Sometime in early 2013, one of the delivery operations engineers at Tesla leaned back in his chair and took a look around the Silicon Valley office. “It was a sunny day, and I looked up and I thought, ‘Why are these lights on with full power, when full sunlight is coming through the window?’” says Neil Joseph. An online search for a better, responsive bulb only yielded a few expensive commercial products. That October, Joseph (who says even as a kid, his two fascinations were lights and cars) left Tesla to start his own lighting company.

The company is Stack, and its first product is Alba (alba is Italian for ‘sunrise’). The Alba bulbs are designed to work autonomously, both by adjusting light output based on sunlight and by learning and adapting to its owners' household habits. As Joseph sees it, it’s the first in a new wave of lighting products to follow the Philips Hue and the LIFX. Those bulbs are smarter than the usual drugstore variety—they can sync with a smartphone app, and even keep rhythm with a song—but they aren’t intelligent by the same standards as the Nest Thermostat or even a tool like Google Maps. In short: They’re connected, but not responsive.

More Than a Gimmick

Embedded in Alba’s light diodes are sensors for motion, occupancy, and ambient light. This meant cofounder Jovi Gacusan, who worked on sensors at NASA, had to create a new core technology, because in order to work efficiently Alba has to both read and react to available light. "If you think about noise-canceling headphones, we have to cancel out the light being emitted by the light itself to understand how much light is in the light source,” Joseph says. The result is a light bulb that can see-saw with natural light and in doing so uses 60 to 80 percent less energy than a regular LED bulb.

Stack

Alba’s other main function involves tailoring itself around its owners. Like the Nest, Alba runs algorithms and remembers user habits at home. “If we notice that people are in a certain part of the house, at certain times of day, and then they mosey on over to a bedroom, and then they spend more time awake in the bedroom before they go to bed we can start to light a pathway,” Joseph says. Alba emits light with blue tones in the morning, to help users become alert, and then glows warmer shades of white as the day wears on. Users can adjust all this in the Stack app, and create profiles (‘dinner party,’ ‘nap time,’ and so on), and Alba will fold that data into its learning curve too.

It’s fairly easy to see how Stack, by riding the light bulb’s coattails, could quickly become the spine of the connected home. Everyone has to buy light bulbs, and many of them. And because each Alba bulb contains a Bluetooth module that acts like iBeacon technology, the hardware is already poised to start talking to other smart gadgets.

For now, it’s being used to track users and their movement patterns around the house. (This feature has a dystopian ring to it. Joseph says, “We don’t track any personal data, or anything that’s on an individual user. It’s environmental and used for learning and product performance.”) Down the line, though, Joseph has ambitions of partnering with other companies, from “thermostats to smart beds that track how people sleep,” to eventually build a home that goes beyond convenience, and is actually healthier. “The more data we have, we can see if you’re in a REM cycle, and then know not to wake you.”

Alba is sold as a starter kit with two bulbs, for $150.

1UPDATED 8:45 a.m. Eastern 09/24/14. This story was updated to clarify Neil Joseph's role as a delivery operations engineer at Tesla.