Showing posts with label Anthropic principle. Show all posts
Showing posts with label Anthropic principle. Show all posts

Monday 12 September 2022

The Uncaused Multiverse: And What It Signifies


By Keith Tidman

Here’s an argument that seems like commonsense: everything that exists has a cause; the universe exists; and so, therefore, the universe has a cause. A related argument goes on to say that the events that led to the universe must themselves ultimately originate from an uncaused event, bringing the regress of causes to a halt.

But is such a model of cosmic creation right?


Cosmologists assert that our universe was created by the Big Bang, an origin story developed by the Belgian physicist and Catholic priest Georges Lemaitre in 1931. However, we ought not to confuse the so-called singularity — a tiny point of infinite density — and the follow-on Big Bang event with creation or causation per se, as if those events preceded the universe. Rather, they were early components of a universe that by then already existed, though in its infancy.

It’s often considered problematic to ask ‘what came before the Big Bang’, given the event is said to have led to the creation of space and time (I address ‘time’ in some detail below). By extension, the notion of nothingness prior to the Big Bang is equally problematic, because, correctly defined, nothingness is the total, absolute absence of everything — even energy and space. Although cosmologists claim that quantum fluctuations, or short bursts of energy in space, allowed the Big Bang to happen, we are surely then obliged to ask what allowed those fluctuations to happen.

Yet, it’s generally agreed you can’t get something from nothing. Which makes it all the more meaningful that by nothingness, we are not talking about space that happens to be empty, but rather the absence of space itself.

I therefore propose, instead, that there has always been something, an infinity where something is the default condition, corresponding to the impossibility of nothingness. Further, nothingness is inconceivable, in that we are incapable of visualising nothingness. As soon as we attempt to imagine nothingness, our minds — the act of thinking about it — causes the otherwise abstraction of ‘nothingness’ to turn into the concreteness of ‘something’: a thing with features. We can’t resist that outcome, for we have no basis in reality and in experience that we can match up with this absolute absence of everything, including space, no matter how hard we try to picture it in our mind’s eye.

The notion of infinity in this model of being excludes not just a ‘first universe’, but likewise excludes a ‘first cause’ or ‘prime mover’. By its very definition, infinity has no starting point: no point of origin; no uncaused cause. That’s key; nothing and no one turned on some metaphorical switch, to get the ball rolling.

What I wish to convey is a model of multiple universes existing — each living and dying — within an infinitely bigger whole, where infinity excludes a ‘first cause’ or ‘first universe’.

In this scenario, where something has always prevailed over nothingness, the topic of time inevitably raises its head, needing to be addressed. We cannot ignore it. But, I suggest, time appears problematic only because it's misconceived. Rather, time is not something that suddenly lurches out of the starting gate upon the occurrence of a Big Bang, in the manner that cosmologists and philosophers have typically described how it happens. Instead, when properly understood, time is best reflected in the unfolding of change.

The so-called ‘arrow of time’ traditionally appears to us in the three-way guise of the past leading to (causing) the present leading to the future. Allegorically, like a river. However, I propose that past and future are artificial constructs of the mind that simply give us a handy mechanism by which to live with the consequences of what we customarily call time: by that, meaning the consequences of change, and thus of causation. Accordingly, it is change through which time (temporal duration) is made visible to us; that is, the neurophysiological perception of change in human consciousness.

As such, only the present — a single, seamless ‘now’ — exists in context of our experience. To be sure, future and past give us a practical mental framework for modeling a world in ways that conveniently help us to make sense of it on an everyday level. Such as for hypothesising about what might be ahead and chronicling events for possible retrieval in the ‘now’. However, future and past are figments, of which we have to make the best. ‘Time reflected as change’ fits the cosmological model described here.

A process called ‘entropy’ lets us look at this time-as-change model on a cosmic scale. How? Well, entropy is the irresistible increase in net disorder — that is, evolving change — in a single universe. Despite spotty semblances of increased order in a universe — from the formation of new stars and galaxies to someone baking an apple pie — such localised instances of increased order are more than offset by the governing physical laws of thermodynamics.

These physical laws result in increasing net disorder, randomness, and uncertainty during the life cycle of a universe. That is, the arrow of change playing out as universes live and peter out because of heat death — or as a result of universes reversing their expansion and unwinding, erasing everything, only to rebound. Entropy, then, is really super-charged change running its course within each universe, giving us the impression of something we dub time.

I propose that in this cosmological model, the universe we inhabit is no more unique and alone than our solar system or beyond it our spiral galaxy, the Milky Way. The multiplicity of such things that we observe and readily accept within our universe arguably mirrors a similar multiplicity beyond our universe. These multiple universes may be regarded as occurring both in succession and in parallel, entailing variants of Big Bangs and entropy-driven ‘heat deaths’, within an infinitely larger whole of which they are a part.

In this multiverse reality of cosmic roiling, the likelihood of dissimilar natural laws from one universe to another, across the infinite many, matters as to each world’s developmental direction. For example, in both the science and philosophy of cosmology, the so-called ‘fine-tuning principle’ — known, too, as the anthropic principle — argues that with enough different universes, there’s a high probability some worlds will have natural laws and physical constants allowing for the kick-start and evolution of complex intelligent forms of life.

There’s one last consequence of the infinite, uncaused multiverse described here. Which is the absence of intent, and thus absence of intelligent design, when it comes to the physical laws and materialisation of sophisticated, conscious species pondering their home worlds. I propose that the fine-tuning of constants within these worlds does not undo the incidental nature of such reality.

The special appeal of this kind of multiverse is that it alone allows for the entirety of what can exist.

Monday 30 July 2018

The Anthropic Principle: Was the Universe Made for Us?

Diagram on the dimensionality of spacetime, by Max Tegmark
Posted by Keith Tidman
‘It is clear that the Earth does not move, and that it does not lie elsewhere than at the center [of the universe]’ 
— Aristotle (4th century BCE)

Almost two millennia after Aristotle, in the 16th century, Nicolas Copernicus dared to differ from the revered ‘father of Western philosophy’. Copernicus rattled the world by arguing that the Earth is not at the center of the universe — in a move that to many at the time seemed to knock humankind off its pedestal, and reduce it from exceptionalism to mediocrity. The so-called ‘Copernican principle’ survived, of course, along with the profound disturbance it had evoked for the theologically minded.

Five centuries later, in the early 1970s, an American astrophysicist called Brandon Carter came up with a different model — the ‘anthropic principle’ — that has kept philosophers and scientists debating its significance cosmologically and metaphysically. With some irony, Carter proposed the principle at a symposium to mark Copernicus’s 500th birthday. The anthropic principle points to what has been referred to as the ‘fine-tuning’ of the universe: a list of cosmological qualities (physical constants) whose extraordinarily precise values were essential to making intelligent life possible.

Yet, as Thomas Nagel, the contemporary American philosopher, suggested, even the physical constants known to be required for our universe and an intelligent carbon-based life form need to be properly understood, especially in context of the larger-scaled universe:
‘One doesn’t show that something doesn’t require explanation by pointing out that it is a condition of one’s existence.’
The anthropic principle — its adherence to simplicity, consistency, and elegance notwithstanding — did not of course place Earth back at the center of the universe. As Carter put it, ‘Although our situation is not necessarily central, it is inevitably privileged’. To widen the preceding idea, let’s pose two questions: Did the anthropic principle reestablish humankind’s special place? Was the universe made for us?

First, some definitions. There are several variants of the anthropic principle, as well as differences among definitions, with Carter originally proposing two: the ‘weak anthropic principle’ and the ‘strong anthropic principle’. Of the weak anthropic principle, Carter says:
‘… our location in the universe [he was referring to the age of the universe at which humankind entered the world stage, as well as to location within space] is necessarily privileged to the extent of being compatible with our existence as observers.’
Of the strong anthropic principle, he explained,
‘The universe (and hence the fundamental parameters on which it depends) must be such as to admit the creation of observers within it at some stage’.
Although Carter is credited with coining the term ‘anthropic principle’, others had turned to the subject earlier than him. One in particular among them was the 19th-century German philosopher Arthur Schopenhauer, who presented a model of the world intriguingly similar to the weak anthropic principle. He argued that the world’s existence depended on numerous variables, like temperature and atmosphere, remaining within a very narrow range — presaging Carter’s fuller explanation. Here’s a snapshot of Schopenhauer’s thinking on the matter:
‘If any one of the actually appearing perturbations of [the planets’ course], instead of being gradually balanced by others, continued to increase, the world would soon reach its end’.
That said, some philosophers and scientists have criticized the weak variant as a logical tautology; however, that has not stopped others from discounting the criticism and favoring the weak variant. At the same time, the strong variant is considered problematic in its own way, as it’s difficult to substantiate this variant either philosophically or scientifically. It may be neither provable nor disprovable. However, at their core, both variants (weak and strong) say that our universe is wired to permit an intelligent observer — whether carbon-based or of a different substrate — to appear.

So, what kinds of physical constants — also referred to as ‘cosmic coincidences’ or ‘initial conditions’ — does the anthropic principle point to as ‘fine-tuned’ for a universe like ours, and an intelligent species like ours, to exist? There are many; however, let’s first take just one, to demonstrate significance. If the force of gravitation were slightly weaker, then following the Big Bang matter would have been distributed too fast for galaxies to form. If gravitation were slightly stronger — with the universe expanding even one millionth slower — then the universe would have expanded to its maximum and collapsed in a big crunch before intelligent life would have entered the scene.

Other examples of constants balanced on a razor’s edge have applied to the universe as a whole, to our galaxy, to our solar system, and to our planet. Examples of fine-tuning include the amount of dark matter and dark energy (minimally understood at this time) relative to all the observable lumpy things like galaxies; the ratio of matter and antimatter; mass density and space-energy density; speed of light; galaxy size and shape; our distance from the Milky Way’s center; the sun’s mass and metal content; atmospheric transparency . . . and so forth. These are measured, not just modeled, phenomena.

The theoretical physicist Freeman Dyson poignantly pondered these and the many other ‘coincidences’ and ‘initial conditions’, hinting at an omnipresent cosmic consciousness:
‘As we look out into the universe and identify the many accidents of physics and astronomy that have worked together to our benefit, it is almost as if the universe must in some sense have known we were coming.’
Perhaps as interestingly, humankind is indeed embedded in the universe, able to contemplate itself as an intelligent species; reveal the features and evolution of the universe in which humankind resides as an observer; and ponder our species’ place and purpose in the universe, including our alternative futures.

The metaphysical implications of the anthropic principle are many. One points to agency and design by a supreme being. Some philosophers, like St. Thomas Aquinas (13th century) and later William Paley (18th century), have argued this case. However, some critics of this explanation have called it a ‘God of the gaps’ fallacy — pointing out what’s not yet explained and filling the holes in our knowledge with a supernatural being.

Alternatively, there is the hypothetical multiverse model. Here, there are a multitude of universes each assumed to have its own unique initial conditions and physical laws. And even though not all universes within this model may be amenable to the evolution of advanced intelligent life, it’s assumed that a universe like ours had to be included among the infinite number. Which at least begins to speak to the German philosopher Martin Heidegger's question, ‘Why are there beings at all, instead of nothing?’