- Homemade liquid nitrogen generator using Joule Thomson Throttling (homemadeliquidnitrogen.com)
I determined that there was no good tutorial on how the average person can liquefy nitrogen or air. A few references to cryocoolers, which use an internal helium Stirling engine to create a cold head exist, and I even saw one person use this as a means to liquefy nitrogen, allowing the gas to condenses as it passes over the head. This method is cheating because it relies on a self-contained refrigeration unit. I wanted to do this using regenerative cooling just like Carl Linde back in 1895.
- Phecda (stars.astro.illinois.edu)
PHECDA (Gamma Ursae Majoris). Few figures in the sky move us more than the Big Dipper, its seven bright stars laid out in a long bent row that the British call the Plough. All but one of its stars are second magnitude, though Phecda, the third one in from the end of the bowl, and southernmost of the bowl stars, is just on the edge of third (2.44).
- Nitrogen (Wikipedia)
Nitrogen is a chemical element; it has symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element bond to form N2, a colorless and odorless diatomic gas. N2 forms about 78% of Earth’s atmosphere, making it the most abundant uncombined element in air. Because of the volatility of nitrogen compounds, nitrogen is relatively rare in the solid parts of the Earth.
