|Feb12-13, 10:08 AM||#1|
Question on Planck units
Planck units are defined here
Length, mass and time are defined via G, c and [itex]\hbar[/itex] and do not involve kB;
But temperature contains all G, c and [itex]\hbar[/itex] and kB;
Perhaps this is okay; just seems "uneven" that kB appears with a zero power in the definitions of length, mass and time but with nonzero power in the definition of temperature.
It seems a bit "ad hoc"... Would anyone have a comment on these definition choices?
|Feb12-13, 03:40 PM||#2|
Mass, space and time are connected both via gravity and via quantum theory. This is not true for temperature. It is just (directly) related to energy.
It is not a choice. If you set all those constants to 1, you have no choice how to get planck units (apart from constant prefactors).
|Feb12-13, 03:49 PM||#3|
The reason I am asking is I read this thread (thread) on Planck units.
It says that c, G and [itex]\hbar[/itex] form a "vector basis" (1,0,0) (0,1,0) and (0,0,1) where adding vectors corresponds to multiplication of units.
It is interesting that adding kB happens only for temperature, as if temperature has a "4-dimensional" unit, while L, T, M are less-dimensional. Wondering what the implications of this could be.
|natural units, planck units|
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