Parallax Pendulum: The Missing Axis

About Parallax Pendulum: The Missing Axis

Parallax Pendulum: The Missing Axis is a balance puzzle set in a laboratory built in a tree canopy, where the botanists hang their specimens on mobiles. Bamboo beams hang from vines, one beneath another, each with hooks at whole steps either side of its vine, and glass specimen jars already hang from some of them. You finish each mobile with blueprint stamps from a small tray: seed pods that weigh one, two or three.

The test is the evening breeze. When it blows, every beam must hang level. A load pulls by its weight times its distance from the vine, so a pod of two two steps out pulls like a pod of one four steps out, and a beam lower down counts with everything hanging from it. Balance the lowest beams first, then the ones above them.

The missing axis is the hidden beam. In every mobile one beam has turned edge-on to you behind a cluster of leaves, so its distances are lost: you can see which side each hook is on and their order outward, but not how far out they are. The breeze answers for it. Let it blow and every beam tips left, tips right or hangs level, and from those tilts you reason out what the leaves hide. Breezes are free; the fewest earn three stars. Twelve hand-ordered mobiles add beams, jars and depth one step at a time, each proved by the game's own solver, then crown mobiles without end and a daily mobile that is the same for everyone. Nothing is timed. Your progress stays in this browser.

How to play

Hang seed pods so every beam hangs level when the breeze blows.
Tap an empty hook to hang a pod; tap again for a heavier one, then to take it off.
A load pulls by weight times distance from the vine. A beam below counts with everything on it.
One beam is hidden behind the leaves: you see the side and order of its hooks, not their distances. The breeze shows which way it tips.
Fewer breezes earn more stars. There is no clock.

Controls

Tap or click an empty hook — hang a pod; again for a heavier one, then off
Arrow keys, WASD, D-pad, N and B — walk the cursor over the hooks; Enter — hang or change; X — take off
Space or Breeze — test the mobile; H — a hint
Backspace, Z or Undo — undo; R or Reset — take every pod off
P, Escape or Start — pause

Frequently asked questions

How does a beam balance?

Each load pulls by its weight times its distance from the vine the beam hangs on. Add the pulls on each side: when they are equal the beam hangs level. A beam hanging from a hook counts as one load with the total weight of everything on it.

What does the hidden beam show?

It is turned edge-on behind the leaves, so you see each hook's side and its order outward (first, second, third from the vine), but not its distance. Distances are whole steps, one to three. The breeze shows whether that beam tips left, tips right or hangs level, and that is enough to reason the distances out.

Are breezes limited?

No. Every breeze is free and shows how every beam tips. Stars count breezes against par: reason first and you need fewer. A hint shows one pod of an answer and limits that mobile to two stars.

Why is there a spare pod?

Each tray holds one more pod than the answer needs, so you cannot simply use everything. The fewest answers use exactly the others.

Can I play without telling the colours apart?

Yes. Pods show one, two or three pips and grow with weight, jars carry their weight on a label, hidden hooks show tags such as L1 and R2, and tilts show an arrow. Every breeze is described in words for screen readers.

Does the game save?

Yes, in this browser: balanced mobiles, stars, and the pods you had hung on the mobile you were working on. Nothing is uploaded.