600 Seconds Heartbeat T-ShirtI designed this t shirt as a tribute to the steady, predictable rhythm of the Bitcoin network. The "600 Seconds Heartbeat" T Shirt uses the number 600s because that's the target time, 10 minutes, between each new block being added to the timechain. For the original graphic, I paired this number with a clean, minimalist EKG (heartbeat monitor) line. It's my visual metaphor for the constant, reliable pulse of the protocol. Its a piece of designer