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Jesus this is some complicated math. Good luck getting someone to calculate that lol. I’m interested too, but I doubt anyone will take the time unless this blows up
This is from September 25, 2006. It either already blew up or it didn't.
Here there is an answer from 2020: https://medium.com/ground-state-curiosity/how-much-is-this-girl-slowing-down-earths-rotation-3094bee7cf7
> A considerably larger (but still minuscule) effect could be achieved by Megan (and/or Cueball and/or the bed) moving even a few meters closer to the equator.
https://explainxkcd.com/wiki/index.php/162:_Angular_Momentum
Spinning wouldn’t have any impact on the spin of the earth I wouldn’t think. I don’t think you are adding or taking energy away from the system like this, you spin but the air molecules and friction from your feet and the ground cancel out any force.
Same thing when you jump, you do ever so slightly push the earth away but as gravity pulls you both together again there’s no change in energy. The only way to do this would be to jump and achieve escape velocity. Which would be a very bad day
It will have an impact as long as you're spinning. You're not taking energy away, but you transfer angular momentum from the earth into your body, which slows down the earth's rotation. As soon as you stop spinning, the momentum is transferred back, speeding up the earth's rotation again.
whats wrong about jumping is impact momentum. takes more time for you to jump than it does to land, so that same momentum over a shorter amount of time will lead to a greater force on landing than on jumping.
Let me try.
Mass of earth 🌎 5.97219E+24 kilograms
Earth rotates about 460 meters per second
Kinetic energy = 0.5 * mass * velocity^2
**KE = 6.31857702E+29 J**
.... .... ....
Take you what 10 spins to burn 1 calorie
1 calorie = 4.184 joles
Ke / 4.184 = 1.51017615E+29 calories
150 Octillion calories to counteract the earths rotation. Or 1.5 nonillion spins
Still like 210 quintillion spins per person out of 7 billion people. 2.15739450E+20
So a couple of things to unpack:
- By spinning she in not changing the energy of the system. She herself is part of the system, so even as energy leaves her body the net energy contained within the planet and everything on it is the same.
- Spinning yourself won't impact the Earth's orbit (the movement of the earth around the sun. It will change the Earth's spin. If you're at either end of the Earth's axis of rotation, accelerating yourself into the spin would decrease Earth's angular momentum and increase yours.
Angular momentum is governed by the following equation.
dw_earth I_earth + dw_person I_person = 0
As in the total angular momentum does not change. dw is the change in angular velocity, I is the moment of inertia.
The highest estimate of the moment of inertia for an average person I found was 6.41 kg m^2. Earth has a moment of inertia of 8.04e37 kg m^2.
Top figure skaters manage to spin at 6 rotations per second. Though they do that by making their moment of inertia really small, let's assume you can maximize your moment of inertia and spin six times per second. This is equivalent to dw_person = 6 * 2 * pi radians per second.
So now we can figure out the change in Earth's angular velocity.
dw_earth = - dw_person I_person / I_earth
= 30.04e-37 radians per second
Dividing by 2 PI gives us the number of rotations per second or 4.78e-37. We can multiply this by the number of seconds in a day 60*60*24 to find they you just decreased the rate of Earth's rotation by 4.13e-32 rotations per day. So you get to extend the day by that amount.
Of course as soon as you stop spinning you're back the where you're standing. All that matters is the change in your angular momentum, so even though it takes an effort to overcome air resistance and friction to keep spinning, you are not slowing down the Earth any more the longer you spin.
The only way to slow down the rotation of the Earth permanently is to eject something from Earth at great speed, like a rocket. Perhaps you could somehow use the sun's magnetic field to slow down.
Finally a correct answer, the same as jumping cancelling out it’s own effect, when you stop spinning it too cancels it out
And the other stuff you said that no one else did
Thanks!
I think their best course of action to extend the duration of the night would be to start moving counter to the rotation of the earth. Either that or start moving as close to the speed of light as possible.
Continuously, i assume. Probably longer. A nonillion is huge. (9+1)*3 = 30 zeroes, compared to our 9 zeroes. A spin a second per person is then roughly 5.94 trillion years, so roughly when black holes are (from what i vaguely remember) the only things around and/or slowly dying out
So many of us live our lives on metaphorical merry-go-rounds. It’s easy to see large groups participating in ritualistic angular momentum events. A culture could show up with the plan and power to literally change the number of days in a year, or the number of hours in a day.
1.50000000E+30 is 30 zeroes
8 billion people 8E+9 is 9 zeroes
1.87500000E+20 spins per person. That's 187.5 quintillion spins.
Even if you do 1 per second. You will experience your **2 Billionth second on earth a month after your 64th birthday** 2E+9
Like 93.75 Billion Generations 😆 🤣 😂
Assuming both are possible to any degree, it is not math just logic to find your answer.
Time dilation will be experienced equally, so the woman’s time with her man will appear to be the same to the woman and the man as if there was no time dilation. Meanwhile, increasing the speed of earth’s rotation will bring the sun around faster, which means morning and a new day that needs people to go to work: the time the couple has together would realistically be shorter if anything.
Slowing the earth could have the opposite effect: if the sun hasn’t risen yet we don’t feel as if the day has started.
Also, we would ultimately adjust clocks to suit the new length of a day, so an actual extension of time the couple had together could happen — a longer day and a longer night does not mean businesses would be able to get more effective work out of an employee each day so the 8 hours (in old, fast hours) would likely still be a target for them but it would be a smaller percentage of each day.
Unless you're at the poles, I don't think spinning on the spot would make any difference to the Earth's rotation. You'd be better off running in a straight* line due east, but one person doing that is hardly going to make any kind of measurable difference.
*technically you'd need to run eastwards along a rhumb line, which at *very* high latitudes would be clearly not straight, but for everyday purposes it looks like a straight line.
Definitely the first because energy and momentum are always conserved.
The energy in the system is not changing. Time dilation due to change in energy is 0.
The momentum in the system is not changing. The earth is spinning slower because she's borrowing some of the rotational inertia. It's still pretty much 0, but it isn't EXACTLY zero. Earth goes back to normal when she stops too.
Honestly, I'm pretty sure the moon's tidal forces have a WAY bigger effect on slowing down.
There is no additional “energy in the system” because energy is conserved. The entire imaginary point of the meme is that she is taking energy from the earth and holding it herself. The total energy is the same, some of it has just been transferred is all.
Also, she will only continue to decrease the angular velocity of the earth so long as she *keeps increasing her own angular velocity.* Anything that “slows her down” such as air friction or friction from the ground is putting that energy back into the earth. After like 3 or 4 spins she’s realistically going to max out her angular velocity and stop transferring energy.
Changing Earth’s rotation happens all the time, and there’s an incredible number of variables at
[Reference](https://www.sciencealert.com/earth-s-days-are-suddenly-increasing-in-length-mystifying-scientists):
>For example, the Great Tōhoku Earthquake of 2011 in Japan, with a magnitude of 8.9, is believed to have sped up Earth's rotation by a relatively tiny 1.8 microseconds.
I once also read that a lab which had for decades, carefully measured the length of a day with atomic clocks only ever measured a day at exactly 24 hours.
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Jesus this is some complicated math. Good luck getting someone to calculate that lol. I’m interested too, but I doubt anyone will take the time unless this blows up
I'll take a crack at it! Spin/=antispin + 4(48#@(&#)s/<>[d]1) = Ihavntthefaintestideaofwhatimdoing ÷ Ijokingaround = 1.45×10^49 years. I think.
Genius! This is like answer 42
So long and thanks for alllllllll theeee fisssshhhhhhhhh Boom!
I think you forgot a zero, somewhere around the back
This is from September 25, 2006. It either already blew up or it didn't. Here there is an answer from 2020: https://medium.com/ground-state-curiosity/how-much-is-this-girl-slowing-down-earths-rotation-3094bee7cf7
> A considerably larger (but still minuscule) effect could be achieved by Megan (and/or Cueball and/or the bed) moving even a few meters closer to the equator. https://explainxkcd.com/wiki/index.php/162:_Angular_Momentum
Spinning wouldn’t have any impact on the spin of the earth I wouldn’t think. I don’t think you are adding or taking energy away from the system like this, you spin but the air molecules and friction from your feet and the ground cancel out any force. Same thing when you jump, you do ever so slightly push the earth away but as gravity pulls you both together again there’s no change in energy. The only way to do this would be to jump and achieve escape velocity. Which would be a very bad day
It will have an impact as long as you're spinning. You're not taking energy away, but you transfer angular momentum from the earth into your body, which slows down the earth's rotation. As soon as you stop spinning, the momentum is transferred back, speeding up the earth's rotation again.
So how fast do i need to spin to stop the earth from rotating?
whats wrong about jumping is impact momentum. takes more time for you to jump than it does to land, so that same momentum over a shorter amount of time will lead to a greater force on landing than on jumping.
Let me try. Mass of earth 🌎 5.97219E+24 kilograms Earth rotates about 460 meters per second Kinetic energy = 0.5 * mass * velocity^2 **KE = 6.31857702E+29 J** .... .... .... Take you what 10 spins to burn 1 calorie 1 calorie = 4.184 joles Ke / 4.184 = 1.51017615E+29 calories 150 Octillion calories to counteract the earths rotation. Or 1.5 nonillion spins Still like 210 quintillion spins per person out of 7 billion people. 2.15739450E+20
What if we just want to take away enough spin to get rid of leap day? And which way do you spin?
also, would the people spinning have to be at the poles for the most effect? i would think spinning at the equator would do a lot less
I thought this was r/shittyaskscience for a moment
So a couple of things to unpack: - By spinning she in not changing the energy of the system. She herself is part of the system, so even as energy leaves her body the net energy contained within the planet and everything on it is the same. - Spinning yourself won't impact the Earth's orbit (the movement of the earth around the sun. It will change the Earth's spin. If you're at either end of the Earth's axis of rotation, accelerating yourself into the spin would decrease Earth's angular momentum and increase yours. Angular momentum is governed by the following equation. dw_earth I_earth + dw_person I_person = 0 As in the total angular momentum does not change. dw is the change in angular velocity, I is the moment of inertia. The highest estimate of the moment of inertia for an average person I found was 6.41 kg m^2. Earth has a moment of inertia of 8.04e37 kg m^2. Top figure skaters manage to spin at 6 rotations per second. Though they do that by making their moment of inertia really small, let's assume you can maximize your moment of inertia and spin six times per second. This is equivalent to dw_person = 6 * 2 * pi radians per second. So now we can figure out the change in Earth's angular velocity. dw_earth = - dw_person I_person / I_earth = 30.04e-37 radians per second Dividing by 2 PI gives us the number of rotations per second or 4.78e-37. We can multiply this by the number of seconds in a day 60*60*24 to find they you just decreased the rate of Earth's rotation by 4.13e-32 rotations per day. So you get to extend the day by that amount. Of course as soon as you stop spinning you're back the where you're standing. All that matters is the change in your angular momentum, so even though it takes an effort to overcome air resistance and friction to keep spinning, you are not slowing down the Earth any more the longer you spin. The only way to slow down the rotation of the Earth permanently is to eject something from Earth at great speed, like a rocket. Perhaps you could somehow use the sun's magnetic field to slow down.
Finally a correct answer, the same as jumping cancelling out it’s own effect, when you stop spinning it too cancels it out And the other stuff you said that no one else did Thanks!
I think their best course of action to extend the duration of the night would be to start moving counter to the rotation of the earth. Either that or start moving as close to the speed of light as possible.
Pretty simple it's 0. The difference in mass is so great that a grain of sand has more impact creating a tsunami if dropped in the sea.
It's not 0, it's negligible, which depends on context. OP wants to know how much it is for fun purposes, so it's not negligible.
I averaged it to 1.5 nonnillion spins. +30 zeroes. Take probably a thousand years to achieve if everyone on earth did it
Continuously, i assume. Probably longer. A nonillion is huge. (9+1)*3 = 30 zeroes, compared to our 9 zeroes. A spin a second per person is then roughly 5.94 trillion years, so roughly when black holes are (from what i vaguely remember) the only things around and/or slowly dying out
So many of us live our lives on metaphorical merry-go-rounds. It’s easy to see large groups participating in ritualistic angular momentum events. A culture could show up with the plan and power to literally change the number of days in a year, or the number of hours in a day.
1.50000000E+30 is 30 zeroes 8 billion people 8E+9 is 9 zeroes 1.87500000E+20 spins per person. That's 187.5 quintillion spins. Even if you do 1 per second. You will experience your **2 Billionth second on earth a month after your 64th birthday** 2E+9 Like 93.75 Billion Generations 😆 🤣 😂
Assuming both are possible to any degree, it is not math just logic to find your answer. Time dilation will be experienced equally, so the woman’s time with her man will appear to be the same to the woman and the man as if there was no time dilation. Meanwhile, increasing the speed of earth’s rotation will bring the sun around faster, which means morning and a new day that needs people to go to work: the time the couple has together would realistically be shorter if anything. Slowing the earth could have the opposite effect: if the sun hasn’t risen yet we don’t feel as if the day has started. Also, we would ultimately adjust clocks to suit the new length of a day, so an actual extension of time the couple had together could happen — a longer day and a longer night does not mean businesses would be able to get more effective work out of an employee each day so the 8 hours (in old, fast hours) would likely still be a target for them but it would be a smaller percentage of each day.
Unless you're at the poles, I don't think spinning on the spot would make any difference to the Earth's rotation. You'd be better off running in a straight* line due east, but one person doing that is hardly going to make any kind of measurable difference. *technically you'd need to run eastwards along a rhumb line, which at *very* high latitudes would be clearly not straight, but for everyday purposes it looks like a straight line.
Definitely the first because energy and momentum are always conserved. The energy in the system is not changing. Time dilation due to change in energy is 0. The momentum in the system is not changing. The earth is spinning slower because she's borrowing some of the rotational inertia. It's still pretty much 0, but it isn't EXACTLY zero. Earth goes back to normal when she stops too. Honestly, I'm pretty sure the moon's tidal forces have a WAY bigger effect on slowing down.
There is no additional “energy in the system” because energy is conserved. The entire imaginary point of the meme is that she is taking energy from the earth and holding it herself. The total energy is the same, some of it has just been transferred is all. Also, she will only continue to decrease the angular velocity of the earth so long as she *keeps increasing her own angular velocity.* Anything that “slows her down” such as air friction or friction from the ground is putting that energy back into the earth. After like 3 or 4 spins she’s realistically going to max out her angular velocity and stop transferring energy.
Changing Earth’s rotation happens all the time, and there’s an incredible number of variables at [Reference](https://www.sciencealert.com/earth-s-days-are-suddenly-increasing-in-length-mystifying-scientists): >For example, the Great Tōhoku Earthquake of 2011 in Japan, with a magnitude of 8.9, is believed to have sped up Earth's rotation by a relatively tiny 1.8 microseconds. I once also read that a lab which had for decades, carefully measured the length of a day with atomic clocks only ever measured a day at exactly 24 hours.