![]() In the mid-nineteenth century, Sir William Huggins compared the spectra of the sun and distant stars and showed that both are made largely of Hydrogen, making clear that our sun is just a star up close and that we are made of the same stuff as the cosmos. Nowhere has the impact of physics on astronomy been greater than with the introduction of spectroscopy. ![]() By monitoring the coalescence of two black holes into one larger one, some of the most fundamental predictions of general relativity will be tested. Soon, LIGO and other gravitational-wave detectors around the world will be “listening” to the collisions of black holes and neutron stars across the Universe. LIGO detectors (in Hanford, WA and Livingston, LA) are 4-km Michelson interferometers which are used to detect the tiny (10 -15 cm) changes in the separation of the mirrors due to passing gravitational waves. Michelson interferometers are also being used in the quest to directly detect gravitational waves. ![]() These interferometers will soon image distant planetary systems, black hole accretion disks, and the surfaces of stars. Wilson and on the European Southern Observatory’s Cerro Paranal in Chile, where the light of four 8-meter telescopes can be combined. Today, optical interferometers are in operation at Mt. The use of an interferometer to combine the light from two telescopes to create a telescope of larger effective diameter–the separation of the two telescopes–vastly increases its resolving power. Michelson not only showed that the speed of light is frame independent, but he also introduced interferometry to astronomy. This discovery, featured on the cover of Time Magazine in March 1966, opened our eyes to the “extreme Universe” of relativistic objects like neutron stars and black holes. The 200-inch was used to discover quasars, now known to be super-massive black holes powered by the accretion of matter. Hubble went on to discover the expansion of the Universe, revealing our big bang origin. He showed that they were “island universes” and not gas clouds within our own Milky Way galaxy, thereby enlarging the known Universe by a factor of 100 billion. Palomar, and he left a great scientific legacy in the discoveries made by these telescopes.Įdwin Hubble used the 100-inch Hooker telescope to solve the riddle of the mysterious nebulae that had been catalogued for more than 100 years. On the best mountaintops seeing can be 0.3 arcseconds which results in a hundredfold gain.) Four times Hale built the largest telescope in the world: the 40-inch refractor at Yerkes Observatory in Wisconsin and the 60-and 100-inch reflectors at Mt. (When observing point-like objects, sensitivity improves as the point-spread function squared. After starting the first Department of Astronomy and Astrophysics at the University of Chicago, Hale took astronomy to the mountains of California where the seeing (image quality) is much better. George Ellery Hale, the MIT-educated solar-physicist, was the pre-eminent telescope builder of the 20th century. Newton made a few other contributions relevant to astronomy including his invention of the fields of gravitational physics and spectroscopy. The introduction of the reflecting telescope by Newton in 1669 paved the way to virtually all modern telescopes. The sheer weight of a large glass lens makes a refracting telescope larger than about a 1 meter in diameter impractical. The telescope Galileo used was a simple refractor. ![]() Galileo was not only the first physicist to turn a telescope to the sky, but the telescope and microscope were the first instruments of science that extended our ability to explore the physical world. These new and more powerful eyes have continued to deliver stunning discoveries.īecause physicists have contributed so significantly to the improvement of the performance of “our eyes on the Universe” and in shaping the science of astrophysics, it is appropriate that our Society take part in the celebration of this anniversary (the International Year of Astronomy) through the theme–New Eyes on the Universe: 400 years of telescopes–and content of the April Meeting. Since then, the sensitivity of optical telescopes has improved by another factor of 100 million, and we have added radio, infrared, UV, x-ray, gamma-ray, cosmic-ray, and neutrino eyes on the Universe. His discoveries, including the phases of Venus and the resolution of the Milky Way into stars, established the Copernican paradigm and profoundly changed our view of the Universe. ![]() Four-hundred years ago Galileo turned a 2-cm telescope to the sky and increased the sensitivity of human eyes on the Universe by a factor of 100–an increase only matched since by that of the Hubble Space Telescope. ![]()
0 Comments
Leave a Reply. |