Search results
Results From The WOW.Com Content Network
As the universe expanded, the plasma cooled to below 3000 K—a low enough energy such that the electrons and protons in the plasma could combine to form neutral hydrogen atoms. This recombination happened when the universe was around 379,000 years old, or at a redshift of z = 1089 . [ 4 ]
In physics, sound energy is a form of energy that can be heard by living things. Only those waves that have a frequency of 16 Hz to 20 kHz are audible to humans. However, this range is an average and will slightly change from individual to individual.
Hugh Everett's universal wavefunction supports the idea that observed and observer are all mixed together: . If we try to limit the applicability so as to exclude the measuring apparatus, or in general systems of macroscopic size, we are faced with the difficulty of sharply defining the region of validity.
The equation of state for ordinary non-relativistic 'matter' (e.g. cold dust) is =, which means that its energy density decreases as =, where is a volume.In an expanding universe, the total energy of non-relativistic matter remains constant, with its density decreasing as the volume increases.
An Answer to Everything; An extensive online companion site was produced to accompany the documentary. The online companion covers history of cosmology, unanswered questions and other topics related to the program. It was designed to function as both a supplement to the series and a stand-alone web piece.
On March 6, 2008, the United States Postal Service released a 41-cent stamp honoring Hubble on a sheet titled "American Scientists" designed by artist Victor Stabin. [46] His citation reads: [ 61 ] Often called a "pioneer of the distant stars", astronomer Edwin Hubble (1889–1953) played a pivotal role in deciphering the vast and complex ...
Gerson Goldhaber (1924–2010) used supernova observations to measure the energy density of the universe; J. Richard Gott (1947–) proposed the use of cosmic strings for time travel; Alan Guth (1947–) explained the isotropy of the universe by theorizing a phase of exponential cosmic inflation soon after the big bang
He is a key figure in the 17th-century Scientific Revolution, best known for his laws of planetary motion, and his books Astronomia nova, Harmonice Mundi, and Epitome Astronomiae Copernicanae, influencing among others Isaac Newton, providing one of the foundations for his theory of universal gravitation. [6]