How Does Setting c=1 Affect g's Value?

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Homework Help Overview

The discussion revolves around the implications of setting the speed of light, c, to 1 in the context of gravitational acceleration, g. Participants explore how this redefinition affects the value of g in different unit systems.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • One participant attempts to redefine the meter to maintain c=1 and questions whether this approach aligns with the original question. Others suggest that the question may be ill-posed and explore the implications of using different scales for length and time.

Discussion Status

The discussion is ongoing, with various interpretations being explored. Some participants have offered insights into the convenience of using specific units in certain contexts, such as interstellar travel, while others have raised questions about the clarity of the original problem.

Contextual Notes

There is uncertainty regarding the assumptions about the units of measurement and whether both c and g should be set to 1 simultaneously. The original poster's interpretation of the question is also questioned.

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Homework Statement


In the usual units where c=3x10^8 m/s and g=10m/s², what is g in the units where c=1?

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The Attempt at a Solution



I said, let's redefine the meter like so: [itex]\tilde{m}:=3\times 10^8 m[/itex] so that now [itex]c=1\tilde{m}/s[/itex]. And then I calculated g by substituting m for [itex](3\times 10^8)^{-1}\tilde{m}[/itex]... but is this what the question is asking? Because I might as well have chosen to derefine the seconds and since it is s² that pops in in the units of g, the answer would have been different. And the question seems to talk like there is only one answer: "what is g in the units where c=1?"
 
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The question is, indeed, ill-posed.
Perhaps you are meant to use a standard meter as your new length scale as well, but who knows?
Perhaps you are meant to use the second as your new time scale..
 
In the context of interstellar travel with g = 1, it is often convenient to use years and lightyears, and g then also has a fairly nice value.
 
Eeh, you meant c=1, George?
Of course using both c=1 and g=1 make those two values very nice, indeed..
 
arildno said:
Eeh, you meant c=1, George?
Of course using both c=1 and g=1 make those two values very nice, indeed..

Yikes!

Instead of "with g = 1", I meant "with proper acceleration a = g".

Thanks arildno.
 
c=1 LY/Y, as any reader of the New York Times knows.
Just calculate g in LY/Y^2. That proves that God exists,
and God is 1.
 

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