Sunday, August 4, 2019

Revolution in Cosmology Resolves Dispute over Universes Age Essay

Revolution in Cosmology Resolves Dispute over Universe's Age Just under seven years ago, astronomers using the Hubble space telescope presented results they hoped would help answer one of the most contentious issues in astronomy of the 20th century – the question of the distance scale of the universe. But there was some unease when the result was announced. According to the report, other galaxies were close enough that, extrapolating backwards from their current rate of recession and making adjustments for the influence of gravity, they all would have been together (that is, the Big Bang would have occurred) as recently as 8 billion years ago. Unfortunately, there was strong evidence already in place that some stars were at least 12-15 billion years old – apparently predating the origin of the universe itself! While these two highly irreconcilable values for the universe's age certainly posed a serious challenge to astronomers, most simply assumed that better measurements would place the distance scale back in line with the older age. What no one expected is that resolution to this problem would lie not in corrected measurements but a revolution in cosmology, and the apparent discovery of what amounts to a mysterious new essence of the cosmos – a "fifth element" that hides in vacuum and drives the expansion of the universe. The scientific study of the age and origin of the universe is intimately linked with the measurements of extragalactic distance, and consequently the science did not even exist until measurement techniques accurate to such scales were invented. Distance measurement has always been difficult for astronomers – until the 1800s, no one knew even the distance to the nearest star (other than the Sun), and th... ...pressure and a whole host of other strange properties that gravitationally repel all surrounding space, expanding the universe in absence of any physical substance. Furthermore, by expanding the universe, more empty space is created, creating even more antigravitational force and making the universe expand ever faster, leading to a runaway expansion that will eventually culminate in the dilution of all remaining matter into nothingness. And in this lies the solution to the long-standing age issue. If the universe's expansion is constantly getting faster, it must have been slower in the past, pushing the age of the universe upward to around 13 billion years, right in line with the ages of stars. So without any major revision to the distance to nearby galaxies or the ages of stars, the question of the true age of the universe has been solved in a way no one expected.

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.