![]() ↑ Eugenie Samuel Reich Published online 27 June 2011| Nature| doi: 10.1038/news.2011.385. ![]() "… if redshifts are velocity shifts which measure the rate of expansion, the expanding models are definitely inconsistent with the observations that have been made … expanding models are a forced interpretation of the observational results" Hubble himself did not see his 1929 data as evidence for an expanding Universe. This discovery lead to the notion of the expanding universe which is the centre-piece of the cosmology of the present day. The linear velocity-distance relation was established.The distribution of galaxies was found to be homogeneous in distance (the galaxies were all over the universe, not in any particular location).Hubble settled decisively the question of the nature of the galaxies (as being other things like the Milky Way).A classification system for nebulae, both galactic (diffuse) and extragalactic (both nebulae inside our Milky Way galaxy, and other galaxies outside it).The Hubble Space Telescope was named after Hubble.įour major achievements Īccording to Sandage, Hubble achieved four main things: Some have incorrectly said that Hubble discovered the Doppler shift in the spectra of galaxies, but this had already been observed earlier by Vesto Slipher, whose data Hubble used. This work helped to establish that the universe is expanding. Light traveling through stretching space experiences a Hubble-type redshift. Today, the 'apparent velocities' of galaxies are understood as an increase in proper distance which occurs due to the expansion of space. Nevertheless, the idea bears Hubble's name to this day. Georges Lemaître, a Belgian priest and astronomer, had published the idea two years before in an obscure journal. The law states that the greater the distance between any two galaxies, the greater their relative speed of separation. In 1929 Hubble formulated what is called Hubble's law. Redshift is observed in the light spectrum Doppler effect is the change in pitch or colour when an object or sound comes in (higher pitch, brighter color) or moves away (lower and darker). Hubble found the degree of Doppler effect ( redshift) from a galaxy increased in proportion to its distance from Earth. Then he proved the galaxies were moving away from each other. Also, he developed a method for classifying galaxies. In 1925 he showed that there are galaxies beyond our own, the Milky Way. Hubble's findings changed the scientific view of the universe. Wavelength increases up towards the red and beyond (frequency decreases).Įdwin Powell Hubble (November 20, 1889 – September 28, 1953) was an American astronomer. He died in 1953, with that ambition unfulfilled, but he would have been thrilled to know that the first space telescope is named after him.Absorption lines in the optical spectrum of a supercluster of distant galaxies (right), as compared to absorption lines in the optical spectrum of the Sun (left). But all the effort was in vain because there was no category for astronomy. Four times as powerful as the Hooker, the Hale would be the largest telescope on Earth for decades.ĭuring his life, Hubble tried to obtain a Nobel Prize, even hiring a publicity agent in the late 1940s to promote his cause. In 1949, he was honoured by being allowed the first use of the instrument. Hubble’s last significant contribution to astronomy was playing a central role in the design and construction of the Hale 200-inch Telescope on Palomar Mountain. Now Hubble had demonstrated that Einstein had been right in the first place. More than a decade earlier, Einstein himself had bowed to the observational wisdom of the day and corrected his equations, which had originally predicted an expanding Universe. It was a revelation and overturned the conventional view of a static Universe by showing that the Universe itself was expanding. This relationship is now known as Hubble's Law. In 1929 he made a startling find: most galaxies seemed to be receding from us with velocities that increased in proportion to their distance from us. ![]() He began to study and classify all the known nebulae. This discovery was a breakthrough, but Hubble's greatest moment was yet to come. Thus it was a galaxy in its own right, containing billions of stars. It showed Hubble that Andromeda was far away – a million light-years at least – and so was outside the Milky Way. After careful examination of photographic plates of the same area taken previously by other astronomers, he realised that it was a particular kind of variable star, known as a Cepheid, which could be used to measure distance. In October 1923, using the Hooker telescope, Hubble spotted what he first thought was a nova star flaring up dramatically in the Andromeda 'nebula'.
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