Friday, April 05, 2013

Marcelo Gleiser - Where Did Life Come From? The Mind? The Universe? Can We Even Know?

The title of this post comes from the first article of three by Marcelo Gleiser at NPR's 13.7 Cosmos and Culture blog. This is a pretty interesting series of articles on life, the mind, and the universe. Enjoy.

Where Did Life Come From? The Mind? The Universe? Can We Even Know?

March 20, 2013

The Universe has an origin; whether we'll ever get to the bottom of it is the question.

Today I'd like to start a discussion on the ways certain kinds of questions present formidable challenges to the conventional scientific method of explanation, based on hypotheses and empirical validation. Given that the topic is vast and space short, I will divide the discussion into three parts (at least). Although there may be many questions that pose a challenge to the scientific method (for example, the much-debated questions of morality and altruism), I am interested in a trio that can be grouped as the "three origins questions": cosmos, life, and mind.

Working with any of these can fill many lifetimes of research, without any promise of success. In fact, how we measure success in answering any of these questions is already part of the challenge. They each invoke different areas of research, with different operational principles and scientific methodologies. Even so, there are points in common, and it is to those that I turn today, and in subsequent blog posts. (There have been many books and essays written on these three issues, taken together or separately. At the end I provide a list of further reading.)

The first point in common is that not so long ago these three questions were not considered scientific. On the contrary, the origin of the Universe, of life, and of mind were thought to be the result of divine work, products of supernatural intervention. Which god or gods were responsible depended (and still does to the vast majority of the world population) on your particular faith. Differences aside, in any religion only an entity that transcended space and time could create the cosmos, which exists within space and time; only an immortal entity had the power to create life; and only an omniscient power could endow His creatures with intelligence and a sense of being.

The confrontation with natural processes is immediate: Nature is within space and time, living entities are not immortal and no one is — or can be — omniscient. (Although the World Wide Web, allied with global human intelligence and powerful search engines, could, in some sense, be called a proto-omniscient entity. Stuff for another week.)

For this reason, it is not at all surprising that scientists encounter such resistance when they state that they are near — or at least making progress — in answering such questions without recourse to divine intervention. According to the scientific viewpoint, the origins of the cosmos, of life and of mind are natural processes that obey material laws and principles. Their complexity and our current lack of answers do not mean that such questions are completely beyond the reach of science, or that such questions can only be addressed through religious belief. In science, ignorance is the pre-condition to knowledge; to not-know is the pathway to knowing.

Perhaps the proper way to phrase the question is not whether science can provide answers to the three origins but how far it can go in answering them. For it may very well be that science can only go part of the way. To see why, let's begin with the one that may, perhaps, be the "easiest" of the three, the origin of life.

Although we are far from understanding the details (see guest blogger Wim Hordijk's recent contribution to these pages), it seems clear that the transition from non-life to life follows from the increasingly complex chemical reactions that took place on primal Earth: at a certain point, networks of chemical reactions became self-sufficient and, partially isolated within protective membranes, were able to absorb energy from the outside environment and to produce copies of themselves with some efficiency. We certainly don't know how this happened here some 3.5 billion years ago (or even earlier).

More to the point, unless someone offers a formal proof that there is only one biochemical pathway toward life — a possibility that I consider highly unlikely — we will never be able to know exactly how life emerged here. At best, we can come up with viable scenarios of the origin of life given the conditions prevalent on primal Earth (another challenge in itself, to find those out).

So, the question of the origin of life, at least in the exact way (or ways, for it may have happened more than once) in which it emerged here or in any other planetary platform out there, is not answerable scientifically. Does this mean that science can't help us understand the origin of life? Not at all. We can only understand the origin of life through science, even if this understanding is necessarily limited. Of the three origins questions, the origin of life is still the most tractable, given that we can simulate conditions and chemical reactions in the laboratory with some degree of control.

Contrary to the origin of the Universe or of mind, the origin of life is a problem we can attack from the outside in. It is for this reason that I call it the "easiest" of the three, although there is nothing easy about it.

Molecular biologists like Gerald Joyce, from the Scripps Research Institute in La Jolla, and Nobel laureate Jack Szostak from Harvard University, among many others, are making spectacular advances toward understanding life. They can manipulate RNA and DNA and coax them into enacting the game of life, that is, respond and adapt to environmental pressure as the theory of evolution dictates; they can strip away cellular structures and genes from living cells to search for the minimum living system; Günter von Kiedrowski in Germany was able to construct auto-catalytic chemical sets that show self-replicating abilities.

These experiments are not yet creating life in the laboratory. But they are certainly steps in the right direction. Even if we will not be able to explain exactly how life emerged on Earth, science still offers the only pathway toward understanding.

A Short Reading List On The Three Origins:

1. Cosmos

The Origin of the Universe, by John Barrow
Big Bang: The Origin of the Universe, by Simon Singh
A Universe From Nothing: Why There Is Something Rather Than Nothing, by Lawrence Krauss
The First Three Minutes: A Modern View of the Origin of the Universe, by Steven Weinberg
The Dancing Universe: From Creation Myths to the Big Bang, by Marcelo Gleiser

2. Life

Origins of Life, by Freeman Dyson
Seven Clues to the Origin of Life: A Scientific Detective Story, by A. G. Cairns-Smith
The Fifth Miracle: The Search for the Origin and Meaning of Life, by Paul Davies
Emergence of Life on Earth: A Historical and Scientific Overview, by Iris Fry
Life's Origin: The Beginnings of Biological Evolution, J. William Schopf, ed.

3. Mind

Origin of Mind: Evolution of Brain, Cognition, and General Intelligence, by David C. Geary
Astonishing Hypothesis: The Scientific Search for the Soul, by Francis Crick
The Age of Insight: The Quest to Understand the Unconscious in Art, Mind, and Brain, from Vienna 1900 to the Present, by Eric Kandel
How the Mind Works, by Steven Pinker
Self Comes to Mind: Constructing the Conscious Brain, by Antonio Damasio

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The Origin of The Universe: From Nothing Everything?

March 27, 2013

A computer simulation of the formation of large-scale structures in the Universe, showing a patch of 100 million light-years and the resulting coherent motions of galaxies flowing towards the highest mass concentration in the centre. The snapshot refers to an epoch about 10 billion years back in time. Klaus Dolag/VIMOS-VLT Deep Survey/ESO

Last week, I started a discussion of what I call "The Three Origins," focusing first on the origin of life. Although we are far from knowing how non-living matter became living organisms on primitive Earth some 3.5 billion years ago (or more), or how to repeat the feat in the laboratory, I consider this the "easiest" of the three questions.

Contrary to the origin of the Universe and the origin of mind, the origin of life is something we can study from the outside in, where we can have an external and objective view of what is going on. Even if, as I have argued, it seems impossible to know exactly how life originated on Earth (unless it could be proven that there is only one pathway from nonlife to life), we can still investigate the biochemical pathways leading to what we may call a living organism. In the case of the cosmos or the mind, things are subtler.

From what we know, all cultures have a creation narrative describing the origin of the world, of how everything came from nothing. As I explored in The Dancing Universe: From Creation Myths to the Big Bang, there are only a small number of possible answers to the origin of the cosmos. All creation myths presuppose the existence of some kind of divine or absolute power capable of creating the world. In the vast majority of cases, the Bible being one example, this absolute power is embodied in God, or a group of gods. In others, the Universe is eternal, without a starting moment in the distant past: it has existed forever and will exist forever. In others still, the cosmos emerges without any divine interference from a primal Nothingness, from an innate tendency to exist. This Nothing can be complete emptiness, a primal egg, or even a struggle between chaos and order. Not every creation myth uses divine intervention or supposes that time started in some moment in the past.

According to modern science, the origin of the universe is part of cosmology. In trying to describe a creation process through scientific language we encounter a serious challenge: if every effect results from a cause, we can follow the chain of causation backwards in time until we arrive at the First Cause. But what caused this cause? Aristotle, for one, used some kind of divine entity to solve this conundrum, the Unmoved Mover, the one that can cause without having been caused. Very convenient, but not scientifically satisfying.

As current astronomical observations resolutely point to a Universe with a beginning in the distant past (according to the latest measurements from the Planck satellite related here last week, at about 13.8 billion years ago), scientific models of the origin of the Universe must face the challenge of explaining or doing away with the problem of the First Cause.

The fundamental question is this: even if a scientific explanation exists, is it an acceptable answer to the question of the origin of the Universe? Defenders of scientism might argue that this is the best that we can do, that it is the only reasonable thing that we can do. Fair enough, if you believe that science should provide an answer to this question and if you are happy with the answers given.

The best answer we have at this point is that the Universe emerged spontaneously from a random quantum fluctuation in some sort of primordial quantum vacuum, the scientific equivalent of "nothing." However, this quantum vacuum is a very loaded nothing: it assumes the whole machinery of quantum field theory, the modern description of how elementary particles of matter interact with one another, was already in operation.

In the quantum realm, even the lowest energy state, the "vacuum," is not empty. Even if the energy of a quantum system is zero, it is never really zero due to the inherent quantum fluctuations about this state. A zero energy quantum state is as impossible as a perfectly still lake, with absolutely no disturbances on its surface. This quantum jitteriness amounts to fluctuations on the value of the energy; if one of these fluctuations is unstable it may grow big, like a soap bubble that blows itself up. The energy remains zero on average because of a clever interplay between the positive energy of matter and the negative energy of attractive gravity. This is the result that physicists like Stephen Hawking, Lawrence Krauss, Mikio Kaku and others speak of when they state that the "universe came out of quantum nothingness," or something to that extent.

The essential question, though, is whether this is indeed a satisfactory explanation to the question of cosmic origins, or simply part of one. The philosopher David Albert raised similar points in a recent review of Lawrence Krauss's book. Here is Krauss's response.

It is obvious that this quantum nothingness is very different from an absolute nothingness. Physicists may shrug this away stating that concepts like absolute nothingness are not scientific and hence have no explanatory value. It is indeed true that there is no such thing as absolute nothingness in science, since the vacuum is pregnant with all sorts of stuff. Any scientific explanation presupposes a whole conceptual structure that is absolutely essential for science to function: energy, space, time, the equations we use, the laws of Nature. Science can't exist without this scaffolding. So, a scientific explanation of the origin of the universe needs to use such concepts to make sense. It necessarily starts from something, which is the best that science can ever hope to do.

Even if we move on to the multiverse, things still need to be formulated in terms of fields, energy, spacetime, derivatives, etc. Furthermore, scientific hypotheses need to be testable and falsifiable, and we don't yet know how to do this with a quantum fluctuation that generates a universe. We can't set this experiment in the laboratory and examine the right conditions for universes to emerge from the quantum vacuum. Contrary to the origin of life question, we can't step out of the Universe to examine it from the outside in. At best, and this should be quite enough for a scientific explanation of cosmic origins, a model for the quantum origin of the Universe should lead to a cosmos compatible with current observations. Stepping out into the abstract multiverse may provide us with different plausible cosmoids and help us understand why our own Universe is so special. But unless there is a very clear selection principle that doesn't predicate our existence, the question as to why this Universe and not another will remain open.

And this is not at all bad. The fact that science answers so many questions doesn't mean it should answer all; or that some questions should only be answered through science. Before I am accused of advocating obscurantism, let me be clear. What I mean is that a scientific explanation to the origin of the Universe, at least one based in the current way we do science, cannot be self-contained. Sometimes we must have the humility to accept that our modes of explanation have limits and make peace with what we can do; and marvel at how much we can do without the pretense of knowing how to do everything.

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Mind and Matter: Confessions Of A Perplexed Soul

April 03, 2013

Charles Rex Arbogast/AP

After a week on the origin of life and another on the origin of the universe, we now turn to the third installment of this series, a digression on the origin(s) of mind. The plural expresses the many ways in which we can think of mind and its origin. I shall touch on some of these without any hope or intention of being either exhaustive or coherent. For when it comes to mind, I confess my perplexity. And I am sure I am not alone.

First some definitions, just to start the controversy. Since I am not a cognitive psychologist or a philosopher of mind, I hope my co-bloggers Tania Lombrozo and Alva Noë will come to the rescue in due course. We play with three words, "brain," "mind" and "consciousness," and possibly a fourth, "intelligence."

Brain is easy. All vertebrate animals have it in their skull; it's the central organ of the nervous system. An interesting but tangential question is which is the simplest brain, or what animal has the simplest brain. Jellyfish, for example, have diffuse nerve nets but no central nervous system. The winners are worms, who have small bundles of neurons arranged as nerve cords running along the length of their bodies.

Mind, consciousness and intelligence are hard. From a scientific perspective, all three are products of the brain. There is matter and nothing else. The question then is to figure out how the brain does it: how we can ask profound questions and write essays about them while dogs and chimps can't, even though they are arguably intelligent. There are levels of intelligence, levels of consciousness and levels of mindfulness. So, one of the questions about origin of mind is how it evolved to the level we see today.

In this connection, I note the recent New York Review of Books essay by John Searle on Christof Koch's book, Consciousness: Confessions of a Romantic Reductionist. Searle criticizes Koch for his attempt to indiscriminately use information theory to explain consciousness, starting with attributing it to devices such as thermostats or cellphones. Koch claims that even a photodiode is conscious: It turns on when the light is on and off when the light is off. So, its consciousness has two states (on and off) and minimal information.

Perhaps Koch is paving the road to conscious machines, but I must agree with Searle that unless there is some level of subjective understanding of the action that is undertaken, there is no consciousness to speak of. When cellphones start chatting with one another, we should be duly impressed.

Consciousness needs a conscious observer. And that's the rub.

To facilitate things, let's say that mind is a faculty that conscious, intelligent beings have, the ability to think, feel and reflect about the world and the subjective experiences it presents. It is then legitimate to ask whether other animals have minds or whether machines can one day have them too. This is a key aspect of the debate, since the mind-body problem has traditionally split the line between two sides: Mind is a property of brains that reach a certain level of cognitive complexity and hence a state of matter; or mind is not matter — it is something that can't be reduced to how the brain works.

Of course, this kind of mind-matter dualism dates back at least to Descartes, something that nowadays is mostly not seriously considered, at least by cognitive neuroscientists. (See, for example, the very heated debate surrounding philosopher Thomas Nagel's latest book, Mind and Cosmos. For a good review with many references, see the contribution by Jennifer Schuessler to the New York Times. See also the powerful essay on Nagel's book by Adam Frank in these pages. Nagel goes against scientific reductionism and proposes that mind is a property of the universe, something beyond the merely quantifiable. He is not alone, even among scientists.)

Attributing some sort of teleology to the universe in order to explain mind is merely an updated version of the biblical aspirations that we are special creatures because we were created with a purpose. Instead, I would argue that we can be special without having been created, that what makes us special is precisely the opposite — the fact that we evolved in a universe that is pretty hostile to life, especially complex multicellular life. If you don't believe life is rare, take a look around our planetary neighbors. (Yes, there should be life elsewhere in the universe; but no, it doesn't follow that this life would have evolved to the level of intelligence we see here.)

The wonder lies not in some sort of unknowable property of the cosmos but in the fact that we do have a mind to ponder such things. The answer is within our heads, and the challenge is to find it without being able to step outside and take an objective look.

Recently, Brazilian neuroscientist Suzana Herculano-Houzel, from the Federal University of Rio de Janeiro, showed that the often-quoted figure that the human brain has about 100 billion neurons is off by some 14 billion. The proper number is around 86 billion, connected through trillions of synapses, all packed in about 2.8 pounds. How perplexing that this little bundle of nerve cells can do what it can! Noninvasive probes such as fMRIs provide amazing activity maps of what goes on whereas different stimuli are teased. Without getting lost in the immense maze of cognitive experiments being performed today, it is clear that the brain integrates sensorial stimuli from the outside and re-creates our sense of reality from within.

The only reality we can perceive is the one our brain allows us to. This thought has all sorts of implications to the nature of reality, and to how we define what is real, something Adam touched on in his essay and that I hope to come back to sometime in the near future.

What we call the world happens inside our brains, teased from the outside or from the inside. (Dreams are worlds within, with arbitrary physical laws and narrative rules.) A key question to be answered is whether consciousness needs organic matter to sustain it or whether it can exist merely through electronic circuits. Of course, we all like to think that circuits will do it, that it is a matter of time before we build an intelligent, conscious machine. But we don't really know whether that's even possible, do we?

NOTE: I'd like to add one more book to the reading list from the first week:

Out of Our Heads: Why You Are Not Your Brain, and Other Lessons from the Biology of Consciousness, by Alva Noe.

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