On Tuesday, Roger Penrose of Britain, along with Reinhard Genzel of Germany and Andrea Ghez of the US, won the Nobel Prize in Physics. The award was given to the trio for their discoveries about the Black Hole, one of the most exotic phenomena in the universe.
According to the Nobel Committee, 89-year-old Penrose, who is based at Oxford University, was honoured “for showing that the general theory of relativity predicts the formation of black holes."
Black Hole refers to a region in space where gravity is very strong.
Penrose had visited Kerala in 2011, a year after the launch of his famous book 'Cycles of Time'.
During the visit, Kerala's popular science writer Dr A Rajagopal Kamath got a rare opportunity to interview Penrose in Thiruvananthapuram.
Nine years later, Onmanorama is publishing the edited excerpts of the informative interview.
Rajagopal Kamath (RK): You had proposed that there would be a singularity at the beginning of the Universe as well as in the end. The initial singularity was there in your idea. But what sort of singularity would be there at the beginning of the next Aeon?
Roger Penrose (RP): The singularity that constitutes the Big Bang is a space-time singularity according to Einstein's space-time picture of the Universe. But in my extended 'conformal picture', the Big-Bang singularity becomes a smooth 3-surface. Although some models in Einstein's theory have a singularity in the future, usually referred to as a Big Crunch, I have not particularly favoured these models. Current observations indicate that the universe is likely to continue in its accelerated expansion indefinitely, and this is the picture that I will hold to myself for our current Aeon.
In my own picture, the expansion of the Universe never reverses but continues indefinitely. In the very late stages, the Universe becomes devoid of massive particles, in my scheme. At that stage, the Universe loses track of the scale of things, as massive particles are needed in order to define clocks, these being needed so that the overall scale of the universe can be determined by its contents. Accordingly, large and small become equivalent and the infinitely thinned out, cold universe of the remote future becomes identical to the very dense and hot big bang of the subsequent aeon.
This new big bang would be very much like our own and would have the smoothed-out character that ours appears to have had which allowed it to possess the relatively low entropy that provides a second law of thermodynamics for the subsequent aeon.
RK: Do You propose that there would be successive Big Bangs and expansion. Was there a beginning for this chain of events that is the original beginning? How does the new theory explain the real beginning?
RP: I suppose it is possible, within my own scheme, for there to have been a "first Aeon". On the other hand, I am somewhat more sympathetic to the proposal that the Aeons simply continue indefinitely into the past, and also into the future. This is not altogether unlike the sort of scheme that Bondi, Gold, and Hoyle put forward with their steady-state model of the universe, at least with regard to its philosophical underpinnings, if not in detail. If this is correct, then there would never have been a beginning. This was the intriguing proposal made in the steady-state scheme and, in a sense, I am taking over their idea, though in a different form.
RK: You have avoided the possibility of multiple Universes. The concentric circles in the Cosmic Microwave Background Radiation (CMB) could be from the events that occurred in other Universes. What is the possibility of this?
RP: In my scheme (Conformal Cyclic Cosmology), the Aeons occur Sequentially. I do not have a role for 'parallel' Universes. I suppose that one might contemplate such parallel universes even in CCC, but I have not adopted this idea. The circles in the CMB sky would indicate activities in the Aeon prior to ours which would have occurred completely (before) our own Aeon and there is no branching (sideways) into other parallel universes.
RK: What is the possibility for the constants with different values in previous Aeons? If there is a possibility for that then our interpretation of the real World will not be complete.
RP: There is certainly the possibility that the fundamental constants of nature took different values in previous aeons from those in ours. I rather hope that this is not the case, since a change in the constants would make it more difficult for us to make clear-cut predictions of the implications of CCC. On the other hand, CCC does offer the possibility that one might be able to ascertain, by observation, whether or not the constants of nature have indeed changed in the passage from the aeon prior to ours to our own aeon. Such observations would, in principle be an exciting possibility.
RK: Human beings hold a very negligible place in the Universe. The cosmological principle says that. Still, we feel that what we think as real is indeed real. Is there a different, Real World out there? In that World the constants of nature may not appear the same as it is experienced by us.
RP: I am not quite sure how to respond to this question. Of course, whether or not we regard human beings as insignificant is related to the issue of how important we regard the presence of consciousness in the universe. Whereas those parts of the Universe where consciousness flourishes may indeed be a small measure in terms of ordinary volume, it may well be that 'volume' is not really the best measure when we are talking about what is really important in the universe as a whole. I do not think that, at the moment, we can make much headway with these questions, but I think that ultimately they are important ones. This is the best answer that I can give to you at the moment, inadequate though it may well be.
RK: Will your Conformal Cyclic Model (CC) lead to a paradigm shift like proposed by Thomas Kuhn?
RP: I have never been too keen on Kuhn's terminology of a paradigm shift since it always seemed to me to be a strange use of that word, rather suggesting that what is shifting is merely a way of looking at things and not really a fundamental advance in human understanding of an objective world "out there". However, I suppose that if CC turns out to be correct and commonly accepted, then such a term as this might be applied.
RK: Do you think that you stand a chance to win the Nobel Prize since there is evidence from WMAP satellite that establishes your theory?
RP: At the moment, there is an awful lot of controversy and a reluctance to take these ideas seriously, so I don't see that your comments have a great deal of relevance to what is going on at the moment, but I suppose we shall have to wait and see if things would develop in a different direction. One must certainly take these ideas as being very speculative as things stand.
(Dr A Rajagopal Kamath is a popular science writer and researcher. He is currently based at Kozhikode).