Carbon

We are stardust.

Caveat Lector: The following observations and predictions are literally about elemental carbon. They don't build up to a metaphor or anything. If armchair chemistry isn't really your thing, feel free to skip this one, and come on back next week.

Like many folks hearing of mRNA vaccines for the first time, I've recently been inspired to learn a little bit about molecular biology. The importance of a single element, carbon, is immediately striking: It's the backbone of DNA and RNA, amino acids and proteins, and any number of tiny structures critical to life on Earth. The processes that we collectively call “life” require complex interactions among a number of different elements, and carbon's primary job seems to be carrying those other elements around on its back. Carbon isn't the “application code” so much as the infrastructure. I find that realization gobsmacking.

When I worked in the semiconductor industry, silicon was the present, but carbon always seemed like the future. As microprocessors comprise increasingly minuscule transistors, quantum effects begin to dominate classical ones, making silicon harder to work with. Carbon, on the other hand, can be used to build almost arbitrarily complex structures out of individual atoms. Nobody really knows what form of carbon might replace traditional semiconductors, partly because the element is so versatile. Carbon can form geodesic buckyballs, or graphene-like loafs that can be sliced absurdly thin, or nanotube-based substances so dark they look like holes in reality. Carbon, without any help from other elements, composes a menagerie of exotica that make mere diamonds seem mundane by comparison.

Here's what's making my head spin: Not only is carbon set to headline the integrated electronics show, it also plays a key supporting role in a completely different domain. It's simultaneously the world's greatest movie star, and a beloved character actor.

We are stardust. We are golden. We are billion year old carbon.

—Joni Mitchell

Undergraduate Electrical & Computer Engineering (ECE) programs will eventually have to teach organic chemistry, already an infamously difficult subject for aspiring biologists. But ECE “orgo” will fundamentally differ from its biomedical counterpart, focusing entirely on pure carbon rather than an assortment of merely carbon-based molecules.

One of the chief benefits of silicon has always been its plenitude. Now that it's getting scarce, we'll need a replacement that's relatively easy to come by. As of this writing, real-world quantum computers apparently use neither silicon nor carbon, but a metal called niobium. If I had to bet on the future, though, I'd still put all my money on carbon.