Things I learned lately - 19 January

• In the 1400s, we used to write with pure graphite. But it was expensive stuff, so it was mixed with clay. A #2 pencil has less graphite than a #1, but is a good compromise. The more graphite, the darker the line.
• Artists who have declined to perform at the inauguration (so far): R. Kelly; Elton John; Celine Dion; Kiss; Andrea Bocelli; Kanye West; Garth Brooks; David Foster; Paul Anka; Charlotte Church; Moby; Justin Timberlake; Bruno Mars; Katy Perry.
• The CMHC says about 1,500 newly-built housing units sat vacant across Calgary in December 2016 and more than 800 were apartment-style condos.
• While the song Bobby Brown by Frank Zappa never got played on American radio, Norwegian kids would slow dance to it like it was Stairway to Heaven.
• Google was originally called BackRub. Thankfully that changed, because using it as a verb, as in "you should 'back rub' that" sounds pretty awkward.
• SpongeBob was originally called Spongeboy. They couldn't use that name because it was copyrighted by a mop company.
• The people involved in making tetra-ethyl lead (for leaded gasoline) knew it was poisonous way back in 1922, but they made TEL it anyway. "A colourless liquid of sweetish odor, very poisonous if absorbed through the skin, resulting in lead poisoning almost immediately." 
• Monks made the first pretzels, either in Northern Italy or Germany, around 600 CE. The holy men reportedly took scraps of dough, twisted them to depict arms folded in prayer, and awarded them to children for memorizing Bible verses. Since the Catholic Church banned eggs and bread during Lent, the pretzel became a go-to snack, and it migrated to Austria and Belgium.