Was Alvy Right? Does the Universe’s Fate Affect Purpose?

 

By Keith Tidman

In the 1977 movie “Annie Hall,” Woody Allen played the role of a fictional protagonist Alvy Singer, who iconically portrayed a nebbish character: timid, anxious, insecure. All in all, vintage Woody Allen. But equally, these less-than-stellar traits were apparent in Alvy as a young boy. Which is why, when Alvy and his mother went to the doctor’s, she reported that her son was depressed and refusing to do his homework. She thought that Alvy’s unease stemmed from “something he read.”

 

In response to the doctor’s inquiries, Alvy gingerly elaborated on the whys and wherefores of his disquiet: “The universe is expanding…. Well, the universe is everything, and if it’s expanding, someday it will break apart, and that would be the end of everything.” At which point, Alvy’s mother interjects, “Why is that your business? What has the universe got to do with it? You’re here in Brooklyn! Brooklyn is not expanding!” To which Alvy, perhaps channeling Albert Camus’s absurdism, concludes dejectedly, “What is the point?”

 

The way in which this dialog unfolds has been dubbed “Alvy’s error”. That is to say, Alvy — along with the philosophers and scientists who similarly argue over the meaninglessness of life in a universe seemingly on track to die leading to the extinction of our species and civilization — have been accused of “assessing purpose at the wrong level of analysis”.

 

As the ‘errors’ reasoning goes, instead of focusing on a timescale involving billions, or even trillions, of years, we should keep the temporal context within the frame of our own lifespans, spanning days to years to decades. That being said, one might reasonably ask why timescales, cosmic or otherwise, should matter at all in calculating the purpose of human life; the two are untethered.

 

On balance, I suggest Alvy actually got it right, and his mom got it wrong. It’s a conclusion, however, that requires context — the kind provided by the astrophysicists who reported on a recent study’s stunning new insights into the universe’s life cycle. At the center of the issue is what’s called “dark energy,” a mysterious substance that astrophysicists believe exists based on its cosmological effects. It’s a repulsive force that pushes apart the lumpy bits of the universe — the galaxies, stars, and planets — incidentally setting off Alvy’s bout of handwringing by causing the universe to expand ever faster.

 

To be clear, dark energy is no trifle. It is estimated to compose seventy percent of the universe. (In addition, equally unseen dark matter composes another twenty-five percent of the universe. By comparison, what we experience around us everyday as observable matter — when we agonizingly stub our toe on the table or gaze excitedly upon vast cosmic swaths, star nurseries, and black holes — composes just a tiny five-percent sliver of cosmic reality.)

 

That our species is able to persistently ponder alternative models of cosmology, adjusting as new evidence comes in, is remarkable. That our species can apply methods to rigorously confirm, revise, or refute alternative models is similarly remarkable. The paradox is that three of the four models now in play by astrophysicists will lead to humankind’s extinction, along with that of all other sophisticated intelligent species and their civilizations ever to inhabit the universe. How can this be so?

 

For starters, the universe’s expansion has consequences. That said, recent observations and research has added a new twist to what we understand regarding issues of cosmology — from how the universe’s initial spark happened 13.8 billion years ago, and especially how things might end sometime in the future. Alvy was gripped by angst over one such consequence: he contemplated that the increasing acceleration might continue until the universe experiences a so-called Big Rip. Which is when everything, from galaxy clusters to atomic nuclei, fatally “breaks apart,” to borrow Alvy’s words, leading to a grand-scale extinction.

 

But, according to the most recent studies of the standard cosmological model, and of the increasingly understood role of dark energy, there’s a paradox as to a possible cosmic end state other than a Big Rip. Because there is an alternative outcome of accelerating expansion, in which the distance between stars and galaxies greatly increases, such that the universe eventually goes cold and dark. This is sometimes called the thermodynamic death of the universe, moved along by the destructive role of entropy, which increases the universe’s (net) state of disorder. No less fearful, surely, from the standpoint of an already-timorous Alvy.

 

The third possibility that dark energy creates is that its pushing (repulsive) effects on the cosmic lumps start to weaken, in turn causing the universe’s expansion to slow down and reverse, eventually leading to contraction and a so-called Big Crunch. Whether the crunch segues to another Big Bang is hypothesized, but the recent cosmological and dark-energy research doesn’t yet speak to this point about a cosmic bounce. Either way, extinction of our species and of all other intelligent life forms and civilizations remains inevitable as our full cosmic history plays out.

 

The fourth and last option is less existentially nihilistic than the preceding three possibilities — and is one that might be expected to have had a calming effect on Alvy, if he only knew. In this less-likely cosmological model, dark energy’s effect on cosmic expansion might slow but stabilize rather than implode. In averting the fate of a Big Rip, or a heat death, or a Big Crunch, there would be no extinction event occurring. Rather, circumstances would lead to a universe existing stably into infinity.

 

No matter how one dices reality, the existentialism and nihilism espoused by, for example, Schopenhauer, Sartre, and Nagel, as well as ideas about will-to-power advanced by Nietzsche, hang over the inconvenient realities of a universe fated to reach an all-encompassing expiry date, depending on the longer-term influences of dark energy.

 

From a theist’s standpoint, striving to live Aquinas’s “beatific vision,” one might wonder why a god would create a highly intelligent, conscious species like ours — along with innumerable cosmic neighbors (extraterrestrials) of unimaginably greater intelligence and sophistication because of earlier starts — when every species is assured to go poof. There will be no exceptions; the scale of annihilation will be cosmic. 

So, what’s the meaning and intent, if any, of such teasing capriciousness? "What's the point?," as Alvy muttered with deep resignation. And how realistic can a transcendental force be, purportedly serving as a prime first cause of us and of our cosmic co-inhabitants subject to such conditions? Besides, contrary to some assumptions, even the existence of a god does not vouchsafe purpose for our species; nor does it vouchsafe purpose for the universe itself. 

 

On the other hand, from a secular, naturalistic viewpoint, life might be imagined as meaningful in the sense of “purpose in life.” That is, where we make decisions and perform deeds as moral, empathic individuals and community members — not on the scale of an entire species. By definition, these secular events occur in the absence of a divine plan, such that we emerge from the physical laws of nature, to go on to create personal value, purpose, and social norms. As to purpose in life, where meaning is defined on the scale of a single personal, the prospect of “the end of everything” might be seen as less vexing, as meaning is acquired on the level of a single person.

 

In the sense, however, that’s conveyed by the slightly altered phrase “purpose of life” — where the one-word change shifts the focus from the individual and to the species — cosmic extinction looms more consequentially in terms of the lack of purpose and meaning. Given the prospect of such cosmic annihilation, Alvy might be excused his existential musings.

 

Are We Alone in the Universe, or Not? And Does It Matter?

Peering through Saturn’s rings, the Cassini probe caught a glimpse of a faraway planet and its moon. At a distance of just under 900 million miles, Earth shines bright among the many stars in the sky, distinguished by its bluish tint.

By Keith Tidman

The writer and futurist Arthur C. Clarke once wrote: “Two possibilities exist: Either we are alone in the universe, or we are not. Both are equally terrifying.” 

But are the two alternatives really terrifying? And even if they were, then what might be the upshot?

 

In exploring the possible consequences of Clarke’s thought experiment, I’ll avoid enmeshing us in a discussion of whether extraterrestrials have already visited Earth, or whether we will get to visit their planets in the near term. For the foreseeable future, the distances are too large for that to happen, where suspected extraterrestrial civilisations are thousands, millions, or billions of light-years away. Those distances hamper hunts for signals engaged in by the Search for Extraterrestrial Intelligence (SETI) Institute, which metaphorically dips only an infinitesimally small scoop into the vast cosmic ocean. And such distances hamper interstellar travel.

 

Accordingly, we are currently in no position to respond definitively to the challenge Enrico Fermi, also known as “the architect of the nuclear age,” raised with his lunchtime colleagues at the Los Alamos National Laboratory in New Mexico in 1950, referring to extraterrestrials: “Where is everybody?”

 

One piece of crucial context for our conversation here is that of scale: the known universe is currently thought to be some 93 billion light-years in diameter. Recall that a light-year is a measurement of distance, not time, so that in Earthly ‘miles,’ the cosmic diameter is an easy, but boggling, calculation: 93 billion multiplied by 5.8 trillion miles. Add that, in the case of travel or electromagnetic communications (beamed signals) between us and extraterrestrials, the velocity of light is the fixed upper limit — as far as current science is concerned, anyway. All of which is problematic for detecting aliens and their biomarkers or technomarkers, quite apart from anyone engaging in neighbourly interstellar space visitation.

 

Yet, in a universe kickstarted some 13.8 billion years ago — with hundreds of billions of galaxies, and trillions of stars and planets (many of those exoplanets conceivably habitable, even if not twins of our world) — it’s surely arguable that extraterrestrial civilisations, carbon-based or differently constituted physically, are out there, similarly staring toward the skies, quizzically pondering. Alien cosmologists asking, “Where is everybody?,” making great strides developing their own technology, and calculating probabilities for sundry constants and variables assumed necessary for technologically advanced life to prosper elsewhere.

 

There are two key assumption in asking whether we are alone in the universe or we are among teeming alien life strewn throughout the universe. The first assumption, of a general nature, is to define ourselves as a conscious, intelligent, sophisticated species; the second is to assume the extraterrestrials we envision in our discussion are likewise conscious and intelligent and sophisticated — at least equally or maybe considerably more so, options we’ll explore.

 

A third assumption is an evolutionary process, transitioning from physics to chemistry to biology to consciousness. Higher-order consciousness is presumed to be the evolutionary apex both for our species — what it is like to be us — and for extraterrestrials — what it is like to be them. Consciousness may end up the evolutionary apex for our and their machine technology, too. Given that higher-order consciousness is central, we need a baseline for what we mean by the term. Taking a physicalist or materialist point of view, the mind and consciousness are rooted in the neurophysiological activity of the brain, reducible to one and the same. This, rather than existing dualistically in some ethereal, transcendental state separate from the brain, as has sometimes been mythologized.

 

As a placeholder here, consciousness is assumed to be fundamentally similar in its range of domains both for our species and for extraterrestrials, comprising variations of these features: experience, awareness, perception, identity, sentience, thought experimentation, emotion, imagination, innovation, curiosity, memory, chronicled past, projected future, executive function, curation, normative idealism, knowledge, understanding, cognition, metacognition — among others. On these important fronts, the features’ levels of development between us and extraterrestrials may well differ in form and magnitude.

 

As for one of Arthur C. Clarke’s alternative scenarios — that our species is alone in the universe — I can’t help but wonder why, then, the universe is so old, big, and still rapidly growing, if the cosmic carnival is experienced by us alone. We might scratch our heads over the seeming lack of sense in that, whereby the imposing panorama captured by space-based telescopes dwarfs us. We might, therefore, construe that particular scenario as favouring an exceptional place for our species in the otherwise unoccupied cosmic wonderment, or in a different (and more terrifying?) vein suggesting our presence is inconsequential.

 

That is, neither aloneness nor uniqueness necessarily equates to the specialness of a species, but to the contrary a trifling one-off situation. Where we have to come to grips with the indeterminacy of why this majestic display of light-years-sized star nurseries, galaxies rushing toward or away from one another, the insatiability of hungry supermassive black holes, supernovas sending ripples through the faraway reaches of spacetime, and so much more.

 

As for the possibility of sophisticated other life in the universe, we might turn to the so-called anthropic principle for the possible how and why of such occurrences. The principle posits that many constants of the Earth, of the solar system, of the Milky Way, and of the universe are so extraordinarily fine-tuned that only in those ways might conscious, intelligent, advanced life like ours ever to have evolutionarily come into being.

 

The universe would be unstable, as the anthropic principle says, if any of those parameters would shift even a minuscule amount, the cosmos being like a pencil balanced precariously on its pointed tip. It’s likely, therefore, that our species is not floating alone in an unimaginably vast, roiling but barren cosmic sea; according to a more expansive view of the error-less anthropic principle, the latter makes the creation and sustenance of extraterrestrial life possible, too, as fellow players in the cosmic froth. Fine-tuned, after all, doesn't necessarily equate to rare. 

 

We might thus wonder about the consequences for our self-identity and image if some among these teeming numbers of higher-order intelligent extraterrestrials inhabiting the universe got a developmental jumpstart on our species’ civilisation of a million or more years. It’s reasonable to assume that those species would have experienced many-orders-of-magnitude advances biologically, scientifically, technologically, culturally, and institutionally, fundamentally skewing how humanity perceives itself.

 

The impact of these realities on human self-perception might lead some to worry over the glaring inequality and possibly perceived menace, resulting in dents in the armour of our persistent self-exceptionalism, raising larger questions about our purpose. These are profoundly philosophical considerations. We might thereby opt to capitulate, grasping at straws of self-indulgent excuses. Yet, extraterrestrials capable of interstellar travel might choose — whether for benign purposes (e.g., development, enlightenment, resource sharing), or for malign ones (e.g., hegemonism, hubris, manifest destiny, self-exceptionalism, colonisation), or for a hybrid of reasons — that interventionism, with its mix of calculated and unpremeditated consequences, might seem the natural course.

 

Our reactions to gargantuan inter-species differences might range from giddy exceptionalism at one end to dimmed significance at the other. On a religious front, a crisis might ensue in the presence of remarkably advanced extraterrestrials, influencing factors surrounding faith, creeds, dicta, values, patriarchy. Some of our religious constructs — scriptures, symbology, philosophies — might collapse as shallow affectations. For example, in light of hyper-advanced extraterrestrials, our history of expressing religious imagery in anthropomorphic terms (our species described doctrinally as being “in God’s image,” for example) may no longer make sense, fundamentally altering belief systems.

 

We would have to revisit the principles of ethics, including the degree that ethics are culturally and societally contingent. Or the impact might lead to our being elated that life has advanced to such a remarkable degree, covetous for what it might mean for benefits for our species — to model what seems to have worked magnificently for a cutting-edge alien civilisation. The potential for learning vastly advanced natural science and technology and societal paradigms would be immense, where, for instance, extraterrestrials might be hybrids of the best of biology and the best of machines.

 

As potentially confounding either of Clarke’s scenarios might prove, neither need be terrifying; instead, both scenarios have the potential of being exhilarating. But let me toss one last unavoidable constant into the cosmic cauldron. And this is the concept of entropy — the irreversibly increasing (net) disorder within a closed, isolated system like the universe, with its expanding galactic and stellar separation accelerating toward a thermodynamic demise. Entropy is a fact of life of the universe: providing an expiry date, and eventually rendering everything extinct. The end of history, the end of physics — and the end of metaphysics.

 

And the Universe Shrugged

Posted by Keith Tidman

It’s not a question of whether humankind will become extinct, but when.

To be clear, I’m not talking about a devastatingly runaway climate; the predations of human beings on ecosystems; an asteroid slamming into Earth; a super-volcano erupting; a thermonuclear conflagration; a global contagion; rogue artificial intelligence; an eventual red-giant sun engulfing us; the pending collision of the Milky Way and Andromeda galaxies. Nor am I talking about the record of short-lived survival of our forerunners, like the Neanderthals, Denisovans, and Homo erectus, all of whom slid into extinction after unimpressive spans.

Rather, I’m speaking of cosmic death!

Cosmic death will occur according to standard physics, including cosmology. Because of the accelerating expansion of the universe and the irrepressibility of entropy — the headlong plunge toward evermore disorder and chaos — eventually no new stars will form, and existing stars will burn out. The universe will become uninhabitable long before its actual demise. Eventually a near vacuum will result. Particles that remain will be so unimaginably distanced from one another that they’ll seldom, if ever, interact. This is the ultimate end of the universe, when entropy reaches its maximum or so-called thermodynamic equilibrium, more descriptively dubbed ‘heat death’. There’s no place to duck; spacefaring won’t make a difference. Nowhere in the universe is immune.

Assuredly, heat death will take trillions of years to happen. However, might anyone imagine that the timeframe veils the true metaphysical significance of universal extinction, including the extinction of humans and all other conscious, intelligent life? And does it really make a difference if it’s tens of years or tens of trillions of years? Don’t the same ontological questions about being still searingly pertain, irrespective of timescale? Furthermore, does it really make a difference if this would be the so-called ‘sixth extinction’, or the thousandth, or the millionth, or the billionth? Again, don’t the same questions still pertain? There remains, amidst all this, the reality of finality. The consequences — the upshot of why this actuality matters to us existentially — stay the same, immune to time.

So, to ask ‘what is the meaning of life?’ — that old chestnut from inquiring minds through the millennia — likely becomes moot and even unanswerable, in the face of surefire universal extinction. As we contemplate the wafer-thin slice of time that makes up our eighty-or-so-year lifespans, the question seems to make a bit of sense. That select, very manageable timeframe puts us into our comfort zone; we can assure ourselves of meaning, to a degree. But the cosmological context of cosmic heat death contemptuously renders the question about life’s purpose without an answer; all bets are off. And, in face of cosmic thermodynamic death, it’s easy to shift to another chestnut: why, in light of all this, is there something rather than nothing? All this while we may justifiably stay in awe of the universe’s size and majesty, yet know the timing and inevitability of our own extinction rests deterministically in its hands.

A more suitable question might be whether we were given, evolutionarily, consciousness and higher-order intelligence for a reason, making it possible for us to reflect on and try to make sense of the universe. And where that ‘reason’ for our being might originate: an ethereal source, something intrinsic to the cosmos itself, or other. It’s possible that the answer is simply that humankind is incidental, consigning issues like beginnings to unimportance or even nonsense. After all, if the universe dies, and is itself therefore arguably incidental, we may be incidental, too. Again, the fact that the timeframe is huge is immaterial to these inquiries. Also immaterial is whether there might, hypothetically, be another, follow-on Big Bang. Whereby the cosmological process restarts, to include a set of natural physical laws, the possible evolution of intelligent life, and, let’s not overlook it, entropy all over again.

We compartmentalise our lives, to make sense of the bits and pieces that competitively and sometimes contradictorily impact us daily. And in the case of cosmic death and the extinction of life — ours and everyone else’s possibly dotting the universe — that event’s speck-like remoteness in distant time and the vastness of space understandably mollifies. This, despite the event’s unavoidability and hard-to-fathom, hard-to-internalise conclusiveness, existential warts and all. To include, one might suppose, the end of history, the end of physics, and the end of metaphysics! This end of everything might challenge claims to any singular specialness of our and other species, all jointly riding our home planets to this peculiar end. 

Perhaps we have no choice, in the meantime, to conduct ourselves in ways that reflect our belief systems and acknowledge the institutional tools (sociological, political, spiritual) used to referee those beliefs. As an everyday priority, we’ll surely continue to convert those beliefs into norms, to improve society and the quality of life in concrete, actionable ways. Those norms and institutions enable us to live an orderly existence — one that our minds can plumb and make rational sense of. Even though that may largely be a salve, it may be our best (realistically, only) default behaviour in contending with daily realities, ranging from the humdrum to the spectacular. We tend to practice what’s called ‘manic defence’, whereby people distract themselves by focusing on things other than what causes their anxiety and discomfort.

The alternative — to capitulate, falling back upon self-indulgent nihilism — is untenable, insupportable, and unsustainable. We are, after all, quite a resilient species. And we live every day with comparatively attainable horizons. There remains, moreover, a richness to our existence, when our existence is considered outside of extraordinary universal timeframes. Accordingly, we go on with our lives with optimism, not dwelling on the fact that something existential will eventually happen — our collective whistling past the graveyard, one might say. We seldom, if ever, factor this universal expiry date into our thinking — understandably so. There would be little to gain, on any practical level, in doing otherwise. Cosmic thermodynamic death, after all, doesn’t concern considerations of morality. Cosmic death is an amoral event, devoid of concerns about its rightness or wrongness. It will happen matter of factly.

Meanwhile, might the only response to cosmic extinction — and with it, our extinction — be for the universe and humanity to shrug?

On Quanta and Trees

Does Observation Create Physical Reality?

Image found on Mythapi Facebook page. Author unknown

Posted by Keith Tidman

The intervention of conscious observation into the quantum world — that observing an object to be in a particular location causes it actually to be there — is one of the core tenets of quantum theory. A tenet rigorously upheld through multiple experiments. The observer — his or her consciousness — cannot be separated from that physical reality. There is no reality independent of observation. 

As the visionary quantum physicist John Wheeler stated it, “No . . . property is a property until it is observed.” Which seems to apply as much to macro-sized objects — things in everyday life — as to micro-sized objects.

Three hundred-plus years ago, the philosopher George Berkeley prefigured the spirit of quantum theory’s then-future influence on the nature of reality, declaring, esse est percepi [to be is to be perceived]. Perception, he presciently advocated, is the essential benchmark — the necessary condition — for existence. The reality of things thus emerges from perception. As long as conscious observation is involved — a manifestation of the observer's capacity to consummate physical reality — all objects, large and small, acquire their existence.

So, how does this work? Quantum theory explains that until observation occurs, a potential object was in what’s called a state of ‘superposition’. An object, while in superposition, can be in any number of places, with observation causing it to be in just one location. There was no object isolated in space before it was observed or measured. Upon being observed, the object went from potentiality to actuality in that one location, the same for everyone.

What’s in superposition is the so-called ‘wave function’ — a mathematical description of all the possible states of an object. Only upon being observed does the wave function instantaneously and irreversibly ‘collapse’, causing the object to be in just one location. There is no distinction between the wave function and the object. According to the physics, the wave function is the object — in one-to-one correspondence with the physical thing.

The effect of observation and measurement has also been demonstrated by the so-called ‘double-slit experiment’. A stream of photons (light particles) passes one at a time through a screen with two slits. Behind the screen is a photographic plate, to capture what comes through the slits. In the absence of an observer, each photon will have appeared to pass through both slits simultaneously before creating a distinct interference pattern on the back plate — acting, in other words, like a wave, able to pass through both slits at once. However, in the presence of an observer — a person or detecting device in front of or behind each slit to see which slit the photon goes through — the interference pattern no longer shows up. Each photon appears to have passed through only one slit or the other. The photon has no location in spacetime until it’s observed or measured.

As suggested by both examples — the collapse of a wave function and the double-slit experiment — observation may be performed by a person directly and in real time. Or, observation may be accomplished by an apparatus (detector), whose measurements are observed by scientists later. In either case, observation remains critical, as explained by physicist and philosopher Roger Penrose:

“Almost all the interpretations of quantum mechanics . . . depend to some degree on the presence of consciousness for providing the ‘observer’ that is required [for] the emergence of a classical-like world.”

Meanwhile, the effects of these events also play into what’s known as quantum entanglement — what Albert Einstein famously dubbed ‘spooky action at a distance’. Quantum entanglement occurs when two particles remain ‘connected’, without regard to time and distance — that is, instantaneously, even at enormous distances — in such a way that actions performed on one particle are observed to have an immediate and direct effect on the other. This curious phenomenon, spooky or not, has been confirmed.

So, to the point, what does all this tell us about physical reality?

Causing the reality of an object by observation points to this initial moment of creation being subjective. It’s where an observer first intervenes — until which there is only ‘potential reality’. Accordingly, ‘initial reality,’ as we might call it, requires intervention by an observer — either a person or measuring device. Again, that initial moment of reality is subjective.

However, once initial conscious observation has occurred, the object henceforth exists for everyone. Further instances of observation change nothing about the physical reality already having been created. Reality is thus locked in for everyone — everywhere. Everyone who looks will find the object there, already existing. At that moment, reality is objective — the initially observed object remains so, existing for everyone.

In sum, then, the key takeaway is the presence of both a subjective and objective aspect to reality, depending on the moment — initial observation followed by subsequent observation.

At the moment of causing the object to exist, the observer also causes that object’s entire history to exist. Observation causes both the current reality and related past realities (history) to exist. Whether this is so for literally all observed things remains debatable — quantum mechanically, cosmologically, and philosophically.

Might the notion include, for example, the whole universe — the ultimate macro-sized object? As Wheeler postulates, in our looking rearward to the universe’s beginnings, might our observations result in selecting one out of alternative possible cosmic quantum histories, back to the Big Bang almost fourteen billion years ago? And, in line with the ‘anthropic principle’, might that quantum history account for the many finely tuned features of the universe essential for its and our existence — resulting in an objective macro-reality, the same for everyone, throughout the universe?

Accordingly, Berkeley argued that observation accounts for what gives material things their experienced qualities — an object’s initially experienced reality (its presence and qualities) as well as an object’s subsequently experienced reality.

Where Berkeley’s philosophy converges with the core of this discussion regarding the basis of objects’ reality is his argument for observation — perception — being essential for something to exist. What has been characterised as Berkeley’s empirical idealism. Berkeley argued that material objects are dependent on, not independent of, observation. In this important sense, observation and existence are the same. That is, they ‘cohere’.

Picture Post #20 Olber's Paradox raising insoluble questions

---

'Because things don’t appear to be the known thing; they aren’t what they seemed to be neither will they become what they might appear to become.'

Posted by Martin Cohen and Tessa den Uyl

A NASA  image from the Hubble Telescope looking into the 'Deep Field'

This is a patch of BLACK sky - empty when initially seen - even through the largest earthbound telescopes. Yet, with the  Hubble space telescope and a long-enough exposure time, even the darkness of space soon comes to glowing life. The point is, every bit of sky is actually packed with light - not merely with stars but with uncountable distant galaxies.

Heinrich Olbers (1758–1840) was a Viennese doctor who only did astronomy in his spare time, but realised that there was a bit of a logical problem about the night sky. And ‘O’ is for ‘Olbers Paradox’*,  which can be summed up by saying that if the universe is really infinite in size, the the night sky should not only be bright – but should be infinitely bright. Put short, we should see stars everywhere we look. So why don't we and why isn't the night sky all lit up ?

The paradox touches upon profound issues in cosmology, or the study and theory of the origins of the universe. Simply saying that most of the stars are too far away to see is not enough. Certainly it is true that starlight, like any other kind of light, dims as a function of distance, but at the same time, the number of light sources in the ‘cone of vision’ increases – at exactly the same rate. In fact, on the mathematics of it, given an infinite universe, with galaxies and stars distributed uniformly, the whole night sky should appear to be not black, not speckled, but white!

Olbers’ paradox is a ‘thought experiment’ in the very good sense that most of the reasoning is done by hypotheticals. What if the universe is infinitely large? And infinitely old? If the stars and galaxies are (on average) spread out evenly?

Various possible explanations have been offered to explain the paradox. Such as that stars and galaxies are not distributed randomly, but rather clumped together leaving most of space completely empty. So, for example, there could be a lot of stars, but they hide behind one another. But in fact, observations reveal galaxies and stars to be quite evenly spread out.

What then, if perhaps the universe has only a finite number of stars and galaxies? Yet the number of stars, finite or not, is definitely still large enough to light up the entire sky…

Another idea is that there may be too much dust in space to see the distant stars? This seems tempting, but ignores known facts. Like that the dust would heat up too, and that space would have a much higher. The astronomers who took this image claim it shows some kind of spectral shift into the red specturm. Or is it only the dust? The questions are not really resolved, even yet.

So what is the best answer to Olbers’ riddle? The favoured explanation today is that although the universe may be infinitely large, it is not infinitely old, meaning that the galaxies beyond a certain distance will simply not have had enough time to send their light over to fill our night sky. If the universe is, say, 15 billion years old, then only stars and galaxies less than 15 billion light years away are going to be visible. Add to which, astronomers say that the phenomenon of red shift may mean some galaxies are receding from us so fast that their light has been ‘shifted’ beyond the visible spectrum.

After reading this, and then standing here on planet Earth and watching the night sky, one might feel a little trapped by the questions. Our sight is limited and it always will be but maybe this is our hope for we can continue to philosophise: afte rall, what are we thinking? The picture above might as well represent pieces of coloured glass, under water visions where fluorescent life flows in deep dark sees, a pattern for printed cloth. Our brain only represents what we think we see, not necessarily the reality in which we live? In the incredible immensity of space, mankind has always been aware of this, even if, once in a while, the tendency is to forget.

---

* Although the paradox carries Olbers’ name,  it can really be traced back to Johannes Kepler in 1610.  In Wittgenstein's Beetle and Other Classic Thought Experiments, Martin’s book, which talks a little more about all this,