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Asteroid wiped out dinosaurs in spring + What makes a bestselling science textbook?

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Q&A: What makes a bestselling science textbook?
https://news.mit.edu/2022/qa-what-makes-...ithms-0223

INTRO: The Department of Electrical Engineering and Computer Science (EECS) recently learned that “Introduction to Algorithms,” a textbook coauthored by department professors Charles Leiserson and Ronald Rivest, alongside Dartmouth College’s Tom Cormen SM ’86, PhD ’93  and Columbia University’s Cliff Stein SM ’89, PhD ’92, has now officially sold over 1 million copies worldwide.

Lauded for its clarity, the book is premised on a “start from fundamentals” approach that welcomes students of many backgrounds and learning styles, regardless of their familiarity with advanced mathematics. We conducted interviews over Zoom with Charles Leiserson, and by email with co-author Tom Corman, about “Introduction to Algorithms” — its origins, its runaway success, and its impact over the years... (MORE - the interview)


An asteroid killed dinosaurs in spring—which might explain why mammals survived
https://arstechnica.com/science/2022/02/...he-spring/

EXCERPTS: Some 66 million years ago, a catastrophic event wiped out three-quarters of all plant and animal species on Earth, most notably taking down the dinosaurs. The puzzle of why so many species perished while others survived has long intrigued scientists.

A new paper published in the journal Nature concludes that one reason for this evolutionary selectivity is the timing of the impact. Based on their analysis of fossilized fish killed immediately after the impact, the authors have determined that the extinction event occurred in the spring—at least in the Northern Hemisphere—interrupting the annual reproductive cycles of many species.

[...] One site in particular seemed of interest: a deposit in North Dakota from the so-called Tanis event. The asteroid's impact was so powerful that it rocked the continental plate, producing enormous waves in rivers and lakes that transported tons of sediment. The sediment easily engulfed the fish in those lakes and rivers, burying them alive. Meanwhile, glass beads of melted rock (impact spherules) rained down from the sky just after impact, becoming embedded in the gills of the dying fish. All of this created the Tanis deposit, which features a beautifully preserved fossilized ecosystem that existed at the time of impact.

[...] The scientists took X-ray scans of the samples to create 3D reconstructions and then projected the bone deposition patterns onto those virtual models. In this way, they were better able to visualize the seasonal fluctuations over the life cycle of the fish.

[...] The scientists recognized the telltale lines of arrested growth (LAGs) in the samples, which (much like tree rings) are key indicators of annual growth cycles over the life span of the fish. The distribution, shape, and size of the bone cells are also known to fluctuate with the seasons.

The analysis showed that all six fish stopped growing (i.e., died) while a new growth zone was forming just after a LAG had been deposited. So the fish likely died in the early stage of their most favorable growth season: the spring.

[...] "Species with longer incubation times, such as non-avian reptiles, including pterosaurs and most dinosaurs, were arguably more vulnerable to sudden environmental perturbations than other groups (such as birds)," the authors wrote. In fact, "Southern Hemisphere ecosystems, which were struck during austral autumn, appear to have recovered up to twice as fast as Northern Hemisphere communities, which is consistent with a seasonal effect on biotic recovery." (MORE - missing details)
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