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Curated by: Xah Lee (847 videos)


Currently Playing: Xah Ep777. Wolfram language coding. Geometry. Light ray reflection on curve. caustics.

python coders, javascript coders, java, c++ coders, must watch. 01:13:28 real-time formatting of code and 2d typeset math. Video Summary (Generated by AI, Edited by Human.) In this video (0:05), Xah Lee live-codes in the Wolfram Language to draw geometrical caustics, which are the envelopes of light rays reflected off or refracted through curves (0:19). The goal is to visualize complex mathematical curves that were previously documented in his visual dictionary 30 years ago (0:48). Video Highlights: • Demonstration: Xah shows images of caustic curves generated by parabolas (0:52) and discusses the properties of a nephroid curve (17:16). • Mathematical Explanation: The video explains how to find the tangent line to a curve, calculate the normal line, and use these to compute the reflection of light rays (13:15, 30:07). • Practical Example: Xah attempts to demonstrate the cardioid effect inside a coffee cup, explaining that the liquid level and light strength are crucial for visibility (7:29-9:54). • Coding in Wolfram Language: Xah writes code to generate these visuals using parametric equations for circles and other shapes (22:10). He also highlights unique features of the Wolfram Notebook editor, such as expanding selection based on syntactical units (1:15:30). • Comparison: Xah discusses the similarities between Wolfram Language and Lisp (1:20:00).


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