Across
- 1. process by which two light atomic nuclei combine to form a single heavier one while releasing massive amounts of energy
- 4. the strong force the weak force the electromagnetic force and the gravitational force
- 11. a theory of exponential expansion of space in the early universe
- 14. cosmic body of extremely intense gravity from which even light cannot escape
- 15. the distance light travels in one year 6 trillion miles
- 16. substance composed of subatomic particles that have the mass electric charge and magnetic moment of the electrons protons and neutrons of ordinary matter but for which the electric charge and magnetic moment are opposite in sign
- 17. gravitationally bound system of stars stellar remnants interstellar gas dust and dark matter
- 18. component of the universe whose presence is discerned from its gravitational attraction rather than its luminosity
- 19. physical interaction among electric charges magnetic moments and the electromagnetic field
- 20. measure of hotness or coldness
- 22. widely held theory of the evolution of the universe
- 23. a dark or bright line in an otherwise uniform and continuous spectrum resulting from an excess or deficiency of photons in a narrow frequency range compared with the nearby frequencies
- 25. the average density of matter required for the Universe to just halt its expansion but only after an infinite time
- 26. shift of light waves traveling away from Earth
- 28. device that measures the strength of electromagnetic radiation in the range from ultraviolet to infrared and including the visible spectrum
- 29. SI base unit of temperature, named after the Belfastborn and University of Glasgow based engineer and physicist William Thomson
- 30. change in frequency of a wave in relation to an observer who is moving relative to the wave source
- 31. a completely empty space
Down
- 2. electromagnetic radiation filling the universe that is a residual effect of the big bang 13.8 billion years ago
- 3. used Hubble to observe the most distant stars and galaxies as well as the planets in our solar system
- 5. radiation era in the Big Bang theory during which the Universe was hot and dense and was dominated by the effects of radiation
- 6. a pair of equal and oppositely charged or magnetized poles separated by a distance
- 7. an account or theory of the origin of the universe
- 8. observed displacement of an object caused by the change of the observer's point of view
- 9. flat spherical and hyperbolic
- 10. region of space where the curvature of spacetime becomes infinite
- 12. if heat is recognized as a form of energy then the total energy of a system plus its surroundings is conserved
- 13. the era that started when the gravitational effect of matter began to dominate the effect of radiation pressure
- 21. displacement of the spectrum to shorter wavelengths in the light coming from distant celestial objects moving toward the observer
- 24. continued progress of existence and events in the past present and future regarded as a whole.
- 27. a type of star that pulsates radially varying in both diameter and temperature and producing changes in brightness with a welldefined stable period and amplitude