About Time

by Adam Frank

  While the cultural and political impact of telecommunications satellites was immediate (consider how nightly newscasts of the Vietnam War affected U.S. policy), the broader changes in human experience, and the experience of time, would play out over longer periods. The creation of twenty-four-hour cable news networks such as Sky News and CNN would not be possible without telecom satellites serving as their broadcast backbone. From the Olympics to the indelible images of the World Trade Center Towers collapsing in ruin, space-based telecommunications satellites altered the human experience of space and time by creating that all-important global instant. Just as telegraph cables had crudely stitched the world together one hundred years earlier, the swarm of satellites inhabiting Earth’s orbit played their own unique role in reshaping human time in ways appropriate to the space age.

  It should not be seen as a coincidence, therefore, that at the very moment this new human time was emerging, the same technologies that made it possible allowed scientists to stumble across the final act in the discovery of the Big Bang.

  THE BIG BANG TRIUMPHANT: AN ACCIDENTAL UNIVERSE

  The 1950s were not kind to Big Bang cosmology. Gamow and Alpher’s theory remained unable to cross the mass gap and explain the creation of elements heavier than helium.60 In addition, continuing concerns about the time scale of cosmic evolution led many scientists to conclude that Big Bang cosmology still predicted a universe younger than its stars. While each of these problems would eventually be worked out, many scientists still harboured a deep suspicion of cosmologies that began with a bang. Beginning time was never a popular option for scientists.

  The reasons for this bias are an important part of cosmology’s narrative. While we like to believe that science is a dispassionate search for the truth, in reality scientists come to their investigations saturated with beliefs that can turn their investigations in certain directions and set their minds with particular convictions. What makes science unique is the ability for the data eventually to speak for itself and trump personal convictions. But as we explore the braided evolution of human and cosmic time, we would be in error if we neglected the ways individual and institutional paradigms shape both research and its interpretation. Nowhere is this more apparent than in cosmology, with its close links to the domains of religion and mythology.

  It was religion, or the reaction to it, that spurred work on a popular alternative to the Big Bang. In November 1951, Pope Pius XII gave endorsement to the combined work of Gamow, Alpher and Lemaître.61 In an address to the Pontifical Academy of Sciences the pope proclaimed that “present-day science, with one sweep back across the centuries, has succeeded in bearing witness to the august instant of the primordial Fiat Lux [Let there be light]”. He said, “Hence, creation took place. We say, therefore, there is a Creator. Therefore God exists.”62

  Lemaître, the Catholic priest and scientist, was horrified. He knew that his or any other theory could always be disproved. Travelling to Rome, he counselled the pope against linking the faith to any contingent scientific hypothesis. Others, however, were just as clear as the pope on links between the Big Bang and biblical Genesis, and they had their own, very different reasons to be hostile.

  In the Soviet Union, official communist doctrine’s disgust for religion meant that any cosmological theorizing with traces of Christian dogma was suspect. Big Bang cosmology was officially viewed as “astronomical idealism, which helps clericalism.”63 It did not help that at least two scientists who had supported Friedmann’s original relativistic models of the expanding universe had died in Stalin’s purges. In response, Soviet astronomers in the 1950s largely gave up “the study of the universe as a whole”.64

  In England, a more rational objection—and alternative—to the beginning of time was born. Fred Hoyle, a Yorkshireman of considerable energy and wit, deeply distrusted religion and found the idea of a “moment of creation” untenable.65 With fellow Cambridge physicists Hermann Bondi and Thomas Gold, Hoyle proposed a new model, a steady-state alternative to Gamow’s ideas. Steady-state cosmology accepted the universe’s expansion but sought to make it eternal and unchanging. By allowing matter to be continuously created throughout the universe, new galaxies could form in the empty voids that opened up by cosmic expansion. Thus, the universe could be dynamic and expanding and still always appear the same. Any region of space viewed at any time in cosmic history would look like any other: a few new galaxies forming while the rest expand away from one another. The steady-state model was parsimonious with continuous creation. Just a single hydrogen atom popping into existence each year “in a volume equal to St Paul’s Cathedral” was enough to do the trick.66

  While many scientists scoffed at this “magic” creation of matter as a feature of the steady-state model, Hoyle responded that it was no stranger than having all the mass-energy appear at once at the beginning of time. It was Hoyle who, during a BBC lecture series on the nature of the universe, coined “Big Bang”—as a term of derision. Unfortunately for Hoyle, both the term and the theory it described stuck. But the BBC programme did make Hoyle a household name in 1950s En gland and it gave the professor and his wife the opportunity to purchase a cherished electrical appliance—a fridge.67

  By the beginning of the 1960s, cosmology seemed stuck in a ditch. The steady-state model had both strong supporters (mostly in Britain) and strong critics. Along with the other cosmological theories still in circulation, such as the work of Lemaître and Gamow, it remained a viable explanation for cosmic history that could embrace the one piece of data everyone agreed on—cosmic expansion.

  There had, however, been some good news for the Big Bang during these years. Its two major empirical objections were overthrown. Astronomers had come to understand that all elements heavier than lithium were built at the centre of stars rather than at the origin of the universe. With stellar nucleosynthesis working so well for heavy elements, Big Bang nucleosynthesis could focus on what it did best—explain the origin of light elements. Astronomers had also revisited Hubble’s early estimates of the cosmic expansion rate. The age of the universe in Big Bang models was moved closer to ten billion years, which put it in line with the age of stars. But in spite of these advances, astronomers remained sceptical. With so much conflict and so little hard data, the field of cosmology was largely ignored, making the cosmological surprise waiting in New Jersey all the more remarkable.

  In 1964 Bell Laboratories had facilities scattered across the country. These labs were scientific powerhouses pushing forward the frontiers of everything from transistors and lasers to computers and, of course, satellite telecommunications. In 1959, in a field just outside of Holmdel, New Jersey, Bell Labs’ Crawford Hill facility had constructed a giant ultrasensitive antenna for bouncing signals off the Echo 1 satellite. Once Telstar was launched, the fifteen-metre, horn-shaped microwave receiver was freed up for other uses. Two Bell Labs employees with PhDs in astronomy, Arno A. Penzias and Robert W. Wilson, jumped at the chance to put the antenna to astrophysical use. The two astronomers planned an ambitious research programme examining distant objects using microwave light. But as they prepared the horn to take data they encountered what appeared to be a technical problem that brought their ambitions to a screeching halt.

  There was a noise in the system that would not go away. A steady microwave hiss persisted in the horn regardless of the direction the astronomers pointed their antenna. At first Wilson and Penzias were sure the signal was nothing more than an electronic artefact and they struggled for weeks to root out the problem. The electronics were rebuilt but nothing changed. Layers of pigeon guano were scrubbed from the antenna surface, to no avail. Nothing worked. It was as if the entire sky was saturated with microwave radiation that peaked at a wavelength of 7.35 centimetres. The pair realized the truth of their situation only when a friend handed Penzias an article written by astronomers at nearby Princeton University.

  The sky was saturated with microwave radiation. More important, the 7.35-centimetre radiation
was exactly the consequence of what Alpher, Herman and Gamow predicted in their groundbreaking, and now all but forgotten, papers fifteen years before. Penzias and Wilson had found an all-important relic of the hot Big Bang, an electromagnetic fossil of the universe’s earliest epochs.

  THE COSMIC MICROWAVE BACKGROUND AND THE BIG BANG’S TRIUMPH

  Gamow’s Big Bang was always a kind of cosmic nuclear archaeology. The first few moments of the universe left traces on the world we see today. If we were clever enough, we could read those traces. In his earliest work, Gamow considered the cosmic abundance of elements to be just such an imprint. As he, Alpher and Herman sharpened their conception of the hot Big Bang with detailed calculations they found other relics that should have survived billions of years of cosmic evolution. Seven different times in their various papers, Alpher and collaborators predicted that a Big Bang would leave the universe saturated with a particular kind of fossil electromagnetic radiation.

  FIGURE 7.7. From telecommunications to cosmology. Wilson and Penzias stand in front of the horn-shaped receiver (designed for satellite communications) they used to discover microwave “echoes” of the Big Bang.

  While the universe would only be hot and dense enough to forge elements for a few minutes, the end of the nuclear era did not end the universe’s particle alchemy. As space continued to expand, the temperature and density of the cosmic soup continued to drop. Matter, in the form of protons, electrons, helium nuclei and other particles, was well mixed with photons (quanta of light). The physics of this mix imprinted the photons with a fixed signature—a fossil imprint of history—that was discovered by Penzias and Wilson’s curious probing.

  In the late 1800s, physicists learned that any hot, dense object emits light with a characteristic pattern called a blackbody spectrum. The red glow of an iron rod in a fireplace is a common example of blackbody light. Within the heated iron rod matter and photons are strongly coupled together exchanging energy in rapid-fire reactions. Physicists also learned that most of the light a blackbody emits comes at a wavelength strongly dependent on the blackbody’s temperature. Place the same iron rod in a blast furnace and it will glow white-hot as the peak blackbody emission shifts to include more visible wavelengths (colours). Astronomers routinely exploit this property of blackbody emission. Hot, dense objects (such as a star) can have their temperatures taken from millions of light-years away simply by recording their spectra, confirming its blackbody character and noting where the peak emission occurs.

  As exotic as the early universe might have been, it was still a collection of hot, dense stuff. Thus, the entire early universe was a blackbody. Matter particles and photons jostled together. Matter absorbed the photons and then spat them out again in endless reactions. In this way, the young universe was saturated with blackbody light. Then, about three hundred thousand years after the birth of time, the blackbody photons were frozen out of the party.

  The key event was the capture of electrons by protons to form the first hydrogen atoms. The newly formed hydrogen could not absorb the blackbody photons. The physics of hydrogen’s internal constitution made interactions with the blackbody photons all but impossible. A “decoupling” of matter (the now ubiquitous hydrogen atoms) and the bath of blackbody photons occurred relatively swiftly. The photons were left without dance partners. Just a few thousand years before, they could not travel more than a millimetre through the universe without being absorbed, but after decoupling they were left orphaned, free to wander the universe unimpeded. As time marched forward, the only change this fossil light would experience was a stretching in wavelength directly tied to the expansion of space itself.

  Through their calculations Alpher and Gamow saw how the nuclear thermodynamics of a hot Big Bang implied a universe full of fossil blackbody radiation. They even knew its temperature. In one of the great acts of scientific prescience they predicted a cosmic background of “thermal photons” with an average temperature of about five degrees kelvin (five degrees above absolute zero). This is exactly what Penzias and Wilson stumbled upon.

  The Bell Labs scientists did not make this monumental third “discovery” of Big Bang cosmology (after Lemaître and then Gamow, Alpher and Herman) alone. The paper Penzias had been given was from Princeton physics professor Robert Dicke and his collaborators. Dicke had unknowingly re-derived Alpher’s results. Just as Penzias and Wilson were calling to seek a consultation with the Princeton physicist, Dicke was in the process of building his own microwave detector to look for the background radiation. After listening to Penzias explain their findings, Dicke reportedly put down the phone and said, “We’ve been scooped.”68

  Alongside Hubble’s recognition of the expanding universe and the abundance of light elements, Alpher and Gamow’s prediction of the cosmic microwave background (CMB) ranks as one of the greatest cosmological advances of the twentieth century. By unwittingly confirming such a specific prediction of hot Big Bang cosmology, Arno and Penzias found the lever and fulcrum needed to upend all competing models of the universe. The microwave photons filling the sky with their perfect blackbody signature were direct proof that the universe had once been far hotter and denser than the cold, empty darkness we see today. The steady-state model offered no ready explanation for the fossil photons filling space, and it soon disappeared as a viable alternative.

  By the end of the 1960s the hot Big Bang, with its marriage of subatomic scale, quantum physics and universal-scale general relativity, was cosmology. The Big Bang had triumphed. Cosmic time had a beginning even if no one understood what that really meant.

  As the decade came to a close an appropriate resonance in popular imagery and theoretical ideas had emerged, linking cosmological beginnings and human endings. New cosmologies always require imaginative interpretations. From Egyptian murals of sky gods to angels on the ceiling of the Sistine Chapel to Depression-era WPA murals invoking the march of science, cosmologies are always ultimately a public endeavour. Attempts to imagine the first instants of the Big Bang—the blinding light and the rush of superheated matter—required their own set of visual metaphors. The necessary images were already close at hand, emanating from the same nuclear science that gave the hot Big Bang cosmology its success. Thermonuclear bomb explosions were a Big Bang of truly awesome power that everyone had already seen.

  Chapter 8

  INFLATION, MOBILE PHONES AND THE OUTLOOK UNIVERSE

  Information Revolutions and the Big Bang Gets in Trouble

  BIRMINGHAM, ENGLAND • DECEMBER 2002, 11:39 A.M.

  Maybe she could just drop out entirely, tell people to call her on the phone or send a letter by the post.

  She popped open the Outlook window on her screen. There were forty-two new messages. Tami in PR wanted to add her to Thursday’s meeting. Thomas in HR needed a consult on the new hire by day’s end. The Manchester team was asking for specs on the new modules. And that new wanker from management had sent another motivational message. She sagged backwards in her seat. Forty-two new messages in an inbox that already had 206 unread e-mails, and she hadn’t even had lunch yet.

  She had come in early this morning just to clean out her e-mail inbox. A full hour and a half wasted sorting through requests, reviews, jokes, chain letters and spam.

  Reply, file, delete, reply, reply, delete, delete, delete.

  By 9:00 a.m. she’d got down to a mere 168 messages. Hit delete all, she’d thought, smiling to herself. But she resisted and tried moving on, focusing on the PowerPoint slides for tomorrow’s tech review (neatly blocked out as a forty-five-minute blue rectangle on her Outlook calendar). She’d resolved to not even glance at her e-mail inbox.

  But she’d failed.

  By 9:50 a.m. there’d been eighteen new messages waiting for her attention. Another ten new e-mails had appeared by the time she was ready for a cuppa at 10:45. When she dropped her bag back on her desk at 11:01, nine more messages had shown up. Why even bother responding when that would just generate more replies?

&nbs
p; She looked at the Outlook calendar again. Twenty-one minutes till the lunchtime sales briefing. Then what? More blue blocks partitioning the afternoon into teleconferences, interviews and meetings. Another day of wasting time being just-in-time. Another day spent getting nothing substantial done. Maybe she should just browse for images of cute kittens.

  ACCELERATION

  The last decades of the twentieth century were witness to yet another revolution in material engagement, institutional facts and human temporal experience. This time, however, we were the witnesses to the revolution. Everyone over the age of twenty has a foot on either side of the divide as human culture and human time stepped from its analogue era into the digital domain. Many of us can still dig up memories of a world unmediated by material engagement in the form of silicon microcircuit chips.

  Remember when you had to be home to get a call?

  Remember when you had to order a map from The AA to plan a trip?

  Remember when your calendar was something that hung on the wall?

  We have been fully present during this transformation in material engagement, institutional facts and cultural time. We have seen the process, still very much ongoing, emerge from below our direct consciousness to seep into every aspect of culture, reshaping our most intimate experiences of life through time.

  Before the advent of mobile phones, for example, we were fundamentally more alone with our thoughts and more present in the lives directly before us. There was nowhere else to be. Urgent or nonurgent communication had to wait until we could find a device connected by a wire to the wall. Now we reach out to communicate at a whim, filling time simply because we are bored or responding to a thought that crossed our mind. The simple act of walking down the street and calling a friend to check in is as profound and radical a shift in the experience, use and conception of time as anything that passed before, from the Neolithic to the industrial revolution.