Just how do you get a measure of the universe? A guide to its size is a good starting point. And for that you really need an idea of scale.

If life is going to exist in a Universe of this size, then the one thing it cannot afford to have is a sense of proportion.”

Is that a bright thing far away or a dim thing close up?

If only there was a recognised way to gauge just how far away is that thing. Something like a system based on knowing just how bright it should be, and how bright it actually appears to be from where you’re standing.

Bring out the yardstick, get the measure.