Big Bang Theory

2. A colorless,odorless,highly flammable gas,the chemical element of atomic number 1.
4. The scientific study of celestial objects (planets,stars,galaxies,black holes) and phenomena originating outside Earth´s atmosphere.
5. American astronomer who revolutionized cosmology by proving the existence of galaxies outside the Milky Way and discovering that the universe is expanding.
10. Renowned American avant-grade theater director,playwright, and visual artist.
13. The faint nearly uniform remnant radiation leftover from the Big Bang filling all space in the observable universe.
16. A massive, gravitationally bound system consisting of stars,stellar remnants,interstellar gas,dust,and dark matter.
17. A colorless, odorless, tasteless, and non-toxic noble gas.
18. German-born theoretical physicist recognized as the father of modern physics.

1. German-American physicist and radio astronomer.
3. Renowned English astronomer and mathematician.
6. The entire range of all possible frequencies wavelengths, and photon energies of electromagnetic radiation, extending from low energy radio waves to high energy gamma rays.
7. The totality of all space, time, matter, and enegry
8. The narrow segment of the electromagnetic spectrum roughly 380-780 nm in wavelength.
9. How astronomers explain the way the universe began.
11. An apparatus for photographing or otherwise recording spectra.
12. The capacity to do work.
14. The scientific phenomenon where light or other electromagnetic radiation from an object is increased in wavelength.
15. The displacement of the spectrum to shorter wavelengths in the light coming from distant celestial objects moving toward the observer.