Charles Babbage’s Difference Engine automated mathematical tables, while his Analytical Engine introduced programmable control, memory and processing. Here is how the two machines worked, why they were never completed in his lifetime and why their ideas still matter.
Luigi Galvani’s famous frog experiments led to a deeper question: was the electricity coming from the animal or from the metals in his apparatus? His later metal-free experiments helped move science toward the modern understanding of bioelectricity and electrophysiology.
Luigi Galvani found that a frog leg could twitch even after his electrical machine was removed. The explanation involved both electrically excitable animal tissue and the metals used in his experimental circuit.