Renowned popular-science writer and prizewinning author Timothy Ferris (Coming of Age in the Milky Way, The Mind’s Sky) opens his seminal book titled The Whole Shebang – A State-of-the-Universe(s) Report (1997) with the statement “We live in a changing universe, and few things are changing faster than our conception of it,” and truer words were never spoken. In this illuminating work, he tackles some of the most current research in cosmology in the ‘90s and gives a masterly account of modern cosmology that even the cosmologically illiterate will be able to grasp. He draws together up-to-the-minute research on black holes, dark matter, big bang, and how cosmic evolution led from simple atoms to the complexity of life. He also sets the stage for the crescendo of discoveries that will continue into the next century.
Ferris follows the footsteps of Steven Weinberg’s , Carl Sagan’s Cosmos and Stephen Hawking’s A Brief History of Time. He shares their enthusiasm, eloquence, and ability to communicate difficult concepts and complex ideas in science to the masses. He’s a master storyteller who can write about the most recondite topics using zippy and relatively jargon-free language. He also has an attractive, cool style and with a sure grasp of some of the most arcane topics in cosmology. His book The Whole Shebang is broad in scope and gives the reader a better sense of how science is done than most philosophers or writers of science, in a way that a good military memoir—by Erwin Rommel, say, or Omar Bradley—gives a better sense of the nature of war than the generality of General Carl von Clausewitz’s military classic Vom Kriege (On War).
Dark Energy, CMB, and the Quest for the Holy Grail of Cosmology
Almost twenty years after its publication, cosmology has entered a remarkable era in which experimental and theoretical advances have precipitated a more extensive and detailed description than anyone would have believed possible. This field is now experiencing a wonderful period of creativity, a golden age in which new observations and new theories are extending our understanding of the universe in remarkable ways.
And one of these major discoveries by two groups of astronomers that baffled and stunned the scientific community is the so-called “dark energy,” a mysterious antigravity force that pervades the whole universe and possesses enormous tension. This discovery rocked the foundation of cosmological theory because it was thought that the cosmic expansion would be decelerating under its own gravity but it was found out that the expansion was accelerating instead when they discovered that distant supernovae were dimmer than expected. (Three of the astronomers who discovered it shared the 2011 Nobel Prize for Physics.)
The discovery of the cosmic microwave background which is an afterglow of the Big Bang is also part of that eternal quest and marks an important step forward in this golden age of cosmology and this period of rapid progress culminated on February 11, 2003 when the space satellite named WMAP (Wilkinson Microwave Anisotropy Probe) has given scientists a detailed picture of the universe when it was a mere 380,000 years old and it propelled cosmology into the 21st century.
But the epic discovery last March 17, 2014 (1 year after the discovery of the Higgs Boson) of the BICEP2 team led by John Kovac of the Harvard-Smithsonian Center for Astrophysics had sent shock waves that reverberated around the world with the announcement of the Cosmology’s Holy Grail—a telltale signature of ripples in the very fabric of space called the primordial gravitational wave that was generated as it “inflated” during our cosmic origins. These waves or ripples in the very fabric of space-time predicted by Einstein will take astronomers inside the most violent events in the cosmos, black hole collisions and the Big Bang itself. If this will be confirmed as early as this year by the joint collaborations of Planck and the BICEP2 teams, this could be the discovery of the century and it will give us our first direct glimpse of a period even before the Big Bang.
On the theoretical foundation of cosmology, I think the development that had probably the most important impact on theoretical work is the idea known as ADS-CFT (anti-deSitter-conformal field theory) duality, introduced by Juan Maldacena in the late 90’s. It has had a powerful impact on the development of the M-theory, cyclic universes and other alternatives to the widely accepted Big Bang cosmology. But I will not go into further details because it’s highly technical.
Speculation, speculation^2 – and cosmology
I am really excited about these remarkable discoveries because cosmology is a favorite subject of mine. Some people can never pass up a chocolate cookie, or a mixed martial arts fight on TV. For me, I am a sucker for bright, visually resplendent magazine covers that feature multiverses, stellar nursery, globular clusters, blazing galaxies, parallel universes, exploding supernovae, or merging black holes, which I find irresistible. So writing an article about cosmology is almost akin to the feeling of a kid in a candy store. Some people seek transcendence in religion, philosophy, music and arts, literature, etc. I seek mine in cosmology and other related subjects because they have the ability to grab hold of me at a profound and visceral level because an understanding of how things began feels like the closest thing we may ever come to understanding why they began. The study of cosmology, in particular, does hold the promise of giving us our most complete understanding of the arena of the why the universe came into being.
I don’t want to sound very graphic but Stephen Hawking had said it best: “I won’t compare it to sex (i.e. the excitement and enthusiasm), but it lasts longer.”
What many people don’t realize though is that the field of cosmology used to be derided decades ago as a pseudoscience because there was an almost total absence of reliable observations and it cannot predict anything about the universe unless it makes some assumptions about the initial conditions. Here’s my favorite story: According to Cambridge University folklore, the renowned Nobel Prize-winning nuclear physicist Ernest Rutherford is said to have issued this warning to his subordinates and students: “Don’t let me catch anyone talking about the universe in my department.” That was in the 1930s and, according to cosmologist Paul Davies, cynics quipped even in the 1960s in London that there’s speculation, speculation squared – and cosmology. But that is certainly the case no longer. The field has since emerged from a pseudoscientific backwater into a truly quantitative and observational science, a process dramatically accelerated by the discovery and study of primordial fluctuations in the CMB by COBE, WMAP and Planck space satellites. And with the flood of new data we are receiving today, with new tools such as space satellites which can scan the universe, with new-generation gravity-wave detectors in the near future such as Advanced LIGO, LISA, Big Bang Observer, among others, we are really in the golden age of cosmology.
A Big Bang Primer: The Beginning of Space and Time
If you have any plan of visiting Los Angeles, California, for some “star watching,” most people would likely assume you mean the famous Hollywood stars. Yet SoCal (Southern California) boasts some of the most impressive astronomical facilities in the world (e.g., Griffith Observatory, Palomar Observatory, Mount Wilson Observatory, NASA’s Jet Propulsion Laboratory, etc.) and it would be a shame for astronomy buffs not to visit these areas. From the discovery that the universe is expanding to building the next-generation Mars rovers, SoCal has it all.
As a matter of fact, our current picture of the cosmos was born outside of Los Angeles which is located just a few miles away from where I write this article, at a newly built telescope atop Mount Wilson in Pasadena, California. It was the brainchild of one flamboyant man: Edwin Hubble. He’s the famous astronomer who almost single-handedly created the modern observational cosmology in the same manner as how Albert Einstein single-handedly formulated the general relativity and laid the theoretical foundation of modern cosmology without simultaneous contributions by other researchers and without the aid of experimental tests aside from a minute advance of the perihelion of Mercury. Hubble also showed among other things that the galaxies were moving away from us, ergo, the whole universe was expanding! Given this finding, we can “run the film backward” when the entire universe was compacted into a single, unbelievably hot, dense point. The scenario in which spacetime and all others we see in the universe began in the past and has been expanding and cooling ever since is known as the Big Bang.
Since astrophysicist Fred Hoyle coined the term “Big Bang” as a misnomer for a theory he despised, it has become an everyday usage and nowadays part of our common language. The idea that the Universe we observe today originated from an enormously energetic, singular event, which spewed forth everything we see on the observable universe.
And here is the most current account that is now widely accepted by almost all working astronomers and cosmologists: About 14 billion years ago (13.82 billion years ago, according to the latest Planck’s result) the universe began with a “Big Bang,” a powerful explosion of space-time that sent energy and matter reeling outward—not into empty space, but into nothingness. The evidence is abundant and rests upon some compelling observational pillars, from the underpinnings of Einstein’s general theory of relativity, to the detection of various relics of the early universe such as the CMB and five isotopes of the lightest elements, found spectroscopically in interstellar matter that has not yet processed into stars, and to the confirmation of ripples in the fabric of space-time. When the Big Bang occurred, matter, energy, space and time all formed, and the universe was infinitely dense and incredibly hot. The standard theory also says that the universe expanded and cooled rapidly following the Big Bang. Astronomers estimate that the primeval fireball reached a scorching 15 billion kelvins I second after the creation. By the time cosmic clock read 380,000 years, the temperature had cooled below 3000K. Electrons combined with protons, and the resulting hydrogen atoms allowed light to travel unimpeded for the first time. We see this light today as the cosmic microwave background (CMB), which glows at a temperature of 2.73K above absolute zero. And this is the radiation cosmologists observe from space with instruments such as NASA.s WMAP and the ESA’s Planck satellite.
Cosmic conundrum: Before the initial spacetime singularity
Although these observations probe the universe’s state back nearly to the Big Bang, they still don’t answer the questions of what triggered it all. The idea of a Big Bang doesn’t so much answer questions as raise new ones. If the universe as we know it originated in the Big Bang, what came before it? And would it make any sense at all to ask such a question that many consider as a taboo subject?
Now known as a space-time singularity, this miniscule point is where conventional cosmological theories of space and time literally begin. Scientists have long viewed conjecture about what happened before the clock started ticking not only as pointless and hopeless but also meaningless, like questions about what happens at temperatures below zero or what is north of the North Pole—a place where north has no meaning. That is, the concept of “prior to big bang singularity” just doesn’t make any sense. (The Big Bang is often referred to as the initial singularity because Einstein’s equations of general relativity break down when the temperature and density become infinite.)
Interestingly, the person to understand this who also happened to have some powerful insights into the nature of a universe where time and space came into being as a single entity was not a physicist but a bishop: St Augustine of Hippo (Hippo was a Roman city in North Africa, now Annabe in Algeria). In Confession, Augustine deals with the time before creation. Rather unexpectedly, he begins with a joke. “What, the pagans asked, was God doing before he made heaven and earth?” the way someone else did, but nonetheless the joke is on the alleged reply, “He was preparing hells for people who inquire into profundities.” However, when he got to the crux of the matter, his insights have deeply impressed even the modern cosmologists. His argument was theological, but parallels the arguments of the modern cosmologists. According to Augustine, just like Einstein, time was part of the same bundle as space. Time, noted Augustine, is something created. He said that it was meaningless to ask what God was doing “before” in the beginning because there was no “before”. As the Nobel Prize-winning physicist Steven Weinberg noted, it is common in research papers on cosmology to quote the very prescient comments by Augustine in the discussion of time. But Augustine was not the only one who thought the same. Even Moses Maimonides said that “the foundation of our faith is the belief that God created the Universe from nothing; that time did not exist previously, but was created.”
Alternative Universes: Cosmic version of the Groundhog Day
For the past few years, however, theoretical physicists have been arguing over more recent explanations for the Big Bang that avoid singularities—ideas such as string cosmology, eternal inflation, cyclic models, loop quantum cosmology and holographic principle. Opinions among cosmologists have been shifting lately, toward a more complicated picture of the origin of the universe that avoid singularities. Recent progresses in string theory and quantum cosmology suggest answers to the above questions, providing us with mathematical tools able in principle to reconstruct the history of the universe before the big bang.
In eternal inflation, cosmic expansion runs amok and spawns an infinite number of “bubble universes.” Theoretical physicist and cosmologist Alexander Vilenkin first floated the idea that the universe sprang out of nothing as the result of a cosmic “quantum fluctuations” and that we live in a small “bubble” of universes.
Then there’s another competing theory for the pre-big bang model by Gabriele Veneziano which comes from the string theory called string cosmology in which the universe started out as a black hole. In this emerging cosmological scenario the Universe, at the epoch of the big bang, instead of being a “new born baby” was actually a rather “aged” creature in the middle of its possible infinitely enduring evolution.
There’s also the highly controversial and paradigm-shifting Steindhardt-Turok cyclic models emanating from the string theory or its latest incarnation, the M-theory, where our universes arose when two parallel “braneworlds” collided; such collisions and subsequent cosmic rebirths repeat regularly and endlessly. This is kind of akin to Ramis’s movie Groundhog Day, where Bill Murray’s character Phil Connor lives the whole day over and over again. In the cosmic version, some cosmologists believe that the universe cycles through endless collapses into a Big Crunch followed by endless rebirths in new Big Bangs. According to Paul Steinhardt and Neil Turok, the Big Bang was not the beginning of time but the bridge to a past filled with endlessly repeating cycles of evolution, each accompanied by the creation of new matter and the formation of new galaxies, stars, and planets.
And finally, there are explanations that claim a potentially infinite loop of quantum cosmology repeatedly recycles the universe through a process of expansion, contraction, and collapse leading to a cosmic bounce that initiates a new round of expansion.
Putting the pre-Big Bang to the Test
Although most of the scenarios describing the time before the big bang might seem to be strictly theoretical exercises and speculative sciences, observational cosmologists are not totally out of the loop. Take eternal inflation, for example. “If we are hit by a bubble that has a higher vacuum energy than ours, after the collision it will turn around and retreat,” says Vilenkin. The effect of such bubble collision could be seen as a cold spot in the CMB.
In the meantime, observational cosmologists are racing to confirm traditional inflation theory. The pattern of polarization caused by the gravitational waves, so-called B-mode polarization, would be an indicator of inflation. If the Planck and BICEP detect B-mode polarization, the Steinhardt-Turok cyclic model couldn’t survive.
There are about a dozen ground-based and balloon-based instruments coming forward in the next few years to search for B-mode polarization. And Planck’s cosmology results will come in the next few months or so. Other gravity-wave detectors that could create an upheaval in scientific knowledge in the future are the LISA and the NASA’s Big Bang Observer which could also detect gravity waves from the instant of the Big Bang with more sensitivity and detailed accuracy. And hopefully, such next-generation instruments will help unveil the final theory of everything and move past Einstein’s tour de force of the Big Bang singularity.
The Mother of All Strings
Personally, I like the idea of the cyclic universe but bouncing or colliding membranes are very dependent on the M-theory (The “M” stands for meta, mother, mystery, magic, membrane, matrix, master, or whatever one prefers), a beautiful theory that unites all five string theories, including supergravity, within a single theoretical framework. Of all the theories proposed in the past century, the leading candidate for the unification of general relativity and quantum mechanics is the M-theory. This theory could allow us to “read the Mind of God,” as Einstein eloquently put it. Such an understanding could be achieved in the future by next Einsteins or some bright graduate students through mathematical deductions or it could be derived from experimental discoveries such as the nature of the gravity waves which could unveil the final laws of nature.
Exciting time ahead in the future of cosmology
Higgs Boson. Dark Matter. Dark Energy. CMB. Gravitational Wave. Extra Dimension. There has never been a more exciting time in cosmology and particle physics. It’s a wonderful time to be alive in this era of humanity because we’re in the most thrilling and exciting time in human history. This is a remarkable time we’re not going to have in human history again. We have learned the history of the universe and we’ve come incredibly far in that quest to understand its mystery. And we are all lucky to be alive to witness some of the greatest cosmic discoveries in the history of mankind.
[The discoveries, concepts and theoretical insights explored in this article derive from the work and writings of several physicists, astronomers, cosmologists and popular-science writers including Albert Einstein, Edward Witten, Stephen Hawking, Roger Penrose, Steven Weinberg, Michio Kaku, Brian Clegg, Paul Davies, Edwin Hubble, Sean Carroll, Bruce Dorminey, Lee Smolin, Craig Hogan, Brian Greene, Paul Steinhardt, Neil Turok, Alex Vilenkin, Gabriele Veneziano, Juan Maldacena, John Kovac, among others.]