Nader AbdlGhani
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Despite being a constant, It has both dimensions and a unit, can someone kindly explain why ?
Planck's Constant is a dimensional constant with both dimensions and a unit, specifically relating energy to frequency. This discussion clarifies that not all constants are dimensionless; for example, the speed of light (c) is another constant that possesses dimensions and units. The confusion arises from conflating mathematical constants, which may be dimensionless, with physical constants that inherently have dimensions. The fine structure constant (alpha) is highlighted as a dimensionless physical constant, contrasting with Planck's constant and the speed of light.
PREREQUISITESStudents of physics, educators explaining the concept of constants, and researchers interested in the foundational principles of quantum mechanics.
Nader AbdlGhani said:Despite being a constant, It has both dimensions and a unit, can someone kindly explain why ?
Actually I intended to ask generally, but then I went for the example spontaneously, I have just studied units and dimensions and they told me that constants don't have dimensions and units, for example, number one itself, angle of measure 60° etc, and what came in my mind are constants which are in many relations in physicsZapperZ said:This question is puzzling. Are you saying that the property of a "constant" includes NO dimensions and NO units?
"c", the speed of light in vacuum, is a constant. It has "dimensions and units". Why are you not asking about that as well?
Zz.
Bystander said:
Nader AbdlGhani said:Actually I intended to ask generally, but then I went for the example spontaneously, I have just studied units and dimensions and they told me that constants don't have dimensions and units, for example, number one itself, angle of measure 60° etc, and what came in my mind are constants which are in many relations in physics
As zapperz has pointed out, you are confusing terms. The examples you site are not physical constants, they are just numbers. If used in an equation, they can be called constants as far as math is concerned, but that has nothing to do with physical constants like cNader AbdlGhani said:Actually I intended to ask generally, but then I went for the example spontaneously, I have just studied units and dimensions and they told me that constants don't have dimensions and units, for example, number one itself, angle of measure 60° etc, and what came in my mind are constants which are in many relations in physics