Computational Planet, Star and Galaxy Formation

星系变化如此缓慢，以至于它们在天空中以数十亿颗恒星照亮的美丽星云的形式固定在天空中。计算机模拟实现了天文学家亲眼看到它们进化的梦想。当加速到数百万年的瞬间时，星系是动态的地方，在那里恒星不断地诞生和爆炸死亡。******我们现在可以人工制造出由闪闪发光的气体、尘埃和恒星组成的精致螺旋形星系，与附近天空中的星系难以区分。挑战在于把事情做到极致：对星系进行建模，因为它们在一起碰撞，产生巨大的新恒星爆发，并将物质驱动到超大质量的黑洞中，这些黑洞的质量相当于潜伏在天空中几乎每个星系中间的数百万颗恒星。这些合并在早期宇宙中是很常见的，当时星系是更加狂暴的地方，更像是被风暴蹂躏的云，而不是螺旋盘，并且饱和的气体、尘埃和辐射水平远远高于我们今天的银河系。了解这段暴力的过去将有助于我们理解今天我们周围的宇宙，其中的恒星和元素大多是在数十亿年前形成的。******这也是我们的未来：10亿年后，我们的银河系将疯狂地围绕着仙女座星系，最终将摧毁它们美丽的星系盘，而我们遥远的后代将在一个老化的太阳系中毫发无损。令人惊讶的是，在这个过程中几乎不可能有任何恒星发生物理碰撞。然而，它会产生大量的新恒星形成，消耗两个星系的气体，在遥远的未来把我们留在一个单一的、巨大的椭圆星系中。******我们的研究将辐射、气体和尘埃联系在一起；行星、恒星和星系。所有这些都是相互依存的，相互影响。超级计算机是一种工具，可以让我们研究这些太慢、太难的过程，用其他任何方式都无法研究。挑战在于利用令人惊叹的新仪器来产生天文学家在天空中看到的多样性，这些仪器可以看到从附近恒星和行星形成的气体（智利的阿塔卡马大型毫米阵列）到早期星系的尘埃和光线（即将到来的30米望远镜和詹姆斯韦伯太空望远镜）。

Galaxies change so slowly that they appear fixed on the sky in the form of frozen beautiful nebulae lit by billions of stars. Computer simulations enable the astronomer's dream of seeing them evolve before their very eyes. When sped up so that millions of years pass in moments galaxies are dynamic places, swirling vortices where stars are constantly being born and explosively dying.******We can now artificially generate galaxies with delicate spiral patterns of sparkling gas, dust and stars indistinguishable from those nearby in the sky. The challenge is to take things to the extreme: to model galaxies as they smash together and create giant bursts of new stars and drive material into super-massive black holes with the mass of millions of stars lurking in the middle of nearly every galaxy in the sky. These mergers are commonplace in the early universe when galaxies were far more violent places, more like storm-wracked clouds than spiral disks and saturated with levels of gas, dust and radiation far above what our Milky Way Galaxy experiences today. Understanding this violent past will help us understand the universe around us today, whose stars and very elements were mostly made billions of years earlier.******This is also our future: in a billion years our Milky Way will wrap itself around the Andromeda galaxy in a frenzy that will ultimately destroy their beautiful disks as our distant descendants watch unscathed from an aging solar sytem. Amazingly, it is quite unlikely any stars will physically collide in this process. It will however, spawn rafts of new star formation, consuming the gas of both galaxies and leaving us inside a single, great elliptical galaxy in the distant future.******Our research links together radiation, gas and dust; planets, stars and galaxies. All of them are interdependent and affect the others. Supercomputers are the tool that lets us study these processes that are too slow and too difficult to study any other way. The challenge is to produce the diversity that astronomers see on the sky using amazing new instruments tuned to see everything from nearby star and planet forming gas (The Atacama Large Millimetre Array in Chile) to dust and light from early galaxies (the upcoming Thirty Meter Telescope and the James Webb Space Telescope).