ChikRoad

ChikRoad is a pocket spectroscope drawn in the style of a Victorian instrument room.
Point it at a light source, fan the beam into a chromolithograph ribbon of colour,
and read the dark Fraunhofer lines that tell you which elements are drinking the
light.

THE SPECTROSCOPE
The heart of ChikRoad is a working instrument, not an animation 🎬. Three brass controls
sit under the plate:

• Dispersion (×0.90–1.10) stretches and compresses your observed trace against the
ruled scale.
• Calibration zero (±8 nm) slides the whole trace left or right until it registers.
• Redshift z dials in a receding source so a distant galaxy's lines march back to
their rest wavelengths.

The reference comb stays fixed on the paper; your observed lines slide onto it. When
a line comes into true it SEATS with a soft detent you can feel. As the pattern 🔢
locks, a candidate element ignites in the margin cartouche and its confidence climbs.
Seat the lines on the wrong ❌ element and the residuals refuse to close — a false seat
is called out, and the solve stays blocked until you work it honestly.

The maths underneath is real spectroscopy: an affine instrument model
(observed = rest × dispersion + shift), inverse registration, de-redshifting by
(1 + z), an RMS residual over the seated lines, and a tightness-weighted confidence
score 🔢. The wavelengths are the real ones — the sodium D doublet at 589.0 and
589.6 nm, the hydrogen Balmer rungs at 656.3 / 486.1 / 434.0 / 410.2 nm, the
Ca II H and K lines at 393.4 and 396.8 nm.

THE ELEMENT CENSUS
55 spectroscopic sources — elements, ions and notable astronomical objects — each
with its principal lines, a fingerprint strip you can learn 📖 by eye, its discovery
story, its flame test, where in the sky or the lab you meet it, and cross-references
to the elements it is easily confused with. Filter 🎚️ by category or difficulty 📏, and
pin your favourites.

THE DRILLS
15 order-gated exercises that build 🔨 the eye, from finding the slit to reading a
receding source. Interactive drills hand you straight to the instrument with a live
trace waiting; teaching drills walk you through the reasoning first.

THE CALIBRATION LEDGER
Every solve is written into the ledger with its residual, its first-seat accuracy
and its time ⏱️. Per-difficulty 📏 splits and an inked residual-trend 📈 curve show whether
your hand is actually getting steadier.

THE PLATE CABINET
Name a solved spectrum and file it as a plate you can revisit — its settings, its
identified elements, its matched lines. Attach a photo 📸 of the real lamp or source
for reference, and save 💾 a branded spectrogram plate card to your gallery 🖼️.

THREE PLATES, THREE MOODS
Fraunhofer Chart 📊, Nocturne Plate and Verdigris Atelier — full palette identities
that retint the whole instrument, not just an accent colour.

WORKS ENTIRELY OFFLINE 📴
No account. No sign-in. No ads. Nothing to buy. ChikRoad makes no network calls and
sends nothing anywhere — every plate, drill and ledger entry lives on your device 📱.

Split the light. Read the lines.