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Focal Length vs. Focal Ratio: What They Do Conceptually! #astronomy #science #telescope
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Telescopes, Resolution and Angular Size
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Most Versatile Focal Length for a Telescope?
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Proper Motion and Parallax
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Faraday, Maxwell and the Aether
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Transporting Energy in the Sun
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Astro Tutorial #1.5: Focal Length and Aperture
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