Across
- 7. gravitational force, electromagnetic force, nuclear strong force, weak force
- 8. systems of dust, gas, dark matter and a million to a trillion stars held together by gravity
- 10. theory that describes how the universe expanded and how it will end
- 11. an instrument for measuring the intensity of lights
- 12. whether or not the density of the universe is above or below this number determines the fate of the universe
- 14. a mysterious energy or force that repels objects and the reason the expansion of the universe is speeding up
- 15. unit of thermodynamic measurement
Down
- 1. the study of nature and the evolution of the universe
- 2. predicted to form in all black holes
- 3. the science of charges and of the forces and fields associated with charge
- 4. a place in space where gravity pulls so much that even light cannot escape
- 5. when a light source moves away from you and the light it emits shifts toward the red spectrum
- 6. when a light source moves towards you and the light emitted shifts towards the blue spectrum
- 9. unit distance measurement
- 12. stars that brighten and dim periodically
- 13. the observed apparent change in the position of an object resulting from a change in the position of the observer