超级计算机在3周内创造了800万个模拟宇宙

超级计算机在3周内创造了800万个模拟宇宙

Figuring out how our reality took shape over billions of years is no easy task for scientists. Theories about how the Big Bang played out and the immediate aftermath are a dime a dozen, but researchers led by a team from the University of Arizona think they might stumble upon some of the secrets of galaxy formation by asking a supercomputer to simulate millions of virtual universes and seeing which ones come closest to what we see today.

对于科学家来说，虽然弄清楚几十亿年来我们的现实是如何形成的并不容易，但关于宇宙大爆炸是如何发生的，以及随之而来的后果的理论还是十拿九稳的，但是由亚利桑那大学的一个研究小组领导的研究人员认为，他们可能会通过让一台超级计算机，模拟数百万个虚拟宇宙并看到星系形成的一些秘密。哪一个最接近我们今天看到的。

In a new research paper published in Monthly Notices of the Royal Astronomical Society, the team explains how they used a supercomputer system nicknamed the “Universe Machine” to watch billions of (virtual) years of galaxy formation play out before their eyes.

在《英国皇家天文学会月刊》上发表的一篇新研究论文中，研究小组解释了他们如何使用一个绰号为“宇宙机器”的超级计算机系统，来观察数十亿年(虚拟的)星系形成过程。

NASA, ESA, and J. Lotz and the HFF Team/STScI

“On the computer, we can create many different universes and compare them to the actual one and that lets us infer which rules lead to the one we see,” Peter Behroozi, lead author of the study, said in a statement.

这项研究的主要作者彼得·贝鲁齐在一份声明中说：“在计算机上，我们可以创建许多不同的宇宙，并将它们与实际的宇宙进行比较，这样我们就可以推断出是哪些规则导致了我们看到的宇宙。”

This approach allowed the scientists to test long-held theories about how galaxies formed in the wake of the Big Bang and it’s already offered some eye-opening insights. Hot gas building in a galaxy due to activity from black holes, stellar explosions and the gravitational pull of dark matter should be a death sentence for a galaxy, preventing new stars from forming. The researchers say that in simulations that match real-world observations, that’s not the case.

这种方法使科学家们能够测试长期以来关于星系是如何在大爆炸后形成的理论，并且它已经提供了一些令人大开眼界的见解。由于黑洞的活动、恒星爆炸和暗物质的引力作用，在星系中形成热气体应该是一个星系的终结，防止新恒星的形成。研究人员说，在与实际观测相匹配的模拟中，情况并非如此。

“As we go back earlier and earlier in the universe, we would expect the dark matter to be denser and therefore the gas to be getting hotter and hotter,” Behroozi explained. “This is bad for star formation, so we had thought that many galaxies in the early universe should have stopped forming stars a long time ago. But we found the opposite: galaxies of a given size were more likely to form stars at a higher rate, contrary to the expectation.”

贝鲁兹解释说:“当我们回到宇宙中越来越早的时候，我们预计暗物质的密度会越来越大，因此气体会变得越来越热。”“这不利于恒星的形成，所以我们认为，早期宇宙中的许多星系应该在很久以前就停止了恒星的形成。但我们发现了相反的情况:特定大小的星系更有可能以更高的速度形成恒星，这与预期相反。”

All of this work required some intense computing power and the researchers enlisted the help of NASA as well as resources from German scientists, combined with their own supercomputer at the university, to make it happen. A total of 2,000 processors ran simultaneously for three weeks to generate over 8 million virtual universes.

所有这些工作都需要强大的计算能力，研究人员得到了NASA的帮助，以及德国科学家的资源，再加上他们自己在大学里的超级计算机，才得以实现这一目标。总共有2000个处理器同时运行了三周，生成了超过800万个虚拟宇宙。