Name: 中子星的生命週期--大衛-倫尼 (The life cycle of a neutron star - David Lunney)
Uploaded: 2021-01-14T07:59:02.000Z
Duration: 5 min 17 s

我們的銀河某處， 有一個大質量的星體

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

將該星體的氫氣融入到 更重的元素當中，

into heavier elements like helium, carbon, and nitrogen— all the way to iron.

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，

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。

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

and form a frictionless liquid  called a superfluid—

它裡面的質子和電子融入中子，

形成一種沒有摩擦力的液體， 叫做超流體，

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

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

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 call “nuclear 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.

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。

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，

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.

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

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.

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.

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，

光束就會像燈塔指引信號一樣旋轉，

which appear to blink  when viewed from Earth.

The detection of one of these  tantalizing flashing signals

1967 年，天體物理學家約瑟琳貝爾

was in fact the way we indirectly discovered neutron stars

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

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,

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.

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。

when gravitational-wave observatories  LIGO and VIRGO

在至少一百年前 就預測了這個現象，

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,

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

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，

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,

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

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

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。

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。

那能夠協助我們了解，這些高密度