Victor Stenger2013-05-22T15:13:16-04:00Victor Stengerhttp://www.huffingtonpost.com/author/index.php?author=victor-stengerCopyright 2008, HuffingtonPost.com, Inc.HuffingtonPost Blogger Feed for Victor StengerGood old fashioned elbow grease.Kepler's Arktag:www.huffingtonpost.com,2013:/theblog//3.31393802013-04-23T12:06:34-04:002013-04-23T16:06:31-04:00Victor Stengerhttp://www.huffingtonpost.com/victor-stenger/two newly discovered planets in the system are potentially capable of supporting life, as we know it.
Kepler-62 is 1,200 light-years from Earth. Even travelling at the speed of light it would take 1,200 years to get there as measured on Earth, so future colonization by earthlings when our planet becomes unlivable would seem unlikely.
However, it is not impossible. Imagine building a spaceship that can leave Earth and accelerate at a constant one g, the acceleration of gravity on Earth. The passengers and crew would be able to travel with all the comforts of home, without having to worry about their muscles atrophying.
Applying Einstein's theory of special relativity, after the spaceship has traveled a distance x from Earth, the elapsed time as measured by any clocks onboard the ship, including the body clocks of the human crew and passengers, is given by the equation s = acosh(gx + 1)/g, where acosh is the arc hyperbolic cosine.
Of course, the ship can't continue to accelerate, since it needs to be moving at the same speed as the planet when it arrives. When it reaches the halfway mark at 600 light-years from Earth, the crew turns the ship around so it then decelerates at one g for the remainder of the trip. Those onboard notice no change. They continue to experience the equivalent of gravity on Earth.
Plugging x = 600 light-years in the above formula, we find that 7 years have elapsed on the ship clocks at the halfway mark, although six centuries have passed on Earth. The ship travels for another 7 years and arrives at Kepler-62 with a crew and passengers that are 14 years older than they were when they left home while 1,200 years have gone by back on Earth.
Now, building a spaceship capable of accelerating at one g for 14 years is not within any known technology, but we can't prove it's impossible. However, while also not impossible, it is highly unlikely that the space travelers will find a planet orbiting Kepler-62 that they can simply beam down to like Captain Kirk and Mr. Spock, breath the air, find food, and generally settle down and build a colony.
News reports on the discovery of "habitable" planets are highly misleading. What scientists define as habitable just means that conditions may exist that are adequate for life based on carbon chemistry, such as the generic type of life we have on Earth. The chances that such life would be exactly like ours, with the same proteins and DNA, would seem very unlikely. Furthermore, finding a planet anywhere in the galaxy so closely resembling Earth that humans could live on it without life support strikes me as to close to impossible as anything that is possible can get.
In the meantime, our intrepid travelers at Kepler-62 might decide to turn around and go back to Earth. By that time a new generation would have been born onboard ship and they would arrive back on Earth 14 years later. There, 2,400 years would have elapsed. They would be in the same position as humans returning now after having left in the fifth century BCE, at the time of Socrates.
However, for the Keplerians, by 2400 CE Earth would probably have cleansed itself naturally of the detritus left behind as earthlings destroyed themselves. Perhaps the young Keplerians, born and raised in space will do a better job as they recolonize Earth and give humanity another chance.]]>Happy Birthday, Emmy Noethertag:www.huffingtonpost.com,2013:/theblog//3.29248892013-03-21T14:51:36-04:002013-05-21T05:12:01-04:00Victor Stengerhttp://www.huffingtonpost.com/victor-stenger/
Because she was a woman, Noether was only allowed to audit classes in mathematics at Erlangen University, where her father taught. Still, in 1903 she qualified for the German equivalent of a bachelor's degree. After the university relaxed some of its restrictions against women, in 1907 she completed a dissertation on invariants for ternary biquadratic forms.
For the next eleven years, thanks to the sponsorship of the great mathematician David Hilbert, Noether taught at Erlangen and then Göttingen. However, she received no pay. In 1918 she was given an untenured professorship and by 1923 she was receiving a small salary. Despite many academic accomplishments, however, she was never given tenure, nor was she elected to the Göttingen Academy of Sciences.
Being a Jew, Noether was dismissed from her post upon the Nazi rise to power. In 1933, she emigrated to the U.S. and took a position at Bryn Mawr. Tragically, she died of uterine cancer just two years later, at age 53. Einstein wrote the New York Times that Noether was "the most significant creative mathematical genius thus far produced since the higher education of women began."
Not being a mathematician, I cannot testify to Emmy Noether's mathematical accomplishments. As a physicist, however, I can tell you that the theorem she published in 1915, which was not taught in any class I took on my way to a Ph.D. in physics, completely changed my understanding of the nature of physical law.
I always thought, as most physicists still think, that the laws of physics are restrictions on the behavior of matter that are somehow built into the structure of the universe. Although she did not put it in these terms, Noether derived a theorem that implied otherwise.
Noether's theorem proves that for every continuous space-time symmetry there exists a conservation principle. Three conservation principles form the foundational laws of physics: conservation of energy, conservation of linear momentum, and conservation of angular momentum.
Noether showed that conservation of energy follows from time translation symmetry; conservation of linear momentum follows from space translation symmetry; and conservation of angular momentum follows from space rotation symmetry.
What this means in practice is that when a physicist makes a model that does not depend on any particular time, that is, one designed to work whether it is today, yesterday, 13 billion years ago, or 13 billion years in the future, that model automatically contains conservation of energy. The physicist has no choice in the matter. If she tried to put violation of energy conservation into the model, it would be logically inconsistent.
If another physicist makes a model that does not depend on any particular place in space, that is, one designed to work whether it is in Oxford, Timbuktu, on Pluto, or on the recently discovered galaxy MACS0647-JD that is 13.3 billion light years away, that model automatically contains conservation of linear momentum. The physicist, once again, has no choice in the matter. If he tried to put violation of linear momentum conservation into the model, it would be logically inconsistent.
And, any model that is designed to work with an arbitrary orientation of a system must necessarily contain conservation of angular momentum.
Since these three principles form the basis of classical mechanics, it can be said that the laws of physics do not govern the behavior of matter. They govern the behavior of physicists.
Although this is not widely recognized, Noether's connection between symmetries and laws can be applied beyond space-time to the abstract internal space occupied by the state vector of quantum mechanics. These abstract spaces are not so obvious as the three dimensional space we experience. They are introduced to describe observed forces and transformations. By noting what particular quantities are conserved we can infer what symmetries apply.
In this case, we have a principle called gauge symmetry, which is equivalent to rotational symmetry in multidimensional state vector space. The various conservation principles that apply in this regime, in particular conservation of electric charge, arise from gauge symmetry. Furthermore, when the equation of motion of a charged particle is made locally gauge symmetric, that is, independently symmetric at every point in space and time, Maxwell's equations of electromagnetism fall right out of the mathematics. In other words, the electric and magnetic fields are fictitious forces, like the centrifugal and Coriolis forces, inserted into theories to preserve certain symmetries.
Gauge symmetry did not stop with classical physics. In the late 1940s it was applied to quantum electrodynamics and in the 1970s to the highly successful standard model of elementary particles that received its final corroboration last year with the observation of the Higgs boson at the Large Hadron Collider (LHC) in Geneva, almost fifty years after it was first predicted as the source of the masses of elementary particles.
In the standard model, three of the four forces of nature -- the electromagnetic and the weak and strong nuclear forces -- arise from local gauge symmetry. The electromagnetic and weak forces are united in a single electroweak force, but its symmetry only holds it at the very high energies just now being reached at the LHC. It is spontaneously (accidentally) broken at lower energies. Gravity is still treated separately with Einstein's theory of general relativity, but it is also heavily based on symmetry principles.
While the standard model is a long way from Noether's original work, it confirms the general idea that what we call the laws of physics are simply logical requirements placed on our theories if we want them to be objective, that is, independent of the point of view of any particular observer. In my 2007 book The Comprehensible Cosmos. I called this principle point-of-view invariance and showed that virtually all of classical and quantum mechanics can be derived from it. The book subtitle is: Where Do the Laws of Physics Come From? The answer: They didn't come from anything. They are either the necessary requirement of symmetries that preserve point-of-view invariance or accidents that happen when these symmetries are broken.
Notes
The biographical material on Emmy Noether was taken from an article in the March 2013 issue of APSNews, a publication of the American Physical Society.
One of my mentors when I was a graduate student at UCLA in the early 1960s, theoretical physicist Nina Byers, has championed the place of Noether in physics and mathematical history. See Byers, 1996.
The development of particle physics from Democritus to the Higgs boson is discussed in my latest book, God and the Atom.
]]>Science and Religion Cannot Be Reconciledtag:www.huffingtonpost.com,2013:/theblog//3.27192802013-02-19T18:23:43-05:002013-04-21T05:12:02-04:00Victor Stengerhttp://www.huffingtonpost.com/victor-stenger/This essay is based on my 2012 book, God and the Folly of Faith (Prometheus Books).
Religious apologists, spiritualist gurus, and accommodating atheists have been bombarding us with assertions that science and religion have no reason not to get along. This may be politically convenient, but it's simply untrue. Science and religion are fundamentally irreconcilable, and they always will be.
Faith is belief in the absence of supportive evidence and even in the light of contrary evidence. No one disputes that religion is based on faith. Some authors claim that science is also based on faith. They argue that science takes it on faith that the world is rational and that nature can be ordered in an intelligible way.
However, science makes no such assumption on faith. It analyzes observations by applying certain methodological rules and formulates models to describe those observations. It justifies that process by its practical success, not by any logical deduction derived from dubious metaphysical assumptions. We must distinguish faith from trust. Science has earned our trust by its proven success. Religion has destroyed our trust by its repeated failure.
Using the empirical method, science has eliminated smallpox, flown men to the moon, and discovered DNA. If science did not work, we wouldn't do it. Relying on faith, religion has brought us inquisitions, holy wars, and intolerance. Religion does not work, but we still do it.
Science and religion are fundamentally incompatible because of their unequivocally opposed epistemologies -- the separate assumptions they make concerning what we can know about the world. Every human alive is aware of a world that seems to exist outside the body, the world of sensory experience we call the natural. Science is the systematic study of the observations made of the natural world with our senses and scientific instruments.
By contrast, all major religions teach that humans possess an additional "inner" sense that allows us to access a realm lying beyond the visible world -- a divine, transcendent reality we call the supernatural. If it does not involve the transcendent, it is not religion.
No doubt science has its limits. However, that fact that science is limited doesn't mean that religion or any alternative system of thought can or does provide insight into what lies beyond those limits. For example, science cannot yet show precisely how the universe and life originated naturally, although many plausible scenarios exist. But the fact that science does not at present have a definitive answer to this question does not mean that ancient creation myths such as those in Genesis have any substance, any chance of eventually being verified.
Most of the scientific community in general goes along with the notion that science has nothing to say about the supernatural because the methods of science as they are currently practiced exclude supernatural causes. However, if we truly possess an inner sense telling us about an unobservable reality that matters to us and influences our lives, then we should be able to observe the effects of that reality by scientific means.
If someone's inner sense were to warn of an impending earthquake unpredicted by science, which then occurred on schedule, we would have evidence for this extrasensory source of knowledge. Claims of "divine prophecies" have been made throughout history, but not one has been conclusively confirmed.
So far we see no evidence that the feelings people experience when they perceive themselves to be in touch with the supernatural correspond to anything outside their heads, and have no reason to rely on those feelings when they occur. However, if such evidence or reason should show up, then scientists will have to consider it whether they like it or not.
We cannot sweep under the rug the many serious problems brought about by the scientific revolution and the exponential burst in humanity's ability to exploit Earth's resources made possible by the accompanying technology. There would be no problems with overpopulation, pollution, global warming, or the threat of nuclear holocaust if science had not made them possible. The growing distrust of science found now in America can be understood by observing the disgraceful examples of scientists employed by oil, food, tobacco, and pharmaceutical companies who have contributed to the unnecessary deaths of millions by allowing products to be marketed that these scientists knew full well were unsafe.
But does anyone want to return to the pre-scientific age when human life was nasty, brutish, and short? Even fire was once a new technology.
Unsafe products are more than overshadowed by miracle drugs, foods, and technologies that have made all our lives immeasurably better than those of humans in the not-too-distant past. At least in developed countries, women now rarely die in childbirth and most children grow to adulthood. This was not the case even just a few generations ago. Unlike our ancestors, we lead long, fulfilling lives largely free of pain and drudgery. The aged are so numerous that they are becoming a social problem. All this is the result of scientific developments.
We can solve the problems brought about by the misuse of science only by better use of science and more rational behavior on the part of scientists, politicians, corporations, and citizens in all walks of life. And religion, as it is currently practiced, with its continued focus on closed thinking and ancient mythology, is not doing much to support the goal of a better, safer world. In fact, religion is hindering our attempts to attain that goal.
Today science and religion find themselves in serious conflict. Even moderate believers do not fully accept Darwinian evolution. Although they claim to see no conflict between their faith and evolution, they insist that God still controlled the development of life so humans would evolve, which is not at all what the theory of evolution says. Evolution, as understood by science, has no room for God. Anti-evolution fundamentalists are absolutely right about that.
In another example, greedy corporate interests and unscrupulous politicians are exploiting the antiscience attitudes embedded in popular religion to suppress scientific results on issues of global importance, such as the overpopulation and environmental degradation, that threaten the generations of humanity that will follow ours.
Those who rely on observation and reason to provide an understanding of the world must stop viewing as harmless those who rely instead on superstition and the mythologies in ancient texts passed down from the childhood of our species. For the sake of the future of humanity, we must fight to expunge the fantasies of faith from human thinking.
Religious faith would not be such a negative force in society if it were just about religion. However, the magical thinking that becomes deeply ingrained whenever faith rules over facts warps all areas of life. It produces a frame of mind in which concepts are formulated with deep passion but without the slightest attention paid to the evidence that bears on the concept. Nowhere is this more evident than in America today where the large majority of the public hold on to a whole set of beliefs despite the total lack of evidence to support these beliefs and, indeed, strong evidence that denies them. Magical thinking and blind faith are the worst mental system we can apply under these circumstances. They allow the most outrageous lies to be accepted as facts.
From its very beginning, religion has been a tool used by those in power to retain that power and keep the masses in line. This continues today as religious groups are manipulated to work against believers' own best interests in health and economic well-being in order to cast doubt on well-established scientific findings. This would not be possible except for the diametrically opposed world-views of science and religion. Science is not going to change its commitment to the truth. We can only hope religion will change its commitment to nonsense.]]>No Belief Gaptag:www.huffingtonpost.com,2013:/theblog//3.26728422013-02-12T18:50:03-05:002013-04-14T05:12:01-04:00Victor Stengerhttp://www.huffingtonpost.com/victor-stenger/"Celebrating Darwin: Religion And Science Are Closer Than You Think" posted on Darwin's birthday, February 12, MIT physicist Max Tegmark reported on a survey he conduced with Eugena Lee and Meia Chita-Tegmark, The MIT Survey on Science, Religion, and Origins: the Belief Gap. While the survey covers many denominations, the central result is that although almost half of Americans, 46 percent according to Gallup, believe that God created humans in their present form less than 10,000 years ago, only 11 percent belong to a religion that openly rejects evolution.
Tegmark and his colleagues didn't ask the right questions. Or, at least, they should have defined evolution better for their respondents. As I reported in a Huffpost blog on October 6, 2012 titled "Is Evolution Compatible With Religion?," the same 2010 Gallup poll Tegmark refers to, linked above, found that only 16 percent of Americans believe in "Naturalist Evolution," defined as the view that "Man has developed over millions of years from less advanced forms of life [and] God had no part in the process." This is exactly the same percentage of Americans who declare themselves unaffiliated with any religion.
It may be that the only Americans who accept naturalist evolution are those who do not participate in any organized religion.
Although the Catholic Church and moderate Protestant churches claim they support evolution by natural selection, the fact is they do not. In a message to the Pontifical Academy of Sciences on October 22, 1996, Pope John Paul II refers to encyclical Humani Generis (1950) composed by Pope Pius XII as stating that "there was no opposition between evolution and the doctrine of the faith about man and his vocation, on condition that one did not lose sight of several indisputable points." Pope John Paul hedged considerably on his acceptance of evolution, implying it has not yet been validated and there is more than one hypothesis in the theory. And he made it very clear that mind or the spiritual soul did not emerge from matter but is a creation of God.
To reinforce this teaching, in his 2011 Easter Homily Pope Benedict XVI said:
It is not the case that in the expanding universe, at a late stage, in some tiny corner of the cosmos, there evolved randomly some species of living being capable of reasoning and of trying to find rationality within creation, or to bring rationality into it. If man were merely a random product of evolution in some place on the margins of the universe, then his life would make no sense or might even be a chance of nature. But no, Reason is there at the beginning: creative, divine Reason.
Virtually all Christians who accept that species evolve, contrary to the Bible that they believe is the word of God, think evolution is God-guided. This is not Darwinian evolution. God-guided evolution is intelligent design creationism. How many American Christians believe in evolution, as it is understood by science? The data indicate none.]]>Darwin and the Atomtag:www.huffingtonpost.com,2013:/theblog//3.26531582013-02-09T14:19:45-05:002013-04-11T05:12:01-04:00Victor Stengerhttp://www.huffingtonpost.com/victor-stenger/
In the fifth century BCE, the Greek philosophers Leucippus and Democritus proposed a simple model of reality: all that exists are material atoms and the void. Atoms were defined as elementary objects that cannot be further subdivided. The universe composed of atoms and void is infinite in extent and eternal in time. Events happen by chance, with no ultimate purpose. Any gods that may exist play no role in the world or in human life.
Atomism contradicted the predominant philosophical teachings of the age, notably those of Aristotle, Plato, and the Stoics. However, it became the basis of the philosophical school established by Aristotle's contemporary, Epicurus. Later, around the time of Julius Caesar, the Roman Lucretius composed an epic poem De rerum natura (On the Nature of Things) in Latin that immortalized the teachings of Epicurus and the atomists who preceded him. The atomic model contributed to the significant scientific progress that occurred in Greece and Rome during those centuries.
However, most of this progress, along with atheistic atomism, was suppressed when Christianity took over the Roman Empire in the fourth century CE, initiating the thousand-year period known as the Dark Ages. Only by sheer luck did a copy of De rerum natura survive. When it was discovered during the Renaissance, it helped encourage the scientific revolution that followed. The atomic picture of particles moving around and colliding with one another became the essence of Newtonian mechanics.
In the nineteenth century, atoms were identified with the chemical elements. In the early twentieth century, these "chemical atoms" were separated into more fundamental constituents. By the 1970s, these constituents were reduced further to the quarks, leptons, and bosons of the standard model of elementary particles and forces. The ultimate triumph of atomism, and the standard model, came in July, 2012 when it was announced that the Higgs boson, a particle predicted forty-eight years earlier as the source of the masses of elementary particles, had been confirmed by two independent experiments involving thousands of scientists.
The nature of matter was not the only insight of the first atomists that has found support in modern science. Quantum mechanics and Darwinian evolution before it established the central role of chance in the world. Furthermore, modern cosmology strongly indicates an eternal "multiverse" in which our universe just one of perhaps and unlimited number of others.
In none of this do we find any need to introduce immaterial elements into our models to describe observations. The atheism of ancient atomism is confirmed by the science of today.
I expect to get disagreement from dualists who will say that because we still don't have a consensus material explanation of consciousness, the door is still open for there to be a nonmaterial component to the human mind. However, models that introduce immaterial elements into the human cognitive process have failed to produce any supportive evidence comparable to materialistic brain science. So far, brain science, which is very much based on atomism, has been making steady progress in explaining the features of consciousness. Dualism has made none.
Now, here's what this has to do with Darwin: Lucretius anticipated evolution by natural selection. He talks about how, in the beginning, there were many freaks with various deformities that made them unable to reproduce or forage for food and so their species died off. You will get objections from some scholars that this was not really evolution, so I will just provide the following excerpt:
Many kinds of creatures must have vanished with no trace
Because they could not reproduce or hammer out their race.
For any beast you look upon that drinks life-giving air,
Has either wits, or bravery, or fleetness of foot to spare,
Ensuring its survival from its genesis to now.
(Translation by A. E. Stallings)
]]>Materialism Deconstructed?tag:www.huffingtonpost.com,2012:/theblog//3.22283622012-12-02T17:44:37-05:002013-02-01T05:12:01-05:00Victor Stengerhttp://www.huffingtonpost.com/victor-stenger/last blog I objected to a statement made by physicist David Tong in the December 2012 Scientific American who said it is a "lie" that the building blocks of nature are discrete particles such as the electron or quark. Rather, Tong asserted, the building blocks of our theories are quantum fields.
Here I want to explain why this is not just a pedagogical issue, a trivial dispute between two eggheads. It has real consequences on how scholars outside of physics, as well as the reading public, interpret the dramatic developments in fundamental physics, both experimental and theoretical, that began early in the twentieth century and continue today. Believe it or not, the particle-field debate affects heavy discussions on theology, spirituality and the interaction of religion and science.
Those who read the popular literature on science and religion, such as Tong's article, may receive the impression that modern physics has refuted the picture of atoms and the void proposed by Democritus and other Greek philosophers millennia ago. For example, in The New Sciences of Religion: Exploring Spirituality From the Outside in and Bottom Up, Christian apologist William Grassie says, "The concept of materialism deconstructed itself with the advent of quantum mechanics and particle physics."
To be ecumenical, Grassie quotes the Hindu physicist Varadaraja V. Raman: "Physics has penetrated into the substratum of perceived reality and discovered a whole new realm of entities there, beyond the imagination of the most creative minds of the past."
Now, maybe Democritus did not imagine quarks. But he did imagine material particles, and the quarks, at least in the current model, are material particles. The "new realm of entities" uncovered in modern physics is hardly beyond imagination. They are imagined in the quantum theory of fields, although just imagining something does not make it real -- despite what some theologians claim and what some physicists seem to believe.
The claim that quantum mechanics has revealed a reality beyond matter is based on the notion that two separate realities exist: discrete, particulate matter and a plenum that is reminiscent of the long-discredited aether. However, at least the electromagnetic aether was material. The new aether is more abstract, more in tune with the duality of mind and body that is embedded in all religious thought. Unsurprisingly, theologians and spiritualists delight in this new dualism -- handed to them on a platter by theoretical physicists.
The idea that abstract, holistic quantum fields are the deeper reality while particles are simply the excitations of the fields did not begin with David Tong. Indeed, it has almost become a mantra. For example, in The Atom in the History of Human Thought, historian Bernard Pullman writes,
To the extent that a Democritean influence has shaped our conception of the world, there has been a tendency to stress the corpuscular aspect of the standard model and to introduce a certain formal distinction between particles of matter and intermediary particles associated with force fields. As a result, we may have given the impression that that this corpuscular aspect provides the most exact description of physical reality. Such a view would be unfortunate, as it might obscure what is considered today as the most plausible picture of reality, which not only unifies the concepts of particles and fields, but even considers fields preeminent over particles ... The fundamental and underlying reality of the world is embodied in the existence of a slew of fields and in their interactions.
Pullman is applying the Platonic view of reality, which, as I have discussed previously, is the working assumption of most theoretical physicists and mathematicians. In order to test their models, physicists assume that the elements of these models correspond in some way to reality. But they are compared against the data that flow from our so-called "particle detectors" on the floor of an accelerator lab. It is the data that form the concrete foundation of our knowledge. What is fundamental in our model is not necessarily fundamental to our knowledge. Models are squiggles on the whiteboards in the theory section of the physics building. Those squiggles are easily erased; the data aren't.
Indeed, unpublished results are beginning to trickle in that the whiteboard squiggles of a generation of theorists describing their speculations on a theory called supersymmetry may soon be erased by data from the LHC. Although we need to wait and see, such a result would provide dose of humility to those who think they can infer reality by their thoughts alone, as well as an impetus to explore more unorthodox approaches.
The application of Platonic reality to physics is fraught with problems. First, theories are notoriously temporary. We can never know if quantum field theory will someday be replaced with another more powerful theory that makes no mention of fields (or particles, for that matter). Second, as with all physical theories, quantum field theory is a model -- a human invention. We test our models to find out if they work; but we can never be sure they correspond to "reality." That's metaphysics. If there were an empirical way to determine ultimate reality, it would be physics, not metaphysics. Third, quantum fields all have quanta that we associate with the so-called elementary particles.
In relativistic quantum field theory, which is the fundamental mathematical theory of particle physics and the basis of the standard model, each quantum field has an associated particle called the quantum of the field. These are the elementary particles of the highly successful standard model developed in the 1970s. The recent confirmation of the Higgs boson was a great triumph of the theory. The photon is the quantum of the electromagnetic field. The electron is the quantum of the Dirac field. The Higgs boson is the quantum of the Higgs field. I know of no empirically verified example where a quantum field exists without its quantum. Particles are just as much building blocks of our theories as fields. In fact, they are the same building blocks.
There are no exceptions. For every field, we have a particle; for every particle, we have a field. So, it is incorrect to think that field and particle exist as separate realities. We do not have a field-particle duality. We have, as Pullman says, a field-particle unity.
Please note that the elementary particles of the standard model are not to be thought of as classical objects like billiard balls; they obey all the rules of quantum mechanics. For example, as Feynman showed back in 1948, electrons can zigzag back and forth in space-time and thereby appear many places at the same time. This is usually called "nonlocality" but a better term is "multilocality." Note that, in this picture, the electron never moves faster than the speed of light. No superluminal connections of any kind are required when you recognize that time is reversible in physics. I'll expand on that at another time.
How does all this relate to the so-called wave-particle duality that you read about in books on quantum mechanics (textbooks as well as popular books)? The authors often write, "An object is either a particle or a wave, depending on what you decide to measure." This is very misleading and has led to the widespread misconception that quantum mechanics shows that human consciousness has the ability to control reality, namely, to decide whether an object is a particle or a wave. That object could be a pulse of light from galaxy 13 billion light-years away. So, the implication is that if we can control the nature of reality with our minds, this must occur not just here and now but throughout the universe and for every moment in time, past and future. Do you believe this? This is exactly what the quantum spiritualists, who hear that particles (which cannot travel faster than light) are a lie, are saying.
For those who have not moved beyond non-relativistic Schrödinger wave mechanics, the wave picture provides a perfectly good model to compute quantum effects, without having to think about what mysterious aether is doing the waving. To nuclear and particle physicists who must deal with higher energy phenomena, relativistic quantum mechanics and quantum field theory provide the tools for their calculations, without having to think about which is more real--fields or particles. Both theories are fully materialistic and constitute triumphs for Democritean atomism.
In short, quantum physics has not done away with matter. Matter can be defined as stuff that kicks back when you kick it. When you kick a rock, it kicks back. And when you kick an electron, it kicks back. And that's no lie.
References
William Grassie, The New Sciences of Religion: Exploring Spirituality From the Outside in and Bottom Up, (New York: Palgrave Macmillan, 2010), p. 169.
Varadaraja V. Raman, Truth and Tension in Science and Religion, (Center Ossipee, NH: Beech River Books, 2009), p. 115.
Bernard Pullman, The Atom in the History of Human Thought; a Panoramic Intellectual History of a Quest That Has Engaged Scientists and Philosophers for 2,500 Years, (Oxford and New York: Oxford University Press, 1998), pp. 346-47.]]>Particles Are for Realtag:www.huffingtonpost.com,2012:/theblog//3.21773612012-11-23T18:40:32-05:002013-01-23T05:12:01-05:00Victor Stengerhttp://www.huffingtonpost.com/victor-stenger/Scientific American, physicist David Tong makes the following statement:
Physicists routinely teach that the building blocks of nature are discrete particles such as the electron or quark. That is a lie. The building blocks of our theories are not particles but fields: continuous, fluidlike objects spread throughout space.
This is highly misleading. No one has ever observed a quantum field. Quantum fields are purely mathematical constructs within quantum field theory.
Every quantum field has associated with it a particle that is called the "quantum of the field." The photon is the quantum of the electromagnetic field. The electron is the quantum of the Dirac field. The Higgs boson is the quantum of the Higgs field. In other words, like love and marriage, you can't have one without the other. The building blocks of our theories are fields and particles.
But note that what Tong calls "a lie" is the notion that the building blocks of nature are discrete particles while it is fields that are the building blocks of our theories. That is, he is equating nature to theory.
Tong is revealing his acceptance of a common conception that exists among today's theoretical physicists (Paul Dirac and Richard Feynman, among other twentieth-century greats, were not part of that school). That is, the symbols that appear in their mathematical equations represent "true reality" while our observations, which always look like localized particles, are just the way in which that reality manifests itself.
The association of mathematical symbols with true reality is precisely the philosophy that was proposed by Plato 2,400 years ago in his theory of forms. Platonism is more theology than science, and Plato was no scientist. He claimed that a divine craftsman called the Demiurge constructed the cosmos according to a divine plan. There are two realms: a realm of forms or ideas that is perfect and a material realm in which these forms or ideas are imperfectly replicated (Lindberg, p.36).
As someone who 40 years as an experimental elementary particle physicist, I carry a different perspective. I started in the 1960s analyzing bubble chamber pictures where one sat at a scanning table and traced the beautiful tracks of bubbles photographed during the time the superheated liquid in the chamber was exposed to a pulsed beam from an accelerator.
It never occurred to my collaborators and me to describe what we observed as some kind of field in an abstract multidimensional space. (Quantum fields do not live in familiar space-time, despite Tong's assertion). We interpreted the trails of bubbles as the effect of charged particles ionizing the atoms of the liquid and producing localized boiling along their paths. The paths were curved because of an external magnet that produced a magnetic field inside the chamber, and by measuring the curvature of an individual path the momentum of the particle could be determined. From the rate at which the particle slowed down as it lost energy to ionization we could also determine its speed and, from these two measurements, determine the particle's energy.
These measurements enabled us detect the presence of many new objects, which we also called "particles," that had never before been observed. Some were so unstable that they did not live long enough to leave a measurable track in the chamber. They were detected by the missing mass calculated from the measurements of the particle tracks for a complete event.
For example, suppose the chamber is filled with hydrogen and exposed to a beam of very high-energy pions. Then you will observe the track of a pion coming in and colliding with a proton in the hydrogen. That is called an "event." You then measure the momenta and energies of the outgoing tracks and use energy and momentum conservation to determine any missing mass.
While the detectors found at today's giant colliders, such as the Large Hadron Collider, are far more sophisticated than the bubble chamber, they operate on the same general principle. They measure momentum and energy by magnetic curvature and energy deposit.
And, the workers at the LHC do not talk about colliding the quantum fields of two protons together to measure the wavelengths of some abstract wave oscillating in some imaginary aether. They speak of banging particles together and measuring the particles they see coming out.
The point is, while our mathematical theories are expressed in terms of abstract fields, what we always measure is best described as particles.
For example, consider the famous double slit experiment. Light described as an oscillating electromagnetic field or "wave" passes through two narrow slits producing an intensity pattern on a screen that is characterized by a series of alternating, equally spaced bright and dark "interference" fringes. The distance between the fringes can be used to calculate the wavelength of the oscillating field.
However, if in place of the screen you have an array of photodetectors sensitive at the one-photon level, you will detect individual photons -- the particles that constitute light according to Einstein's 1905 theory of the photoelectric effect. That is, you do not detect a field or a wave. You detect a particle. The fringe pattern does not appear until you have accumulated the statistical distribution of a large number of photons. The so-called "wave nature" of light is thus not a characteristic of a single photon; it is a characteristic of the behavior of an ensemble of many photons.
Now, other philosophical schools exist besides Platonism. Most experimentalists, if dragged kicking and screaming into having to think about a philosophical question, would probably say that the objects they observe, which they call particles, are "real." But then, they have no better means to prove that assertion than their theoretical colleagues have to insist that only fields are real.
Questions on the nature of reality are metaphysics. They entail no observations that can adjudicate the questions scientifically. If they did, they would be physics and not metaphysics. I know of only two other ways by which we might determine the nature of reality outside the realm of observation: revelation and reason. I doubt many theoretical physicists believe in revelation, and those few that do make no attempts to apply it to their work and thereby invite ridicule from their colleagues.
That leaves reason. Plato, Aristotle, St. Augustine, St. Thomas Aquinas, Immanuel Kant, and many other great thinkers throughout history have claimed that reason absent observation is capable of discovering truths about the world. The trouble is, despite thousands of years of trying, they haven't yet come up with a single example of such a truth that has been objectively verified.
No one doubts the moon is real, and it's just a particle when viewed from far enough away. How is it any different from a photon registered in a photodetector? So, even if I can't prove it, it seems reasonable that photons, electrons, quarks, neutrinos, and Higgs bosons are for real.
Reference
David C. Lindberg. The Beginnings of Western Science: The European Scientific Tradition in Philosophical, Religious, and Institutional Context, Prehistory to A.D. 1450. 2nd ed. (Chicago: University of Chicago Press, 2007).]]>We Must Do More Than Think. We Must Observetag:www.huffingtonpost.com,2012:/theblog//3.21007062012-11-09T11:38:04-05:002013-01-09T05:12:01-05:00Victor Stengerhttp://www.huffingtonpost.com/victor-stenger/op-ed piece in the New York Times on June 10, 2012 titled, "Physicists, Stop the Churlishness," essayist Jim Holt criticizes the public disdain that many top contemporary physicists unfortunately hold for philosophy. Holt quotes the late Richard Feynman as mocking "cocktail party philosophers" for thinking that they can discover things about the world "by brainwork rather than experiment." I have not been able to find the precise quotation, which Holt does not reference. However, Feynman does mention "cocktail-party philosophers" (note: not professional philosophers) several times in chapter 16, volume 1, of his classic Lectures on Physics. In any case, Holt remarks, "Leucippus and Democritus ... didn't come up with [the idea of atoms] by doing experiments."
He is dead wrong. While is true that Leucippus, Democritus, nor any other ancients performed the type of carefully controlled experiments that mark science today, the idea of atoms did not arise from pure thought alone.
The philosophy of the ancient atomists, in particular Epicurus, was recorded for posterity in the epic poem De rerum natura (The Nature of Things) written in Latin hexameter at the time of Julius Caesar by the Roman Lucretius Carus. The following excerpts make it clear that careful observation played an important part in the thinking of ancient atomists (translation by A. E. Stallings).
Just in case you start to think this theory [atoms] is a lie,
Because these atoms can't be made out by the naked eye,
You yourself have to admit there are particles
Which are but which cannot be seen. . . (I, 165-169)
For example:
Thus clearly there are particles of wind you cannot spy
That sweep the ocean and the land and clouds up in the sky. (I, 277, 278)
Most significantly, in Book II Lucretius adds
There's a model, you should realize,
A paradigm of this that's dancing right before your eyes --
For look well when you let the sun peep in a shuttered room
Pouring forth the brilliance of its beams into the gloom,
And you'll see myriads of motes all moving many ways
Throughout the void and intermingling in the golden rays. (II, 112-117)
...
Such turmoil means that there are secret motions, out of sight,
That lie concealed in matter. For you'll see the motes careen
Off course, and then bound back again, by means of blows unseen. (II, 126-128)
This last, remarkable passage precisely describes the Brownian motion that Einstein and Jean Baptiste Perrin used in the early twentieth century to demonstrate conclusively the existence of atoms. Gaston Bachelard has suggested that observations involving dust provided the essential notion of atoms so that it was not just a product of pure thought:
Without this special experience, atomism would never have evolved into anything more than a clever doctrine, entirely speculative, in which the initial gamble of thought would have been justified by no observation. Instead, by virtue of the existence of dust, atomism was able to receive from the time of its inception an intuitive basis that is both permanent and richly evocative.
In his Critique of Pure Reason, Immanuel Kant argued that experience was not the only source of knowledge, that in addition our minds have certain built-in a priori concepts. One of his major examples was our intuition that space is described by Euclidean geometry. Of course, we now know that other geometries exist and that Einstein used non-Euclidean geometry to describe space in his general theory of relativity. So much for what Kant called the synthetic a priori.
Another belief, still common today, is that we can reason ourselves to knowledge about reality. How often have you read "proofs" of the existence, or non-existence, of God or some other deep question? A logical deduction can tell you nothing that is not already embedded in its premises. All a logical deduction does is enable you to determine whether or not some conclusion is consistent with some set of premises.
Today, most physicists and philosophers hold that our only source of knowledge about the world is observation. While scientists use reason and logic, their premises must be based on data. And the justification for this position is not some metaphysical reasoning but the fact that it works.
References
Gaston Bachelard, Les Intuitions Atomistiques (Atomistic Intuitions): Essai De Classification, 2nd ed., (Paris: J. Vrin, 1975).
Richard P. Feynman, Robert B. Leighton, and Matthew L. Sands. The Feynman Lectures on Physics. New millennium ed. (New York: Basic Books, 2011).
Jim Holt. "Physicists, Stop the Churlishness." New York Times, June 10, 2012.
A.E. Stallings, and Richard Jenkyns. Lucretius: The Nature of Things. (London; New York: Penguin, 2007).
]]>The Argument from Ignorancetag:www.huffingtonpost.com,2012:/theblog//3.20047432012-10-23T08:12:53-04:002012-12-23T05:12:01-05:00Victor Stengerhttp://www.huffingtonpost.com/victor-stenger/To surrender to ignorance and call it God has always been premature, and it remains premature today.
-- Isaac Asimov
In my last HuffPuff, "Not Dead Experiences (NDEs)" I remarked that neurosurgeon Dr. Eben Alexander had used the "argument from ignorance" in claiming that his personal near-death experience provided proof of the reality of heaven. His book Proof of Heaven: A Neurosurgeon's Journey Into the Afterlife (Simon & Schuster) has just been released.
Several readers asked how I could accuse Alexander of ignorance given his credentials as a neurosurgeon. I did not accuse him of ignorance. I said he was using the argument from ignorance. I am sure he is a very knowledgeable and experienced neurosurgeon. However, performing brain surgery requires very different intellectual and physical skills from those required for understanding how the brain works. Some people are astronauts; others are astrophysicists. Alexander is not a qualified neuroscientist and may not be aware of the proposed natural mechanisms for near-death-experiences, consistent with existing knowledge, that have been described in the scientific literature.
Alexander is quoted as saying, "According to current medical understanding of the brain and mind, there is absolutely no way that I could have experienced even a dim and limited consciousness during my time in the coma, much less the hyper-vivid and completely coherent odyssey I underwent." That is, just because his medical expertise doesn't include an explanation of his experience, no scientific explanation is possible. This is the argument from ignorance: just because Alexander doesn't know the answer, no answer can ever be found.
As I explained in my previous article, the argument from ignorance is a logical fallacy, also known as the God-of-the-gaps argument, whereby someone says, "I am unaware of a natural explanation for [some phenomenon]; therefore we have evidence for the supernatural." The argument fails because it does not prove that a natural explanation will never be possible.
Until evidence is found that cannot be plausibly explained naturally, the more parsimonious conclusion that is forced upon us by reason and Ockham's razor is that the phenomenon is purely natural. Let me put it this way: What is more likely to be correct? (1) After thousands of years of searching, we finally have here, in the personal anecdote of a medical doctor, not trained in objective scientific research, scientific proof of life after death. Or, (2) The NDE experience was all in his head.
As I pointed out, one can think of examples of religious experiences that would be difficult or even impossible to explain naturally. All that has to happen is that the subject return with knowledge that could not have been in her head all along.
In recent days, we have seen the appearance of another variation on the claim that there must be more to the world than the purely materialist picture provided by physics, biology, and neuroscience.
Philosopher Thomas Nagel has just published a book titled Mind and the Cosmos: Why the Materialist Neo-Darwinian Conception of Nature is Almost Certainly Wrong (Oxford). According to the publisher's synopsis, "The modern materialist approach to life has conspicuously failed to explain such central mind-related features of our world as consciousness, intentionality, meaning, and value. This failure to account for something so integral to nature as mind, argues philosopher Thomas Nagel, is a major problem, threatening to unravel the entire naturalistic world picture, extending to biology, evolutionary theory, and cosmology."
Nagel is quoted as writing, "The world is an astonishing place, and the idea that we have in our possession the basic tools needed to understand it is no more credible now than it was in Aristotle's day." Now there's an argument from ignorance if there ever was one. We are just as ignorant of scientific methodology today was we were in Aristotle's day!
Here I must admit that I have not yet read the two books, they having been just released; I am going by quotations, reviewer comments and publishers' summaries. Nevertheless, it appears that, while Alexander is a practicing Christian, Nagel is a professed atheist and his goals seem less clear. Nagel seems to claim problems with materialism and Darwinism, in particular the reduction of everything to physics.
Neither author provides objective data to support his conclusion, each of which is presented with dogmatic certainty. Alexander has only his subjective experience to go by, which he then interprets with his limited knowledge of the brain. Nagel also relies on the subjective, arguing that science "flies in the face of common sense," that it is so inconsistent with "evident facts about ourselves," that it "require[s] us to deny the obvious."
The only "evident facts" that are worth considering are objective facts. And any number of objective facts exist that strongly support the view that the thinking process is a purely material phenomenon. Otherwise, why would thoughts be affected by drugs, disease, and brain injury?
The world, as Nagel observes, is indeed an astonishing place. But this does not mean that we must accept, on the basis of such non-scientific ''evidence'' as Alexander and Nagel present, that some ingredient other than matter must be introduced to understand the observations of the world made with our senses and scientific instruments.
This is the only rational position one can take given our current level of knowledge. It is not a dogmatic position, however. When and if real evidence for an immaterial world becomes available--not subjective anecdotes and empty philosophical arguments--then scientists are more than ready to follow whatever direction that evidence leads.]]>Not Dead Experiences (NDEs)tag:www.huffingtonpost.com,2012:/theblog//3.19579202012-10-11T14:20:46-04:002012-12-11T05:12:01-05:00Victor Stengerhttp://www.huffingtonpost.com/victor-stenger/Watch Ric Elias' TEDTalk on the three things he learned while his plane crashed.
Newsweek magazine can always be counted on to give us the latest scientific evidence for God. The cover of its October 7, 2012 issue proclaims, "Heaven is Real." Inside is the story of Dr. Eben Alexander, a neurosurgeon and son of a neurosurgeon who writes:
"I had always believed there were good scientific explanations for the heavenly out-of-body journeys described by those who narrowly escaped death. ... Although I considered myself a faithful Christian, I was so more in name than in actual belief. I didn't begrudge those who wanted to believe that Jesus was more than simply a good man who had suffered at the hands of the world. I sympathized deeply with those who wanted to believe that there was a God somewhere out there who loved us unconditionally. In fact, I envied such people the security that those beliefs no doubt provided. But as a scientist, I simply knew better than to believe them myself."
But then in the fall of 2008, Dr. Alexander spent seven days in a coma and "experienced something so profound that it gave me a scientific reason to believe in consciousness after death." He had what is commonly called a near-death experience (NDE) in which an unconscious person whose brain is minimally functioning catches glimpses of what they are convinced is a world beyond -- heaven. Usually they see a tunnel with light at the other end, and often meet Jesus (if they are Christians) or Buddha (if they are Buddhists), and loved ones, dead or alive.
Dr. Alexander claims from his knowledge of the brain that his own glimpses of heaven occurred while his cortex was not just malfunctioning but totally shut down. He does not explain how he knows that his experience occurred during that time and not the period just after losing consciousness, or the period just before regaining consciousness, when his brain was almost if not fully functional. Furthermore, current brain monitoring technology does not preclude some undetected brain activity.
He writes, "According to current medical understanding of the brain and mind, there is absolutely no way that I could have experienced even a dim and limited consciousness during my time in the coma, much less the hyper-vivid and completely coherent odyssey I underwent."
This is nothing more than the classic argument from ignorance, which forms the basis of almost all ostensibly scientific arguments for the existence of the supernatural. The argument from ignorance is a less polite but more descriptive name for the God-of-the-gaps argument. This argument often appears in dialogues on the existence of God or anything supernatural. Basically, it says: "I can't see how this [observed phenomenon] can be explained naturally; therefore it must be supernatural."
The flaw in the argument should be obvious. Just because someone--or even all of science--currently cannot provide a natural explanation for something, it does not follow that a natural explanation does not exist or will never be found. Indeed, the history of science is nothing more than the story of humanity filling in the gaps in its knowledge about the world of our senses. In the case of NDEs, plausible natural explanations do exist (Augustine, 2011).
Despite its worthlessness, the argument from ignorance continues to be the mainstay of religious apologetics. Nowhere is this more prevalent than in the argument from design, which goes back to Plato. Commonly one hears today, "I can't see how the eye could have evolved naturally; therefore it must have been designed by God."
Most recently, the argument from design has appeared in the form of the argument from fine-tuning: If the values of the parameters of physics were slightly different, life would not have been possible; thus they must have been fine-tuned by God to make life, and in particular, human life, possible.
According to our best scientific knowledge, the parameters of physics and cosmology are not so constrained that some form of life could not have formed over a wide range of parameters (Stenger 2011a). But even if this were not the case, no one has proven that a natural explanation for the constants of physics is forever beyond our reach.
Near-death experiences have been studied for over thirty years. Almost every year or two a book appears claiming incontrovertible proof of the afterlife based on NDEs. They are usually instant bestsellers. But they never convince anyone except those who want to be convinced because none present anything more than personal anecdotes such as those provided by Dr. Alexander. And, "anecdote" is not another name for "data."
In my own writing on the subject (Stenger 2011b, 2012), I have pointed out that the supernatural interpretation of near-death experiences, if true, can easily be verified scientifically. To provide a specific example, place a target such as a card with some random numbers on it on a high shelf facing the ceiling of the operating room so that it is unreadable not only to the patient on the table but to the hospital staff in the room. Then if a patient has an NDE that involves the commonly reported sensation of moving outside her body and floating above the operating table, she should be able to read that number.
This experiment has been tried several times without success. So have other attempts to provide verifiable evidence -- what researchers in the field call "veridical perception" (Holden 2009, p. 209). The principle is simple and can be applied to anyone who claims to have communicated with another world beyond matter. All that has to happen is a subject claiming such a communication return with some important piece of knowledge she could not have possibly known previously, such as the exact date and epicenter location of the future earthquake that will destroy Los Angeles.
Researchers in the field of near-death studies have honestly admitted that the evidence is still not there. The well-respected NDE researcher Kenneth Ring has written:
"There is so much anecdotal evidence that suggests [experiencers] can, at least sometime, perceive veridically during NDEs ... but isn't it true that in all this time there hasn't been a single case of a veridical perception reported by an NDEr under controlled conditions? I mean, thirty years later, it's still a null class (as far as we know). Yes, excuses, excuses--I know. But, really, wouldn't you have suspected more than a few such cases at least by now? (Holden 2009, p. 210)."
The way to defeat ignorance is with evidence. After thousands of reported religious experiences of various kinds, including near-death-experiences, no one has ever provided a single item of verified new knowledge.
I will be very surprised if Dr. Alexander gets his observations published in a reputable medical journal. No doubt his book, Proof of Heaven: A Neurosurgeon's Journey into the Afterlife, will do well.
Holden, Janice Minor et al., eds., 2009, The Handbook of Near-Death Experiences: Thirty Years of Investigation, Praeger Publishers: Santa Barbara, CA; Denver, CO; Oxford England.
Stenger, Victor J. 2011a, The Fallacy of Fine-Tuning: How the Universe is Not Designed for Us, Prometheus Books, Amherst, NY.
Stenger, Victor J. 2011b, "Life After Death: Examining the Evidence" In The End of Christianity, edited by John W. Loftus, Prometheus Books: Amherst, NY, pp. 305-32.
Stenger, Victor J. 2012, God and the Folly of Faith: The Incompatibility of Science and Religion, Prometheus Books: Amherst, NY.
Ideas are not set in stone. When exposed to thoughtful people, they morph and adapt into their most potent form. TEDWeekends will highlight some of today's most intriguing ideas and allow them to develop in real time through your voice! Tweet #TEDWeekends to share your perspective or email tedweekends@huffingtonpost.com to learn about future weekend's ideas to contribute as a writer.]]>Is Evolution Compatible With Religion?tag:www.huffingtonpost.com,2012:/theblog//3.19450832012-10-06T15:16:30-04:002012-12-06T05:12:01-05:00Victor Stengerhttp://www.huffingtonpost.com/victor-stenger/National Academy of Sciences. Teaching About Evolution and the Nature of Science. Washington, DC: National Academy Press, 1998, p. 58).
In fact, this attempt by scientists to convince the American public that evolution poses no threat to faith has largely fallen on deaf ears, perhaps because it is simply untrue, and believers can see this clearly enough.
A 2010 Gallup Poll found that only 16 percent of Americans believe in "Naturalist Evolution," defined as the view that "Man has developed over millions of years from less advanced forms of life [and] God had no part in the process." This is exactly the same percentage of Americans who declare themselves unaffiliated with any religion. It may be that the only Americans who accept naturalist evolution are those who do not participate in any organized religion.
Of 34 developed nations surveyed for their acceptance of evolution, defined as humans and apes sharing the same ancestor, only Turkey was lower than the U.S.
So, what is it that the Americans who do participate in organized religion believe? The Gallup Poll found that 30 percent of all Americans agree with "Theistic Evolution" defined as "Man has developed over millions of years from less advanced forms of life, but God guided this process, including man's creation." And, an amazing 40 percent adopt the "Creationist View" in which "God created man pretty much in his present form at one time within the last 10,000 years." This is despite the fact that only 26.3 percent of all Americans belong to Evangelical churches where the Bible is taken literally. This suggests that almost half of the churchgoers who reject evolution do so not because it disagrees with the Bible, but because it disagrees with their personal view of humanity's place in the scheme of things -- that humans are special.
Darwin is remembered as a great thinker because he saw that pure random variation was enough to allow natural selection to work. If he had said that supernaturally guided variation created the biological world, nobody would know his name today because that theory has no explanatory power. It just pushes the puzzle off into the never-never-land of the supernatural.
The evidence that Darwin began to marshal and that other scientists have accumulated over the nearly 150 years since he published The Descent of Man not only shows how humans descended from ape-like ancestors by a combination of random variation and natural selection. It also implies that the specific outcome of the human species, or any species for that matter, came about by chance. Humans evolved due to luck, not divine purpose. This fact is fundamentally destructive to what every religion teaches about humanity.
In his 2003 book Life's Solution: Inevitable Humans in a Lonely Universe, paleontologist Simon Conway Morris claimed that evolution converges on certain solutions. However, it's a huge jump from simple convergence, which is the most the data imply, to the inevitably of humans that Conway Morris claims in his title. Convergence is fully consistent with basic Darwinism (See Jerry Coyne, Why Evolution is True).
Several prominent biologists are devout believers as well as articulate defenders of evolution, although they are part of a small minority. In 2005, a federal court in Dover, PA, ruled that the teaching of intelligent design in the Dover public schools was unconstitutional. One of the star witnesses for the plaintiffs was biologist and Catholic Kenneth Miller. In his 1999 book, Finding Darwin's God, Miller argued that God could still be behind the randomness in evolution. As I point out in Quantum Gods, however, Miller's god is a "God who plays dice" that bears no resemblance to the Abrahamic God who plays a very active role in the universe and in human lives.
Likewise, the current director of the National Institutes of Health and previous administrator of the Human Genome Project, Francis Collins, also sees God as the author of evolution. In his 2006 bestseller The Language of God, in a section on "Theistic Evolution," Collins writes:
God, who is not limited in space or time, created the universe and established natural laws that govern it. Seeking to populate this otherwise sterile universe with living creatures, God chose the elegant mechanics, of evolution to create microbes, plants, and animals of all sorts. Most remarkably, God intentionally chose the same mechanism to give rise to special creatures who would have intelligence, a knowledge of right and wrong, free will, and a desire to seek fellowship with Him (pp. 200-201, first edition).
He doesn't tell us how he knows all this.
Most scientists and science organizations in America wish to stay on good terms with the believing majority, and so the fundamental incompatibility between random evolution -- which is what science says happened -- and divinely-guided evolution -- for which no evidence exists -- is kept under wraps. However, the time has come for scientists and their societies to face up to the fundamental incompatibility between naturalist and theistic evolution.]]>The Disappointing Higgs and Sterile Neutrinostag:www.huffingtonpost.com,2012:/theblog//3.18840042012-09-14T12:25:30-04:002012-11-14T05:12:01-05:00Victor Stengerhttp://www.huffingtonpost.com/victor-stenger/major discovery that generated worldwide attention. The two independent experiments at the Large Hadron Collider that reported the discovery on July 4, involving thousands of physicists, engineers, and technicians, were conducted with praiseworthy skill and effort.
However, all that has been learned so far is that its mass is 125-126 GeV (billion electron-volts). Otherwise, the data look exactly as predicted by the standard model of elementary particles and forces that was formulated in the 1970s and has agreed with all observations since.
Scientists had anticipated that the LHC would point the way to new physics beyond the standard model. And, this will hopefully still happen, especially after its energy is doubled in 2013. One expectation that has not yet been fulfilled is the production of new particles predicted by a theoretical hypothesis called supersymmetry (SUSY). This principle postulates that the laws of physics are the same for integer spin particles, called "bosons," and half-integer spin particles called "fermions." SUSY predicts that every boson will have a fermion partner and every fermion will have a boson partner of the same mass. So, the spin ½ electron will have a spin zero "spartner," the selectron. And, the spin 1 photon will have a spin ½ spartner, the photino. My favorite is the spartner of the quark, which is called the "squark."
Since squarks, selectrons, and photinos have never been observed, physicists are forced to conclude these sparticles, if they exist at all, are so much more massive than their normal partners that they could not be produced by previous particle accelerators. It was anticipated that the energy of the LHC would be sufficient to reach the regime where supersymmetry comes into play and sparticles would appear. Theorists had, in fact, expected sparticles to appear by now, but it hasn't happened. By contrast, the Higgs showing up so soon was a pleasant surprise.
Supersymmetry has been a favorite idea among theoretical physicists for decades. It appears to be essential for any future quantum theory of gravity. A generation of young theorists has spent their careers developing the SUSY-based String theory, which they hope to be the ultimate theory-of-everything (TOE). If SUSY is falsified, it is unlikely that String theory will survive.
Actually, that would not be all that bad. Any TOE would mean the end of physics.
One of the big questions in science today is the nature of the dark matter. For years, the favorite candidate has been WIMPs, weakly interacting massive particles. And the most popular WIMPs are supersymmetric particles referred to generically as neutralinos.
While reports that SUSY is dead are exaggerated, other options for the dark matter are currently receiving renewed attention. A recent cover story in New Scientist (September 10, 2012) talked about the role that neutrinos play in the search for physics beyond the standard model. Of particular note are sterile neutrinos, which could constitute both the ingredient of dark matter and a pointer to new physics. (See Nature News Vol 464, March 18, 2010).
In 1998, an underground experiment in Japan called Super Kamiokande reported the first evidence that neutrinos have mass. I played a small role as a collaborator on this experiment, my final research endeavor before retiring from the University of Hawaii in 2000.
Massless particles with spin have the feature of always spinning either in the same direction as their motion, like a right-handed screw, or opposite. Neutrinos are observed to have left-handed "helicity," that is, to spin opposite to their direction. Antineutrinos are right-handed, like a normal screw.
However, when a particle has mass it can have either helicity. It follows that neutrinos must have a small right-handed component while antineutrinos have a small left-handed part. Since these components are not observed, they may possibly be "sterile," meaning, they interact only gravitationally. In that case, they are good candidates for dark matter.
To constitute the dark matter, a sterile neutrino would have to have a mass of at least 1 keV (thousand electron-volts) and a lifetime of billions of years. These features are not ruled out by any known physics.
Interest in sterile neutrinos has also been piqued by several hints in neutrino experiments and astronomical observations. None are sufficiently significant, however, to claim a discovery.
In any case, over 20 experiments are now planning to search for evidence of sterile neutrinos. For all you could want to know about sterile neutrinos, including details on each of these proposals, see the draft of a white paper under preparation by over 200 physicists. As someone who worked on neutrino physics and astrophysics for 30 years, I'm delighted to see neutrinos continue to be a crucial factor in our understanding of nature.]]>A Fat Cat Wants Outtag:www.huffingtonpost.com,2012:/theblog//3.18200262012-08-21T19:05:02-04:002012-10-21T05:12:12-04:00Victor Stengerhttp://www.huffingtonpost.com/victor-stenger/New York Times on Monday, August 20, titled "Why This Fat Cat Likes Obama's Tax Plan," Norman Litz of La Jolla, California tells us that his income has averaged over eight figures annually for the past seven years. He warns that if Obama is re-elected, he expects his total tax bill, including California, to exceed 50 percent, in which case he will shutter his equity business, putting his dozen employees out of work and cutting in half his so-far unimplemented plan to provide $50 million to charity. Instead, he and his fiancée Rachael will indulge in a mutual passion -- world travel.
I suppose private equity companies perform some useful services, but do these fully justify the huge profits they make, not to mention the human suffering that results from all the layoffs that inevitably seem to accompany the restructuring that always takes place when they take over a company?
In his sobering book, The Price of Inequality, Nobel laureate economist Joseph Stiglitz, former chief economist of the World Bank, and chairman of the Council of Economic advisors under Bill Clinton, ascribes the number one cause of the gross economic inequality in today's America to what economists call "rent-seeking." This is when, instead of creating new wealth via advanced technologies or greater efficiencies, a business or industry, or individual, seeks to gain a greater share of already existing wealth, thus contributing nothing to society. Often this involves manipulating the economic environment by buying political advantage and gaining special privileges such as government subsidies and favorable legislation.
Litz made his fortune as a private equity investor, and clearly believes he earned every million with his hard work and business genius. But I have some questions for him. How does all that hard work and genius justify an income hundreds of times greater that the equally hardworking farmer, factory worker, and schoolteacher who can't afford a full-page ad in the Times to present their cases? As an equity investor, what actual useful service, what tangible product did you provide to improve our economy and contribute to society that compares with that provided by the great bulk of working men and women in this country? What did you invent? What did you build? How many lives did you make better?
Indeed, how many lost their jobs in the companies you restructured?
Norman, I hope you and Rachael get to take your long-awaited trip around the world. America will be better off in your absence.]]>Higgs and the Mass of the Universetag:www.huffingtonpost.com,2012:/theblog//3.16735922012-07-14T16:04:45-04:002012-09-13T05:12:07-04:00Victor Stengerhttp://www.huffingtonpost.com/victor-stenger/
This is not to say that the Higgs boson is not important. The main role of the Higgs in the standard model of elementary particles is to provide for the symmetry breaking of the unified electroweak force by giving mass to the weak bosons and splitting the electromagnetic and weak nuclear forces. It also gives mass to the other elementary particles. If elementary particles did not have mass, they would all be moving at the speed of light and never stick together to form stuff like stars, cats, and you and me.
The mass of the universe, however, is not simply the sum of the masses of the elementary particles that constitute matter. Einstein showed that the mass of a body is equal to its rest energy. If that body is not elementary but composed of parts, then its rest energy as a whole will be the sum of all the energies of its parts. This sum will include the kinetic and potential energies of the parts in addition to their individual rest energies.
Now, for the bodies of normal experience, such as your neighbor's cat, the kinetic and potential energies of their parts are small compared to their rest energies. So, so for all practical purposes, the total mass of a cat is equal to the sum of the masses of its parts.
This is even true at the microscopic scale. The masses of chemical elements are, typically, thousands of MeV (million electron volts, in energy units), while the kinetic and binding energies are a few tens of electron volts. Only when you get down to the nuclei of the chemical elements do you get kinetic and potential energies that are measurable fractions of their rest energies.
Inside nuclei, we have nucleons--protons and neutrons--that are themselves composed of quarks. Since quarks do not appear as free particles outside nucleons, their masses must be estimated from studying the effects of their mutual interactions on the masses and other properties of nucleons and other particles that are composed of quarks. Fortunately, there are only six quarks but hundreds of particles made from these quarks to provide data to pin down quark properties. By using supercomputers, physicists have obtained reliable estimates of quark masses. The result: the masses of the quarks inside a proton or neutron constitute only 1 percent of its mass.
The objects familiar to most humans, including most scientists, have masses that are essentially given by the number of protons and neutrons they contain. So, we can say that only 1 percent of that mass arises from the masses of quarks. Furthermore, this normal stuff is itself only 5 percent of the total mass of the universe.
Now, where does that leave Mister Higgs? While the Higgs mechanism gives masses to elementary particles, other processes may contribute to the masses of quarks. I need not get into these. Even if all the mass of a quark comes from the Higgs mechanism, the Higgs contribution to the mass of the universe is less than one part in 2,000.]]>Higgs and Significancetag:www.huffingtonpost.com,2012:/theblog//3.16498082012-07-05T08:28:58-04:002012-09-04T05:12:15-04:00Victor Stengerhttp://www.huffingtonpost.com/victor-stenger/
When subatomic particles are smashed together at high energy, they create a complex mix of secondary particles. Before you can claim a new discovery in that mix, you have to show, among other things, that the effect upon which you base the claim is very unlikely to be simply a statistical artifact.
The effect reported from CERN is of a type that particle physicists have been exploring for over fifty years. Basically, they looked for evidence of a particle with such a short lifetime that it would not leave any measurable track in the detector. Instead, it decays into secondary particles after travelling only a few nuclear diameters.
When I was a graduate student at UCLA in the early 1960s, bubble chambers and other detectors at the Lawrence Radiation Laboratory in Berkeley (now Lawrence Berkeley Lab), Brookhaven National Laboratory on Long Island, and CERN in Geneva were finding signs of many such short-lived particles that had never before been seen or even anticipated. They were clearly not composed of the well-known particles such as protons, neutrons, and electrons but seemed elementary in their own right.
We experimenters did then just as the Higgs-searchers are doing now, measured the energies and momenta of all the outgoing particles produced in high-energy particle collisions. Using these data, we formed a quantity called the "invariant mass" for each of the various particle combinations. Accumulating a large number of collision events, we then looked at the statistical distribution of the various invariant masses. When an unexpected "bump" appeared above what was the expected background, we had a candidate for a new particle.
Of course, everyone wanted to discover a new elementary particle and we all got excited whenever even the smallest bump appeared. At first, it seemed that a bump of three standard deviations, that is, "3-sigma," above the background was sufficient for a discovery. At the time, most physicists were not experts in statistics (and still aren't) and this struck us as reasonable. If the statistical fluctuations were given by a normal distribution (bell curve), then in only one in every 740 times you look at such a distribution will you get a 3-sigma bump or larger from a statistical fluctuation. That is, what is called the "p-value" was 1/740 = 0.00135.
We had a simple rule of thumb that drove statistics experts crazy, and still does. If the background under the bump, estimated by looking at either side, or calculated from some model, contained N events, then sigma was set equal to the square root of N-1.
Now, here my fifty-year old memory gets hazy, and I have not been able to dig up any documentation. (If anyone has any, I would greatly appreciate getting a copy). As I recall, at first the journals were publishing 3-sigma results. But many were not being independently replicated. So, again according to what I remember, the primary physics journal for rapid publication, Physical Review Letters, asked Art Rosenfeld at Berkeley to come up with a criterion for publication. He used frequentist probability arguments, which advocates of Bayesian statistics despise but have served us particle physicists well over time.
Art counted up all the experiments being done, all the plots being looked at, all the bins on the plots, all the combinations of particles for which invariant masses were being measured, and came up with a rule that has been at least informally in use since: the probability of the bump being a statistical fluctuation must be less than 1 in 10,000. For a normal distribution, only one in 31,574 times will you get an upward statistical fluctuation of 4-sigma or greater. The observed 5-sigma fluctuation for the Higgs, or a larger one, would result only once in 3.5 million trials.
However, this method of analysis is open to question. Several observers have pointed out a flaw, which is known in the literature as "sampling to a foregone conclusion." That is, the experimenters keep collecting data until the reach the level, in this case 5-sigma, where they then can reject the null hypothesis. The proper method according to the experts is to decide ahead of time what criterion you will use and also how much data you will take before rejecting the null hypothesis. Since that is not generally done, it is technically illegitimate to interpret the result as a probability.
But it's the method we have used in particle physics for half-century and, so far, it has not resulted in any major discovery claim being later proven to be in error. Furthermore, in my experience I saw many 3-sigma bumps go away as more data were accumulated. In any case, physicists no longer leave it just at that. They perform sophisticated Monte Carlo computer simulations of the experiment using their best available models and compare results with (signal plus background) and without (background only) the assumed signal. This was a major activity of mine when I was in research.
The assumption of a normal distribution of fluctuations may not be a good one. In today's experiments, the events are cut in so many different ways that biases away from normal statistics can occur. The Monte Carlo analyses can avoid this by calculating the relative probabilities for the data fitting to signal plus background and background alone.
Of course, statistical significance is a major concern in all experimental sciences, and for a long time I have been critical of what I regard as unacceptably low publication standards used in some fields.
I still remember going to the World Skeptics Conference in Buffalo in the 1996, which featured many prominent speakers including Stephen Jay Gould and Chris Carter, the creator of X-Files. One speaker was Jessica Utts, a professor of statistics at UC Davis. She argued that the standard that was used for publication in medicine and psychology, p-value = 0.05, was adequate to show that ESP exists. She said that evidence for ESP was just as good as the evidence that aspirin helps avoid heart attacks.
I stood up and protested that this implied that one out of every twenty reports of some positive effect was a statistical fluctuation. Furthermore, since negative results are often not published, one can only wonder how many reports in these fields are trustworthy, if any.
Note the difference between an extraordinary claim (ESP) and an ordinary one (aspirin). In the case of aspirin, we can provide a simple explanation: aspirin thins the blood and makes arterial blockages less likely. We have no explanation for ESP within existing knowledge. Claims that it is supported by quantum mechanics are total nonsense.
And there's more. Here again I must rely on memory, since to my knowledge no documentation exists. When in the 1980s I was working on very high-energy gamma ray astronomy on Mt Hopkins in Arizona, using the atmospheric Cherenkov technique, a collaborator reported to the rest of us that he thought he saw a signal from a certain pulsar. We all rushed to a meeting at his university and spent the better part of a week going over the data. His original estimate of the probability that the observation was a statistical fluctuation was one in a billion. After we counted all the various combinations he had looked at, the probability dropped to one in a thousand. This would have been more than adequate for a parapsychology or other pseudoscientific journal, but not a physics or astronomy one. We didn't publish. No one else since has reported a gamma ray signal from that pulsar.
I have looked at the results just reported by the two experiments at CERN, Atlas and CMS. Both show 5-sigma signals for a range of secondary particles at a mass of 125-126 GeV. The standard model of elementary particles and forces predicted a 4.6-sigma effect at that mass, although the value of mass itself was not predicted. Not only is each individual result significant, rejecting the null hypothesis at a probability of one in over three million, the fact that two independent experiments agree surely makes the case for a previously unknown particle at 125 GeV proven beyond a reasonable doubt. Whether it is the long sought-after Higgs boson or a composite of known particles is yet to be definitively established.]]>