Anyone here understands how a [overhead fan works?]

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Discussion Overview

The discussion explores the mechanics and implications of an overhead fan operating at extreme speeds, particularly near the speed of light. Participants consider the effects on airflow and the physical consequences in a closed room environment.

Discussion Character

  • Exploratory, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant questions the effects of a fan reaching 90% the speed of light in a closed room, wondering about potential physical consequences.
  • Another participant suggests that at such speeds, the air would perceive the fan as a solid circular plate, implying no significant effect on airflow.
  • A third participant references a website that discusses hypothetical scenarios involving everyday objects at relativistic speeds, indicating that the fan blades' structural integrity would be a concern.
  • Further, it is proposed that the extreme speeds could lead to catastrophic outcomes, such as induced fusion and the creation of plasma clouds, if the fan blades were to remain intact.
  • Participants agree that for practical discussions on airflow, speeds should be more realistic, around the speed of sound.

Areas of Agreement / Disagreement

There is no consensus on the physical implications of a fan operating at relativistic speeds, with multiple competing views on the effects and feasibility of such a scenario.

Contextual Notes

Participants express uncertainty regarding the structural limits of fan blades at high speeds and the assumptions about airflow dynamics in extreme conditions. The discussion does not resolve these complexities.

Meggriffin
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Ello, does anyone here understand how a standard overhead fan and air flow works? If so, what would happen if you're just chilling in your room with the door closed,windows shut and fan off, then the fan just speeds up to around90% thespeed of light for a second. Would that kill me, suck me through the roof/force me through the ground? Just wondering.
 
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Probably.
 
"0.9 c?" Nothing --- the air in the room would "see" the volume swept by the fan as a solid circular plate.
 
What if is a great site answering these sorts of questions. This one will give you an idea what an everyday object would do close to c;
https://what-if.xkcd.com/1/
 
billy_joule said:
What if is a great site answering these sorts of questions. This one will give you an idea what an everyday object would do close to c;
https://what-if.xkcd.com/1/
In addition, we could ask how the fan blades could stay attached to the fan long enough. Induced fusion is enough to evaporate the whole building in either case, but if we start with a few blades moving at up to 90% the speed of light we get several plasma clouds moving in different directions!

To get an effect on air flow alone, we have to keep the speed more realistic (of the order of the speed of sound).
 

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