Search results
Results from the WOW.Com Content Network
H 0 is Hubble's constant and corresponds to the value of H (often termed the Hubble parameter which is a value that is time dependent and which can be expressed in terms of the scale factor) in the Friedmann equations taken at the time of observation denoted by the subscript 0. This value is the same throughout the universe for a given comoving ...
The observational result of Hubble's law, the proportional relationship between distance and the speed with which a galaxy is moving away from us, usually referred to as redshift, is a product of the cosmic distance ladder. Edwin Hubble observed that fainter galaxies are more redshifted. Finding the value of the Hubble constant was the result ...
The particle horizon, also called the cosmological horizon, the comoving horizon, or the cosmic light horizon, is the maximum distance from which light from particles could have traveled to the observer in the age of the universe. It represents the boundary between the observable and the unobservable regions of the universe, so its distance at ...
This would be the "light travel distance" (see Distance measures (cosmology)) rather than the "proper distance" used in both Hubble's law and in defining the size of the observable universe. Cosmologist Ned Wright argues against using this measure. [75] The proper distance for a redshift of 8.2 would be about 9.2 Gpc, [76] or about 30 billion ...
The universe's expansion rate, a figure called the Hubble constant, is measured in kilometers per second per megaparsec, a distance equal to 3.26 million light-years.
The ratio between these quantities gives the Hubble rate, in accordance with Hubble's law. Typically, the distance is measured using a standard candle, which is an object or event for which the intrinsic brightness is known. The object's distance can then be inferred from the observed apparent brightness. Meanwhile, the recession speed is ...
If interpreted that way, Hubble's measurements on 46 galaxies lead to a value for the Hubble constant of 500 km/s/Mpc, which is much higher than the currently accepted values of 74 km/s/Mpc [33] [34] (cosmic distance ladder method) or 68 km/s/Mpc [35] [36] due to errors in their distance calibrations.
The most powerful telescope to be launched into space has made history by detecting a record number of new stars in a distant galaxy. NASA's James Webb Space Telescope, history's largest and most ...