The Big Bang Theory

Flashcards about the Big Bang Theory, evidence supporting it, and its alternative theories.

Big Bang Theory

The prevailing cosmological model for the universe that states that all matter and energy started out concentrated in a small area, smaller than an atom, followed by a gigantic explosion.

Expansion of the Universe

Evidence for the Big Bang Theory. Galaxies are moving further apart over time.

Redshift

The displacement of spectral lines toward longer wavelengths (the red end of the spectrum) in radiation from distant galaxies and celestial objects. Indicates that the universe is expanding.

Hubble's Law

States that the farther away a galaxy is, the faster it is moving away from us, demonstrating the expansion of the universe.

Cosmic Microwave Background Radiation (CMBR)

Longwave microwave radiation that appears to be coming from everywhere in the universe, which is considered as an evidence for the Big Bang Theory.

Abundance of Light Elements

The Big Bang theory predicts how much of each element should have been made in the early universe. Observed ratios of light elements (Hydrogen, Helium, Lithium) match predictions.

Steady State Theory

A theory that opposes the Big Bang Theory; stating that the universe has always been essentially the same as it is today and that it will continue that way forever.

Electromagnetic Spectrum

All energy produced by the sun and transmitted through radiation, including radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

Doppler Effect

The change in frequency or wavelength of a wave (or other periodic event) for an observer moving relative to its source.

Blueshift

The displacement of spectral lines toward shorter wavelengths (the blue end of the spectrum) when an object is moving towards the observer.