sanctus Posted June 26, 2005 Report Share Posted June 26, 2005 This is quite stupid question I guess, but if trying for half an hour doesn't give me what I looked for.One caan get very easily e^2/(h/2*pi)*c=1/137 in the gaussian units.How is the calculation done in SI-units (=MKSA units)? i tried with the conversion table in the J.D. Jackson, but never got to the result. Quote Link to comment Share on other sites More sharing options...
Erasmus00 Posted June 27, 2005 Report Share Posted June 27, 2005 This is quite stupid question I guess, but if trying for half an hour doesn't give me what I looked for.One caan get very easily e^2/(h/2*pi)*c=1/137 in the gaussian units.How is the calculation done in SI-units (=MKSA units)? i tried with the conversion table in the J.D. Jackson, but never got to the result. Your forumla for the fine structure constant e^2/((h/2pi)*c) isn't quite valid in SI units. You need a factor of Coulumb's constant (1/(4pi*epsilon)). Working that out gives you the 1/137. -Will Quote Link to comment Share on other sites More sharing options...
infamous Posted July 9, 2005 Report Share Posted July 9, 2005 Your forumla for the fine structure constant e^2/((h/2pi)*c) isn't quite valid in SI units. You need a factor of Coulumb's constant (1/(4pi*epsilon)). Working that out gives you the 1/137. -Will Thats exactly the reason why I choose to use the cgs/esu form of units. Much easier to deal with, at least from my perspective. The problem occurs when trying to use the SI unit which defines (e), it is the elementary charge measured in electromagnetic units. When using the cgs/esu figures, (e) is calculated in electrostatic units which work quite nicely with planks constant (h/2pi) times c when all units are defined in cgs terms. Quote Link to comment Share on other sites More sharing options...
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