Baryon acoustic oscillations

"If you wish to make an apple pie from scratch, you must first invent the Universe." -Carl Sagan The Universe is a lot like an extremely intricate cake. We view it today as a snapshot in time, now that it's complete. Image credit: Blogger user Hilly of http://makesbakesfakes.blogspot.com/. We can view the whole thing from one point of view, determined by where we happened to be located. But we can also look intricately inside certain sections of it, so long as we have the right tools. Image credit: Blogger user Hilly of http://makesbakesfakes.blogspot.com/. But if we truly want to…
"Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people." -Carl Sagan Our night sky, quite literally, is our window to the Universe. Image credit: Miloslav Druckmuller, Brno University of Technology. Well, it's kind of a window to the Universe. I say only "kind of" because, with the exception of those two faint, fuzzy clouds in the lower right, everything else visible in the image above is part of our own Milky Way galaxy. In fact, practically…