Try an investigation
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https://blackhole.org/universe/labs/
A useful experiment starts with a question you can answer by changing or comparing something. These six investigations connect a physical model to an observable result. Make a prediction first; then change one control and explain why the result changed.
Choose an investigation
Section titled “Choose an investigation”- Investigation Moon-phase laboratory Connect the orbital view with the Moon's appearance from Earth. Angles
- Investigation Exoplanet transit laboratory Compare an idealized transit with a documented observation. Ratios and graphs
- Investigation H–R diagram explorer Compare model stars using temperature, radius, and luminosity. Ratios and graphs
- Investigation Black-hole scale explorer Calculate the horizon radius and diameter in the Schwarzschild model. Ratios
- Investigation Binary-star laboratory Change a binary system's masses and viewing angle to discover what velocity curves can measure. Ratios and graphs
- Investigation Spectrum detective Match spectral patterns with measured starlight. Graphs and ratios
What the laboratories represent
Section titled “What the laboratories represent”The Moon model connects illumination and viewpoint. The transit model computes the overlap of two disks and compares the result with an observed light curve. The H–R explorer connects effective temperature, radius, and luminosity. The black-hole explorer calculates a horizon scale from a mass in a stated geometry. The binary-star model shows how masses and viewing angle shape the measured velocities of an orbiting pair.
Spectrum Detective compares several spectral features and applies one common wavelength ratio. Its separate Vega panels contain locally stored calibrated Hubble measurements. The template’s marker heights do not measure abundance, and its velocity control does not fit or move the observed data.
Each model leaves things out. The Moon lab is not a sky forecast, arbitrary model stars are not evolutionary tracks, a transit-shaped dip does not by itself confirm a planet, and calculating a radius does not establish an event horizon. The article and laboratory pages explain these boundaries beside the results.
The downloadable model notes give equations, assumptions, reference values, and reproduction commands for the Moon, transit, H–R and binary-star investigations. The black-hole calculator provides its constants and source beside its worked example.
Work without an interactive
Section titled “Work without an interactive”Every lab includes a static example and a question with an explained answer. Diagrams have text or table alternatives. Use ordinary links to move between the lab and its explanation; no account or saved answers are required.
For a classroom sequence, open For classrooms and clubs. To practice a common method across several topics, follow How astronomers know.