Sign up for the Starts With a Bang newsletter Travel the universe with Dr. Ethan Siegel as he answers the biggest questions of all. If there’s one thing most of us can be certain of it’s this: that our observed, physical reality actually exists. Although there are always some philosophical assumptions behind this conclusion, it’s an assumption that isn’t contradicted by anything we’ve ever measured under any conditions: not with human senses, not with laboratory equipment, not with telescopes or observatories, not under the influence of nature alone nor with specific human intervention. Reality exists, and our scientific description of that reality came about precisely because those measurements, conducted anywhere or at any time, are consistent with that very description of reality itself. But there had previously been a set of assumptions that came along with our notion of reality that are no longer universally agreed upon, and chief among them is that reality itself exists in a fashion that’s independent of the observer or measurer. In fact, two of the greatest advances of 20th …