How much do you know about where we are in the universe? I’d hazard a guess that nearly everyone can say that we’re the 3rd planet from our sun and that we reside in a large spiral galaxy called the Milky Way. You might not know though that we’re towards the end of one of the Milky Way’s tendrils and that we’re part of a larger group of galaxies called the Local Supercluster. However the definition of what constitutes the Local Supercluster had always been a little loose, essentially just a sphere of space in which all contained galaxies were defined as part of it. Scientists in Hawaii though, led by R. Brent Tully, have come up with a new way of defining superclusters and have dubbed our new home Laniakea.
It’s reminiscent of when the International Astronomical Union refined the definition of what constitutes a planet. Sure the new definition might mean that some previously neighbouring galaxies will get excluded, and new ones included, however rigorous definitions like these are what form the basis of good science. We might feel some kind of attachment to the ideas (I was honestly surprised by how many people were outraged by Pluto losing its planet status) however science abhors hand waving and sometimes we have to accept some loss in order to make further progress.
However I find the science behind Laniakea to be incredibly beautiful. Instead of our local group of galaxies being defined by some arbitrary points we’re now a group of celestial bodies all sharing the same journey. We might not ever see each other, nor ever cross paths, but the idea that we’re sharing the same galactic journey with billions and billions of other balls of matter is, to me, incredibly poetic.
