Adamantite! Rearden Metal! Uru! Durasteel! Dalekanium! Unobtanium! Thousands of fictional characters have fought and died for these equally fictional super-materials. So what is the real-life strongest substance on our puny, sun-warmed planet?
Mankind's pursuit of the "strongest" material hasn't exctly been a concerted, organized effort, but it figures into history in incredibly profound ways. Hell, anyone who's played Age of Empires or Civilization—or read a book—knows that historians name entire eras after materials. The Iron (and steel) Age followed the Bronze Age, which followed the Copper Age. Materials got stronger, and humanity advanced. The two were hugely correlated.
It's been a while since we've had a good ol' material-based epoch. Too long! So let's find the next one. Goodbye Age of Computers, hello Age of ________.
To say that a material is "strong" describes so many different things that it can end up meaning nothing. A piece of chalk is stronger than a piece of string cheese in one way, but not another. Spiderweb may be stronger than steel in a particular test, but it's still a bendy, silky mess. So what do we mean when we talk about strength?
Mark Hersam, Professor of Materials Science (and Chemistry) at Northwestern University, has an answer. Well, a few answers: "Typically when people talk about strength, they're talking about the amount of stress that needs to be applied before fracture. It's possible they could also be referring to how quickly it deforms." It's also possible that they could be talking about compressive strength, which is a measure of how easy it is for a material to get crushed. You could even be referring to impact strength, which is a material's ability to sustain a sudden smack. Arg! Make up your minds, people!
Fortunately, the 20/20 hindsight of history can guide us forward. Remember our ages? Iron, steel, copper, bronze—these are materials that we make things out of, be they structures or instruments. Hard things. Tough things: swords or trucks or skyscrapers or bridges. We're looking for hardness, yield strength—that's resistance to deformation, like denting or stretching—and tensile strength, which basically refers to bending. A material of world champion strength would be an optimum hybrid of these two qualities.
Tungsten carbide is phenomenally hard and has great yield strength, but is worryingly brittle when smashed or bent. Osmium alloys follow that same trend: extremely hard, but shatterable and lacking in true tensile strength. Diamonds are harder than either, but nearly impossible to work with or use in practical products and very, very rare. (Ever heard of a molded diamond? A diamond fighter jet? Right.)
Titanium alloys can be flexible and boast high tensile strength, but aren't as hard as steel alloys. Amorphous alloys like Liquidmetal, Apple's new squeeze, are among the strongest materials all-around, with respectable hardness, huge tensile strength and resistance to fatigue—though it's not superlative in any way. Every metal has its weaknesses, is what I'm saying.
The real super-materials, well, they don't quite exist yet. But we're getting closer. You've probably heard a lot about graphene in the last few weeks, after a couple of scientists won Nobel Prizes for their work with the material. You've probably heard that it's hard. (200x harder than steel.) That it's flexible. That it conducts electricity, and happens to be transparent. What you've probably heard, in a nutshell, is that it's awesome. It has immediate and obvious applications in electronics, and Andre Geim, one of the recipients of the prize, went so far as to tell the AP, "[Graphene] has all the potential to change your life in the same way that plastics did."