I'm calculating the Alfven velocity in space plasma.
B = 4.2 nT (nanoTesla)
mu_0 = 1.25663706212e-06 (vacuum permeability in Henry per meter)
n = 21.8906 (number density in 1/cm^3)
m_p = 1.67262192369e-27 (proton mass in kg)
The Alfven velocity equation is:
V_A = B/sqrt(mu_0*n*m_p)
I calculated it as
V_A = (4.2*1e-9)/sqrt(mu_0*n*1e-6*mp)
here obviously, 4.2*1e-9 for changing from nanoTesla to Tesla and n*1e-6 for 1/cm^3 to 1/m^3
The result is 18741529400.533485 m/s or 18741529.400533486 km/s
Which is too fast, even faster than the speed of light, which is 3*10^8 m/s.
So, am I doing something wrong here?
