We’ve all noticed that, in the Spiderman movies, the hero ejaculates tremendous amounts of protein constantly to make those spider threads he’s swinging on and splattering all over the bad guys. Part of that is plausible; spider silk is amazingly strong stuff, and if you could produce it, sure, thin strands would support your weight. The problem is the volume. Mark Lorch calculates how much protein Spiderman would have to consume to make the thread for one scene in the movie.
From the time of Spidey’s fall, we can calculate that he fell about 240m (wow, that’s one high balcony). Plus, assuming the silk stretches to its maximum, a stopping distance, it will be a fall of about the height of the Eiffel Tower. The impact force on the silk rope as they slow down would be about 35 times their weight.
Which is about six times greater force than when Spidey is just hanging around on the end of his line of silk. But taking into account the length of the fall (240m) and the extra force, he will need 1.3 kg of silk to catch his fall. So I reckon he must have had about 900 eggs for breakfast that morning, just to have enough silk for that one scene. I think Aunt May might have noticed.
In the movies, he is spontaneously producing this stuff biologically, but as I recall from the comic books he instead built some gadgets that squirted the spider silk. That doesn’t solve the problem! He’d then have to carry around a silk reservoir that, in that scene, would have weighed roughly 100 pounds, and would have been completely depleted at the end.
This is the kind of thing that just ruins comic book movies for me. Good thing I really enjoy reality.