When it comes to the Universe, there are some things we can be confident are out there based on what we observe. We know that the Universe was hotter, denser, and more uniform in the distant past. We know that the stars and galaxies in the Universe have grown up and evolved as the Universe has aged. We know that gravitation has formed the large-scale structure in the Universe, and that structure has grown more complex over time. And we also know how much normal matter, altogether, is present in... Read this story
