By Vikas Datta

Jaipur, Jan 26 (IANS): Man has made giant strides in understanding the science that underlies the universe, but huge gaps still remain - especially in knowing what makes the bulk of matter, how it affected the dinosaurs and influenced the evolution of mammals and eventually mankind, and these three questions' mind-boggling relationship, says an American theoretical physicist.

"We know that over six dozen million years ago, the entire class of dinosaurs was wiped out, along with almost other living beings, animal or plant, when a giant asteroid plunged into our planet - and it is only after this that mammalian life started to evolve," said Lisa Randall of Harvard at a session of cosmic implications on the first day of the Jaipur Literature Festival 2018 here.

And while the scientist, who was named as one of Time magazine's 100 Most Influential People in 2007 but makes her point - and her role - more strongly by alluding to her unheralded and brief appearance on popular American sitcom "The Big Bang", says while this progression of life is a known fact, the reason why this cataclysm occurred is not entirely understood. And that is where "dark matter", an unknown typical constituent or rather framework of the universe, amounting to, along with "dark energy", as much 95 per cent of its mass, comes in.

Randall, who has sought to explain this in her spell-binding "Dark Matter and the Dinosaurs: The Astounding Interconnectedness of the Universe", which "ties together how the universe, the galaxy, the solar system, and life, as we know it, came about" for understanding this is as necessary for present scientific research as is study of social sciences for human benefit and development.

But dark matter, she admitted, is not an easy concept for it is a hypothetical kind of matter, composed of particles different from electrons, protons, neutrons, and neutrinos - the constituents of ordinary matter. And while dark, or rather "transparent", matter has never been observed like these "normal" sub-atomic particles, its existence is clear since its gravitational effects have been observed.

But whatever we call it, says Randall, its importance cannot be underestimated for it helps, "like a scaffolding", to give the galaxy its form and thus making possible and promoting life on our planet.

And mocking those who do not believe established scientific principles, she quipped: "Even though the Copernican Revolution happened a long time ago, it still upsets some people to know that we are not at the centre of the universe. Now we know we don't even make the bulk of the matter in it."

Randall, in her book, postulates, that it was dark matter that might have spelt the dinosaurs' doom when the Sun passed through a plane of it during its oscillation, creating a massive gravitational imbalance that engendered the cosmic cataclysm which made them extinct. And when life resumed, it was not dinosaurs again, but mammals.

"So it could be that our very existence had to do with dark matter," she maintained.