Esteban

“The sixty-story John Hancock Tower was built in Boston in the 1970s, and it was discovered to have an unexpected torsional instability. The interplay of the wind between the surrounding buildings and the tower itself was causing it to twist. Despite being designed in line with current building codes, torsional instability found a way to twist the building, and people on the top floors started feeling seasick. Once again, it was tuned mass dampers to the rescue! Lumps of lead weighing 330 tons were put in vats of oil on opposite ends of the fifty-eighth floor. Attached to the building by springs, the lead weights damp any twisting motion and keep the movement below noticeable levels.”
― Matt Parker, Humble Pi: A Comedy of Maths Errors

“People stepping up and down should not be a problem, and even the 1-Hertz sideways back-and-forth movement of humans walking should not have been a problem, as everyone is likely to be stepping at different times. For anyone pushing with their right foot, another person would be pushing with their left, and all the forces would pretty much cancel each other out. This sideways resonance would only be a problem if enough people walked perfectly in step. This is the “synchronous” in “synchronous lateral excitation” from pedestrians. On the Millennium Bridge, people did start to walk in step, because the movement of the bridge affected the rhythm at which they were walking. This formed a feedback loop: people stepping in sync caused the bridge to move more, and the bridge moving caused more people to step in sync.”
― Matt Parker, Humble Pi: A Comedy of Maths Errors

“I wish it need not have happened in my time," said Frodo.
"So do I," said Gandalf, "and so do all who live to see such times. But that is not for them to decide. All we have to decide is what to do with the time that is given us.”
― J.R.R. Tolkien, The Fellowship of the Ring

“Living, as we do, at the bottom of an ocean of air, it is easy not to look up. To see only our immediate environment in two-dimensional terms. It is probably no accident that the first ones to question this view, to see something others missed, were a father and son who watched the weather go by from mountain peaks near the top of the world. Vilhelm and Jacob Bjerknes were Norwegian meteorologists who, during the First World War, organised a network of weather stations across their country. By releasing instrumented balloons and comparing observations, they became aware that the air was not homogenous, that it moved across the face of Earth in deep waves. They identified distinct chunks of air, independent volumes with definite properties. And, with the War still much on their minds, it seemed natural to them to describe the turbulent boundaries between these moving masses as ‘fronts’. The discovery that local air did not suddenly become cool or warm, moist or dry, but was completely replaced by a new and different volume, was vital. It gave rise to modern meteorology.”
― Lyall Watson, Heaven's Breath: A Natural History of the Wind