Graphene is a sheet of carbon one atom thick, arranged in a hexagonal honeycomb. It is about 200 times stronger than structural steel, absorbs only 2.3 percent of visible light, and conducts heat ten times better than copper. For decades physicists believed such a two-dimensional crystal could not survive in the real world. Then, in 2004 at the University of Manchester, Andre Geim and Konstantin Novoselov isolated it by peeling graphite with sticky tape, work that earned the 2010 Nobel Prize in Physics.

This episode traces the century-long hunt for a material that was hiding in every pencil, from Benjamin Brodie’s observations of graphite oxide in 1859 to P.R. Wallace’s 1947 calculations, which used a single layer only as a mathematical shortcut. It then moves into the strange physics inside the lattice, where electrons act as if they have no mass, and the stubborn manufacturing problems that keep graphene out of most everyday devices twenty years later.

• A pencil tip snaps because the weak van der Waals forces between layers let graphene sheets slide apart, even though each sheet is nearly unbreakable.
• Theory held that a free two-dimensional sheet would crumple into a nanotube or buckyball, which pushed labs toward costly epitaxial growth in vacuum chambers.
• The Manchester team made invisible flakes visible by placing them on silicon coated with about 300 nanometers of silicon dioxide, where interference cast a faint purplish shadow.
• At the Dirac points the valence and conduction bands touch, so electrons travel ballistically at roughly one three-hundredth the speed of light.
• A 2022 study found fruit fly larvae fed low doses of graphene oxide developed faster, lived longer, and resisted starvation and temperature stress better.