Prof. Carl Sagan
@ProfCarlSagan • 71,021 subscribers
Tribute to the man who taught us skepticism, critical thinking, and a sense of wonder for the natural world.
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American chemist Wallace Carothers discovered nylon in 1935 while leading research at DuPont. His goal was to create synthetic "superpolymers" with protein-like structures to emulate or replace natural silk. During his 1976 Christmas Lectures, George Porter amazed children in the audience by making nylon right there in the lecturessolved theatre. ( 🎥 Royal Institution (now on Bluesky) )
Prof. Carl Sagan369,826 次观看 • 7 个月前
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Carl Sagan explained in his 1977 Christmas Lectures that Earth's initial hydrogen-rich atmosphere was lost to space because Earth's gravity was too weak to hold onto the light hydrogen atoms, which could easily achieve escape velocity. This allowed the atmosphere to evolve into the second, more stable composition (rich in volcanic gases like CO2, methane, etc.) before oxygen became dominant.
Prof. Carl Sagan200,181 次观看 • 7 个月前
Carl Sagan explains why a child’s simple question may be deeper than most adults realize. “Mommy, why is the grass green?” And very often the child gets an answer like: “Oh, who knows?” But that is not a silly question. It is an extremely profound question. Because hidden inside it are the fundamentals of biology, light, chemistry, and physics. How much better it would be to say: “That’s a good question.” “Maybe we can look it up.” “Maybe when you grow up, you can find the answer.” The tragedy is that many children learn the wrong lesson. They learn that asking deep questions is somehow bad. And when that happens, we lose something precious. We lose intellectual resources. We lose curiosity. We lose future thinkers. Because the complex and subtle problems we face can only be solved by people capable of complex and subtle thoughts. A child’s question is not an interruption. Sometimes, it is the beginning of science.
Prof. Carl Sagan24,930 次观看 • 23 天前
