昨天天文界在传播谣言，还不止一个谣言。第一个谣言说，暗能量不是爱因斯坦的宇宙学常数，而是phantom，我对这个消息取中立态度。对于一些弦论家，这毫无疑问是坏消息，landscape，人择原理，有可能随风而去 。最可惜的是Lenny Susskind的第三次超弦革命 。不过，假如Brad Schaefer真的是对的，我是欢呼得最早的，因为弦论家就得第二次接受现实的挑战，第二次忍痛修改我们对世界的成见。不过请放心，弦论家是一群非常非常聪明的人，没有什么可以难住他们。

第二个谣言让我不舒服，传说中的宇宙弦的候选人CSL-1被肯定不是宇宙弦。这是Motl的blog上的一段话：

I received two messages about this sad news almost simultaneously - from Mark Jackson and Joe Polchinski. Guiseppe Longo (and maybe his collaborators) has downloaded the pictures from the Hubble Space Telescope, and it is “just a pair of interacting ellipticals sitting in a rather faint cluster,” not a cosmic string.

比较早怀疑CSL-1是宇宙弦的文章是这篇。

Motl的blog更新了，后来他又加了一段话：

Let me add to the main text that Joe Polchinski’s estimated probability that a cosmic string could be seen was something about 10%. Joe would have therefore told you a smaller number for this particular case, I think. In this sense, it is not a surprise that the conjecture that CSL-1 was a cosmic string was falsified. While it is not a surprise, it is still a disappointment.

A confirmation that it is a cosmic string would have meant much more obvious progress. This observation has falsified one particular case but it has not falsified the idea of cosmic strings in general. And just to be sure: it has of course told us nothing about the validity of string theory as a fundamental theory.

Motl希望的图是这样的：

这年头，研究天文、宇宙学就像在水上写字，不过，有了互联网，谣言和消息传播得和光速一样快。（以上改自张爱玲研究红楼梦中的一段话）