暗物质可能只是隐藏的行星吗?

天体物理学家凯蒂·麦克给了我们这个答案……

凯蒂:所以暗物质是一种我们看不见的物质。当它第一次被发现是宇宙中存在的东西时，它是通过它影响星系旋转的方式被发现的。我们生活在银河系中，它是一种圆盘状的形状，中心有很多恒星和东西，然后它就变平了。恒星围绕星系中心运行;这需要数百万年的时间。你可以通过观察很多不同的星系来判断恒星围绕它们运行的速度比你想象的要快得多。如果你观察星系，计算星系中心所有的光以及所有来自恒星，气体和尘埃的光，甚至假设中心有一个超大质量黑洞，恒星在外边缘的运动速度仍然比它们应该的要快。你可能会认为它们会被抛向太空，因为从你所看到的来看，没有足够的引力来留住它们。基于这个和大量其他的东西，我们得出结论，星系实际上主要是由一些看不见的东西组成的，一些我们看不见的东西，一些提供额外引力的物质，把所有的东西聚集在一起。在很长一段时间里，我们都没有任何想法。 It was just something that wasn't putting out light. But we've determined that it really can't be anything like planets or dust or atoms, regular stuff, because it doesn't absorb light. So if it were something like rogue planets, then it wouldn't be invisible, it would be opaque. And we don't see that. And we also don't see the dark matter sort of collapsing together into a disc the way that regular matter does. So in a similar way as how, if you had a lump of pizza dough and you spin it, everything in space, when it comes together with gravity, there's some overall spin and then it all averages out to that kind of discy shape, and dark matter doesn't seem to do that. We can see evidence that dark matter stays kind of puffy and rounded in a way that regular matter doesn't. So we have a number of reasons to suspect that it's not regular matter. It's not something like planets. It does seem to be something different, something that can bump into other dark matter and just pass right through and not collide and get stuck in the middle. And we have a few pieces of evidence for that as well, where we've seen entire clusters of galaxies collide with each other. And a lot of the regular matter gets stuck in the middle, but the bulk of the gravity, the dark matter, passes right through the collision. And we see it show up on the other side after these collisions. So we're pretty sure that there's something weirder than that, we think maybe it's some kind of new particle that we didn't know about before, that just doesn't interact in the ways that most other particles do. Specifically, doesn't do electromagnetism, which is light and magnetism and electrostatic repulsion and all of that. You know, like a neutrino, which is another kind of particle that doesn't seem to do that force. It doesn't do electromagnetism. It's probably some kind of new particle.