From a future human, light blob is made of the metal Tungsten. Bamboo is flame retardant but it can be burnt. Still I admire the author’s creativity. Bamboo is cheap, growing fast, which can be mass production easily.
The next step is to figure out how to maintain the electricity without using human’s kinetic energy.
Reality aside, Seiroku is really a great brother full of encouragement. Kids usually have more creativity on ideas so thinking like a child is not a bad thing when it comes to creation. Seiroku then wrote down the execution plans (or at least some hints) for the invention. This is showing how he believed his little brother’s idea . It’s a bit painful to see Seiroku try to prevent talking anything close to be last word to Kihachi even he knew he had high chances not able to survive from the war. He simply wants his brother to be hopeful.
