4 ms·
A first-year physics teacher once told the class something that stuck with me (paraphrasing): "Nothing is big or small by itself. I want you to always follow th
by lefra 6mo ago
A first-year physics teacher once told the class something that stuck with me (paraphrasing): "Nothing is big or small by itself. I want you to always follow these words with 'compared to ...'".
- cubefox 6mo agoShe: It's not that big. He: I think we can agree everything below the average between a Planck length and the size of the observable universe is objectively small, and everything above is objectively large. Using the geometric mean, that average is about 0.12 mm. Therefore my penis is actually large. She: I shouldn't have married a physicist.
- leni536 6mo agoAverage? So around half the size of the observable universe?
- quietbritishjim 6mo agoThey specified the geometric mean. The arithmetic mean (what you're thinking of) of 1 and 100 is 50.5. The geometric mean of 1 and 100 is 10. It gives a sense of the average magnitude.
- leni536 6mo agoThey edited the comment, previously it did not mention geometric mean.
- cubefox 6mo agoThe geometric mean seems to be the natural mean for relative comparisons between lengths, because the mean of (Planck length, observable universe) is clearly very different from the mean of (house, observable universe).
- zahlman 6mo ago> Using the geometric mean, that average is about 0.12 mm That's... actually kinda cool to know.
- cubefox 6mo agoIt's true! https://www.wolframalpha.com/input?i=Geometric+mean+of+%28Planck+length%2C+diameter+of+the+observable+universe%29 https://www.wolframalpha.com/input?i=Geometric+mean+of+%28Pl...
- bo1024 6mo agoSewing machine. https://xkcd.com/2754/ https://xkcd.com/2754/