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MathGroup Archive 2007

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physical constants

  • To: mathgroup at smc.vnet.net
  • Subject: [mg82018] physical constants
  • From: "Chris Chiasson" <chris at chiasson.name>
  • Date: Tue, 9 Oct 2007 05:44:35 -0400 (EDT)

ElectronCharge has the wrong sign.

ElementaryCharge, if it existed, should have the sign that
ElectronCharge currently has.

In[1]:=
<< PhysicalConstants`
ElectronCharge

Out[2]=
1.60218*10^-19 Coulomb

Also, to continue beating a dead horse from a couple of years ago:

VacuumPermittivity is incorrectly defined as a machine precision
float. VacuumPermittivity should be defined as an exact transcendental
number. The following links and code make this clear:

http://physics.nist.gov/cgi-bin/cuu/Value?eqep0
http://physics.nist.gov/cgi-bin/cuu/Value?eqmu0
http://physics.nist.gov/cgi-bin/cuu/Value?c

In[3]:= VacuumPermittivity

Out[3]= (8.85419*10^-12 Ampere Second)/(Meter Volt)

In[5]:=
(1/(VacuumPermeability*SpeedOfLight^2))
% // N

Out[5]=
(625000 Ampere Second)/(22468879468420441 Meter \[Pi] Volt)

Out[6]=
(8.85419*10^-12 Ampere Second)/(Meter Volt)




-- 
http://chris.chiasson.name/


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