Stop the world, I'm getting dizzy

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Discussion Overview

The discussion explores a hypothetical scenario where everyone in the world walks east simultaneously to determine if this action could stop the Earth's rotation. It includes considerations of angular momentum and comparisons to other thought experiments.

Discussion Character

  • Exploratory, Conceptual clarification, Debate/contested

Main Points Raised

  • Some participants propose that if everyone walked east at the same time, it might affect the Earth's rotation, questioning the feasibility of stopping it temporarily.
  • Others mention the conservation of angular momentum, raising questions about the angular momentum of the Earth compared to that of the people walking.
  • Specific calculations of angular momentum are presented, with one participant suggesting values for both the Earth and the collective mass of people walking at a certain speed.
  • A participant draws a parallel to the "airplane on a treadmill" problem, suggesting a similarity in the dynamics involved.

Areas of Agreement / Disagreement

Participants express various viewpoints on the scenario, and there is no consensus on whether the proposed actions could effectively stop the Earth's rotation.

Contextual Notes

Limitations include assumptions about the uniformity of mass distribution and the effects of walking speed on angular momentum calculations.

tribdog
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Okay if everyone in the world started walking east at the same time would that be enough to stop the world from spinning, at least until they stopped walking? If we all had parachutes to use to stop would we be able to keep the world stopped?
 
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tribdog said:
Okay if everyone in the world started walking east at the same time would that be enough to stop the world from spinning, at least until they stopped walking? If we all had parachutes to use to stop would we be able to keep the world stopped?

Angular momentum would be conserved …

so what is the angular momentum of the Earth, and what would be the angular momentum of 6 billion people of average mass at say 1 metre/second walking round the equator? :smile:
 
tiny-tim said:
Angular momentum would be conserved …

so what is the angular momentum of the Earth, and what would be the angular momentum of 6 billion people of average mass at say 1 metre/second walking round the equator? :smile:

[tex]7 \times 10^{33} m^2 kg/s[/tex]

calc

[tex]2 \times 10^{18} m^2 kg/s[/tex]

calc
 
Last edited:
Wouldn't this be similar to the airplane on a treadmill problem? Save that people really are stuck on the tread mill.
 

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