The Strange Results We Get When We Measure the Expansion of the Universe

Daniel: How do you know that your universe is not just expanding around you but maybe it's shrinking everywhere else in which case the universe itself as a whole is not expanding. All we can do is measure the relative expansion of the universe meaning how far apart are things. So if we're here in this another galaxy a million light years away what we're interested in is how far apart is that galaxy in a year or in ten years or in a thousand years. And this is a little bit different from any sort of relative velocity our galaxy might have to a different galaxy like our galaxy could be moving away from or closer to the undramatic galaxy. It just means that we're both inside