級 中文 美國腔 TED-Ed 中子星 星體 重力波 質量 光束

中子星的生命週期--大衛-倫尼 (The life cycle of a neutron star - David Lunney)

  • 507 42
    April Lu 發佈於 2021 年 01 月 14 日
影片單字