🧠 on Instagram: "The Three Gorges Dam in China is the world’s largest hydroelectric dam, holding back over 39 billion cubic meters of water. When the reservoir filled, the huge amount of water concentrated in one area slightly altered Earth’s mass distribution. According to physics, this change caused the planet to rotate a bit slower, adding roughly 0.06 microseconds to the length of a day. While this tiny difference is impossible to notice without highly precise instruments, it demonstrates h