Here is a fact I can't quite get used to. On the day you were born, sunlight reflected off the Earth - off the hospital roof, the parking lot, the weather that afternoon - and some of it left. It has been leaving ever since, at the only speed light knows, and it has never stopped. Right now it is a thin shell, one day thick, expanding outward at exactly your age in light-years. For most adults that shell has already passed the nearest stars. Somewhere out there, if anything is looking back with a good enough eye, the day you were born is arriving for the first time.
I built Born Among Stars because I wanted to hold that thought in my hand. You give it a date; it gives you a boarding pass. Behind the pass is unglamorous arithmetic: the date becomes a Julian Day Number, the single running count of days astronomers have used for centuries because it doesn't care about months or leap years or which calendar a country happened to be using. From there you get your cosmic address - planet, star, spiral arm, galaxy, group - and a note on how far your birth-light has gotten, and which stars it has reached.
A life is broadcast whether or not anyone tunes in. The physics doesn't wait for an audience.
Two small things about how it's made, because they're the parts I actually care about. Every image in it is bundled with the page rather than fetched from somewhere else, which sounds like a technicality until you notice what it prevents: no third party is told which birthday you typed in, because no third party is contacted. And the little descriptions of the bodies - the thirty-odd stars and planets it knows about - are written by hand, not pulled from a feed, because I wanted the thing to read like a person talking about the sky rather than a database reciting it.
It's a toy. It is also, quietly, the same set of instincts I bring to serious work: do the real math, keep other people's information to yourself even when nobody is checking, and make the result something a human wants to read. The scale is different. The posture isn't.