The Big Bang

3. The first element formed during the big bang
4. Radiation A form of energy that travels as waves through space, including light.
9. effect The effect causes the sudden change in pitch noticeable in a passing siren, as well as the redshift seen by astronomers.
11. A celestial object primarily composed of hydrogen and helium that emits light and heat.
13. The space between stars and galaxies.
15. Bang Theory The initial “bang” that resulted in the formation of the universe
16. Light Spectrum The range of electromagnetic waves that are visible to the human eye.
17. A particle of light.

1. The study of the universe, including its origin, structure, and evolution.
2. The entirety of space, time, matter, and energy in existence.
5. Shift A shift in the wavelength of light toward the red end of the spectrum, indicating motion away from an observer.
6. Electromagnetic waves with wavelengths longer than visible light.
7. A massive collection of stars, gas, dust, and dark matter bound together by gravity.
8. Hubble The American astronomer who first observed that galaxies are receding from Earth.
10. Background Radiation The faint radiation that fills the universe and is a remnant of the Big Bang.
12. Zero The lowest possible temperature, where particles have zero thermal motion.
14. Year A unit of measurement for the distance that light travels in one year.