this post was submitted on 09 Sep 2023
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NonCredibleDefense
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Note: like most memes I post, this is not mine. Specifically, I am not an engineering student; I passed high school math with a 59.5%.
Thank you for the transparency
I would hate to be convicted of meme fraud!
In the same spirit: I laughed at this and upvoted it, but I don't know what the square cube law is or what it has to do with mechs. I don't really understand the joke and I'm honestly a fraud for upvoting it and engaging with it, at all.
The square-cube law is the rule saying that if you increase something's size, its volume will also increase proportionally.
Ie: if you have a 1x1x1 cube it's volume is 1, but if you have a 2x2x2 cube it's volume is 8.
With mech design, making a huge bipedal robot means putting a massive amount of weight on relatively weak joints at the legs.
Thanks, I don't think I like the square-cube law. Just make the joints stronger. It'll be fine!
Think about any part of your body... say your arm. Now imagine scaling it up to double the size.
Your muscles are now double the length but also have to move a doubled distance. That changes nothing.
That same muscle (it's roughly a tube) has doubled it's diameter, so it 2² = 4 times as strong because it's cross-section is a circle and the surface of a circle is (d/2)² * pi.
But your whole arm has doubled it's size in all 3 directions. So it's volume/mass is now 2³= 8 times as high.
So in short: double your size and you are 2² = 4 times as strong, but you also have to move 2³ = 8 times the mass. That's the square/cube thing that makes just scaling up impossible.
PS: Yes, if you ever wondered how you were so incredible good at climbing things when you were a child... small children are much stronger than you compared to their own body weight.