Learning items
Cosmos
No chapter association
ConceptArtificial selection
Artificial selection is selective breeding in which people influence which organisms reproduce.
ConceptCosmic scale
Cosmic scale concerns the very different sizes, distances and times encountered in astronomy.
ConceptElliptical orbit
In an ideal bound two-body Kepler orbit, the path is an ellipse with the attracting body at one focus in the usual relative-coordinate description.
ConceptExperimental test
A scientific model must answer to observations that can check its predictions.
VocabularyLight-year
A light-year is the distance light travels in a vacuum in one year.
