Physicists From The United States

"When we finally got our hands on the paper, we quickly realized that Einstein had put his finger on the essence of the problem and had delineated when it has a solution, before the invention of the modern quantum theory. Moreover, Einstein wrote with great lucidity about the subject, so that it seemed as if he were speaking directly to us, a century later. There was nothing dated or quaint about the analysis. For the first time in a long while, I found myself thinking, “Wow, this man really was a genius.”"

"It was Einstein who had introduced almost all the revolutionary ideas underlying quantum theory, and who saw first what these ideas meant. His ultimate rejection of quantum theory was akin to Dr. Frankenstein’s shunning of the monster he had originally created for the betterment of mankind. Had Einstein not done so, in all likelihood he would be seen as the father of the modern theory."

"Our book originated with a wide-ranging physics course for liberal arts students that in its last weeks focused on the mysteries of quantum mechanics. When I (Bruce) first proposed the course at a department meeting, that final focus prompted a faculty member to object:Though what you are saying is correct, presenting this material to nonscientists is the intellectual equivalent of allowing children to play with loaded guns."

"I was visiting friends in Princeton one Saturday in the 1950s when our host asked his son-in-law, Bill Bennett, and me (Bruce) if we’d like to spend the evening with his friend, Albert Einstein. Two awed physics graduate students soon waited in Einstein’s living room as he came downstairs in slippers and sweatshirt. I remember tea and cookies but not how the conversation started. Einstein soon asked about our quantum mechanics course. […] Einstein persisted in exploring our thoughts about what the theory really meant. But the issues that concerned him were unfamiliar to us. Our quantum physics courses focused on the use of the theory, not its meaning. Our response to his probing disappointed Einstein, and that part of our conversation ended."

"Quantum theory is stunningly successful. Not a single one of the theory’s predictions has ever been shown wrong. One-third of our economy depends on products based on it. However, the worldview demanded by quantum theory is not only stranger than we might suppose, it’s stranger than we can suppose."

"Might a worldview suggested by quantum mechanics have relevance beyond science? Consider earlier discoveries that did have such relevance: Copernicus’s realization that Earth was not the center of the cosmos, or Darwin’s theory of evolution. The relevance of quantum mechanics is, in a sense, more immediate than Copernican or Darwinian ideas, which deal with the far away or long ago. Quantum theory is about the here and now. It even encounters the essence of our humanity, our consciousness."

"Strangely enough, many of the philosophical issues surrounding quantum mechanics are today being used to entice potential students into physics. As quantum computing and quantum communication become a commercial reality, tomorrow’s students may find themselves routinely grappling with the same philosophical questions that challenged their forebears almost a century ago."

"On further reflection, I now think that in arguing his case Bell exaggerated, oversimplified the historical development of both classical electrodynamics and quantum mechanics, and as a result arrived at a definition of "understanding" that may be too rigid in that it reflects a presumption - a prejudice, if you will - as to what constitutes physical reality."

"By taking issue with Bell on this score, I am not saying that I am satisfied with my understanding of quantum mechanics. I share Feynman's belief that no one really understands quantum mechanics. But we should not exaggerate our embarrassment; it is ample as it stands. In any event, I agree with Bell that the foundations continue to merit the closest scrutiny."

"There has never been just one best way to teach quantum mechanics. My goal is neither to sow nostalgia for the philosophically engaged style of Oppenheimer and Nordheim, nor to condemn the pragmatic approach of Fermi, Bethe and Feynman. It is rather to highlight the choices that physicists must always make when stepping into the classroom. Choices of topics to discuss and problems to assign reflect deeper decisions about the ideal type of physicist one seeks to train. Should the new generation be philosophically attuned, concerned with minute details of conceptual interpretation? Or should physicists hone their ability to calculate, pushing Heisenberg’s and Schrödinger’s equations into the service of ever more elaborate problems to solve and phenomena to analyse? Competing ideals have flourished under different pedagogical conditions."

"I, for one, remain unpersuaded that a crisis of major proportions has been identified, but at the same time I am open to the possibility that such a crisis has been glimpsed, though perhaps only subliminally, by Bell and his great predecessors: Einstein, Schrodinger, de Broglie, Bohm and Wigner. This is a roster which should give us all pause. To my understanding, however, this crisis has not yet been formulated with sufficient precision to facilitate the birth of a great offspring."

"That classical theory had catastrophic implications for the constitution of matter was barely appreciated by Planck and others at the turn of the century, and played no substantial role in the development of quantum theory until Bohr's work 13 years later. The lesson that could be drawn from this, and also from the development of general relativity, is that a crisis will only become creative if it is formulated in a mathematically precise manner. This conclusion has an echo in Bell's insistence on having quantum mechanics "fully formulated in mathematical terms, with nothing left to the discretion of the theoretical physicist", but what it really calls for is a critique of the "orthodox" theory fully formulated in mathematical terms with nothing left to the discretion of the critic."

"I have avoided so far the use of the term —the analog in the of the . Certainly, deserves the credit for first exhibiting the mechanism in the context of . But as I have tried to show, it took other people to make it work. The Higgs boson is what is being looked for at . If they find it, we shall all be happy and relieved. And if not? I am reminded of a story about Einstein. He had just received a telegram with the news that the eclipse expeditions had confirmed his general relativity prediction about the Sun bending starlight. He was very pleased with himself and showed the telegram to one of his students, . She asked him what he would have done if the telegram had contained the news that the experiments disagreed with the theory. He replied, “Da könt mir halt der lieber Gott leid tun—die theorie stimmt doch. (Then I would have been sorry for the dear Lord. The theory is right).”"

"Although it is always somewhat dangerous to look for the cause of a complex sociological phenomenon in a single event, nonetheless, I believe that a cause can be made for the proposition that the present widespread interest in the quantum theory can be traced to a single paper with the nontransparent title “On the Einstein-Podolsky-Rosen Paradox,” which was written in 1964 by the then thirty-four-year-old Irish physicist John Bell. It was published in the obscure journal Physics, which expired after a few issues. Bell’s paper was, as it happens, published in its first issue. Bell, who has worked since 1960 at CERN, the gigantic elementary-particle physics laboratory near Geneva, has been known to claim that his paper involves only the use of “high school mathematics”; however, its six pages are dense with an extremely abstract set of arguments, which even professionals in the field must work hard at to understand. In fact, for several years after its publication, few if any professional physicists bothered to try."

"The signs on Bell’s door read “J.Bell” and “M.Bell.” I knocked and was invited in by Bell. He looked about the same as he had the last time I saw him, a couple of years ago. He has long, neatly combed red hair and a pointed beard, which give him a somewhat Shavian figura. On one wall of the office is a photograph of Bell with something that looks like a halo behind his head, and his expression in the photograph is mischievous. Theoretical physicists’ offices run the gamut from chaotic clutter to obsessive neatness; the Bells’ is somewhere in between. Bell invited me to sit down after warning me that the “visitor’s chair” tilted backward at unexpected angles. When I had mastered it, and had a chance to look around, the first thing that struck me was the absence of Mary. “Mary,” said Bell, with a note of some disbelief in his voice, “has retired.” This, it turned out, had occurred not long before my visit. “She will not look at any mathematics now. I hope she comes back,” he went on almost plaintively; “I need her. We are doing several problems together.” In recent years, the Bells have been studying new quantum mechanical effects that will become relevant for the generation of particle accelerators that will perhaps succeed the LEP. Bell began his career as a professional physicist by designing accelerators, and Mary has spent her entire career in accelerator design. A couple of years ago Bell, like the rest of the members of CERN theory division, was asked to list his physics speciality. Among the more “conventional” entries in the division such as “super strings,” “weak interactions,” “cosmology,” and the like, Bell’s read “quantum engineering.”"

"I once asked Bell whether during the years he was studying the quantum theory it ever occurred to him that the theory might simply be wrong. He thought a moment and answered, “I hesitated to think it might be wrong, but I knew that it was rotten.” Bell pronounced the word “rotten” with a good deal of relish and then added, “That is to say, one has to find some decent way of expressing whatever truth there is in it.” The attitude that even if there is not something actually wrong with the theory, there is something deeply unsettling—“rotten”—about it, was common to most of the creators of the quantum theory. Niels Bohr was reported to have remarked, “Well, I think that if a man says it is completely clear to him these days, then he has not really understood the subject.” He later added, “If you do not getschwindlig [dizzy] sometimes when you think about these things then you have not really understood it.” My teacher Philipp Frank used to tell about the time he visited Einstein in Prague in 1911. Einstein had an office at the university that over looked a park. People were milling around in the park, some engaged in vehement gesture-filled discussions. When Professor Frank asked Einstein what was going on, Einstein replied that it was the grounds of a lunatic asylum, adding, “Those are the madmen who do not occupy themselves with the quantum theory.”"

"We have been keeping the peace in the Asia-Pacific theater for decades now, and the essence of the rebalance is to keep that peace and stability going, of which we have been a pivotal part. You ask about India, yes it is difficult. We are two technical and military cultures that grew up on opposite sides of the fence during the Cold War."

"That is what you wake up to every morning. It is what my wife and I think of when we go visit hospitals on the weekend. And so providing our people with all the support they can, you can possibly give them. And that does not always come naturally to this place, which is thinking in budgets and thinking in the future. You always have to remember that they are in danger."

"We need to change because the world is changing, and we need to anticipate what is next and be there first, as the US military has always been. So, the changes in our future, I think is something that we are all completely committed to."

"Our nightmare, any of us, which would change the way we lived our lives, was if we thought that any moment Al Qaeda might detonate a nuclear weapon in a city anywhere in the world, because we learned that they had gotten hold of some plutonium from the North Koreans by sale, or when the North Korean regime collapsed, somebody smuggled it out."

"There was never a conspiracy, never a tremendous fear. This is a society which is now in its third generation of severe political repression, so that children in North Korea have several hours of political education a day. Their parents did, and their grandparents did."

"I don't know how long the North Korean regime can last. But we can't just wait for them to collapse, because in the meantime, they can do lasting damage to our security."

"The military option will remain on the table. If there is a good agreement to have, obviously it's worth waiting for and completing the negotiations."

"I hope that the North Koreans understand that the conclusions that we came to are conclusions that are embedded in America's security situation."

"I have experienced time and again people dismissing the data because they think MOND is wrong, so I am very consciously drawing a red line between the theory and the data."

"Why does MOND get any predictions right? It has had many a priori predictions come true. Why does this happen?"

"... I was deeply shocked when it was not my predictions or any of my immediate colleagues' predictions that came true in my data — but Milgrom's. This was completely outside my conceptual framework."

"People have been looking for this dark matter because there is a Nobel prize, for sure, waiting for whoever discovers it."

"The current cosmological paradigm, the cold dark matter model with a cosmological constant, requires that the mass-energy of the Universe be dominated by invisible components: dark matter and dark energy. An alternative to these dark components is that the law of gravity be modified on the relevant scales. A test of these ideas is provided by the baryonic Tully-Fisher relation (BTFR), an empirical relation between the observed mass of a galaxy and its rotation velocity. Here, I report a test using gas rich galaxies for which both axes of the BTFR can be measured independently of the theories being tested and without the systematic uncertainty in stellar mass that affects the same test with star dominated spirals. The data fall precisely where predicted a priori by the modified Newtonian dynamics."

"... It was (in part) Gross’s excessive enthusiasm for string theory in the mid-80s that drove me (as an impressionable grad student at Princeton) away from theoretical physics (and into astronomy). String theory may have been a beautiful idea, but it made no predictions that could be tested experimentally in the then-foreseeable future. That’s not science. A quarter century later and the theoretical physics community has yet to wake up and realize that there is new physics right under their noses – just not the new physics they’ve been expecting (GUTs, strings, membranes, etc.). Galaxy dynamics are consistent with a single, universal force law, but this unexpected behavior has largely been ignored because it doesn’t fit with particle theorists’ dreams of super symmetric dark matter particles. That we do not understand the observed behavior makes it more interesting than the “expected” (but unobserved) new physics: who ordered this?"

"A long time ago when I first got interested in MOND, having come from the background where I believed in dark matter, I wrote a proposal saying, "Gee, this theory had its predictions come true, ... we should look into that" and it was rejected, you know, very harshly. And I thought "OK, the community is not willing to fund this kind of thing" — this was almost twenty years ago. And so I basically did a global substitute, replaced MOND with dark matter, resubmitted, and I got my money. ... Pavel is totally correct that scientists are focused on getting grants, because that's what you need to support your students, and your postdocs, and getting the data, and all those sort of things. And I would like to believe that that was an anecdote from the distant past, but I am aware of a colleague who had this experience very recently where this person did not even mention MOND in the proposal, but the panel came back saying "MOND is no good — you must not spend money on this." ... the panel had associated ... this person's name with having at some point written a paper about MOND and projected that onto this proposal that ... did not mention MOND. And so it really is that bad."

"The concordance model of cosmology, ΛCDM, provides a satisfactory description of the evolution of the universe and the growth of large scale structure. Despite considerable effort, this model does not at present provide a satisfactory description of small scale structure and the dynamics of bound objects like individual galaxies. In contrast, MOND provides a unique and predictively successful description of galaxy dynamics, but is mute on the subject of cosmology. … it is far from obvious that the mass spectrum of galaxy clusters or the power spectrum of galaxies can be explained in MOND, two things that ΛCDM does well. Critical outstanding issues are the development of an acceptable relativistic parent theory for MOND, and the reality of the non-baryonic dark matter of ΛCDM. Do suitable dark matter particles exist, or are they a modern aether?"

"I came to the subject a True Believer in dark matter, but it was MOND that nailed the predictions for the LSB galaxies that I was studying (McGaugh & de Blok, 1998), not any flavor of dark matter. So what I am supposed to conclude?"

"I've never observed wisdom to emerge from shouting."

"You can lead a theorist to data, but you can't make him think."

"It is often stated that the evidence for is overwhelming. This is not quite correct: the evidence for mass discrepancies is overwhelming. These might be attributed to either dark matter or a modification of gravity."

"One should not only be truthful, but as complete as possible. It does not suffice to be truthful while leaving unpleasant or unpopular facts unsaid."

"A long standing prediction (Milgrom 1983) of MOND is that rotating galaxy curves will fall on a single mass-velocity relation with slope 4: Mb \propto Vf4. This prediction is realized in multiple independent data sets. Gas rich galaxies fall where predicted by MOND with no free parameters. There are not many predictions in extragalactic astronomy that fare so well a quarter century after their publication. … a physical understanding for why galaxy formation in the context of ΛCDM should pick out the particular phenomenology predicted a priori by MOND remains wanting."

"Whenever I come across a case that doesn't make sense in MOND, it usually doesn't make sense in either."

"Obvious results provoke opposition. The more obvious the result, the stronger the opposition."

"... Dark matter provides the additional gravitational pull to bring model and reality broadly into alignment. Researchers now routinely take this model – Einstein plus dark matter, often called the ‘null hypothesis’ – as their starting point and then perform detailed calculations of galactic systems to test it. ... Most recently, Stacy McGaugh at Case Western Reserve University in Ohio and his team documented that the pattern of rotation in spiral galaxies seems to precisely follow the pattern of the visible matter alone, posing yet another challenge to the null hypothesis."

"My gut reaction to all these questions is negative. But it appears that one set or the other must be answered in the affirmative. Either way, we are missing something fundamental about the nature of our universe."

"We don't know what organization is. ...We do know that complex adaptive systems have to be nonlinear and capable of storing information. ...We know a little bit about what distinguishes an adaptive complex system from a nonadaptive system, such as turbulent fluid flow."

"One of the factors that caused Spencer's ideas to lose popularity was social Darwinism... Social evolution is different from biological evolution: it's faster, it's Lamarckian, and it makes even heavier use of altruism and cooperation than biological evolution does. None of this was well understood at the time."

"If we choose, we can use genetic engineering to alter the character of our offspring. ...the motivation to do this will eventually become overwhelming."

"Even though something like Danny Hillis' "connection machine" is big, it's nothing compared with Avogadro's number of processors that nature has at her disposal."

"The basic principle of an autocatalytic network is that even though nothing can make itself, everything in the pot has at least one reaction that makes it, involving only other things in the pot. It's a symbiotic system in which everything cooperates to make the metabolism work—the whole is greater than the sum of the parts."

"The paradox that immediately bothers everyone who learns about the second law is this: If systems tend to become more disordered, why, then, do we see so much order around us? ...It seems to conflict with our "creation myth": In the beginning, there was a big bang. ...no one is saying that the second law of thermodynamics is wrong, just that there is a contrapuntal process organizing things at a higher level."

"We're rapidly creating an extraordinary silicon-based petri dish for evolution of intelligence. By the year 2025... we're likely to have computers whose raw processing power exceeds that of the human brain. Also, we're likely to have more computers than people..."

"Complex adaptive systems have the property that if you run them—by just letting the mathematical variable of "time" go forward—they'll naturally progress from chaotic, disorganized, undifferentiated, independent states to organized, highly differentiated, and highly interdependent states. Organized structures emerge spontaneously... A weak system gives rise only to simpler forms of self-organization; a strong one gives rise to more complex forms, like life."