Month: July 2025

SPECTRAL LINES
Dark or bright lines in a spectrum used to measure redshift and blueshift.

HUBBLE CONSTANT (H₀)
The rate of expansion of the universe.

HUBBLE’S LAW
The observation that galaxies are moving away from us, with speed proportional to their distance.

RELATIVISTIC DOPPLER EFFECT
The change in wavelength due to the motion of an object at speeds close to the speed of light.

COSMOLOGICAL REDSHIFT
The redshift caused by the expansion of the universe, shifting light from distant galaxies.

BLUESHIFT
The shortening of light wavelengths when an object moves toward the observer.

REDSHIFT
The stretching of light to longer wavelengths when an object moves away from the observer.

DOPPLER EFFECT
The change in frequency or wavelength of a wave due to the motion of its source relative to the observer.

STRONG GRAVITY REGIME
A region near massive compact objects where gravitational waves are most intense.