Crystal Palace

The Heartbeat
Every crystal pulses in its own color on a slow ~8 second breath. Whether you're alone or in a group, the color stays yours — you don't blend into the group's color. What you share is the rhythm.

The Charge
Time spent near other crystals builds up a "charge" inside yours. Charge fuels brightness — empty charge means a dim or invisible crystal, full charge means a strong glow. It takes a few hours of being together to fill all the way up, and the charge fades slowly over time when you're alone. Left long enough by itself, a crystal goes dark.

Sync (Kuramoto coupling)
When two or more crystals can hear each other, they pull their heartbeats toward each other and lock into a shared rhythm — every crystal in the group breathing at the same time. The bigger the group, the stronger the pull. Locking from a cold meet takes about a minute or two.

Peak Flash (the reward)
Once you and your friends have been together long enough to charge all the way up, the top of every pulse gets a brighter pop. Since you're all in sync by then, those flashes happen at exactly the same instant — the whole group glowing brightest together for an instant, every breath.

Greetings
When a new crystal joins your nearby list, your next breath glows in their color instead of yours — one full pulse of "hello, you're here." Then back to your own color from the next breath onward. A friend coming back after a few minutes away will trigger this in both crystals at once — yours flashing their color, theirs flashing yours, simultaneously. The same crystal won't trigger another greeting for ~5 minutes, so the effect stays special.

Drift Apart, Drift Back
If you leave the group for more than a couple of minutes, your crystal's rhythm starts drifting at its own slightly-unique pace (every chip has a different natural rhythm baked in). Stay away for 15-30 minutes and you've drifted fully out of sync with the group. When you come back, you watch them slowly pull each other in again — the convergence transient is the whole point. Brief disconnects of less than ~2 minutes don't drift; the rhythm holds while you grab a coffee.

Dying
As charge drops very low (after days alone), the heartbeat skips cycles and the crystal fades to dark. Bringing it back near friends starts the charge climbing again from wherever it left off.

Groups
Crystals only interact with others on the same Group ID. Different groups are invisible to each other — they share the radio but ignore each other's packets.