Online Pendulum: How It Actually Works

What an online pendulum is

An online pendulum is a program that picks one option on a board and shows it to you as a pendulum that swings and comes to rest. Nothing hangs from your fingers: a source of randomness, or a movement of yours, decides which sector it settles over.

That difference matters. With a handheld pendulum, your own muscles move it; on a screen, what moves it depends on the engine you choose. That's why Paths lets you pick the engine and explains each one. You deserve to know what you're looking at when "Yes," "No," or "Not yet" shows up.

What no engine can do

No online pendulum engine knows the answer to your question. Randomness doesn't read your future, a sensor doesn't pick up your intentions, and a physics simulation has no access to anything you don't. Saying so clearly is part of using the tool well.

So what is it good for? The same thing a crystal pendulum is good for in the hands of someone who uses it honestly: it works as a mirror. You see an answer and notice what happens inside you. If you read "No" and felt relief, that relief is telling you something you may not have let yourself hear. The engine supplies the motion; you supply the meaning.

Secure randomness: the default engine

Secure randomness uses your device's cryptographic generator, the same kind of randomness that protects passwords and encrypted connections. Paths takes 32 bytes from it and feeds them to HMAC_DRBG, a generator specified by NIST in its SP 800-90A standard, to produce the numbers that pick the option.

The pick is exact: every option on the board gets precisely the odds it should. On a five-answer board, each answer comes up one time in five over the long run, with no hidden bias. It's the engine we recommend if you just want to ask without thinking about the machinery.

Visible seed: randomness you can replay

The visible seed is reproducible randomness: a starting number you can see on screen that determines the whole sequence. Paths uses xoshiro128**, a classic, fast generator designed by David Blackman and Sebastiano Vigna. With the same seed and the same board, you get the same answer every time, on your phone or your computer.

It's there for anyone who wants a close look at the mechanism: write down the seed, replay the pick, and confirm nothing changed behind your back. It isn't meant for secrets, since anyone with the seed can recompute the result. If you don't enter one, Paths draws a seed with secure randomness and saves it with your reading.

Your question: same question, same minute

The your-question engine turns the question itself into the seed. First it tidies the text, trimming extra spaces and lowercasing everything, so the same sentence typed twice counts as the same question. Then it adds the exact minute (in universal time) and computes a SHA-256 fingerprint of the result. That fingerprint drives the generator.

The behavior is deliberate: ask the same question in the same minute and you get the same answer; a minute later it may change. Many people like this because it echoes a common dowsing habit of not asking the same thing over and over. It also works with a recorded audio question, in which case the recording's fingerprint goes in. This engine is not mixed with secure randomness, because being repeatable is the whole point.

Sensors: your surroundings, mixed with secure randomness

The sensors engine listens for about two seconds to your phone's motion, the timing of your taps, and microphone noise, with a meter on screen while it works. That data is boiled down to a fingerprint and mixed with 32 bytes of secure randomness before the pick.

The mixing has a purpose: the result is never weaker than secure randomness, even if the room is perfectly still. What this engine adds is the sense that the moment takes part: the table, your hand, the sound around you. The raw data isn't stored; only a short piece of the fingerprint remains, proving which material was used.

Physics: a simulated pendulum you push

The physics engine simulates a real pendulum: a weight hanging from a pivot, with gravity and gentle air drag. You give it the first push with a gesture on the screen, a touch of secure randomness is added, and then the simulation runs on its own until the pendulum settles over an option.

Here the swing is the answer, not a decorative animation: the sector where it comes to rest is the result. It's the engine closest to letting go of a pendulum and waiting, except that you know exactly what moves it.

Your hand: the ideomotor effect, made visible

The your-hand engine lets your own micro-movements move the pendulum. On a phone, you hold it as if it were the chain, and the pivot follows the phone's motion (on an iPhone, the browser will ask permission to use the motion sensors). On a computer, the pendulum hangs from your mouse pointer. Whichever swing dominates as the pendulum settles decides the answer.

This is the digital version of what happens with a handheld pendulum. In 1852, William B. Carpenter gave the name ideomotor to the small muscle movements we make without noticing when we hold an idea in mind, and Michel-Eugène Chevreul had already studied how those movements steer a pendulum held between the fingers. Here you can watch it happen: no randomness involved, just your body responding to what you hope for or fear. That's why this engine can show you, very clearly, what you already feel.

What you see and what gets saved

The presentation is separate from the engine: you can see the answer instantly, in 2D from above, or in 3D. With secure randomness, visible seed, your question, and sensors, the answer is picked first, and the animated pendulum gets a soft, invisible nudge so it settles there. With physics and your hand it's the other way around: the motion is what decides.

Every reading records how it was made: the engine, the seed when it's reproducible, and a short fingerprint of the material used. It all stays on your device, with no account, and you'll find it in My readings.

• Secure randomness: the cryptographic generator decides; can't be replayed.
• Visible seed: the seed decides; can be replayed.
• Your question: the question and the minute decide; repeats within that minute.
• Sensors: your surroundings mixed with secure randomness.
• Physics: your push and the simulation.
• Your hand: your micro-movements.

Which engine to choose

Pick an engine based on how you want asking to feel. For simplicity, stay with secure randomness. If you're curious about the machine, try the visible seed. If you like the idea that your question and the moment count, use your question. If you want a ritual that involves your body, go with physics or your hand.

Before you start, you can calibrate your yes, your no, and your "unclear" in My pendulums, and choose a board: yes or no for simple decisions, five answers when you want shades of gray. Whatever the engine, the valuable part stays the same: what you notice in yourself when the answer appears.