Big Bang Theory

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Across
  1. 1. a system of millions or billions of stars, together with gas and dust, held together by gravitational attraction.
  2. 10. the physical interaction among electric charges, magnetic moments, and the electromagnetic field
  3. 11. Temperature is the degree of hotness or coldness of an object
  4. 12. a theory of exponential expansion of space in the early universe.
  5. 13. an increase in the wavelength
  6. 15. A black hole is a region of spacetime where gravity is so strong that nothing, including light or other electromagnetic waves, has enough energy to escape it.
Down
  1. 2. the distance light travels in one year.
  2. 3. Dark matter is a hypothetical form of matter thought to account for approximately 85% of the matter in the universe.
  3. 4. the average density of matter required for the Universe to just halt its expansion, but only after an infinite time.
  4. 5. An alternative term for the radiation era in the Big Bang theory, during which the Universe was hot and dense and was dominated by the effects of radiation.
  5. 6. In the Big Bang theory, the era that started when the gravitational effect of matter began to dominate the effect of radiation pressure.
  6. 7. change in observed wavelength, or frequency
  7. 8. the SI base unit of thermodynamic temperature (equivalent in size to the degree Celsius), first introduced as the unit used in the Kelvin scale.
  8. 9. a completely empty space.
  9. 14. instruments that measure electromagnetic radiation, from ultraviolet to infrared, including the visible spectrum.