点击这里查看首页

两个视频读懂黑洞


来源:网络转载
发布时间:2019-04-14 15:27:00
查看次数:

内容提要:两个视频读懂黑洞


Black holes are among the most fascinating objects in our universe, and also the most mysterious.

A black hole is a region in space where the force of gravity is so strong not even light – the fastest known entity in our universe – can escape.

The boundary of a black hole is called the event horizon, a point of no return, beyond which we truly cannot see.

Once something crosses the event horizon, it collapses into the black hole’s singularity: an infinitely small, infinitely dense point where space, time, and the laws of physics no longer apply.

Scientists have theorized several different types of black holes, withstellar and supermassive black holes being the most common.

Stellar black holes form when massive stars die and collapse. They’re roughly 10 to 20 times the mass of our Sun and scattered throughout the universe. There could be millions of these stellar black holes in the Milky Way alone.

Supermassive black holes are giants by comparison, measuring millions, even billions of times more massive than our Sun. Scientists can only guess how they form, but we do know they exist at the center of just about every large galaxy…including our own.

Sagittarius A, the supermassive black hole at the center of the Milky Way, has a mass of roughly 4 million suns and has a diameter about the distance between Earth and our Sun.

Because black holes are invisible, the only way for scientists to detect and study them is to observe their effect on nearby matter.

This includes accretion disks, a disk of particles that form when gases and dust fall toward a black hole and quasars, jets of particles that -out of supermassive black holes.

Black holes remained largely unknown until the 20th century.

In 1916, using Einstein’s General Theory of Relativity, a German physicist named Karl Schwartzschild calculated that any mass could become a black hole if it were compressed tightly enough.

But it wasn’t until 1971, when theory became reality. Astronomers, studying the constellation Cygnus, discovered the first black hole.

An untold number of black holes are scattered throughout the universe…

Constantly warping space and time, altering entire galaxies, and endlessly inspiring both scientists and our collective imagination.


相关文章
·阅读正当时,书香伴成长04-25
·英文版 《伊索寓言》15 狼和家犬02-28
·梁静茹《勇气》英文版 你听过吗?10-03
·英文版《西游记》10-12集(耳濡目染,用简单快乐的方式学习英语)11-15
·有的人活着,他已经死了01-31
·名师微课| 初高衔接(十五)现在完成时和过去完成时08-31
·英文版 《伊索寓言》17 熊的耳语03-02
·TED 演讲 | 为什么我们总是觉得自己忙得团团转?11-30
·英文电影《奇迹男孩》Wonder (2017)08-07
·《走遍美国》E06 感恩节,中英字幕11-25
最新文章
·2024年世界读书日:眼睛到不了的地方,文字可以04-23
·【视频】“歪果仁”看雄安 感受生态之美04-14
·双语字幕视频 | BBC纪录片《数学的故事》(全4集)04-12
·英文版《伊索寓言》30集汇总04-06
·用英文讲中国故事:清明节04-04
·20240403 模仿朗读 四季中国 清明04-03
·模仿朗读 春分 Spring Equinox 考试版03-20
·英文版《伊索寓言》30 狼和鹤(完)03-17
·英文版《伊索寓言》29 狮子和鹿03-16
·英文版《伊索寓言》28 狗和他的倒影03-15
阅读排行