1/ 450 years ago this month – in November 1572 – a bright new star lit up the night sky. Today we know it was a supernova, the explosive death of a massive star – but in the 16th century, it was a mystery... 🧵 2/ According to the prevailing world-view, the “heavens” were perfect and unchanging. The greatest astronomers of the day puzzled over this strange new object, whose appearance would force us to re-think our conception of the universe...

1/7 On Oct. 31, 1992 -- 30 years ago today -- Pope John Paul II admitted the Roman Catholic Church was wrong to have condemned Galileo. The headline in the New York Times read, "After 350 Years, Vatican Says Galileo Was Right: It Moves." #OTD 2/7 From the NYT: "More than 350 years after the Roman Catholic Church condemned Galileo, Pope John Paul II is poised to rectify one of the Church's most infamous wrongs -- the persecution of the Italian astronomer and physicist for proving* the Earth moves around the Sun."

Carl Sagan was an avowed nonbeliever -- but in 'Contact,' as one of his biographers put it, he gave us "one of the most religious science-fiction tales ever written.” 25 years after the film opened, I look at its continuing influence, for @NautilusMag: nautil.us/a-surprising-s… ^^ It was a pleasure to speak with @SashaSagan for this story, along with radio astronomer Yvette Cendes (@whereisyvette) -- one of many women scientists whose career path was shaped by "Contact."

I’ve just tuned in! Very interesting so far! (Lee McIntyre is terrific!)

https://twitter.com/alexwitze/status/1466068032359321603

2/ Fascinating re the tobacco companies in the 1950s; @LeeCMcIntyre explains how they managed to convince journalists to tell “both sides” of the smoking-and-cancer “debate.”

“The good journalism has gotten better, and the bad journalism has gotten a lot worse.” — @picardonhealth summarizing how #science #journalism has changed since 1987, in tonight’s @RCIScience event, underway now. 2/ @picardonhealth cautions against “false balance” — the all-too- common practise of pretending that two opposing points of view are equally valid (which is especially problematic in health & science reporting). #scicomm

1/n #Hanukkah comes super early this year – it starts tonight! – and in fact, this is the earliest that it *can* occur. Let’s talk about why that’s so! (thread 🧵 ) #Hanukkah2021 2/ The date of #Hanukkah is determined (no surprise) by the Hebrew calendar, not by the Gregorian calendar. More specifically, Hanukkah begins on the 25th day of the Hebrew month of Kislev...

1/n According to numerous colleagues on Twitter, Nobel Laureate physicist Steven Weinberg has died. He was a towering intellect. I'm sure much of the coverage to come will focus on his contributions to science, but (cont'd) (Photo: Jeff Wilson/The Guardian) 2/ ...he was also a first-rate science communicator. His books, and his essays in the @nybooks, were illuminating and authoritative, regardless of the topic.

No-one: Dan, I see the donut-shaped universe idea is back in the news. Didn't you write about that in the last century?
Me: Yes; yes I did. A big eight-page spread in @SkyandTelescope, July 1999, on the topology of the universe: (#space #physics #donuts) And look how they wrapped the headline around the first double-page spread, Pac-Man style. Pretty neat (and apt)!

1. “The Death of a Universe” -- Terrific talk this evening by Dr. Katie Mack (@AstroKatie) at @yorkuniversity. Here are a few highlights. This of course is the CMB, the faint microwave “echo” of the big bang. (cont’d) #physics #astronomy #cosmology (@YorkUScience) @AstroKatie @yorkuniversity @YorkUScience 2. The big bang happened ~13.8 billion years ago. So what lies ahead? Could the universe collapse in a big crunch? Maybe – but as Prof. Mack explained, it's more likely that it will keep expanding. In fact, the universe is currently not only expanding but also accelerating...