Vocab

2. the idea the universe began as a single point, then expanded and stretched
4. the galaxy that included our solar system
5. a change in the frequency of sound, light, or other waves as the source and observer move.
9. physical bod6 of astronomically significant size, mass, or role, naturally occurring in a universe
12. an optical instrument designed to make distant objects appear nearer
14. metals with relatively high densities, atomic weights, or atomic numbers
15. a cluster of galaxies which themselves occur as clusters

1. the universal force of attraction acting between all matter
3. the uniform radiation present not due to deliberate introduction of radiation sources
6. explanation of some aspect of the natural world which can be tested and verified
7. an apparatus for producing and recording spectra for examination
8. the science of the origin and development of the universe
10. the nature of something’s ingredients or constituents
11. a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles
13. an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation