Big Bang Theory

2. German-born theoretical physicist recognized as one of the most influential scientists in history.
4. British mathematician and astronomer.
7. The entire range of all types of light radiation, both visible and invisible, organized by wavelength or frequency.
9. The ability to do work
12. The oldest light in the universe, essentially acting as the fading, leftover glow—or "afterglow"—from the Big Bang.
15. A huge collection of gas, dust, and billions of stars and their solar systems, all held together by gravity.
17. The decrease in wavelength (and increase in frequency) of light from an object moving toward an observer.
18. A 'shift' of light waves traveling away from Earth.

1. The narrow range of electromagnetic radiation that the human eye can perceive, spanning colors from violet to red.
3. An instrument that breaks up a wave into a frequency spectrum.
5. German-born American physicist and radio astronomer
6. Discoverer of the cosmic microwave background radiation.
8. The scientific study of celestial objects (planets, stars, galaxies, black holes) and phenomena originating outside Earth's atmosphere, including their motion, evolution, and composition.
10. The prevailing cosmological model explaining that the universe began approximately 13.8 billion years ago from an extremely hot, dense singularity.
11. Pioneering American astronomer who revolutionized cosmology by proving the existence of galaxies outside the Milky Way.
13. The lightest and simplest chemical element, with atomic number 1, consisting of one proton and one electron.
14. The totality of all space, time, matter, and energy in existence.
16. An odorless and invisible element gas found on the periodic table of elements.