Questions

No, and the guides are written on that assumption. Each one has a section explaining the real science at an adult level — you can read it or skip it — plus the five questions children most often ask, with answers you can give without looking anything up.

It’s built for 8 to 11. Younger children often enjoy the experiments and miss the explanations, which is fine. Older children are usually fine too, though a confident 13-year-old may find the tone young even where the content isn’t.

Thirty minutes, designed as one sitting. Some run over when a child gets interested, which is the good failure mode. The guide gives a timing for every beat so you can see where you are.

For the first Big Idea: nothing. A book, three sheets of paper, a grapefruit, two cups, a ball, water. Later modules occasionally suggest something small; anything over about five dollars is always optional.

Yes — every lesson has a self-guided version that tells them up front what to ask a grown-up for, and won’t let them skip a prediction. We’d still suggest doing the first one together.

Today, nothing that identifies them leaves the browser. Gravity progress stays on your device. The child’s lessons load no analytics and no advertising. When parent accounts exist, a learner will be a nickname, a picture they pick from a set, a grade band, and progress — no child email, password, birthdate, photograph, or free text. Pages meant for adults record page views with Umami; that script is never loaded where a child does the lessons.

No, deliberately. No streaks, no daily targets, no countdowns, no comparison with other children, and nowhere a child can see a price. If the lesson isn’t good enough to come back to on its own, that’s a content problem and we’d rather fix it than paper over it.

Tell us. Every lesson lists its sources so you can check us, and we have already rewritten material because a reviewer showed us a picture that couldn’t be kept. The revision notes stay in the guides on purpose.

We map to it and say which standards a lesson touches, but we go past it on purpose. The standards ask a fifth-grader to describe that gravity pulls things down. We spend three weeks on why that description is the shallow version.

Gravity & Relativity — three lessons, both versions, and a short GPS piece — is playable and free. The other eleven Big Ideas are mapped, not built. There are no accounts yet, and checkout is not live. You can see the whole spine on the curriculum page.