4 ms·
That space is three dimensional is one of those propositions drilled into us as schoolchildren, and which most of us accept on faith. Yet, since it is a statem
by puzzledobserver 7y ago
That space is three dimensional is one of those propositions drilled into us as schoolchildren, and which most of us accept on faith.
Yet, since it is a statement of the real world, it can only be validated by experiment and not by a mathematical proof. Trying to contort one's fingers or sticks in various mutually perpendicular orientations isn't satisfactory since we could be limited by lack of imagination of the dexterity of our hands.
The existence of physical phenomena satisfying the inverse square laws is one of those observations which constrains the geometry of the world.
- evanb 7y agoOn long distances, anyway. The evidence for inverse square laws over short distance is much weaker, and so there is room for curled-up "extra dimensions" we sometimes hear about, both in extensions to the standard model and in stringy ideas.
- fhars 7y ago„Long distance“ here includes anything longer than a 1000th of the classical radius of the hydrogen atom, which is to a very high accuracy described by an inverse square law.
- evanb 7y agoGravity might have extra dimensions on a much larger scale than that, potentially up to the millimeter scale or so.