Indian-priest's work on galaxies changes astronomy as we know it
For most, science vs faith is a choice. For Indian-origin Richard D'Souza, science was simply a way to get closer to the divine. And in doing so, he forever changed astronomy: D'Souza and his colleagues discovered that our Milky Way had a "sibling" centuries ago, which was "devoured" by Andromeda, the nearest major galaxy. This development is expected to alter everything we know about the evolution of galaxies.
To understand this, one has to understand how galaxies are formed. There are two ways, D'Souza explains: they either form their own stars, or merge with smaller galaxies. In the latter case, these smaller ones are destroyed during the merger, "leaving behind a trail of stellar debris around the main galaxy, called its stellar halo." Andromeda is believed to have merged with hundreds of smaller galaxies.
D'Souza and his colleague Eric Bell used computer simulation to discover and prove that most stars in Andromeda's stellar halo came from the shredding of one large galaxy 2bn years ago - the M32p, which was the third-largest in the neighborhood after Milky Way and Andromeda.
Sounds simple at first glance, but the discovery has massive implications for astronomy, D'Souza says, and changes the understanding of galaxies' evolution. For one, scientists now conclusively know about M32p's existence. This also gives hope that now "we could begin to unravel the merger history of distant galaxies." Finally, astronomers now know that Andromeda's disk survived "and probably thickened" during the merger, something hitherto unknown.
So does this mean anything for us, the laypeople? Based on the fresh findings, "we are confident that our own galaxy, the Milky Way, will survive the eventual collision with its satellite galaxy, the Large Magellanic Cloud, in about 1-2 billion years," D'Souza explains.
Pune-born D'Souza spent his childhood in Kuwait and moved to Goa for schooling. While pursuing Jesuit training later, he graduated in physics from St Xavier's, Mumbai, following it up with a master degree from the University of Heidelberg, Germany, and a PhD in astronomy from Ludwig Maximilian University, Munich. He then joined the Vatican Observatory and recently, the University of Michigan for post-doctoral research.
For D'Souza, his lifestyle isn't self-contradictory, as many would assume. It's important to realize "science is based on assumptions and faith," especially in astronomy, he says. "Science cannot provide us meaning in life. Religion and faith do." Many reports have hailed D'Souza as the next Georges Lemaitre - the Belgian Catholic priest and astronomer who propounded the 'Big Bang Theory.' We wish him luck!
