Brussels Philharmonic | A celebration of the cosmos II

A celebration of the cosmos II

What lies beyond our cosmic horizon that gave rise to the flickering primordial heat? What lit the fire that set our universe going in the first place? These are profound unanswered questions. These are also the questions which lie behind much of my work with Stephen Hawking. - Thomas Hertog

What lies beyond our cosmic horizon that gave rise to the flickering primordial heat? What lit the fire that set our universe going in the first place? These are profound unanswered questions. These are also the questions which lie behind much of my work with Stephen Hawking. And it seems we are in good company. In the next work, The Unanswered Question, Charles Ives too asks the perennial questions of existence.

Now I would like to point out that questions about our ultimate origins did not even exist as scientific questions before Einstein. They only crystallized during the 20th century once Einstein had anchored space and time, and the cosmos as a whole, as physical concepts within the sciences.

You may wonder why E himself didn’t provide the answer. After all, he was smart, and he had a new theory. Well, E’s theory of relativity can take us somewhat beyond our cosmic horizon here, but not very much. This is because beyond this horizon lies the big bang, the beginning of our world, where our basic notion of reality in terms of space and time ceases to have any meaning. One could say that “The beginning of the world happened a little before the beginning of space and time”. But this is bad news for E, since without space and time he has no theory. E’s theory has the truly remarkable property that it predicts its own downfall, in a big bang at the origin of time, which itself remains shrouded in mystery.

At the big bang, the large cosmos merges in a sense with the micro world of particles and atoms; E’s relativity clashes with the quantum theory that describes the microscopic world. The BB is in many ways the ultimate Q lab. We now believe that these tiny flickers in the afterglow of the big bang, the seeds of you and me, arose from quantum uncertainty at the birth of our universe. In fact Hawking and I found that even our entire universe bears traces of the quantum fuzziness at its origin. From the same beginning widely different universes emerge, and the cosmos lives them all. The multiverse is essentially an unavoidable consequence of our quantum origins.

But not all universes are habitable. In fact our universe appears to be very special in this respect. The temperature variations we see here, for instance, were just right to evolve over millions and billions of years into galaxies, stars and planets, thus creating a stable habitat for life to emerge. If the primordial variations had been a tiny bit larger there would only be black holes. If they had been slightly smaller, our universe would be nothing but a vast void. Our universe is mysteriously suited for life; it set out on a delicate habitable path. These insights emphasize the profound reality that we are connected to the cosmos. Not just in trivial ways, but in the deepest possible ways. We co-evolved with the universe. The cosmos is also about us, about who we are.

This resonates with one of the great revelations of the space age, namely the perspective that it has given humanity on ourselves.

We thought the Apollo missions were taking us into space, but when the crew of Apollo 11 turned the camera around to photograph the Earth, we realized we were in space already. When we see the Earth from space we see ourselves as a whole; we see the unity and not our divisions. One planet, one human race. A blue dot in a special, delicately habitable cosmos. Let us strive to turn this sense of belonging into an asset for humanity when over the next decades we take into our own hands the future destiny of our planet. Understanding the order of the universe and understanding its purpose are not identical, but they may not be very far apart.

The remarkable habitability of our universe sharpens yet another question, posed so eloquently by Enrico Fermi, an Italian-born Nobel Prize winning physicist. Fermi asked a very simple question: Where is everybody? With `everybody’ Fermi meant aliens. His point was that since the age of the universe is so great and its size so vast, with almost half a trillion stars in the Milky Way alone, many of which with their own planetary systems, then unless the Earth is astonishingly special, the universe should be seething with life, including alien species advanced enough to have visited Earth at some point in our history. So where are they?, Fermi asked. Or are we alone?

It is often said that science is all about knowing. I disagree with this assessment. Scientific thinking is most fundamentally about not knowing. It is a continuous quest for deeper and richer conceptualisations of the World by recognizing and sharpening our ignorance, from Anaximander to Einstein, to the search for gravitational waves today. In this sense Charles Ives, with his work `The Unanswered Question’, touches upon the deepest core of scientific inquiry.

Charles Ives is in fact a contemporary of Albert Einstein and widely recognized as one of the most original American composers. Born in Connecticut, Ives was admired by composers as Arnold Schonberg. His work was largely neglected during his life, but pieces like The Unanswered Question have since been lauded as one of the finest of works ever created by an American artist. My favorite quote of Ives is that he once told a performer “please do not try to make things nice! All the wrong notes are right.”

Throughout The Unanswered Question the strings evoke a sense of eery timelessness. The solo trumpet asks “the question”– seven times in total, I believe. But the strings never gain speed and are never affected by ‘The Question’. Instead, the ‘answerers’ are the woodwinds, whose motifs become more and more agitated, and frustrated. There seems to be an unbridgeable gap between the question and answer. Finally the trumpet states the question one last time, only to be answered by silence. Ives makes the philosophical statement that in the immensity of creation, a question speaks louder than an answer. As a scientist and a cosmologist, I could not agree more.

Please enjoy the depth and the power of not knowing, of having a question unanswered. But remember it wouldn’t be much of a universe if it wasn’t home to the people you love.

- Thomas Hertog

read part I