China constructs massive dam that slows rotation of earth
By Anees Venkat
China erected the three Gorges Dam, a construction that is so massive that it slows the rotation of the earth.
The three Gorges Dam is capable of building the inflowing Yangtze River up 175 meters (575 foot) above sea level.
This humongous wall of water eventually alteres the Earth’s moment of inertia causing the rotation to become slower.
The construction of the dam redistributed billions of tons of water to a higher altitude, which is the same principle in effect with figure skaters when they close their arms in a jump to spin faster. It also makes the earth slightly more round in the middle and flat on the poles.
NASA has calculated that the dam slows the rotation by 0.06 microseconds, which is six hundredths of a millionth of a second.
While that doesn’t sound much, think about what any other man-made building that can claim to have an effect on the planets rotation that is actually measurable?
As a matter of fact, other influences constantly make our planets rotation slightly change pace, event like earthquakes, the moon, or even the climate change e.g in the arctic.
However, a hundredth of a microsecond is not much and one would need to build tens of thousands of similar sized dams to make a change in time perceptible to humans.
When it comes to cosmic measures though the tinest and the largest are worth to be observed and since this is man-made it´s truly a feat for the ages.
Some more data
The 3 Gorges Dam in Hubei province was the world’s largest electricity-generating plant of any kind til 2016 when it got surpassed by the Itaipu Dam, located between Brasil and Paraguay.
The 3 Gorges Dam still produces more energy though. It was first idealised in 1919 but building start not earlier than in 1994 and eventually put in operation in 2003.