Chile’s earthquake has shifted the rotation of the earth

From the Washington Post:

Richard Gross, a scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., and colleagues calculated that Saturday’s quake shortened the day by 1.26 microseconds. A microsecond is one-millionth of a second.

Hat tip to FP.

This reminds me of a question I’ve never heard asked: What would happen if the Chinese government asked everyone in the country to jump up and down at the same time, and they listened?

And why do I think Tyler Cowen could tell me the answer?

Finally: yes, I am aware that DSM-V probably has a name for people like me.

Update: Wow. Tyler Cowen answers in under 20 minutes. More proof of my nagging suspicion: he is actually triplets masquerading  as a single man. Why didn’t I do that?

5 thoughts on “Chile’s earthquake has shifted the rotation of the earth

  1. I’ve long favored an answer like this one:

    “If people weighed on average 1000 lbs, a billion people would weigh a trillion pounds. The earth “weighs” about six sextillion tons. That is more than a trillion times the weight of all the people on earth. So, if all the people on the earth jumped the same direction at the same time, the earth would move less than one trillionth as far in the opposite direction. For example, if everybody jumped two feet directly toward the north star, the earth would move less than a millionth of a millionth of a foot away from that star.

    The real kicker is that as soon as those people jump, they start falling back toward the earth and the earth falls back toward them and the net effect is immesurably close to zero. The earth running into hydrogen atoms, cosmic dust and the occasional meteor as it moves around the sun has a greater effect on its orbit than the mother of all coordinated jumps ever could. ”

    Tyler Cowen

  2. good response, but what if everyone in the world started running/swimming to the east, around and around the world? they wouldn’t subsequently have to run west. this would speed the rotation of the earth permanently.

  3. Babar has a good point – what the about the rural to urban migration in China – people move from further inland towards Beijing and other coastal cities – and the returns to rural areas during Chinese New Year?

    Could these be slowing and speeding the earth’s rotation, causing global climate change?

  4. Don’t swim east. Swim west! Slow the day down a little. It would help us get rid of leap year day, give you just a little extra time every day to sleep or whatever else, and by lowering the rotational pull of earth it will convince your scale you’ve lost one hundredth of an ounce.

  5. The net effect of a migration would be zero, for the same reason that the net effect of jumping is zero. When everyone starts running West (for example) this would momentarily slow down the earth’s rotation as we all push off our Western (back) foot. When we all eventually stop, we would all break on our Eastern (forward) foot, counteracting the effect of the acceleration. The only choice would be never to stop. Alternatively, we could catapult people Westwards into space. Anyone care to calculate how many people we would then need to eliminate the leap year?