Unit 10
Computing in the real world.
Earlier Units at work: ray tracing, a pole balanced by feedback, a robot arm, and a quantum computer that searches.
Before this unit
- How a computer runs a program
- Trigonometry Mathematics
The unit, lesson by lesson
Lessons
4 lessons · 29 practice questions · about 2 hours
Ray tracing
How a computer draws a 3D world: a ray through each pixel, shadow rays to the light, bounces that bring reflections and light from other surfaces, and how many rays it takes for the noise to go.
A feedback loop
A controller balancing a pole on a cart: sensor, controller and motor in a closed loop, too little gain that drops the pole, tuning for the shortest settling time, and overshoot that grows when the correction arrives late.
A robot arm
An arm with three joints: how trigonometry turns the angles into the gripper's position, how to find angles that bring it to a point, two poses for one point, and what the joint limits take away from them.
Qubits and search
A qubit as an arrow on a sphere: a gate that makes a superposition, a measurement that gives 0 or 1 by chance, phase that makes interference, and Grover's search, which finds one item in an unsorted store in far fewer steps than an ordinary search.