by Matthew Cobb
When you were a kid you probably wrote your address out, adding after your country ‘Earth, The Solar System, The Milky Way, Space, Near More Space’ or some such. Well with that final bit you were WRONG. A paper just out in Nature shows that the Milky Way is part of what is called a supercluster of galaxies, which has been given a name: Laniakea, which in Hawaiian means ‘immeasurable heaven’.
I won’t pretend I understand the whole of the article (“It has been shown that with a random Gaussian field, the optimal Bayesian estimator of the field given the data is the Wiener filter minimal variance estimator” – I understand the words, and I know who Gauss, Bayes and Wiener were, but still…), but thankfully Nature has made a fantastic 4-minute video that explains how they did the analysis, and how they defined the existence of these superclusters of galaxies. Watch the video, and be awed:
One of the ways that they did the study was to track the movement of galaxies towards what is known ominously as The Great Attractor – a zone of the sky about 250 million light years away, which seems to be pulling us (and everything else) towards it at around 700 km/second, which is pretty damn slow in space terms, so we aren’t going to be crushed any time soon.
According to Wikipedia ‘The Great Attractor is a gravity anomaly in intergalactic space’ which sounds like something out of Star Trek, but is true. (The Wiki elves have acted quickly and have already added Laniakea…) xkcd had this touching cartoon about what might be at the heart of the Great Attractor a few years back:
Looking the immense scale of the universe portrayed in the video, and the fact that not only is our solar system on the non-descript edge of our galaxy, but our galaxy is in a dull suburb of Laniakea, it is hard to feel that there’s anything special about where we are. And even less that any supernatural being should have been particularly interested in us. I am even tempted to feel that there really must be life elsewhere out there, even if I know that, for the moment, we only have evidence that life appeared once, in our boring fractal surbubia, nearly 4 billion years ago.
Nature News article explaining the discovery in more detail.