Sunday, August 11, 2013

Current Limits of Science -a few of very many.

About six months ago I had a tragi-comic exchange with the principal of a North American day school. One of his students, sixteen years old, challenged his teacher and the rest of the class with the words: "Since science can explain everything, there is no need to believe in G-d." I suppose one should both laugh and cry: laugh at the colossal ignorance of the student, and cry for the damage done by the false impression of the scope of science. Just in case that student is not alone, here is a [very partial] list of some outstanding mysteries for which science has no clue. [I invite readers t write to me with more that I can add.]

1. Dark matter
In astronomy and cosmologydark matter is a type of matter hypothesized to account for a large part of the total mass in theuniverse. Dark matter cannot be seen directly with telescopes; evidently it neither emits nor absorbs light or other electromagnetic radiation at any significant level.[1] Instead, its existence and properties are inferred from its gravitational effects on visible matter, radiation, and the large-scale structure of the universe. According to the Planck mission team, and based on the standard model of cosmology, the total mass–energy of the universe contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy.[2][3]Thus, dark matter is estimated to constitute 84.5% of the total matter in the universe and 26.8% of the total content of the universe.[4].................According to consensus among cosmologists, dark matter is composed primarily of a not yet characterized type of subatomic particle.[6][7] The search for this particle, by a variety of means, is one of the major efforts in particle physics today.[8]

2. Dark energy.
In physical cosmology and astronomydark energy is a hypothetical form of energy that permeates all of space and tends toaccelerate the expansion of the universe.[1] Dark energy is the most accepted hypothesis to explain observations since the 1990s that indicate that the universe is expanding at an accelerating rate. According to the Planck mission team, and based on the standard model of cosmology, the total mass–energy of the universe contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy.[2][3][4]
Two proposed forms for dark energy are the cosmological constant, a constant energy density filling space homogeneously,[5] andscalar fields such as quintessence or modulidynamic quantities whose energy density can vary in time and space. [[In other words, two contradictory proposals mean that we do not understand what it is.]]

[[Taking 1 and 2 together, all our science explains at most 4.9% of the total mass of the universe. And by the way, not all is well with the 4.9% either  Where are the Missing Baryons?
Credit: Spectrum: NASA/CXC/Univ. of California Irvine/T. Fang Illustration: CXC/M. WeissDark energy and dark matter combine to occupy approximately 95 percent of the universe, with regular matter making up the remaining 5 percent. But, researchers have been puzzled to find that more than half of this regular matter is missing. 

This missing matter is called baryonic matter, and it is composed of particles such as protons and electrons that make up majority of the mass of the universe's visible matter.

Some astrophysicists suspect that missing baryonic matter may be found between galaxies, in material known as warm-hot intergalactic medium, but the universe's missing baryons remain a hotly debated topic.]]

3.  See the posts on this blog undr the label "evolution" for the many failures of that theory.

Explanatory gap

From Wikipedia, the free encyclopedia
The explanatory gap is a term introduced by philosopher Joseph Levine for the difficulty that physicalist theories of mind have in explaining how physical properties give rise to the way things feel when they are experienced.[1] In the 1983 paper in which he first used the term, he used as an example the sentence, "Pain is the firing of C fibers", pointing out that while it might be valid in a physiological sense, it does not help us to understand how pain feels.
The explanatory gap has vexed and intrigued philosophers and AI researchers alike for decades and caused considerable debate. Bridging this gap (that is, finding a satisfying mechanistic explanation for experience and qualia) is known as "the hard problem".[2]
To take an example of a phenomenon in which there is no gap, imagine a modern computer: as marvelous as these devices are, their behavior can be fully explained by their circuitry, and vice versa. By contrast, it is thought by many mind-body dualists (e.g. René DescartesDavid Chalmers) that subjective conscious experience constitutes a separate effect that demands another cause, a cause that is either outside the physical world (dualism) or due to an as yet unknown physical phenomenon (see for instance Quantum mind,Indirect realism).
Proponents of dualism claim that the mind is substantially and qualitatively different from the brain and that the existence of something metaphysically extra-physical is required to 'fill the gap'.
The nature of the explanatory gap has been the subject of some debate. For example, some consider it to simply be a limit on our current explanatory ability.[3] They argue that future findings in neuroscience or future work from philosophers could close the gap. However, others have taken a stronger position and argued that the gap is a definite limit on our cognitive abilities as humans—no amount of further information will allow us to close it.[4] There has also been no consensus regarding what metaphysical conclusions the existence of the gap provides. Those wishing to use its existence to support dualism have often taken the position that an epistemic gap—particularly if it is a definite limit on our cognitive abilities—necessarily entails a metaphysical gap.[5]
Others, such as Joseph Levine, have wished to either remain silent on the matter or argue that no such metaphysical conclusion should be drawn.[1] He agrees that conceivability (as used in the Zombie and inverted spectrum arguments) is flawed as a means of establishing metaphysical realities; but he points out that even if we come to the metaphysicalconclusion that qualia are physical, they still present an explanatory problem.
While I think this materialist response is right in the end, it does not suffice to put the mind-body problem to rest. Even if conceivability considerations do not establish that the mind is in fact distinct from the body, or that mental properties are metaphysically irreducible to physical properties, still they do demonstrate that we lack an explanation of the mental in terms of the physical.
However, such an epistemological or explanatory problem might indicate an underlying metaphysical issue—the non-physicality of qualia, even if not proven by conceivability arguments is far from ruled out.
In the end, we are right back where we started. The explanatory gap argument doesn't demonstrate a gap in nature, but a gap in our understanding of nature. Of course a plausible explanation for there being a gap in our understanding of nature is that there is a genuine gap in nature. But so long as we have countervailing reasons for doubting the latter, we have to look elsewhere for an explanation of the former.[6]
Many philosophers consider experience to be the essence of consciousness, and believe that experience can only fully be known from the inside, subjectively. But if consciousness is subjective and not visible from the outside, why do the vast majority of people believe that other people are conscious, but rocks and trees are not?[41] This is called the problem of other minds.[42] It is particularly acute for people who believe in the possibility of philosophical zombies, that is, people who think it is possible in principle to have an entity that is physically indistinguishable from a human being and behaves like a human being in every way but nevertheless lacks consciousness.[43]
The most commonly given answer is that we attribute consciousness to other people because we see that they resemble us in appearance and behavior: we reason that if they look like us and act like us, they must be like us in other ways, including having experiences of the sort that we do.[44] There are, however, a variety of problems with that explanation. For one thing, it seems to violate the principle of parsimony, by postulating an invisible entity that is not necessary to explain what we observe.[44] 
In 2004, eight neuroscientists felt it was too soon for a definition. They wrote an apology in "Human Brain Function":[82]
"We have no idea how consciousness emerges from the physical activity of the brain and we do not know whether consciousness can emerge from non-biological systems, such as computers ... At this point the reader will expect to find a careful and precise definition of consciousness. You will be disappointed. Consciousness has not yet become a scientific term that can be defined in this way. Currently we all use the term consciousness in many different and often ambiguous ways. Precise definitions of different aspects of consciousness will emerge ... but to make precise definitions at this stage is premature."

Mind–body problem[edit source | editbeta]

Illustration of dualism by René Descartes. Inputs are passed by the sensory organs to the pineal gland and from there to the immaterial spirit.
The first influential philosopher to discuss this question specifically was Descartes and the answer he gave is known as Cartesian dualism. Descartes proposed that consciousness resides within an immaterial domain he called res cogitans (the realm of thought), in contrast to the domain of material things which he called res extensa (the realm of extension).[27] He suggested that the interaction between these two domains occurs inside the brain, perhaps in a small midline structure called the pineal gland.[28]
Although it is widely accepted that Descartes explained the problem cogently, few later philosophers have been happy with his solution, and his ideas about the pineal gland have especially been ridiculed.[29] Alternative solutions, however, have been very diverse. They can be divided broadly into two categories: dualist solutions that maintain Descartes' rigid distinction between the realm of consciousness and the realm of matter but give different answers for how the two realms relate to each other; and monist solutions that maintain that there is really only one realm of being, of which consciousness and matter are both aspects. Each of these categories itself contains numerous variants. The two main types of dualism are substance dualism (which holds that the mind is formed of a distinct type of substance not governed by the laws of physics) and property dualism (which holds that the laws of physics are universally valid but cannot be used to explain the mind). The three main types of monism are physicalism (which holds that the mind consists of matter organized in a particular way), idealism(which holds that only thought truly exists and matter is merely an illusion), and neutral monism (which holds that both mind and matter are aspects of a distinct essence that is itself identical to neither of them). There are also, however, a large number of idiosyncratic theories that cannot cleanly be assigned to any of these camps.[30]

[[This list of alternative theories shows how  far we are from an understanding of consciousness.]]

4. The origin of life. [Not to be confused with the theory of evolution which tries to explain only how life develops, not how it originated.] 
For a very thorough review of the decade of scientific despaif dealing iwth this problem, look here

And look at this summary of the various proposals

  • 3 Current models
  • 4 Other models

  • The Scientific American February 2013 contains the following iconoclastic articles:

  • 5. Europe's winter weather

  • New Simulations Question the Gulf Stream’s Role in Tempering Europe’s Winters

    It's the flow of warm tropical water across the Atlantic that keeps European winters mild, right? Maybe not
    For a century, schoolchildren have been taught that the massive ocean current known as the Gulf Stream carries warm water from the tropical Atlantic Ocean to northwestern Europe. As it arrives, the water heats the air above it. That air moves inland, making winter days in Europe milder than they are in the northeastern U.S.
    It might be time to retire that tidy story. The explosion of interest in global climate has prompted scientists to closely study the climatic effects of the Gulf Stream only to discover that those effects are not as clear as conventional wisdom might suggest. Based on modeling work and ocean data, new explanations have emerged for why winter in northern Europe is generally less bitter than winter at the same latitudes in the northeastern U.S. and Canada—and the models differ on the Gulf Stream's role. One of the explanations also provides insight into why winter in the U.S. Northwest is warmer than it is across the Pacific in eastern Russia.
    At the same time, recent studies have been casting doubt on the popular conjecture made a few years ago that melting of Arctic ice could “shut down” the Gulf Stream, thereby wreaking havoc with Europe'sweather. Yet the studies do suggest that climate change could at least affect thestrength of the Gulf Stream, which could lessen the impact of global warming on northern Europe.
    ....later on in the article they say the gulf stream theory is refuted.......

    6. How does the brain store memory? 

    A Single Brain Cell Stores a Single Concept [Preview]

    Each concept—each person or thing in our everyday experience—may have a set of corresponding neurons assigned to it which are described the two theories of memory - millions of cells widely distributed in the brain, or narrow simple storage - that are still in competition after several decades. New discoveries lend some support to the latter, but memory storage in the brain is still not understood
    7. What causes aging? 
    Is the Free-Radical Theory of Aging Dead? [Preview]
    The hallowed notion that oxidative damage causes aging and that vitamins might preserve our youth is now in doubt
    David Gems's life was turned upside down in 2006 by a group of worms that kept on living when they were supposed to die. As assistant director of the Institute of Healthy Aging at University College London, Gems regularly runs experiments on Caenorhabditis elegans, a roundworm that is often used to study the biology of aging. In this case, he was testing the idea that a buildup of cellular damage caused by oxidation—technically, the chemical removal of electrons from a molecule by highly reactive compounds, such as free radicals—is the main mechanism behind aging. According to this theory, rampant oxidation mangles more and more lipids, proteins, snippets of DNA and other key components of cells over time, eventually compromising tissues and organs and thus the functioning of the body as a whole.

    Gems genetically engineered the roundworms so they no longer produced certain enzymes that act as naturally occurring antioxidants by deactivating free radicals. Sure enough, in the absence of the antioxidants, levels of free radicals in the worms skyrocketed and triggered potentially damaging oxidative reactions throughout the worms' bodies. [[But they did not die any faster than normal worms. The whole understanding of he process of aging is now in doubt. ]]
    8. Human origins. 

    Will Scientists Ever Be Able to Piece Together Humanity's Early Origins? [Preview]

    New fossil discoveries complicate the already devilish task of identifying our most ancient progenitors
    By Katherine Harmon 

    mammals, do. This familiar yet strange individual is Lucy, a member of the species Australopithecus afarensis, who lived some 3.2 million years ago. She is one of the oldest creatures presumed to have strode on the evolutionary path leading to our species, Homo sapiens.
    From a distance, you probably would have assumed her to be human. Although she stood only about a meter tall, with long arms and a small head, she walked, if perhaps slightly inelegantly, upright on two legs, as we, alone among living mammals, do. This familiar yet strange individual is Lucy, a member of the species Australopithecus afarensis, who lived some 3.2 million years ago. She is one of the oldest creatures presumed to have strode on the evolutionary path leading to our species,Homo sapiens.
    When Lucy was uncovered in 1974, evidence of bipedal locomotion virtually guaranteed her kind a spot in the human family tree. And although scientists had an inkling that other branches of humans coexisted more recently alongside our own, early human evolution appeared to be a simple affair, with Lucy and the other ancient bipeds that eventually came to light belonging to the same lone lineage. Thus, the discoveries seemed to uphold the notion of human evolution as a unilinear “march of progress” from a knuckle-walking chimplike ape to our striding, upright form—a schema that has dominated paleoanthropology for the past century. Yet as researchers dig back further in time, our origins are turning out to be a lot more complicated than that iconic image would suggest.

    [[...indeed, in the body of the article it is suggested that it is unrealistic to expect that the lineage of homo sapiens will ever be established.]]
    end of articles from the Scientific American.