Big Bang Vocabulary

Big Bang Theory

The leading scientific explanation for the origin of the universe, proposing that it began as a singularity approximately 13.8 billion years ago and has since expanded. This theory is supported by evidence such as cosmic microwave background radiation and the redshift of galaxies.

blueshift

A decrease in the wavelength of light from an object moving towards an observer, indicating that the object is approaching.

cosmic microwave background

The thermal radiation filling the universe, a remnant from the Big Bang, providing evidence of the universe's early hot state.

Doppler effect

The change in frequency or wavelength of light or sound waves from a source due to the relative motion of the source and the observer, commonly observed in astronomical contexts to measure the speed of stars and galaxies.

emission spectrum

A spectrum of light emitted by a substance, showing distinct lines corresponding to specific wavelengths, which can indicate the elements present in that substance.

galaxy

A massive system of stars, stellar remnants, interstellar gas, dust, and dark matter, bound together by gravity.

Hubble’s Law

The observation that the farther away a galaxy is, the faster it is moving away from us, indicating the expansion of the universe.

nucleosynthesis

The process by which elements are formed through nuclear reactions, primarily occurring in stars and during the Big Bang, resulting in the creation of heavier elements from lighter ones.

redshift

An increase in the wavelength of light from an object moving away from an observer, indicating that the object is receding.

spectroscopy

A technique used to analyze the light emitted or absorbed by substances, providing insights into their composition and properties, often used in astronomical observations to determine the redshift of galaxies.

theory

A well-substantiated explanation of some aspect of the natural world, based on a body of evidence and tested through observation and experimentation.

universe

The totality of space, time, matter, and energy, encompassing all galaxies, stars, planets, and the cosmic microwave background.