I don't know, a lot of major discoveries happened independently in a very short time span. The discovery of dark energy was made by two independent groups. Ei

I don't know, a lot of major discoveries happened independently in a very short time span. The discovery of dark energy was made by two independent groups. Einstein was racing against Hilbert to formulate general relativity. The quark model was developed independently by Gell-Mann and Ne'eman. Haumea was discovered independently by Mike Brown's group and Luis Ortiz Moreno's group. The Higgs mechanism was developed by three independent groups in 1964. At a more prosaic level, during my own Ph.D. another group published a paper very similar to one I had been working on. (By a strange coincidence the lead author on that paper had a very similar name to my own.) There is something to the idea that it's a good thing if you have to worry about other groups scooping your work. It means that you're probably on the right track --- it means your work is relevant and that you have a reasonable path to solving an important problem.