Quotes & Sayings About Quantum Mechanics

There is a mathematical underpinning that you must first acquire, mastery of each mathematical subdiscipline leading you to the threshold of the next. In turn you must learn arithmetic, Euclidian geometry, high school algebra, differential and integral calculus, ordinary and partial differential equations, vector calculus, certain special functions of mathematical physics, matrix algebra, and group theory. For most physics students, this might occupy them from, say, third grade to early graduate school - roughly 15 years. Such a course of study does not actually involve learning any quantum mechanics, but merely establishing the mathematical framework required to approach it deeply. — Carl Sagan

Individual events. Events beyond law. Events so numerous and so uncoordinated that, flaunting their freedom from formula, they yet fabricate firm form. — John Archibald Wheeler

String theory?[pause] It closed the conceptual gulp between relativity and quantum mechanics. It postulates that subatomic particles are not points, but strings, about one planck length long. The rate at which strings vibrate can generate the properties of all known particles. Huh? How did I know that? — Willie Garson

People don't learn science in movies. You don't go to the movies thinking, 'I hope I learn some quantum mechanics this afternoon.' But on the other hand, movies are instrumental and influential in getting young people interested in science. — Seth Shostak

Quantum mechanics is just completely strange and counterintuitive. We can't believe that things can be here [in one place] and there [in another place] at the same time. And yet that's a fundamental piece of quantum mechanics. So then the question is, life is dealing us weird lemons, can we make some weird lemonade from this? — Seth Lloyd

Quantum mechanics as it stands would be perfect if we didn't have the quantum-gravity issue and a few other very deep fundamental problems. — Gerard 't Hooft

Just because quantum mechanics is weird does not mean that everything that is weird is quantum mechanics. — Victor J. Stenger

If we look at the way the universe behaves, quantum mechanics gives us fundamental, unavoidable indeterminacy, so that alternative histories of the universe can be assigned probability. — Murray Gell-Mann

I'm beginning to think that love for me is a bit like Quantum Mechanics, something I know to exist, but have no idea how it works. — R.E. Wentz

Quantum theory provides us with a striking illustration of the fact that we can fully understand a connection though we can only speak of it in images and parables. — Werner Heisenberg

You create reality by looking at it, is what Quantum Mechanics suggests. This may sound outrageously magical. Quantum Mechanics or QM, is the physics of the microscopic world. It is a strange theory that took birth in the early 20th century and continues to dazzle scientists and philosophers today. So much so, that QM is regarded as the gateway to the world of consciousness, bringing science and spiritualty together. Science has entered domain of philosophy and consciousness/spirituality through Quantum Mechanics, making it a hot topic for debate among intellectuals from both scientific and philosophical domains. Some physicists even insist on making philosophy of physics! — Sharad Nalawade

I think that the obscurity of the theory is not the fault of quantum mechanics but is rather due to the limited capacity of our imagination. When we try to "see" the quantum world, we are rather like moles used to living underground, to whom someone is trying to describe the Himalayas. Or like the men imprisoned at the back of Plato's cave. — Carlo Rovelli

I'm not looking to be a trophy. When not acting, I spend my time studying metaphysics and quantum mechanics to keep my life as grounded as I can. — Tanit Phoenix

Quantum mechanics makes absolutely no sense. — Roger Penrose

The Theory of Relativity confers an absolute meaning on a magnitude which in classical theory has only a relative significance: the velocity of light. The velocity of light is to the Theory of Relativity as the elementary quantum of action is to the Quantum Theory: it is its absolute core. — Max Planck

Bertrand Russell had given a talk on the then new quantum mechanics, of whose wonders he was most appreciative. He spoke hard and earnestly in the New Lecture Hall. And when he was done, Professor Whitehead, who presided, thanked him for his efforts, and not least for 'leaving the vast darkness of the subject unobscured'. — J. Robert Oppenheimer

A gifted experimentalist, and theoretician, in the best Newtonian tradition ... His contributions to quantum measurements, and elucidative teachings on quantum mechanics, have not yet received the attention they deserve. — Willis Lamb

If you have nothing in quantum mechanics, you will always have something. — Lawrence M. Krauss

[Recent evidence regarding quantum mechanics is] sufficient to rule out all theological options but one - the Bible's. — Hugh Ross

It would take a civilization far more advanced than ours, unbelievably advanced, to begin to manipulate negative energy to create gateways to the past. But if you could obtain large quantities of negative energy - and that's a big "IF" - then you could create a time machine that apparently obeys Einstein's equation and perhaps the laws of quantum theory. — Michio Kaku

True story of quantum mechanics, a truth far stranger than any fiction. — John Gribbin

No credible understanding of the natural world or our human existence - what I am going to call in this book a worldview - can ignore the basic insights of theories as key as evolution, relativity, and quantum mechanics. — Dalai Lama XIV

Anyone not shocked by quantum mechanics has not yet understood it. — Niels Bohr

Should a priest reject relativity because it contains no authoritative exposition on the doctrine of the Trinity? Once you realize that the Bible does not purport to be a textbook of science, the old controversy between religion and science vanishes ... The doctrine of the Trinity is much more abstruse than anything in relativity or quantum mechanics; but, being necessary for salvation, the doctrine is stated in the Bible. If the theory of relativity had also been necessary for salvation, it would have been revealed to Saint Paul or to Moses. — Georges Lemaitre

I finished up my graduate degree in quantum mechanics, but underwent a bit of a personal crisis, recognizing that I didn't want to do that for the rest of my life. It was too abstract, too far removed from human concerns. — Francis Collins

Quantum Mechanics is different. Its weirdness is evident without comparison. It is harder to train your mind to have quantum mechanical tuition, because quantum mechanics shatters our own personal, individual conception of reality — Brian Greene

According to quantum mechanics there is no such thing as objectivity. We cannot eliminate ourselves from the picture. We are part of nature, and when we study nature there is no way around the fact that nature is studying itself. — Gary Zukav

While classical mechanics correctly predicts the behavior of large objects such as tennis balls, to predict the behavior of small objects such as electrons, we must use quantum mechanics. — Ivar Giaever

In the world of the very small, where particle and wave aspects of reality are equally significant, things do not behave in any way that we can understand from our experience of the everyday world ... all pictures are false, and there is no physical analogy we can make to understand what goes on inside atoms. Atoms behave like atoms, nothing else. — John Gribbin

It has been said that the three great develpments in twentieth century science are relativity, quantum mechanics, and chaos. That strikes me the same as saying that the three great developments in twentith century engineering are the airplane, the computer, and the pop-top aluminum can. Chaos and fractals are not even twentieth century ideas: chaos was first observed by Poincare and fractals were familiar to Cantor a century ago, although neither man had the computer at his disposal to show the rest of the world the beauty he was seeing. — Robert L. Devaney

Werner Heisenberg put it, "what we observe is not nature in itself, but nature exposed to our method of questioning." Heisenberg, a German physicist, made this observation regarding quantum mechanics, but it holds equally true for explorations of the animal — Frans De Waal

A. Douglas Stone, a physicist who has spent his life using quantum mechanics to explore striking new phenomena, has turned his considerable writing skills to thinking about Einstein and the quantum. What he finds and makes broadly understandable are the riches of Einstein's thinking not about relativity, not about his arguments with Bohr, but about Einstein's deep insights into the quantum world, insights that Stone shows speak to us now with all the vividness and depth they had a century ago. This is a fascinating book, lively, engaging, and strong in physical intuition. — Peter Galison

Wolfgang Pauli, in the months before Heisenberg's paper on matrix mechanics pointed the way to a new quantum theory, wrote to a friend, "At the moment physics is again terribly confused. In any case, it is too difficult for me, and I wish I had been a movie comedian or something of the sort and had never heard of physics." That testimony is particularly impressive if contrasted with Pauli's words less than five months later: "Heisenberg's type of mechanics has again given me hope and joy in life. To be sure it does not supply the solution to the riddle, but I believe it is again possible to march forward. — Wolfgang Pauli

The very small quantum world, it seems, is a mixture of possibilities. The quantum fields to which all particles belong are the sum of these possibilities and, somehow, one possibility is chosen out of all the existing ones just by seeing it, just by the very act of detecting it, whenever one tries to probe a particle's nature. Nobody knows why or how this happens. — Christophe Galfard

At the heart of quantum mechanics is a rule that sometimes governs politicians or CEOs - as long as no one is watching, anything goes. — Lawrence M. Krauss

Einstein was searching for String Theory. It not only reconciles General Relativity to Quantum Mechanics, but it reconciles Science and the Bible as well. — Roy H. Williams

One of the older professors in the department didn't find my talk very convincing and made sure that everyone in the room knew of his unhappiness. The next day he sent an e-mail around to the department faculty, which he was considerate enough to copy to me: Finally, the magnitude of the entropy of the universe as a function of time is a very interesting problem for cosmology, but to suggest that a law of physics depends on it is sheer nonsense. Carroll's statement that the second law owes its existence to cosmology is one of the dummest [sic] remarks I heard in any of our physics colloquia, apart from [redacted]'s earlier remarks about consciousness in quantum mechanics. I am astounded that physicists in the audience always listen politely to such nonsense. Afterwards, I had dinner with some graduate students who readily understood my objections, but Carroll remained adamant. I hope he reads this book. — Sean Carroll

The belief in causality is metaphysical. It is nothing but a typical metaphysical hypostatization of a well-justified methodological rule- the scientist's decision never to abandon his search for laws. The metaphysical belief in causality seems thus more fertile in its various manifestations than any indeterminist physics metaphysics of the kind advocated by Heisenberg. Indeed, we can see that Heisenberg's comments have had a crippling effect on research. Connections which are not far to seek may easily be overlooked if its continually repeated that the search for any such connections is 'meaningless'. — Karl Popper

When you think about the complexity of our natural world - plants using quantum mechanics for photosynthesis, for example - a smartphone begins to look like a pretty dumb object. — Jeff VanderMeer

The universe, according to quantum mechanics, participates in a game of chance. — Brian Greene

Einstein comes along and says, space and time can warp and curve, that's what gravity is. Now string theory comes along and says, yes, gravity, quantum mechanics, electromagnetism - all together in one package, but only if the universe has more dimensions than the ones that we see. — Brian Greene

If the business of physics is ever finished, the world will be a much less interesting place in which to live . . . — John Gribbin

In relativity, movement is continuous, causally determinate and well defined, while in quantum mechanics it is discontinuous, not causally determinate and not well defined. — David Bohm

The quantum entered physics with a jolt. It didn't fit anywhere; it made no sense; it contradicted everything we thought we knew about nature. Yet the data seemed to demand it ... The story of Werner Heisenberg and his science is the story of the desperate failures and ultimate triumphs of the small band of brilliant physicists who-during an incredibly intense period of struggle with the data, the theories, and each other during the 1920s-brought about a revolutionary new understanding of the atomic world known as quantum mechanics. — David C. Cassidy

In the future, maybe quantum mechanics will teach us something equally chilling about exactly how we exist from moment to moment of what we like to think of as time. — Richard K. Morgan

The answer to the ancient question 'Why is there something rather than nothing?' would then be that 'nothing' is unstable. — Frank Wilczek

Most 20th century academic physicists, and academia as a whole, simply did not want to touch the subject of consciousness. We have seen psychology grow up, and we've seen the development of neurophysiology and other much more sophisticated science, but only in the recent years have the tools of quantum mechanics been applied to anything representing human scale size. — Edgar Mitchell

If there is to be a resolution to the mystery of how mind relates to matter, it will emerge from explaining the data of the human brain in terms of these laws-laws capable of giving rise to a very different view of the causal efficacy of human consciousness. Quantum mechanics makes it feasible to describe a mind capable of exerting effects that neurons alone cannot. — Jeffrey M. Schwartz

The fine structure constant is undoubtedly the most fundamental pure (dimensionless) number in all of physics. It relates the basic constants of electromagnetism (the charge of the electron), relativity (the speed of light), and quantum mechanics (Planck's constant). — David J. Griffiths

A university student attending lectures on general relativity i the morning and others on quantum mechanics in the afternoon might be forgiven for thinking that his professors are fools, or have neglected to communicate with each other for at least a century. — Carlo Rovelli

Men wanted to be strong. One way to be strong was to be knowledgeable. In so many areas, it was not possible to be knowledgeable without getting a Ph.D. and doing a postdoc. Guns and hunting provided an out for men who wanted to be know-it-alls but who couldn't afford to spend the first three decades of their lives getting up to speed on quantum mechanics or oncology. — Neal Stephenson

Is the purpose of theoretical physics to be no more than a cataloging of all the things that can happen when particles interact with each other and separate? Or is it to be an understanding at a deeper level in which there are things that are not directly observable (as the underlying quantized fields are) but in terms of which we shall have a more fundamental understanding? — Julian Schwinger

It is a curious historical fact that modern quantum mechanics began with two quite different mathematical formulations: the differential equation of Schroedinger and the matrix algebra of Heisenberg. The two apparently dissimilar approaches were proved to be mathematically equivalent. — Richard P. Feynman

All perception is the result of electrical impulses in the brain - the world of the individual is tantamount to a highly advanced computer running and analyzing programs in its working memory. — Kevin Michel

All of the patterns we've discussed of course exist in four dimensions rather than three, and the metaphors about braids, cables and trees, shouldn't be taken too literally. The key point is simply that you can be an unchanging pattern in spacetime-the specific details of this pattern are less important for the points we're making. This pattern is part of the mathematical structure that is our Universe, and the relations between different parts of the pattern are encoded in mathematical equations. As we saw in Chapter 8, Everett's quantum mechanics endows you with an even more interesting-but no less mathematical-structure, since a single you (the tree trunk) can split into many branches, each feeling that they're the one and only you
we'll return to this later. — Max Tegmark

Einstein's theory of relativity does a fantastic job for explaining big things. Quantum mechanics is fantastic for the other end of the spectrum - for small things. — Brian Greene

There is a widespread belief about quantum mechanics, as also about relativity, that it is something that one is entitled to ignore for most ordinary philosophical and scientific purposes, since it only seriously applies at the micro level of reality; where 'micro' means something far smaller than would show up in any conventional microscope. What sits on top of this micro level, so the assumption runs, is a sufficiently good approximation of the old classical Newtonian picture to justify our continuing, as philosophers, to think about the world in essentially classical terms. I believe this to be a fundamental mistake. What I shall be arguing...is that the world is quantum-mechanical through and through; and that the classical picture of reality is, even at the microscopic level, deeply inadequate. — Stephen T. DeBerry

What you can show using physics, forces this universe to continue to exist. As long as you're using general relativity and quantum mechanics you are forced to conclude that God exists. — Frank Tipler

When you look at the external reality, you may assume you know everything, but when you close your eyes and try to look into the darkness of your internal reality, all the knowledge of the external life fails to create a way out of the darkness. — Roshan Sharma

When you ask what are electrons and protons I ought to answer that this question is not a profitable one to ask and does not really have a meaning. The important thing about electrons and protons is not what they are but how they behave, how they move. I can describe the situation by comparing it to the game of chess. In chess, we have various chessmen, kings, knights, pawns and so on. If you ask what chessman is, the answer would be that it is a piece of wood, or a piece of ivory, or perhaps just a sign written on paper, or anything whatever. It does not matter. Each chessman has a characteristic way of moving and this is all that matters about it. The whole game os chess follows from this way of moving the various chessmen. — Paul A.M. Dirac

Solipsism may be logically consistent with present Quantum Mechanics, Monism in the sense of Materialism is not. — Eugene Wigner

I liked quantum mechanics very much. The subject was hard to understand but easy to apply to a large number of interesting problems. — Willis Lamb

Any thoughtful physicist, he said, well schooled in quantum mechanics, would agree that all time exists simultaneously, which I subsequently learned was the case. In truth, Father said, as the first instant of the universe, all of time was present, all our yesterdays and today and all our tomorrows, everyone and everything that was and ever would be existed at that moment. — Dean Koontz

The current leading candidates for dark matter are particles predicted to exist from supersymmetric theories, extensions of current particle physics that include a new symmetry of Nature. The reader may recognize the "super" in supersymmetry from superstring theory, a candidate theory for unifying general relativity and quantum mechanics. As of the winter of 2014, no evidence for supersymmetry had been found, despite decades of intense search and the enthusiastic support of many physicists. At this point, it is unclear and somewhat doubtful that supersymmetry is realized in Nature. — Marcelo Gleiser

Scientists, therefore, are responsible for their research, not only intellectually but also morally. This responsibility has become an important issue in many of today's sciences, but especially so in physics, in which the results of quantum mechanics and relativity theory have opened up two very different paths for physicists to pursue. They may lead us - to put it in extreme terms - to the Buddha or to the Bomb, and it is up to each of us to decide which path to take. — Fritjof Capra

Quantum mechanics is so counter-intuitive, physicists have never been able to come up with a comfortable picture of how it works. — Taner Edis

The role of gender in society is the most complicated thing I've ever spent a lot of time learning about, and I've spent a lot of time learning about quantum mechanics. — Randall Munroe

In quantum mechanics no object has a definite position, except when colliding headlong with something else. — Carlo Rovelli

A popular feel for scientific endeavors should, if possible, be restored given the needs of the twenty-first century. This does not mean that every literature major should take a watered-down physics course or that a corporate lawyer should stay abreast of quantum mechanics. Rather, it means that an appreciation for the methods of science is a useful asset for a responsible citizenry. What science teaches us, very significantly, is the correlation between factual evidence and general theories, something well illustrated in Einstein's life. — Walter Isaacson

The scientists often have more unfettered imaginations than current philosophers do. Relativity theory came as a complete surprise to philosophers, and so did quantum mechanics, and so did other things. — Robert Nozick

The basic idea is to shove all fundamental difficulties onto the neutron and to do quantum mechanics in the nucleus. — Werner Heisenberg

I do feel strongly that string theory is our best hope for making progress at unifying gravity and quantum mechanics. — Brian Greene

The theory of relativity and quantum mechanics argue that you can twist time and space, that something can appear out of nothing, and that a cat can be both alive and dead at the same time. This makes a mockery of our common sense, yet nobody seeks to protect innocent schoolchildren from these scandalous ideas. Why? The theory of relativity makes nobody angry, because it doesn't contradict any of our cherished beliefs. Most people don't care an iota whether space and time are absolute or relative. If you think it is possible to bend space and time, well, be my guest. Go ahead and bend them. What do I care? In contrast, Darwin has deprived us of our souls — Yuval Noah Harari

When the province of physical theory was extended to encompass microscopic phenomena through the creation of quantum mechanics, the concept of consciousness came to the fore again. It was not possible to formulate the laws of quantum mechanics in a fully consistent way without reference to the consciousness. — Eugene Wigner

Quantum mechanics says that it is completely correct to say that the universe's
evolution is determined not by how it started in the Big Bang, but by the final
state of the universe. Every stage of universal history, including every stage of logical and human history, is determined by the ultimate goal of the universe. And
if I am correct that the universal final state is indeed God, then every stage of universal
history, in particular every mutation that has ever occurred, or ever will occur
in any living being, is determined by the action of God. — Frank J. Tipler

Quantum Mechanics: The dreams stuff is made of. Quick: try to think of a single movie about the horrors of Stalinism. This is not a failure of imagination. This is moral meltdown. — Mona Charen

Apparently, when people travel between dimensions, their physical forms are "no longer observable," which is a quantum mechanics thing, and explaining it involves this whole story about a cat that's in a box and is simultaneously alive and dead until you open the box, and it gets seriously complicated. Never ask a physicist about that cat. — Claudia Gray

The unsolved problems of the physical world now seem even more formidable than those solved in the twentieth century.

Though in application it works splendidly, we do not even understand the physical meaning of quantum mechanics, much less how it might be united with general relativity.

We don't know why the dimensionless constants (ratios of masses of elementary particles, ratios of strength of gravitational to electric forces, fine structure constant, etc.) have the values they do, unless we appeal to the implausible anthropic principle, which seems like a regression to Aristotelian teleology. — Gerald Holton

A mathematician says that an electromagnetic wave travels from Andromeda to your eye and that it also extends from Andromeda to your eye. — Bill Gaede

You are deluded if you think that the world around you is a physical construct separate from your own mind. — Kevin Michel

When things get tough, there are two things that make life worth living: Mozart, and quantum mechanics — Victor Frederick Weisskopf

I find the idea quite intolerable that an electron exposed to radiation should choose of its own free will not only its moment to jump off but its direction. In that case I would rather be a cobbler, or even an employee in a gaming house, than a physicist. — Albert Einstein

The more we delve into quantum mechanics the stranger the world becomes; appreciating this strangeness of the world, whilst still operating in that which you now consider reality, will be the foundation for shifting the current trajectory of your life from ordinary to extraordinary. It is the Tao of mixing this cosmic weirdness with the practical and physical, which will allow you to move, moment by moment, through parallel worlds to achieve your dreams. — Kevin Michel

While many questions about quantum mechanics are still not fully resolved, there is no point in introducing needless mystification where in fact no problem exists. Yet a great deal of recent writing about quantum mechanics has done just that. — Murray Gell-Mann

In quantum mechanics there is A causing B. The equations do not stand outside that usual paradigm of physics. The real issue is that the kinds of things you predict in quantum mechanics are different from the kinds of things you predict using general relativity. Quantum mechanics, that big, new, spectacular remarkable idea is that you only predict probabilities, the likelihood of one outcome or another. That's the new idea. — Brian Greene

In other words, the idea is the there's a fourth level of parallel universes that's vastly larger than the three we've encountered so far, corresponding to different mathematical structures. The first three levels correspond to noncommunicating parallel universes within the same mathematical structure: Level I simply means distant regions from which light hasn't yet had time to reach us, Level II covers regions that are forever unreachable because of the cosmological inflation of intervening space, and Level III, Everett's "Many Worlds," involves noncommunicating parts of the Hilbert space of quantum mechanics. Whereas all the parallel universes at Levels I, II and III obey the same fundamental mathematical equations (describing quantum mechanics, inflation, etc.), Level IV parallel universes dance to the tunes of different equations, corresponding to different mathematical structures. Figure 12.2 illustrates this four-level multiverse hierarchy, one of the core ideas of this book. — Max Tegmark

There's a lot of things I nerd out over. Quantum Mechanics. I also love Dungeons and Dragons. I want to be an astronaut. — Analeigh Tipton

There was quantum mechanics, string theory, and then there was the most mind-bending frontier of the natural world, women. — Marisha Pessl

Common sense has no place in Quantum Mechanics. — Michio Kaku

One of the most exciting things about dark energy is that it seems to live at the very nexus of two of our most successful theories of physics: quantum mechanics, which explains the physics of the small, and Einstein's Theory of General Relativity, which explains the physics of the large, including gravity. — Adam Riess

The problem is that replacement of Quantum Mechanics by Quantum Field Theory is still very demanding. — Martin Fleischmann

I think we can safely assume that no one understands quantum mechanics. — Richard P. Feynman

Quantum mechanics extends this relativity in a radical way: all variable aspects of an object exist only in relation to other objects. It is only in interactions that nature draws the world. — Carlo Rovelli

Please beware," came his reply, "There are a lot of people who believe that just because we don't have an explanation for something, it's quantum mechanics. — Mary Roach

But, as we have seen, movement does not require a mover, and modern quantum mechanics has shown that not all effects require a cause. And even if they did, why would the Prime Mover need to be a supernatural anthropomorphic deity such as the Judeo - Christian God? Why could it not just as well be the material universe itself? — Victor J. Stenger

Now, what that means is that there is fundamental indeterminacy from quantum mechanics, but besides that there are other sources of effective indeterminacy. — Murray Gell-Mann

The very nature of the quantum theory ... forces us to regard the space-time coordination and the claim of causality, the union of which characterizes the classical theories, as complementary but exclusive features of the description, symbolizing the idealization of observation and description, respectively. — Niels Bohr

Despite the earnest belief of most of his fans, Einstein did not win his Nobel Prize for the theory of relativity, special or general. He won for explaining a strange effect in quantum mechanics, the photoelectric effect. His solution provided the first real evidence that quantum mechanics wasn't a crude stopgap for justifying anomalous experiments, but actually corresponds to reality. And the fact that Einstein came up with it is ironic for two reasons. One, as he got older and crustier, Einstein came to distrust quantum mechanics. Its statistical and deeply probabilistic nature sounded too much like gambling to him, and it prompted him to object that "God does not play dice with the universe." He was wrong, and it's too bad that most people have never heard the rejoinder by Niels Bohr: "Einstein! Stop telling God what to do. — Sam Kean

A theory of reality must not only explain reality, but also knowledge about that reality because knowing reality is part of reality. — Ashish Dalela

In particular, if consciousness is an ontological fundamental-that is, a primary element of reality-then it may have the power to achieve what is both the best-documented and at the same time the spookiest effect of the m ind on the material world: the ability of consciousness to transform the infinite possibilities for, say, the position of a subatomic particle as described by quantum mechanics into the single reality for that position as detected by an observer. If that sounds both mysterious and spooky, it is a spookiness that has been a part of science since almost the beginning of the twentieth century. It was physics that first felt the breath of this ghost, with the discoveries of quantum mechanics, and it is in the field of neuroscience and the problem of mind and matter that its ethereal presence is felt most markedly today. — Jeffrey M. Schwartz