Penguin Books
Harvard University Press
HUMANS have always wanted to understand the universe: where it came from, how it works and how it will end. It is, perhaps, the thing that sets our species apart. The good news is that after hundreds of thousands of years of human evolution, we are finally getting believable answers 鈥� believable, that is, in the sense of passing certain experimental tests.
In a more everyday sense, however, the answers are unbelievable: the findings seem to show that our universe is just one among a myriad, all of which arise from quantum fluctuations. What鈥檚 more, it is filled with stuff that is utterly resistant to every attempt to probe its character.
These strange findings are laid out in two new books that, while very different in scope and tone, are equally fascinating. In Before the Big Bang: The origin of our universe from the multiverse, cosmologist Laura Mersini-Houghton tells the story of her own investigations with delightful intimacy. We see her childhood struggles in communist Albania, where her father was banished to labour camps for ideological crimes and her mother was encouraged to divorce him in order to stay in the family鈥檚 home.
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As an undergraduate, Mersini-Houghton attended rallies against communism and saw her friends head to the West as soon as borders began to open. She stayed, developing a thick skin and a taste for radical thought. It has served her well.
It can be too easy for physicists to dismiss the question of where our universe came from as a lost cause, writes Mersini-Houghton. She is having none of it: 鈥淲e have every right to wonder what existed in the cosmos fifteen billion years ago鈥� and investigate.鈥�
That is exactly what she has done. Assembling clues from inflationary cosmology, string theory and quantum mechanics, Mersini-Houghton had an incendiary thought in a North Carolina coffee shop, writing 鈥淨M on the landscape鈥� on a slip of paper as a reminder 鈥� 鈥渘ot that there was any danger I might forget鈥�, she tells us. She gives a lucid and fascinating explanation of where that thought was to lead.
By the end of her story, she has shown us the evidence that confirmed her predictions. Her conclusion? Our universe 鈥渁rose from a bizarre quantum probability game and鈥� is but a humble member in an intricate, vast and breathtakingly beautiful cosmic family鈥�.
A subtle but important aspect of Mersini-Houghton鈥檚 book is her honesty about being a woman in physics. She tells us that she was afraid to open the door to receive a late-night bunch of flowers that her husband had sent, too worried the dark figure on her doorstep was the male colleague who had been harassing and threatening her daily. Such experiences are 鈥渞outine鈥� for women who have chosen a career in the sciences, she writes.
We catch glimpses of this in The Elephant in the Universe: Our hundred-year search for dark matter, a thorough and sometimes troubling account of the hunt for dark matter by veteran astronomy writer Govert Schilling. He mentions intimidating older male scientists, and cites Cecilia Payne-Gaposchkin, Vera Rubin and Elena Aprile among the astronomers who have had to jump extra hurdles because of their gender.
This is a necessary part of Schilling鈥檚 story because the sexual politics of working in science have probably never been more in the spotlight than they are now. However, it doesn鈥檛 dominate: he deftly steers us through this landscape while masterfully explaining why and how the science is so urgent.
Known as dark matter because it doesn鈥檛 reflect or even absorb light, this exasperating stuff makes up more than 80 per cent of the matter in the universe. If, that is, it really exists. We think it does because stars and galaxies form and move in a way that suggests gravity nearby is stronger than can be accounted for by the mass of the stuff we can see. But it could just be that we don鈥檛 fully understand how gravity works.
In 1922, astronomer Jacobus Cornelius Kapteyn first suggested the existence of dark matter. Schilling is exhaustive but never boring as he traces the evolution of the idea, and the theoretical leaps and experiments that have punctuated this century-long journey. He conveys the hopes and fears of dozens of scientists in these pages: optimism and frustration are ever-present.
The tale of dark matter is ultimately a tale of tenacity 鈥� and it is sometimes hard to see how it will ever end. One researcher, Suzan Ba艧e臒mez du Pree, tells Schilling that she hopes the issue will be solved within a decade, and if not 鈥渨e may need to start thinking of something new. Or design new experiments.鈥�
It seems that we will just carry on looking and speculating forever. The situation is, Schilling says, 鈥渃razy and maddening鈥�. As he warns early in the book, don鈥檛 come here for answers: 鈥淒espite the efforts of many hundreds of persistent scientists, petabytes of data, and thousands of elaborate publications, we still don鈥檛 know the identity of more than 80 per cent of the material universe.鈥�
That said, there is a lot we do know, and Schilling is an expert guide not only to dark matter and the equally baffling dark energy, which gets a good outing here, but to particle physics and cosmology. You won鈥檛 learn what dark matter is, but you will come away with a very good understanding of how the universe works. Well, our universe, anyway.
