Water Computer Build — Full Breakdown & Transcript

I Built a Water Computer Using Siphon Cups

0h 01m video Published Jun 6, 2025 Transcribed Aug 29, 2026 S Steve Mould

Beginner 2 min read For: Anyone curious about how computers work, hobbyists, and educators looking for a hands-on way to explain logic gates.

AI Trust Score 75/100

⚠️ Average / Some Fluff

"Delivers exactly what the title promises: a working water computer built from siphons, with clear logic and a successful demo."

AI Summary

This video demonstrates the construction of a functional water-based computer using siphons and cups to perform binary addition. The creator explains how logic gates (AND, XOR) can be implemented with water flow, then tests the device by adding two random numbers. The build is a playful yet educational exploration of fundamental computing principles using everyday materials.

Chapters

1 Introduction to Water Logic 00:01 2 Building AND and XOR Gates 00:14 3 Testing the Adder 00:55 4 Reset and Conclusion 01:24

[00:01]

Concept: Water as Binary Logic

Computers add numbers using logic gates made of transistors. In this water computer, a '1' is represented by a water volume exceeding half a cup. Two '1's fill the cup, triggering a siphon that outputs a '1' for the AND operation.

[00:29]

Implementing XOR with a Leak

To create an XOR gate (output '1' only when inputs differ), a small hole is drilled to create a slow leak. A single '1' input doesn't trigger the siphon, but two '1's cause the water to drain, preventing a false output.

[00:55]

Two Gates, Two Outputs

The device has two inputs and two outputs: one for XOR and one for AND. This combination allows binary addition, where XOR gives the sum bit and AND gives the carry bit.

[01:09]

Testing with Random Numbers

The creator generates two random numbers (9 and 5) and feeds them into the water computer. The output is 14, correctly demonstrating binary addition (1001 + 0101 = 1110).

[01:39]

Reset Mechanism

The reset process involves lifting and tilting the device, similar to an Etch A Sketch, to clear the water and prepare for the next calculation.

The video successfully shows that basic computing operations can be performed with water and siphons, providing a tangible and memorable demonstration of how logic gates form the foundation of all digital computers.

Mentioned in this Video

Siphons

tool

Cups

tool

Tutorial Checklist

1 00:01 Define binary '1' as a water volume exceeding half a cup.

2 00:14 Connect two input cups to a siphon to create an AND gate: two '1's trigger the siphon, outputting '1'.

3 00:29 Drill a small hole in the cup to create a slow leak, enabling XOR logic: a single '1' doesn't trigger, but two '1's drain the water.

4 00:55 Combine AND and XOR outputs to perform binary addition: XOR gives sum, AND gives carry.

5 01:09 Test with random binary numbers (e.g., 9 and 5) and verify the output (14).

6 01:39 Reset the device by lifting and tilting it, like an Etch A Sketch.

Study Flashcards (5)

How is a binary '1' represented in the water computer?

easy Click to reveal answer

A water volume exceeding half a cup.