Despite a suggestion first made by William Herschel in the 18th century, he shared the accepted view that all nebulae were relatively nearby objects and merely patches of dust and gas in the sky. Hubble had to spend many bitterly cold nights sitting at the powerful Hooker telescope before he could prove Shapley wrong. In October he spotted what he first thought was a nova star flaring up dramatically in the M31 "nebula" in the constellation of Andromeda. After careful examination of photographic plates of the same area taken previously by other astronomers, including Shapley, he realised that it was a Cepheid star.
Hubble used Shapley's method to measure the distance to the new Cepheid. He could then place M31 a million light-years away - far outside the Milky Way and thus itself a galaxy containing millions of stars.
The known Universe had expanded dramatically that day and - in a sense - the Cosmos itself had been discovered! Even The New York Times of the day realised the importance of the discovery: "Finds spiral nebulae are stellar systems. Doctor Hubbel [sic] confirms view that they are 'island universes' similar to our own. This discovery was of great importance to the astronomical world, but Hubble's greatest moment was yet to come.
He began to classify all the known nebulae and to measure their velocities from the spectra of their emitted light. In he made another startling find - all galaxies seemed to be receding from us with velocities that increased in proportion to their distance from us - a relationship now known as Hubble's Law. This discovery was a tremendous breakthrough for the astronomy of that time as it overturned the conventional view of a static Universe and showed that the Universe itself was expanding.
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. Now Hubble had demonstrated that Einstein was right in the first place. The mysterious force causing this acceleration is dubbed dark energy. Hubble was born on November 20, , in Marshfield, Missouri, and moved to Wheaton, Illinois, before his first birthday. He studied mathematics and astronomy at the University of Chicago and earned a bachelor of science degree in He was one of the first Rhodes Scholars at Oxford University, where he studied law.
After serving briefly in World War I, he returned to the University of Chicago and earned his doctorate degree in After a long career entirely at Mt. As with the telescope that bears his name, Edwin Hubble transformed our understanding of the universe. His spirit of discovery lives on today in the Hubble Space Telescope.
This website is kept for archival purposes only and is no longer updated. Wilson Observatory in California, where he would work for the rest of his life. He was researching nebulae, fuzzy patches of light in the sky. In , he announced the discovery of a Cepheid, or variable star, in the Andromeda Nebulae. Since the work of Henrietta Leavitt had made it possible to calculate the distance to Cepheids , he calculated that this Cepheid was much further away than anyone had thought and that therefore the nebulae was not a gaseous cloud inside our galaxy, like so many nebulae, but in fact, a galaxy of stars just like the Milky Way.
Only much further away. Hubble calculated how far away each Cepheid lay — and thus how far to each nebula — and realized they were too distant to be inside of the Milky Way.
Astronomers realized that these nebulae were in fact galaxies like the Milky Way, each containing billions of stars. The universe, once thought to be contained by the Milky Way, expanded significantly in the eyes of astronomers.
Around the same time, Hubble published a standard classification system to use for the galaxies. At the time, a descriptive system existed, and two other systems were proposed soon after, but they were insufficient. Hubble's clear method of organizing the various classes focuses on three galactic types : ellipticals, spiral and barred spirals, and irregulars.
Hubble originally thought that galaxies evolved from ellipticals to spirals, but scientists now know that each galaxy's shape is determined in its early life. In studying the various galaxies, Hubble was able to determine that they did not sit stationary in space. Instead, virtually every galaxy seems to be rushing away from Earth the Andromeda Galaxy is instead rushing toward us and will collide with the Milky Way in about 5 billion years.
0コメント