A Chinese megadam holds back so much water that it measurably slows Earth's rotation, adding imperceptible fractions of a second to every day on the planet. The post There’s a dam in China holding back so much water that NASA scientists calculated it very slightly changed how fast the entire planet spins — lengthening every day on Earth by a fraction of a microsecond, a change too small to feel and too real to deny appeared first on Space Daily .