\magnification=\magstep1

$$
E \quad = \quad {h \nu} \quad = \quad {{h c} \over {\lambda }} 
$$

$$
\lambda \quad = \quad {{ h c } \over {E} } \quad = 
                 \quad {{1240 \thinspace {\rm eV \cdot nm}} \over {E}}
$$

$$
{\theta}_c \quad = \quad 1.22 \thinspace \left( {{\lambda} \over {D}} \right)
$$

$$
\rho(h) \quad = \quad \rho_{0} \thinspace e^{(-h/H)}
$$

$$
{\rm ``seeing"\ \ FWHM} \quad \sim \quad {{\lambda} \over {r_0}}
$$

$$
r_0 \quad \propto \quad {\lambda}^{6/5}
$$

$$
\tau_0 \quad \sim \quad {{r_0} \over {v}}
$$


\bye

