Turning now to the age of the Universe, no other instrument has been more useful in measuring it than the Hubble Space Telescope. Truly, one of the major achievements of human ingenuity, the Hubble Telescope has not only brought out the magnificence and splendour of the cosmos, but also helped measure the age of the universe. Scientific progress usually follows a path of small sequential steps that lead more closely to major breakthroughs. And this has been the case with research on the Universe and its age. For example, Nicholas Copernicus, the great Polish astronomer of the late middle ages, discovered the helio-centric nature of our solar system. While there are other flaws in the model proposed by him, this was a major discovery. Subsequently, people like Tycho Brahe and Johannes Kepler have added valuable insights to the working of the cosmos. Yet, the task of deriving reliable distances between objects in the Universe remained arduous. One method that is used by astrophysicists is called the ‘distance ladder’, where
“there exist steps that allow us to estimate distances sequentially from nearby stars to distant galaxies. In the interest of honesty, however, the distance ladder might better be termed the distance “house of cards,” because the reliability of each level depends critically on the reliability of the previous, presumably more secure, level. The Holy Grail at the top of the distance ladder is the Hubble constant, a measure of the universe’s rate of expansion. The inverse of the Hubble constant provides a measure of the age of the universe by mathematically “turning back the clock.”…For nearly all galaxies in the observable universe, the recession velocity is found to be proportional to distance. What does this look like? Nearby galaxies recede slowly and distant galaxies recede quickly, which is the precise signature of an explosion…” (Tyson, 1995, p.72)
It is believed that understanding the age of the universe can help understand the events of the genesis. But the mind-boggling numbers of the age of various galactic bodies highlights the complexity of the project. For example, one of the prominent galaxies that resembles the Milky Way is measured to be 700 kiloparsecs (similar to lightyears) away. The nearest quasar, named 3C273, is approximately 600 megaparsecs away. The horizon of the observable universe, which the Hubble telescope could barely penetrate is about four gigaparsecs away. All this makes calculations pertaining to the events of the genesis very sensitive – even a minor error in the factored values can totally dismantle a theory. (Tyson, 1995, p.72)
In order to find out the age of the universe (which can provide insights on the events of its origins), an understanding of the cosmic mass density is required. But unfortunately, this number is difficult to pin-down, as it is given to fluctuations. Based on the mass density and the visual information provided by the Hubble telescope, scientists can predict whether the universe will continue its path of expansion and end up in the ‘big chill’; or it collapses into a ‘big squeeze’. Hence, a lot bears upon the accuracy of these numbers. The estimated mass density of the universe ranges “from a small fraction of the critical amount needed to ultimately arrest the cosmic expansion (as inferred from observations) to the critical density itself (as wished for by many theorists). Across this range, a Hubble constant of 80 provides for a universe that is anywhere from about 12 billion down to 8 billion years old.” (Tyson, 1995, p.72)
One of the major challenges in studying the Universe is the propensity for physical constants to change in value. Constants such as the speed of light in a vacuum and the masses of elementary particles, etc are noted to change with time. Although the changes are miniscule, the implications can be very profound, for they could validate or disprove an accepted theory. New findings reveal that the “the ratio between the mass of the proton and that of the electron–a number known as mu-might have decreased by about two-thousandths of a percent in the past 12 billion years. The evidence for the change in the constant, which has a current value of 1,836.153, emerged from light-absorption patterns of hydrogen molecules, the scientists report in the April 21 Physical Review Letters.” (Weiss, 2006, p.259) Once proved correct, this discovery could revolutionize our understanding of the Universe, its age and the distances between its farthest objects.