Aluminum is a lightweight, silvery-white metal that's everywhere in modern life. It's the same material in soda cans, aluminum foil, and airplane bodies. Despite being light enough that you can easily crush a can in your hand, aluminum is surprisingly strong and doesn't rust like iron does.

For most of human history, aluminum was incredibly rare and expensive because it's never found pure in nature. It's always mixed with other elements in rocks and dirt, and separating it out was extremely difficult. In the 1850s, aluminum was more valuable than gold.

Everything changed in 1886 when a 22-year-old inventor named Charles Martin Hall discovered an efficient way to extract aluminum using electricity. Around the same time, a French engineer named Paul Héroult independently came up with a very similar process. Suddenly this once-precious metal became cheap and abundant. Today, aluminum is one of the most common metals in Earth's crust, and we produce about 65 million tons of it every year.

What makes aluminum so useful is its combination of properties: it's light, strong, doesn't corrode easily, and conducts electricity well. These qualities make it perfect for everything from spacecraft to baseball bats.