Apple is obsessed with making its laptops as thin as possible. On Monday, company execs touted the latest Apple laptop, the MacBook, as its thinnest yet.
The image above comes from the company's presentation, and it shows something astonishing: when you crack open the laptop's case, most of the space is taken up by its battery. Or, more accurately, batteries — plural. The irregular brown rectangles in the laptop's four corners, as well as the big one in the middle, are all batteries. The device's logic board — the brains of the laptop — is at the top. At the bottom of the image you can see the underside of the trackpad.
This image provides a beautiful illustration of the differing trajectories of computer chips and batteries, the two inventions that have driven the mobile-computing revolution. A decade ago, that little logic board at the top would have been a lot bigger. But because of Moore's Law, chips keep getting smaller, cheaper, and more powerful, meaning we can now cram a full-powered computer into an area not much bigger than a deck of cards.
But there's no Moore's Law for batteries. While battery technology does get better, the pace of progress is glacial compared with the speed of Moore's Law. The amount of power a given volume of battery can hold hasn't changed much over the past decade. So each time Apple has squeezed a few millimeters of thickness out of its laptops, it has been forced to devote a larger fraction of the internal space to the battery. This has progressed to the point where the latest MacBook is mostly battery inside.