Everyone wants a Eureka moment in their scientific career, whether it’s jumping out of a bath or seeing the first light from a supernova. The truth, though, is that they’re very very rare, but in today’s first plenary talk we got a glimpse of the moment when one of the most important discoveries of the last decade or so took place. Brian Schmidt, from the Australian National University, was part of one of the two teams that independently discovered that the Universe was accelerating, rather than slowing down under the influence of gravity as (almost) everyone expected. He showed the audience the page from the lab notebook belonging to Adam Reiss, who was the first to realise what their observations showed; the underlined conclusion was that without acceleration, the results produced a negative mass for the Universe. Thus the assumption was wrong, and thus acceleration. So that’s it - Adam at least had his Eureka moment (and was at least excited enough to underline it!). Except that for the rest of the team, despite being involved in such a remarkable discovery, there was no Eureka. Brian reported his instantaneous reaction was that the result must be wrong…for them this great discovery was not an eureka, but a slow dawning that their result might just be correct… Dual post : Both Will and I are obviously in the same lecture. Here’s his take