What the explanation leaves out

Pick one explanation everyone already believes, and find the exact edge where it stops being enough.

Due: 24 August 2026 · Weight: 20%

Every physics course, this one included, hands you explanations that are simpler than the truth. Most of the time that is fine. A simplification that gets the important part right and quietly drops a detail nobody needs yet is doing its job.

Some simplifications are doing something else: making a claim sound settled when it is conditional, or standing in for an explanation that was never actually given. Telling the two apart is a skill this course keeps coming back to, starting in Week 1 with a sky that looks empty and turns out not to be.

The brief#

Choose one familiar physics explanation and show exactly where it stops being sufficient.

Pick a claim you have actually heard stated as though it settles the matter — “the night sky is dark because the universe is young”, “you do not fall through the floor because of Pauli exclusion”, “entropy means disorder”, and “particles are both waves and particles” are all fair game, and so is anything else that fits the shape. Say what the simple version gets right first. Most of these phrases exist because they capture something true and useful, and skipping straight to the criticism makes it look like you are attacking a strawman rather than doing the harder work of finding the actual edge.

Then find that edge. Say exactly where the explanation stops being sufficient, what it is quietly assuming, or what condition it depends on that it never states. Finish by naming the physics actually needed to go further — not “it’s more complicated than that,” but what, specifically, closes the gap.

The task is not to declare the explanation wrong. Most of these phrases are not wrong; they are incomplete in a particular, findable way. Find it.

What you submit#

A short written piece, around 600 to 900 words, built around the one explanation you chose. You may take that explanation from anywhere — a textbook, a popular science article, a documentary, an AI assistant. The source is not what is being marked. Your critique of it is.