Things I learned lately - 7 April

• Director Ridley Scott's original ending for Alien had Ripley killed at the end of the movie. When Ripley is in the escape shuttle and it's revealed that the alien is on board, the creature slams through her mask and rips her head off. He would've then cut to the tentacles of the alien pressing buttons on the dashboard. It would mimic Captain Dallas saying, ‘I’m signing off'. A Fox executive threatened to fire Ridley Scott. So they didn’t do that ending.
• Heavy Metal yoga is a thing now.
• The key to knowing whether you're hydrated is the colour of your urine. Watered down lemonade is what you're going for. Anything darker indicates the likelihood of varying stages of dehydration.
• Graphene-oxide membranes may one day filter salt right out of sea water.
• The division sign ÷ represents a fraction where the dots are numbers.
• Tesla set up a solar micro-grid on the island of Ta'u in American Samoa. It uses Tesla's Powerpacks too to store enough electricity for the 600 residents for almost 3 days. The packs recharge 100% with 7 hours of sun. No more diesel power for Ta'u.
• They now make no-touch thermometers, which use infrared technology to measure core body temperature quickly and precisely. Arc’s Insta­Temp is one of them. Once the device is placed roughly an inch from the forehead, it spits out a temperature in 2.5 seconds, coded red, yellow or green, depending on the reading.
• A killer fog hit London for several days, starting on 5 December 1952. It lifted 4 days later with an estimated death toll of at least 12,000 people, with around 150,000 hospitalizations and thousands of undocumented animal deaths. The cause: nitrogen dioxide converting comparatively benign sulfur dioxide into lethal sulfuric acid.
• In Iceland, they often bake rye bread the old fashioned way - buried underground near a hot spring. It takes 24 hours to bake bread this way, at a temperature around 100C.