Edwin Powell Hubble: An Eponym for Hubble Space Telescope
We know the Hubble Space Telescope (HST) and the wonders it has done in changing the astronomical ideas with the help of its unprecedented deep and clear views of the universe. The earth’s thick atmosphere limits the visibility into the space from planets’ surface even with the biggest telescope. Since HST is above the earth’s atmosphere, it helps us to see the objects much beyond what can be seen by the telescopes mounted on the earth. Some of its recent images have revealed many facts about the super-massive Black-holes, Gravitational-lensing, Quasars, Pluto, Supernovae and many more. The farthest object HST has seen is more than 12 billion (109) light years away. The observations made at such a large distance are named as Hubble Ultra Deep Field (HUDF). The images sent by HST are processed at the Space Telescope Science Institute (STScI), Maryland, US.
HST has been named after the century’s greatest astronomical astronomer, Edwin Powell Hubble. Mounted on the Discovery shuttle, it was launched on April 24, 1990 by NASA and is currently orbiting at 600 kilometers above the earth’s surface. It weighed 11.25 tones and cost more than $1.5 billion (Rs. 6000 crore). The heart of the telescope is a 94.5 inch mirror. Edwin Powell Hubble was born on November 20, 1889. He was the son of an insurance clerk in Marshfield, Missouri, United States (US), and grew up tall, athletic and handsome. He won a scholarship to study law at the University of Chicago. He then won a Rhodes scholarship to study jurisprudence in University of Oxford, United Kingdom (UK). Oxford turned Hubble into an English gentleman: he won a half-blue for athletics, spoke good English, and used a Dunhill briar pipe.
First in 1924, he said that some of the nebulae visible in the night sky were not simply hazy patches of light in our galaxy, Milky Way (“Aakash Ganga”), but they are immense galaxies in their own light. He compared the amount of light received by these nebulae with the nearby stars. The difference between the amount of light received tells how far from us these nebulae are. He specifically studied the Andromeda nebula and found that they were so faint they had to be hundreds of thousands of light years away. They were too far to be inside our Milky Way. Subsequently he revealed the presence of other galaxies and that our galaxy is only one among a huge number of these celestial giants.
Five years later in 1929, he proved that all the galaxies are still moving further apart from each other which mean that the universe is constantly expanding with time. This discovery brought a revolutionary idea which contracted the existing theories on static and orderly cosmos. Hubble studied the light coming from distant galaxies. Astronomers usually split the light coming from a star into its components with a prism. They do this because different chemical elements emit different colors and thus astronomers can uncover the elements contained in any star by studying its spectrum.
There is a phenomenon called red-shift in light which similar to Doppler Effect in sound. Anyone who has stood near a railway station would notice that as the train approaches its horn is higher pitched than normal and as soon as it passes the pitch drops distinctly. This phenomenon is called the Doppler Effect in sound. Color is to light as pitch is to sound, so the red-shifted light is equivalent to the lower pitch of receding train. Hubble observed that the spectra of light from nebulae were shifted from their expected position towards the red end of the spectrum which suggests that the stars receding from the earth with time. He also found out that the red-shift was more with the more distant and fainter galaxies.
By the end of 1929, Hubble declared that the red-shift was directly proportional to the distance of the star from the earth. In other words, the galaxies which are farther from us are traveling away at a faster rate from us. Therefore the universe is expanding constantly in all directions. This revelation came as a profound shock to Einstein who had formulated the General Theory of Relativity in 1915 with an idea of static universe. Hubble showed that the theory of relativity was correct and Einstein misunderstood its implications. Later, Einstein admitted his mistake.
In 1935, Hubble discovered an asteroid named “1373 Cincinnati”. Hubble remained active in research nearly until his death on September 28, 1953 at the age of 63. In the later stages of his life, he installed a 200-inch telescope on Mount Palomar in California. He tried to have astronomy considered as a part of physics but his campaign was unsuccessful for a long time. Finally the Nobel Prize committee decided to count his astronomical work towards physics and he was considered for a Nobel Prize in Physics just few months after his death. But the Nobel Prize is never awarded posthumously. So, this great scientist remained deprived of the honor he deserved. He left instructions that there should not be any monuments to him. There was neither a formal funeral nor a memorial service. Although, an asteroid discovered in 1955 is named after him and is called as “2069 Hubble”.
Today, Hubble Space Telescope is a far better monument to the great astronomer than any other stone torso or brick monument as it continues the great work the scientist had started, by revealing more and more secrets of the universe.