Most of us think we understand why Earth’s oceans have tides, but it turns out that there are some misconceptions in the common explanation. Yes, it’s true that the moon’s gravity pulls on water in the ocean, but it equally pulls on everything else, too, and we don’t levitate at high tide! In reality, it’s the distribution of tidal forces across the enormity of the ocean that causes the ocean to bulge along the Earth-moon line and create high and low tides. Lakes, puddles, and humans experience tides, too, but we’re so small that the tidal forces we experience are too tiny to be noticeable. For the full explanation, I encourage you to watch PBS Space Time’s video. Don’t let the 15 minute run-time deter you; the tidal explanation is contained within the first 9 minutes. (Video credit: PBS Space Time; via It’s Okay To Be Smart)
Celebrating the physics of all that flows