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14,018,353 results
LIGHT! Let's talk about it today. Sunlight, moonlight, torchlight, and flashlight. They all come from different places, but they're the ...
989,379 views
8 years ago
An introduction to basic concepts in optics: why an optic is required to form an image, basic types of optics, resolution. Contents: ...
132,296 views
4 years ago
