Back of the envelope calculation: a 1 ms/day slowing would require ~10^20 kg of mass at the equator to be moved a km inward. For scale, wiki helpfully points ou

Back of the envelope calculation: a 1 ms/day slowing would require ~10^20 kg of mass at the equator to be moved a km inward. For scale, wiki helpfully points out that the world's oceans weighs 10^21 kg. https://www.wolframalpha.com/input/?i=rotational+angular+momentum+of+earth+*+1ms%2Fday+*+1%2F1km+*++1%2F%28465.10+m%2Fs%29 https://www.wolframalpha.com/input/?i=rotational+angular+mom... https://en.wikipedia.org/wiki/Orders_of_magnitude_(mass)#1018_to_1023_kg https://en.wikipedia.org/wiki/Orders_of_magnitude_(mass)#101...