This Is Why Understanding Space Is So Hard

If all the matter in the universe suddenly disappeared, would space still exist? Isaac Newton thought so. Space, he imagined, was something like Star Trek’s holodeck, a 3-dimensional virtual-reality grid onto which simulated people and places and things are projected. As Newton put it in the early pages of his Principia: “Absolute space, of its own nature, without reference to anything external, always remains homogeneous and immovable.” ¹

This seems persuasive in everyday life. I’m walking east, you’re walking west, and the post office stays put: The frame of reference remains the set of ever-changing distances between you and those various objects (and their distances from one another), not an “absolute reality.”