% unit macros

\def\u#1{{\rm\,#1}}

% mass
\def\mg{\u{mg}}
\def\gm{\u{g}}
\def\kg{\u{kg}}

% length
\def\m{\u{m}}
\def\mm{\u{mm}}
\def\nm{\u{nm}}
\def\cm{\u{cm}}
\def\km{\u{km}}
\def\um{\,\hbox{$\mu$}}
\def\V{\u{V}}
\def\A{\u{\AA}}
\def\fm{\u{fm}}
\def\pc{\u{pc}}
\def\AU{\u{AU}}

% time
\def\ms{\u{ms}}
\def\sec{\u{s}}
\def\s{\u{s}}
\def\minutes{\u{minutes}}
\def\yr{\u{yr}}
\def\days{\u{days}}
\def\uday{\u{day}}

% dimensionless
\def\mole{\u{mole}}

% frequency
\def\Hz{\u{Hz}}
\def\kHz{\u{kHz}}

% force
\def\dyne{\u{dyne}}
\def\dyn{\dyne}

% energy
\def\meV{\u{meV}}
\def\eV{\u{eV}}
\def\keV{\u{keV}}
\def\KeV{\kev}
\def\MeV{\u{MeV}}
\def\GeV{\u{GeV}}
\def\kW{\u{kW}}
\def\cm{\u{cm}}
\def\erg{\u{erg}}
\def\J{\u{J}}
\def\kcal{\u{kcal}}

% temperature
\def\K{\u{K}}
\def\degC{\,{}^\circ{\rm C}}

% power
\def\W{\u{W}}
\def\kW{\u{kW}}
\def\ergps{\erg\sec^{-1}}

% dimensionless
\def\dB{\u{dB}}

% energy density (or pressure)
\def\ergpcc{\sunits}
\def\sunits{\erg\cm^{-3}}
\def\punits{\dyne\cm^{-2}}
\def\Yunit{\punits}
\def\atm{\u{atm}}

% velocity
\def\kmps{\km\sec^{-1}}
\def\mps{\m\sec^{-1}}
\def\cmps{\cm\sec^{-1}}
\def\mph{\u{mph}}
\def\kph{\u{kph}}

% acceleration
\def\cmpss{\cm\sec^{-2}}
\def\mpss{\m\sec^{-2}}

% density
\def\gcc{\gm\cm^{-3}}
\def\gpcc{\gm\cm^{-3}}

% viscosity (or diffusion constant)
\def\nuunits{\cm^2\sec^{-1}}
\def\kunits{\nuunits}

% resistance
\def\ohm{\,\Omega}
\def\ohmcm{\,\Omega\cdot\rm cm}

% thermal conductivity
\def\Ktail{\cm^{-1}\sec^{-1}\K^{-1}}
\def\Kunitscal{\u{cal}\Ktail}
\def\Kunitscalf{{\u{cal}\over\cm\sec\K}}
\def\Kunits{\erg\Ktail}

% random
\def\ergpg{\erg\gm^{-1}}
\def\kcalpg{\kcal\gm^{-1}}
\def\gyr{\gm\yr^{-1}}
\def\cents{\hbox{\rm\rlap/c}}

