If you're walking along Commonwealth Ave near the BU campus will see bright yellow phone booth with the words “call a boomer” on it. The idea was created by the biotech company Matter Neuroscience. Here's how it works: one phone is on Comm Ave in Boston and the other is in the lobby of Sierra Manor, an affordable housing building for seniors in Reno, Nevada. The phones are free to use. If no one picks up on the other end, you can leave voicemails. Side note: the conversations are being recorded.