PM New build is live: "Wobble Hunter v1: blink comparator parallax game". Reload the game to play it. · 6d
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From arXiv: “The cold substellar frontier in JWST Extragalactic surveys: a robust parallax measurement yields the most distant known ultra-cold Y dwarf”
Build the first version as one self-contained HTML page with a single canvas and no external assets. Starfield: a seeded generator draws about 300 stars with varied brightness and size, soft glows and a faint noise background. A plate scale label shows the conversion (e.g. 1 px = 10 mas). Blink: Space or a Blink button switches between Epoch A and Epoch B. Holding either one auto-blinks at about 2 Hz, and a large label shows the current epoch. Between epochs, a faint reddish target shifts by its true parallax (converted to px) in a random direction. Every star gets about 0.3 px of jitter so the target is harder to spot. Find: clicking or tapping a wrong star flashes it red and costs points. The right pick locks the target with a ring. Measure: drag with mouse or touch from the A position to the B position. A live line and readout show the shift in mas, the distance in pc (1/p, with p in arcsec) and the distance in ly. Submit reveals the true positions, the true parallax and the error %. Score: up to 1000 per level based on accuracy, minus wrong-pick penalties, with a running total. Levels 1–5: the target gets fainter each level and the shift drops from about 400 to about 60 mas. An end screen shows the total score and a Play Again button. Also: short how-to text on screen, and a canvas that scales to fit on desktop and mobile.
A single self-contained HTML page with one canvas, no external assets. - Starfield: a seeded random generator draws about 300 stars with varied brightness and size, a faint background noise layer, and soft glows. Show a plate scale label (e.g. 1 px = 10 mas). - Blink: Space or a button toggles Epoch A/B, and holding it auto-blinks at about 2 Hz. A big label shows which epoch is on screen. Moving between epochs, all stars stay fixed except a reddish faint target that shifts by its true parallax (converted to px) in a random direction. Add a tiny per-star jitter of 0.3 px so the target doesn't stand out too easily. - Find: click or tap a star. A wrong pick costs points and flashes it red. A right pick locks it with a ring. - Measure: drag on the canvas, with mouse or touch, from the A position to the B position. Show a live line and readout of mas and distance (1/p in arcsec gives pc, also show ly). A Submit button reveals the true positions, true parallax, and error %. - Score: up to 1000 per level based on accuracy, minus penalties for wrong picks, with a running total. - Levels 1–5: the target gets fainter and the shift drops from about 400 mas to about 60 mas. Then an end screen with total score and Play Again. - Short how-to text on screen. Works on desktop and mobile (canvas scales to fit, touch events supported). Acceptance: you can complete all 5 levels by blinking, picking, and dragging; distances are computed correctly from 1/p; scoring and the restart both work. The original idea, in the owner's words: “Blink Comparator: Flip between two telescope 'epochs' of a star field, spot the cold brown dwarf that wobbles, and measure its parallax to work out how far away it is. Canvas star fields with procedurally generated stars. One star shifts between epochs. The player clicks the mover, then drags to measure its shift in mas and gets distance = 1/parallax. Levels get fainter and farther, scored on accuracy.”
This spec is clear and complete, so I'm scheduling it as the first build. It will be a single HTML file with a seeded starfield, blink and auto-blink, picking the moving star, drag-to-measure in mas, distance from 1/p in pc and ly, accuracy scoring, 5 levels that get harder, and an end screen with restart. Queued for implementation in an isolated workspace. I’ll report the checks and a pull request here.
Implemented in pull request #1. The project build and tests passed in the isolated workspace. I've built the first version of Wobble Hunter as a single 66 KB `dist/index.html`. It has one canvas and makes no network requests. `npm run build` and `npm test` both pass: 9 of 9 tests, with nothing skipped. **What you get** - **Starfield:** 300 stars from a seeded generator, with varied size, brightness and colour, soft glows, a few diffraction spikes and a faint grainy background. The plate shows a "1 px = 10 mas" label, a scale bar and tick marks. About nine faint red decoy stars mean colour alone won't give the target away. - **Blink:** Space or the Blink button switches between Epoch A and B, and holding either auto-blinks at 2 Hz. A large label shows the current epoch. Only the target moves, by its parallax; every other star shifts 0.2–0.3 px. - **Find:** a wrong star flashes red and costs 150 points. The right one gets a pulsing ring, then the view zooms in on it so measuring is possible even on a phone. - **Measure:** you drag from the A spot to the B spot, and the line's ends can be nudged afterwards. A live readout shows the shift in mas, the distance in pc (1/p) and in ly. Submit reveals the true A and B positions, the true parallax and your error %. - **Score and levels:** up to 1000 per level for accuracy, minus penalties, with a running total. A line of the right length drawn away from the target gets no accuracy points. Over levels 1–5 the target fades and the shift drops from ~400 to ~60 mas. The end screen shows a per-level table, a rank and Play Again. - **Also:** on-screen how-to steps, a layout that fits any window, sound effects made in code with a mute button, and best score saved through `hallway.save` when it's available. **Tests** - Logic: the star field is the same for the same seed, only the target moves, jitter stays within 0.3 px, the level ladder, the pc/ly maths, scoring and picking. - Build: one canvas, no external assets, under 2 MB. - A browser run on a desktop-sized and a phone-sized window plays all five levels with real input: holding Space flips 4–7 times in 1.5 s, one wrong pick costs 150, then pick, drag, Submit. It checks the pc and ly readouts and the totals, and that Play Again resets the game. **Screenshots reviewed** I looked at the intro, find, busy (wrong pick plus auto-blink), measure, reveal and end screens at 1440×900, 920×575, 390×844 and 844×390, plus 360×640. Nothing scrolls at any size. Fixes from that review: - The Next button was cut off with the phone held sideways. - Panel text overflowed at the stream-card size. - The mute button overlapped the title, and the AUTO tag overlapped the epoch letter. - The level-5 target was nearly invisible, so I made the faint end of the ladder brighter. Up close it's now faint but findable. The cover image is saved at `/tmp/projex-shots/cover-1440x900.png`. **Worth knowing** - I read "about 2 Hz" as two full A→B→A cycles per second, so the epoch switches every 250 ms. - The page exposes a small `window.WH` object that the browser test uses to drive the game. - If Playwright isn't installed, the browser test skips itself rather than failing. Nothing is committed or pushed. Verification and merge follow the project’s auto-merge setting. You can follow the pull request in the Code tab.
Auto-merged pull request #1 after a fresh build and test run against the latest main branch. Automatic publishing will follow when enabled and hosting is connected; the live release status appears here.
Published: https://projex.fly.dev/play/project_53fbbfbc-ce1 — fresh build and tests passed, stored content verified, commit c02e421. This is the platform-built version.
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