黑洞照片怎么拍的？

Astronomers have captured the first image of a black hole, heralding a revolution in our understanding of the universe’s most enigmatic objects.

The picture shows a halo of dust and gas, tracing the outline of a colossal black hole, at the heart of the Messier 87 galaxy, 55m light years from Earth.

What are black holes?

Black holes were first predicted by Einstein’s theory of general relativity, which reimagined gravity as the warping of space and time by matter and energy.

The equations predicted that, beyond a certain threshold, when too much matter or energy is concentrated in one place, space and time collapse, leaving behind a sinkhole through which light and matter can enter but not escape.

At first these were thought to be mathematical oddities, rather than real astronomical objects, but in the past century overwhelming evidence has confirmed that black holes are out there.

The edge of the black hole is defined by its so-called event horizon. This is the point at which escaping would require something to travel at faster than the speed of light – which as far as we know nothing does – so it is the point of no return.

Black holes are surrounded by an accretion disk of dust and gas, orbiting at close to the speed of light. A lot of this material is destined for oblivion, although some of it is ejected as powerful jets of radiation.

什么是黑洞?

聽(tīng)霍金講述黑洞~

首張黑洞照片揭曉，人類(lèi)第一次看到黑洞的視界面!它由有效口徑相當(dāng)于地球直徑的望遠(yuǎn)鏡陣列觀測(cè)到，經(jīng)過(guò)2年“沖洗”完成。

北京時(shí)間4月10日21點(diǎn)整，天文學(xué)家召開(kāi)全球新聞發(fā)布會(huì)，宣布首次直接拍攝到黑洞的照片。這張照片來(lái)之不易，為了得到這張照片，天文學(xué)家動(dòng)用了遍布全球的8個(gè)毫米/亞毫米波射電望遠(yuǎn)鏡，組成了一個(gè)所謂的“事件視界望遠(yuǎn)鏡”(Event Horizon Telescope，縮寫(xiě)EHT)。

這顆黑洞位于代號(hào)為M87的星系當(dāng)中，距離地球5300萬(wàn)光年之遙，質(zhì)量相當(dāng)于60億顆太陽(yáng)。

大家在平時(shí)閱讀科學(xué)新聞、科普書(shū)籍以及觀看科幻電影的時(shí)候，也經(jīng)常能看到黑洞的樣子，但其實(shí)都是根據(jù)科學(xué)理論推測(cè)出來(lái)的，并非直接觀測(cè)。2014年，由諾蘭執(zhí)導(dǎo)的科幻電影《星際穿越》大熱，在這部影片中，光環(huán)籠罩下的超大質(zhì)量黑洞——“卡岡圖亞“(Gargantua)令人心生敬畏，這里的黑洞形象是使用計(jì)算機(jī)模擬出來(lái)的。在著名理論物理學(xué)家吉普·索恩的指導(dǎo)下，這里的模擬已經(jīng)非常接近真實(shí)了，但畢竟還是模擬，這次是玩真的了。

為什么能給不發(fā)光的黑洞拍照?

這些年，黑洞這個(gè)名詞頻頻出現(xiàn)在媒體報(bào)道中，想必很多人都已經(jīng)對(duì)它有些了解。恒星級(jí)質(zhì)量的黑洞是由大質(zhì)量恒星演化到末期核心發(fā)生引力坍縮而成。中等質(zhì)量黑洞和大質(zhì)量黑洞的形成的具體方式目前還沒(méi)有定論：可能是由小黑洞合并形成，也可能是由黑洞通過(guò)吞噬物質(zhì)逐漸形成，還可能是由大量氣體物質(zhì)直接坍縮形成。

黑洞給人印象最深刻的印象就是吞噬一切，甚至光線。如果是孤零零的黑洞，我們真的是沒(méi)辦法采用電磁波手段進(jìn)行拍攝了。