These pages are concise, visual references for the scientific ideas that recur across lectures, labs, and projects. They are not a second required reading sequence. A lecture introduces the minimum needed for that day; these cards give you one stable place to return when you need the vocabulary, model, or assumption again.
Astronomy & observables¶
Models & approximations¶
How to use a concept card¶
Start with the page your lecture or project links.
Identify the observable: what is actually measured or computed?
Identify the model: what simplified relationship connects inputs to an output?
Read the limits before treating the result as a statement about nature.