# Lesson 1.1 - Observing the Heavens

This is the first lesson

Here’s some code

echo \$VAR


Or how about some $$\text{inline math}$$ and other math, $$m_\text{AB} = -2.5\log_{10}\left(\frac{f_\nu}{3.63078\!\times\! 10^{-23}\ \ \text{W}\!\cdot\!\text{m}^{-2}\!\cdot\!\text{Hz}^{-1}}\right),$$

$$H(z) = H_0 \sqrt{\Omega_{\text{m},0}(1+z)^3 + \Omega_{\text{r},0}(1+z)^4 + \Omega_\Lambda}.$$

# Fundamental Constants

First, we have the speed of light $$c$$, $$c = 2.997\ 924\ 58\times 10^{8}\ \text{m}\ \text{s}^{-1}.$$