January 28

The first imperial diet of the young Emperor Charles V. Luther came under a safe conduct. The Edict of Worms, issued as the diet broke up, made him an outlaw whom anyone might kill and banned his books throughout the Empire.

Christened in the cathedral the next morning after the saint of his birthday, his grandfather Wolfgang Nikolaus Pertl and his godfather Joannes Theophilus Pergmayr. Theophilus is Greek for “loved by God”: Gottlieb in German, Amadeus in Latin. He signed himself Wolfgang Amadè, and used “Amadeus”…

Gold Rush traffic paid for a 76-kilometre line through swamp and jungle from the Atlantic to the Pacific, the first railway to cross a continent. Workers came from Ireland, China, the West Indies and Colombia. Cholera, malaria and yellow fever killed thousands of them; no reliable count was kept,…

An American company finished the first railway across the isthmus after five years of work through swamp and jungle: about 76 kilometres from Colón to Panama City. It charged $25 in gold for a one-way ticket. The line decided where both canals would run: the French bought it in 1881, and the…

George Coy’s switchboard in New Haven, Connecticut, connected 21 subscribers to one another rather than in fixed pairs. Its first directory, a single card, followed within weeks. Exchanges turned the telephone from a private line into a network.

At sixteen, with his father’s consent, he was released from Württemberg citizenship, and so from German military service. He was stateless for five years until Zurich naturalized him on 21 February 1901. The Swiss army then found him unfit, for flat and sweaty feet and varicose veins.

Trotsky announced that Russia would stop fighting but sign nothing, and walked out. The Germans were astonished; ten days later they gave notice that the armistice was over.

At Children’s Hospital in Boston, John Enders, Thomas Weller and Frederick Robbins grew poliovirus in cultures of human tissue that was not nerve tissue. Virus no longer had to come from monkeys’ spinal cords, and a vaccine became possible. The three shared the 1954 Nobel Prize.

At 24:00 GMT on 27 January, 08:00 on the 28th in Saigon. Both Vietnamese sides had spent the last days grabbing ground, and the fighting never really stopped.

Freezing weather was forecast. On a teleconference with NASA, Morton Thiokol’s engineers, Roger Boisjoly among them, recommended no launch below 53 °F (12 °C), the coldest launch so far, because cold O-rings seal the booster joints slowly. NASA’s Marshall managers pushed back. After an off-line…

0.678 seconds after ignition, film shows puffs of dark grey smoke from the aft field joint of the right solid rocket booster: the O-rings had not sealed. Burnt propellant then plugged the gap for nearly a minute.

The crew of STS-51-L: Dick Scobee, commander Michael J. Smith, pilot Judith Resnik, mission specialist Ellison Onizuka, mission specialist Ronald McNair, mission specialist Gregory Jarvis, payload specialist, Hughes Aircraft Christa McAuliffe, payload specialist, Teacher in Space McAuliffe, a…

STS-51-L, the first shuttle launch from Pad 39B, in air at 36 °F (2 °C), 15 °F colder than any launch before it. It ends here 110 seconds after liftoff, when the range safety officer destroyed the two boosters, still flying on their own.

At 58.788 seconds a plume of flame appeared at the same joint, just as the shuttle flew through the strongest wind shear any flight had met. It played on the strut holding the booster and on the external tank.

Challenger, go at throttle up. — Richard Covey, capsule communicator, Houston Roger, go at throttle up. — Scobee The main engines were back at 104 percent. The crew had no sign of trouble; the last word on the recorder, Smith’s “Uh oh”, came five seconds later.

ChallengerSpace Shuttle Challenger

OV-099, begun as a structural test article and rebuilt to fly. In 10 missions it carried the first American woman in space, the first African American, the first American woman to walk in space and the first untethered spacewalk, and made the first landing in Florida.

73 seconds after liftoff, about 14 kilometres up. The right booster broke loose at its lower strut and ruptured the external tank; the orbiter broke up under aerodynamic forces. It was not an explosion in the usual sense. The crew cabin came away largely intact and struck the ocean about two and…

Thirty-two months without a shuttle flight. The booster joints were redesigned with a third O-ring and heaters, the crew got a bail-out system, and the shuttle stopped carrying commercial satellites. Endeavour was ordered to replace Challenger.

We will never forget them, nor the last time we saw them, this morning, as they prepared for their journey and waved goodbye and ‘slipped the surly bonds of earth’ to ‘touch the face of God.’ — Ronald Reagan He had been due to give the State of the Union that evening and put it off. The closing…

In his State of the Union address George W. Bush asked Congress for $15 billion over five years to fight AIDS abroad, most of it new money. The President’s Emergency Plan for AIDS Relief became the largest commitment by any nation to one disease.

Just after midnight the government ordered its internet providers offline and mobile networks cut, the first shutdown of a whole country’s internet on that scale. Crowds that Friday were larger than ever. Access came back on 2 February.