LightYears - Stardance

Ship #1 Changes requested

@sainiavinash234 on LightYears · 29 days ago

Lightyears finds the REAL star whose light left it on the day you were born.

What it does: enter your birthday, and the app turns your age into light-years, then locates an actual star at that exact distance from a catalog of 8,800+ real stars (HYG v4.1). The light hitting your eyes tonight genuinely left that star the day you were born.

What I built:
• Find your star — your age becomes light-years, mapped to a real star (preferring named/bright ones)
• 3D galaxy (Three.js) — ~8,800 real stars placed by actual coordinates, coloured by temperature. Drag to look around, scroll to zoom. Your star glows with a pulsing ring
• "The universe is watching" — drag a timeline through history and the galaxy lights up the shell of stars at that distance. A star 57 ly away is watching Earth's 1969 Moon landing RIGHT NOW. Real events + your birthday are pinned on the timeline
• Starposts + share cards — pin a message to your star (saved locally per star) and download a beautiful PNG to post anywhere

What was challenging:
• Smoothly brightening a "shell" of 8,800 stars while dragging — solved with a custom shader using shell-radius uniforms (no geometry rebuilds, buttery smooth)
• Getting html-to-image to embed Google Fonts into the share-card PNG — fixed with crossorigin="anonymous" on the font link

What I'm proud of: pure HTML/CSS/JS, no backend, no build step, works on mobile, and the "someone out there is right now watching the day you were born" moment genuinely gives people chills. Real astronomy + real emotion.

How to test: open the live demo, enter any birthday, hit "Find my star". Then try "See who's watching →" (drag the timeline through Earth's history) and "Pin a message ✦" (write something and download the share card).

Live: https://mrcrackman00.github.io/Lightyears/
Source: https://github.com/mrcrackman00/Lightyears

3 devlogs
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Try project → See source code →

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@sainiavinash234 on LightYears · about 1 month ago

45m 58s logged

The breakthrough feature: “The Universe Is Watching” 🛸

This one bends your brain. Light is slow — a star 57 light-years away is RIGHT NOW catching the light that left Earth 57 years ago, in 1969. So someone on a planet there tonight, with a good telescope, would be watching the Moon landing LIVE. Not a recording — live.

Added a timeline slider. Drag it and the 3D galaxy lights up the shell of stars at that exact distance, with a headline naming the moment those stars are seeing. Real events are pinned — first flight, penicillin, Moon landing, first iPhone, first black hole photo. Your own birthday gets pinned too.

All numbers come straight from the real HYG catalog. The shader takes shell-radius uniforms so brightening the right band of stars while dragging needs zero geometry rebuilds. Live demo: https://mrcrackman00.github.io/Lightyears/

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@sainiavinash234 on LightYears · about 1 month ago

15m 23s logged

Shipped the core of Lightyears ⭐

The idea: enter your birthday, and the app turns your age into light-years, then finds a REAL star whose light has been travelling toward Earth for exactly that long. So the light hitting your eyes tonight actually left that star the day you were born.

Built it on the HYG v4.1 star catalog — processed 100k+ stars down to a clean JSON of 8,800 worth showing. Dark, cinematic, mobile-first UI. No backend, pure HTML/CSS/JS.

Next up: turn the flat result card into a real 3D galaxy you can fly through.

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@sainiavinash234 on LightYears · about 1 month ago

2h 35m 6s logged

Tonight, a star is showing you the day you were born. Go find it. First ship of Lightyears! Enter your birthday and it finds the real star whose light left it the day you were born your age becomes light-years, mapped to an actual star from a catalog of 8,800+. Includes an interactive 3D galaxy, a “universe is watching” timeline, and downloadable share cards. Live: https://mrcrackman00.github.io/Lightyears/