Physics Quote of the Day (December 20 - December 26)

"If we look at the fact, we shall find that the great inventions of the age are not, with us at least, always produced in universities." Charles Babbage, born 26 December 1791.

"The light microscope opened the first gate to microcosm. The electron microscope opened the second gate to microcosm. What will we find opening the third gate?" Ernst Ruska, born 25 December 1906.

"My object has been, first to discover correct principles and then to suggest their practical development." James Prescott Joule, born 24 December 1818.

"You cannot possess the truth, you can only search for it." Albert Jacquard, born 23 December 1925.

"This fact, that all charges are integral multiples of a fundamental unit, is still one of the unexplained puzzles of fundamental physics. It does not in any way contradict electromagnetic theory, but it is not predicted by it, and until we have a more fundamental theory that explains it, we shall not feel that we really understand electromagnetic phenomena thoroughly. Presumably its explanation will not come until we understand quantum theory more thoroughly than we do at present." John Clarke Slater, born 22 December 1900.

"A surprising number of physicists are into mountain hiking, and the combination of strenuous physical activity, fresh mountain air and breathtaking views of the Alps is useful to physicists because it is such a contrast to sitting at a table doing calculations." Cecile DeWitt Morette, born 21 December 1922.

"Of course, we must avoid postulating a new element for each new phenomenon. But an equally serious mistake is to admit into the theory only those elements which can now be observed. For the purpose of a theory is not only to correlate the results of observations that we already know how to make, but also to suggest the need for new kinds of observations and to predict their results. In fact, the better a theory is able to suggest the need for new kinds of observations and to predict their results correctly, the more confidence we have that this theory is likely to be good representation of the actual properties of matter and not simply an empirical system especially chosen in such a way as to correlate a group of already known facts." David Bohm, born 20 December 1917.

Physics Quote of the Day (December 13 - December 19)

"It appears, from all that precedes, reasonably certain that if there be any relative motion between the earth and the luminiferous ether, it must be small; quite small enough entirely to refute Fresnel's explanation of aberration." Albert Abraham Michelson, born 19 December 1852.

"The electron: may it never be of any use to anybody!" J. J. Thomson, born 18 December 1856.

"Nothing is so fatal to the progress of the human mind as to suppose that our views of science are ultimate; that there are no mysteries in nature; that our triumphs are complete, and that there are no new worlds to conquer." Humphry Davy, born 17 December 1778.

"When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong." Arthur C. Clarke, born 16 December 1917.

"There is no such thing as a unique scientific vision, any more than there is a unique poetic vision. Science is a mosaic of partial and conflicting visions. But there is one common element in these visions. The common element is rebellion against the restrictions imposed by the locally prevailing culture,..." Freeman Dyson, born 15 December 1923.

"... the end of fundamental physics is nowhere in sight." Giovanni Amelino-Camelia, born 14 December 1965.

"It is seen as the application of a systematic “scientific method” involving wearing a white coat and being dull. I feel that too many young people come into science with this view, and that too many fields degenerate into the kind of work which results: automatic crank-turning and data-collecting of the sort which Kuhn calls “normal science” and Rutherford “stamp-collecting”. In fact, the creation of new science is a creative act, literally, and people who are not creative are not very good at it." Philip Warren Anderson, born 13 December 1923.

Physics Quote of the Day (December 6 - December 12)

"Innovation is everything. When you're on the forefront, you can see what the next innovation needs to be. When you're behind, you have to spend your energy catching up." Robert Noyce, born 12 December 1927.

"I am now convinced that theoretical physics is actually philosophy. It has revolutionized fundamental concepts, e.g., abut space and time (relativity), about causality (quantum theory), and about substance and matter (atomistics). It has taught us new methods of thinking (complimentarity), which are applicable far beyond physics." Max Born, born 11 December 1882.

"Mathematics is the science of what is clear by itself." Gustav Jacobi, born 10 December 1804.

"While science and technology play critical roles in sustaining modern civilization, they are not part of our culture in the sense that they are not commonly studied or well comprehended. Neither the potential nor the limitations of science are understood so that what can be achieved and what is beyond reach are not comprehended. The line between science and magic becomes blurred so that public judgments on technical issues can be erratic or badly flawed. It frequently appears that some people will believe almost anything. Thus judgments can be manipulated or warped by unscrupulous groups. Distortions or outright falsehoods can come to be accepted as fact." Henry Way Kendall, born 9 December 1926.

"Perhaps our ultimate understanding of scientific topics is measured in terms of our ability to generate metaphoric pictures of what is going on. Maybe understanding is coming up with metaphoric pictures." Per Bak, born 8 December 1948.

"God made the integers, all the rest is the work of man." Leopold Kronecker, born 7 December 1823.

"Science is, on the whole, an informal activity, a life of shirt sleeves and coffee served in beakers." George Porter, born 6 December 1920.

Physics Quote of the Day (November 29 - December 5)

"We have to remember that what we observe is not nature herself, but nature exposed to our method of questioning." Werner Heisenberg, born 5 December 1901.

"... elegant generalization is mathematically very appealing; but physics means facing facts. You should take up case by case." K. S. Krishnan, born 4 December 1898.

"I may be a minority of one in advocating that one should NOT separate science and politics—partly because I am old enough to remember the Weimar Republic before 1934 ..." Edwin Salpeter, born 3 December 1924.

"one of my complaints is that you've got far more scientists than ever before but the pace of discovery has not increased. Why? Because they're all busy just filling in the details of what they think is the standard story. And the youngsters, the people with different ideas have just as big a fight as ever and normally it takes decades for science to correct itself. But science does correct itself and that's the reason why science is such a glorious thing for our species." Nigel Calder, born 2 December 1931.

"There is no branch of mathematics, however abstract, which may not some day be applied to phenomena of the real world." Nikolai Lobachevsky, born 1 December 1792.

"As the Knowledge of Nature tends to enlarge the human Mind, and give us more noble, more grand, and exalted Ideas of the AUTHOR of Nature, and if well pursu'd, seldom fails producing something useful to Man." Ebenezer Kinnersley, born 30 November 1711.

"There have been applied sciences throughout the ages. ... However this so-called practice was not much more than paper in nearly all of these cases, and the various applied sciences were only lacking a bagatelle, namely proper scientific practice. The applied sciences show the application of theoretic doctrines in existing events; but that is precisely what it does, it merely shows. Whereas the scientific practice autonomously puts to use these theories." Christian Doppler, born 29 November 1803.

Physics Quote of the Day (November 22 - November 28)

"The relationship between science and the humanities is two-way. Science changes our view of the world and our place in it. In the other direction, the humanities provide the store of ideas and images and language available to us in understanding the world. The exploding star of A.D. 1054, the Crab Nebula, was sighted and documented by the Chinese, but nowhere mentioned in the West, where the Aristotelian notion of the immortality of stars still held sway. We often do not see what we do not expect to see." Alan Lightman, born 28 November 1948.

"It's unnecessary to introduce magic into the explanation of physical and biological phenomenon when in fact there is every likelihood that the continuation of research as it is now practiced will indeed fill all the gaps..." John Maddox, born 27 November 1925.

"Physics is at present a mass of partial theories which no man has yet been able to render truly and clearly consistent. It has been well said that the modern physicist is a quantum theorist on Monday, Wednesday, and Friday and a student of gravitational relativity theory on Tuesday, Thursday, and Saturday. On Sunday he is praying. . . that someone will find the reconciliation between the two views." Norbert Wiener, born 26 November 1894.

"Nature has put itself the problem of how to catch in flight light streaming to the Earth and to store the most elusive of all powers in rigid form. The plants take in one form of power, light; and produce another power, chemical difference." Julius Robert von Mayer, born 25 November 1814.

"Above all, it's creative thinking that lies at the basis of discoveries. You must dare to think differently, see things from different sides, in order to come across fortuitous new ideas frequently. You should develop even the most stupid ideas and when you do this systematically, there will always come something useful out of it." Simon van der Meer, born 24 November 1925.

"Every object in the Universe with a temperature above absolute zero radiates in the infrared, so this part of the spectrum contains a great deal of information." Frank J. Low, born 23 November 1933.

"... in science, we often have predecessors much further back in time than we think a priori." Louis Néel, born 22 November 1904.

Physics Quote of the Day (November 15 - November 21)

"A single part of physics occupies the lives of many men, and often leaves them dying in uncertainty." Voltaire, born 21 November 1694.

"Equipped with his five senses, man explores the universe around him and calls the adventure Science." Edwin Hubble, born 20 November 1889.

"The difficulty, as in all this work, is to find a notation which is both concise and intelligible to at least two people of whom one may be the author." Paul Matthews, born 19 November 1919.

"A physicist must be able to saw with a file and to file with a saw." August Kundt, born 18 November 1839.

"In science, it is not speed that is the most important. It is the dedication, the commitment, the interest and the will to know something and to understand it — these are the things that come first." Eugene Wigner, born 17 November 1902.

"Nothing is more incontestable than the existence of our sensations;" Jean le Rond d'Alembert, born 16 November 1717.

"Here is truly a Hole in Heaven." William Herschel, born 15 November 1738.

Physics Quote of the Day (November 8 - November 14)

"You can forget facts but you cannot forget understanding !" Eric Mazur, born 14 November 1954.

"Facts are more mundane than fantasies, but a better basis for conclusions." Amory Lovins, born 13 November 1947.

"... a young author who believes himself capable of great things would usually do well to secure the favourable recognition of the scientific world by work whose scope is limited, and whose value is easily judged, before embarking upon higher flights." John Strutt, 3rd Baron Rayleigh, born 12 November 1842.

"As an analogy one can imagine an intelligent amoeba with a good memory. As time progresses the amoeba is constantly splitting, each time the resulting amoebas having the same memories as the parent. Our amoeba hence does not have a life line, but a life tree." Hugh Everett, born 11 November 1930.

"It is a fantastic letter. Very understated. He calls it an optical maser, it’s as if a maser was made to run in the optical. No flamboyant phrase, just straightforward science." Peter Franken, born 10 November 1928.

"Imagination will often carry us to worlds that never were. But without it we go nowhere." Carl Sagan, born 9 November 1934.

"... electronics is a fascinating field that I continue to find fulfilling. The field is still growing rapidly, and the opportunities that are ahead are at least as great as they were when I graduated from college. My advice is to get involved and get started." Jack Kilby, born 8 November 1923.

Physics Quote of the Day (November 1 - November 7)

"Humanity needs practical men, who get the most out of their work, and, without forgetting the general good, safeguard their own interests. But humanity also needs dreamers, for whom the disinterested development of an enterprise is so captivating that it becomes impossible for them to devote their care to their own material profit. Without doubt, these dreamers do not deserve wealth, because they do not desire it. Even so, a well-organized society should assure to such workers the efficient means of accomplishing their task, in a life freed from material care and freely consecrated to research." Marie Curie, born 7 November 1867.

"A patent is a legal analog of sticky fly paper: it attracts some of the lowest forms of life." David L. Webster, born 6 November 1888.

"In scientific thought we adopt the simplest theory which will explain all the facts under consideration and enable us to predict new facts of the same kind. The catch in this criterion lies in the world "simplest." It is really an aesthetic canon such as we find implicit in our criticisms of poetry or painting. The layman finds such a law as dx/dt = K(d²x/dy²) much less simple than "it oozes," of which it is the mathematical statement. The physicist reverses this judgment, and his statement is certainly the more fruitful of the two, so far as prediction is concerned. It is, however, a statement about something very unfamiliar to the plainman, namely, the rate of change of a rate of change." John Burdon Haldane, born 5 November 1892.

"If you really look at it, I was trying to sell a dream ... There was very little I could put in concrete to tell these people it was really real." Charles K. Kao, born 4 November 1933.

"It is electromagnetism (EM) in all its many forms that has been so basic, that haunts us and guides us." Nick Holonyak, born 3 November 1928.

"The beauty of physics lies in the extent to which seemingly complex and unrelated phenomena can be explained and correlated through a high level of abstraction by a set of laws which are amazing in their simplicity." Melvin Schwartz, born 2 November 1932.

"... real understanding of a thing comes from taking it apart oneself, not reading about it in a book or hearing about it in a classroom. To this day I always insist on working out a problem from the beginning without reading up on it first, a habit that sometimes gets me into trouble but just as often helps me see things my predecessors have missed." Robert B. Laughlin, born 1 November 1950.

Physics Quote of the Day (October 25 - October 31)

"Sometimes one can improve the theories in the sense of discovering a quicker, more efficient way of doing a given calculation." John Pople, born 31 October 1925.

"Science had better not free the minds of men too much, before it has tamed their instincts." Jean Rostand, born 30 October 1894.

"Science leads to great achievements, which, quite rightly, fill of joy those who seek the truth, but if pursued, teaches us that we must seek other sources of ultimate truth and find answers to existential questions about the meaning of life and the mystery of death." Franco Bassani, born 29 October 1929.

"... the basis of anything is education, so that people not only become qualified, but essentially become able to create new knowledge." José Leite Lopes, born 28 October 1918.

"Mars has global warming, but without a greenhouse and without the participation of Martians. These parallel global warmings -- observed simultaneously on Mars and on Earth -- can only be a straightline consequence of the effect of the one same factor: a long-time change in solar irradiance." Khabibullo Abdusamatov, born 27 October 1940.

"The gravitational force is the oldest force known to man and the least understood." Peter van Nieuwenhuizen, born 26 October 1938.

"... an author never does more damage to his readers than when he hides a difficulty." Évariste Galois, born 25 October 1811.

Physics Quote of the Day (October 18 - October 24)

"The real point of honor [for a scientist] is not to be always right. It is to dare to propose new ideas, and then check them." Pierre-Gilles de Gennes, born 24 October 1932.

"...while I am certainly not asking you to close your eyes to the experiences of earlier generations, I want to advise you not to conform too soon and to resist the pressure of practical necessity. Free imagination is the inestimable prerogative of youth and it must be cherished and guarded as a treasure." Felix Bloch, born 23 October 1905.

"Discoveries in physics are made when the time for making them is ripe, and not before." Clinton Davisson, born 22 October 1881.

"I would like to help dreamers as they find it difficult to get on in life." Alfred Nobel, born 21 October 1833.

"Every great advance in science has issued from a new audacity of imagination." John Dewey, born 20 October 1859.

"It is, indeed an incredible fact that what the human mind, at its deepest and most profound, perceives as beautiful finds its realization in external nature.… What is intelligible is also beautiful." Subrahmanyan Chandrasekhar, born 19 October 1910.

"In quantum physics, however, each observation implies an intervention in the observed. Because of the quantum physical laws of nature, a change of state of the observed is inevitably coupled to the observation process. So it's not a situation independent from the experiment that is observed, but we ourselves call forth the facts (or compel them to go in a certain direction to a disambiguation), that then become an observation." Pascual Jordan, born 18 October 1902.

Physics Quote of the Day (October 11 - October 17)

"...the ultimate objective of teaching physics is promoting a sound physical thinking and not merely tackling a list of topics." Győző Zemplén, born 17 October 1879.

"Quantum theory also tells us that the world is not simply objective; somehow it's something more subtle than that. In some sense it is veiled from us, but it has a structure that we can understand." John Polkinghorne, born 16 October 1930.

"Two polar groups: at one pole we have the literary intellectuals, at the other scientists, and as the most representative, the physical scientists. Between the two a gulf of mutual incomprehension." C. P. Snow, born 15 October 1905.

"We don't want support for scientific research just to keep scientists busy: we want scientists to be looked upon by the public as people who can do things for them that they can't do themselves." J. C. McLennan, born 14 October 1867.

"Opinions derived from long experience are exceedingly valuable, and outweigh all others, while they are consistent with facts and with each other; but they are worse than useless when they lead, as in this instance, to directly opposite opinions." Peter Barlow, born 13 October 1776.

"It frequently happens that a great discovery supplies the wanting links between a number of obscure facts, and thus adds quite as much to our knowledge by its indirect bearings as by the positive additions it makes to the general stock." Josiah Cooke, born 12 October 1827.

"Should there really be suns in the whole infinite space, they can be at approximately the same distance from one another, or distributed over galaxies, hence would be in infinite quantities, and consequently the whole sky should be as bright as the sun. Clearly, each line which can conceivably be drawn from our eye will necessarily end on one of the stars and each point on the sky would send us starlight, that is, sunlight." Heinrich Olbers, born 11 October 1758.

FQXi essay contest statistics and quotes

I took profit of last week and weekend to acquaint myself with the other essays handling the question "What's ultimately possible in physics". I read a dozen of them extensively as well as all abstracts and began to organize my evaluations. I voted for two of them but will leave a definite rate for the others after having checked consistency with respect to a broader set of essays. The fact that strikes me, is how low community voters (mainly authors) score each other. The scale runs from 1 to 10, but presently the highest rating is 4.4. That's detrimental for a healthy rating system because we loose in gradation subtleties.

As for the statistics: 114 essays were submitted by 1 woman and 113 man. There is much to do in order to establish gender parity in physics! From the information I gathered, the great majority have US citizenship (43 authors), Germany (10) and India (9) are also strongly represented, as well as Canada (5), Romania (5), Italy (5) and the Netherlands (5, including mine). Russia and UK have each 4 submissions. The rest comes from Australia (2), New Zealand (2), Spain (2), Croatia (2), Slovenia (2), Austria (1), Belgium (1), Brasil (1), Chili (1), Greece (1), Iraq (1), Korea (1), Moldova (1), Mexico (1), South Africa (1), Sweden (1), Serbia (1) and 2 which I couldn't deduce from the information they gave. These numbers should be taken with a grain of salt because I assumed US citizenship for US residents if not mentioned otherwise. There are no submissions from my country of residence. What am I doing here in Paris if there is nobody to discuss foundational questions with ;-) !

Some authors gave me agreement for quoting them, so here are some interesting quotes:

From “Ultimately anything is possible” by Hrvoje Nikolic, the shortest essay (if you have little time, read it).
“we can never be sure that the laws of physics we know are the final ones, so we always must admit that anything is ultimately possible”.

From “Mechanics of a Self-Creating Universe” by Anton W. M. Biermans, a “cursory overview of the first insights to come out of an investigation into the question whether a universe can create itself out of nothing”.
“If an electron cannot express its charge if there is no other charge in the universe, then it couldn't be charged itself.”

From “ant among giants. . .a fable” by Richard P. Dolan, an enjoyable and entertaining essay, with the message that physicists should listen to people outside of their tribe.
“The ant found its chilly reception perfectly proper and understandable, but always experienced a feeling of frustration when some giant publicly expressed ignorance on a question to which the ant thought it had the answer.”
“the physicists were ensnared in a dense thicket of mathematics, desperately trying to get out by going deeper into the thicket. Only the string theorists thought they had hacked their way out of the thicket, but what they found was a vast landscape of universes that had no predictive power and couldn’t be tested—the end of science.”

From “Ignoramus et Ignorabimus” by Alfred Tang, making the point that physics and theology could benefit one from the other.
“Very often scientific discoveries are made when physics interacts with other disciplines (such as biology). In cross-discipline research, physicists are forced to think outside of the box.”
“precision is only possible if and only if we know exactly what we want to say in closed form. As we approach the limit of physics, we often do not even know what to think. Therefore the exactness of the mathematical language may easily lead to highly specialized rabbit trails down into theoretical blind alleys. When we do not know what we are talking about, it is helpful to take a step back to look at the forest instead of the leaves by thinking in more general terms with common language to develop the proper attitudes. Loquaciousness is perhaps the proper technique for developing attitudes. Proper attitudes constrain the theory space so that theoreticians do not waste time populating the theoretical landscape as in the case of superstring theory.”

From “To be or not to be strictly deterministic?” by Stefan Weckbach, stating that physical laws and consciousness belong to different realms.
“truths can evolve out of beliefs”
“there is no direct path from our abstract knowledge to ultimate reality”

From “On the Impossibility of Time Travel” by JCN Smith, demonstrating that a particular time is defined by the configuration of the universe.
“the changes we observe (as well as those we donʼt observe) are the flow of time. If the configuration of the universe did not change, there would be no flow of time.”

From “Quantum mechanics from a stochastic least action principle” by Joakim Munkhammar, giving a unified vision of classical and quantum least action principle.
“the ultimate possibilities in physics could more clearly be visualized with a better foundation for quantum mechanics.”

From “At the Frontier of Knowledge” by Sabine Hossenfelder, giving good reasons to say that it is impossible to say what's ultimately possible.
“Physicists have a love-hate relationship with no-go theorems”
“Despite long efforts, no progress has been made. This situation is one that seems to bother physicists today more than ever due to the lack of breakthroughs in fundamental physics that has lasted several decades now. This is even more frustrating since meanwhile the world around us seems to change in a faster pace every day.”
“proofs are only about the mathematical properties of certain objects in their assumptions. A physical theory that describes the real world necessarily also needs a connection between these mathematical objects and the corresponding objects of the real world.”
“What we can thus state with certainty at any time is merely “To our best current knowledge...””

Physics Quote of the Day (October 4 - October 10)

"Young people must break machines to learn how to use them; get another made!" Henry Cavendish, born 10 October 1731.

"In the beginning was mechanics." Max von Laue, born 9 October 1879.

"I don't think you 'can' have scientific policy. I think science is something like weeds, it just grows of its own accord, and if you've got the right atmosphere, ... then it grows and develops of its own accord. And I believe that science is best left to scientists, that you cannot have managers or directors of science, it's got to be carried out and done by people with ideas, people with concepts, people who feel in their bones that they want to go ahead and develop this, that, or the other concept which occurs to them." Mark Oliphant, born 8 October 1901.

"Every valuable human being must be a radical and a rebel, for what he must aim at is to make things better than they are." Niels Bohr, born 7 October 1885.

"For every good idea, ten thousand idiotic ones must first be posed, sifted, tried out, and discarded. A mind that's afraid to toy with the ridiculous will never come up with the brilliantly original." David Brin, born 6 October 1950.

"All a quantum state ever does is move in circles." Sean Carroll, born 5 October 1966.

"In the past century, and even nowadays, one could encounter the opinion that in physics nearly everything had been done. There allegedly are only dim 'cloudlets' in the sky or theory, which will soon be eliminated to give rise to the 'theory of everything'. I consider these views as some kind of blindness. The entire history of physics, as well as the state of present-day physics and, in particular, astrophysics, testifies to the opposite. In my view we are facing a boundless sea of unresolved problems." Vitaly Ginzburg, born 4 October 1916.

What's ultimately possible in physics?

I recently applied for the FQXi essay contest on the topic “What is ultimately possible in physics?” FQXi stands for Foundational Questions Institute. It “catalyzes, supports, and disseminates research on questions at the foundations of physics and cosmology, particularly new frontiers and innovative ideas integral to a deep understanding of reality, but unlikely to be supported by conventional funding sources.” It is directed and advised by a wide of array of renown professors and scientists. In fact, like the Perimeter Institute, it is exactly the institution that is concerned about questions which I am involved with for almost twenty years: understanding reality in a deeper way. So, it was not difficult to engage myself in writing an essay. I almost have the topic in my bones. So here's the result: “Ordinary Analogues for Quantum Mechanics”.

There's an evaluation process detailed on the FQXI Essay contest introduction page. The good news is that you may take part in that process as public voters. If you also applied with an essay, you may vote with a different profile: “community voter”. The essays should be “topical”, “foundational”, “original and creative”, “technically correct and rigorously argued”, “well and clearly written” and “accessible to a diverse, highly-educated but non-specialist audience, aiming in the range between the level of Scientific American and a review article in Science or Nature.” So if you feel you can evaluate on these criteria, I encourage you to vote for the different essays and participate in the discussion. Don't let yourself be impressed by some current low ratings. As all authors may vote as community members, there may be some nonconstructive voting from author competitors. Many essays, were rated 1 or 2 on a scale of 10, only a few hours after being posted, while they met the above evaluation criteria (in my view). It is more important to support and discuss good and innovative ideas. So, in order to end up with correctly balanced votes, join us at the essays main page!

For myself, I thought a good way to contribute with balanced votes is to communicate on what I perceive to be the core ideas of each essay I'll read. I intend to read as much as I can. There are currently about 100 essays and there may add some that were posted on the last day October 2nd. I've already read 4 of them and selected some inspiring quotes which I'll post on my twitter profile with hashtag #fqxiquote and here on this blog, apart from the physics quotes of the day.

Physics Quote of the Day (September 27 - October 3)

"Every discovery takes place in more than a scientific context." Charles Pedersen, born 3 October 1904.

"But I am leaving the regions of fact, which are difficult to penetrate, but which bring in their train rich rewards, and entering the regions of speculation, where many roads lie open, but where a few lead to a definite goal." William Ramsay, born 2 October 1852.

"There is no concept in the whole field of physics which is more difficult to understand than is the concept of entropy, nor is there one which is more fundamental." Francis Sears, born 1 October 1898.

"Lastly, and doubtless always, but particularly at the end of the last century, certain scholars considered that since the appearances on our scale were finally the only important ones for us, there was no point in seeking what might exist in an inaccessible domain. I find it very difficult to understand this point of view since what is inaccessible today may become accessible tomorrow (as has happened by the invention of the microscope), and also because coherent assumptions on what is still invisible may increase our understanding of the visible." Jean Baptiste Perrin, born 30 September 1870.

"Where is everybody?" Enrico Fermi, born 29 September 1901.

"Origami helps in the study of mathematics and science in many ways. Using origami anyone can become a scientific experimenter with no fuss." Martin Kruskal, born 28 September 1925.

"We devise heart transplants, but do little for the 15 million who die annually of malnutrition and related diseases. Our cleverness has grown prodigiously - but not our wisdom." Martin Ryle, born 27 September 1918.

Physics Quote of the Day (September 20 - September 26)

"If error is corrected whenever it is recognized as such, the path of error is the path of truth." Hans Reichenbach, born 26 September 1891.

"If you want to move mountains, you just go move mountains. If you don't have a big enough shovel, you get some friends to help you. If you have the enthusiasm to charge ahead, you can do all sorts of things. Some things you can't do. You can't invent a perpetual motion machine. You've got to select your targets. But people can do so much more than they realize." Paul MacCready, born 25 September 1925.

"The greatest advantage in gambling lies in not playing at all." Gerolamo Cardano, born 24 September 1501.

"There were a significant number of questions I had asked myself and, as you know, when you really ask yourself the questions, you give better answers than if we merely read the conventional answers." Albert Messiah, born 23 September 1921.

"Nature is our kindest friend and best critic in experimental science if we only allow her intimations to fall unbiassed on our minds. Nothing is so good as an experiment which whilst it sets an error right gives us a reward for our humility in being refreshed by an absolute advancement in knowledge." Michael Faraday, born 22 September 1791.

"Physics is a wrong tool to describe living systems." Donald Glaser, born 21 September 1926.

"All scientists must communicate their work, for what is the point of learning new things about how the world works if you don't tell anyone about them?" Jim Al-Khalili, born 20 September 1962.

Physics Quote of the Day (September 13 - September 19)

"... conferences with open attendance are very important for the stimulation of young people or other people who are new in the field." Victor Weisskopf, born 19 September 1908.

"Above all, we must be accurate, and it is an obligation which we intend to fulfil scrupulously." Léon Foucault, born 18 September 1819.

"The Earth is the cradle of mind, but one cannot live in a cradle forever." Konstantin Tsiolkovsky, born 17 September 1857.

"Thus the questions (and the quest) go on." George Sudarshan, born 16 September 1931.

"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, born 15 September 1929.

"Our imagination is struck only by what is great; but the lover of natural philosophy should reflect equally on little things." Alexander von Humboldt, born 14 September 1769.

"Science knows no boundaries, and efforts to create barriers – whether to keep new ideas within or to prevent new ones from entering from the outside – have universally proved harmful to progress." Sidney Drell, born 13 September 1926.

Physics Quote of the Day (September 6 - September 12)

"Most probably some law hitherto undiscovered exists." Arthur Schuster, born 12 September 1851.

"There are no surprising facts, only models that are surprised by facts; and if a model is surprised by the facts, it is no credit to that model." Eliezer Yudkowsky, born 11 September 1979.

"The benefits of science are not only material ones. The truths that science teaches are of common interest the world over. The language of science is universal, and is a powerful force in bringing the peoples of the world closer together." Arthur Compton, born 10 September 1892.

"To see worlds in an electron." Hans Dehmelt, born 9 September 1922.

"Those who always take the same paths, usually see the same objects; it is rare that upon following different routes, one won't discover new topics worthy of our most serious attention. Similarly, various attempts give us a greater amount of knowledge. By trying different keys, we can hope to finally find some that open secure paths, short and easy, leading to the wealth of physics." Pierre Polinière, born 8 September 1671.

"Scientific collaborations are akin to marriages, or temporary marriages. Their breakup is not unlike a divorce and rarely avoids acrimony." Peter Freund, born 7 September 1936.

"No longer was light analogous to the discharge of a blunderbuss, but rather to the pulsating flight of birds." Banesh Hoffmann, born 6 September 1906.

Physics Quote of the Day (August 30 - September 5)

"So long as you live and in whatever circumstances the kaleidoscope of life may place you, think for yourself and act in accordance with the conclusions of that thinking; avoid so far as possible drifting with the current of the mob or being too easily influenced by the outward manifestation of things. Take your own look beneath the surface and don't trust others to look for you. If you will follow this rule consistently, I am sure you will keep out of much trouble, will make the most out of your life and, what is more, will contribute most of value to the community life." Frank B. Jewett, born 5 September 1879.

"The progress of science is tremendously disorderly, and the motivations that lead to this progress are tremendously varied, and the reasons why scientists go into science, the personal motivations, are tremendously varied. I have said ... that science is a haven for freaks, that people go into science because they are misfits, and that it is a sheltered place where they can spin their own yarn and have recognition, be tolerated and happy, and have approval for it." Max Delbrück, born 4 September 1906.

"The atom can't be seen, yet its existence can be proved. And it is simple to prove that it can't ever be seen. It has to be studied by indirect evidence – and the technical difficulty has been compared to asking a man who has never seen a piano to describe a piano from the sound it would make falling downstairs in the dark." Carl Anderson, born 3 September 1905.

"Chemistry has been termed by the physicist as the messy part of physics, but that is no reason why the physicists should be permitted to make a mess of chemistry when they invade it. " Frederick Soddy, born 2 September 1877.

"I see a tremendous amount of intricacy in the world and we have probably only begun to scratch at the surface of its intricacy." Roy Glauber, born 1 September 1925.

"... science is the most revolutionary force in the world." George Sarton, born 31 August 1884.

"To see the world for a moment as something rich and strange is the private reward of many a discovery." Edward Mills Purcell, born 30 August 1912.

Physics Quote of the Day (August 23 - August 29)

"You need only a sheet of paper and so mathematics starts." Guido Beck, born 29 August 1903.

"Everything on earth has to function in harmony as a system, and it is only in such a system that humanity can flourish." M.G.K. Menon, born 28 August 1928.

"You have to get a little untrapped from too much prior knowledge." Norman Ramsey, born 27 August 1915.

"... equations that really work in describing nature with the most generality and the greatest simplicity are very elegant and subtle." Edward Witten, born 26 August 1951.

"Whenever I came to him (Fritz Sauter) with a pure physics idea, he would invariably say, with slight sarcasm: "But Mr. Kroemer, you ought to be able to formulate this mathematically! " If I came to him with a math formulation, I would get, in a similar tone: "But Mr. Kroemer, that is just math, what is the physics?" After a few encounters of this kind, you got the idea: You had to be able to go back and forth with ease. Yet, in the last analysis, concepts took priority over formalism, the latter was simply an (indispensable) means to an end." Herbert Kroemer, born 25 August 1928.

"... one of the most detrimental (and least discussed) effects of the crisis in science education in the world today is that we are creating a population increasingly unable to think skeptically about a wide range of issues." Andrew Fraknoi, born 24 August 1948.

"In science, conjecture drives both experiment and theory for it is only by forming conjectures (hypotheses) that we can make the direction of our experiments and theories informed. If such and such is true, then I should be able to do this experiment and look for this particular result or I should be able to find this theoretical formulation. Conversely, experiment and theory drive conjecture. One makes a startling observation or has a sudden insight and begins to speculate on its significance and implications and to draw possible conclusions (conjecture)." Robert Curl, born 23 August 1933.

Physics Quote of the Day (August 16 - August 22)

"Science doesn’t give authentically access to the Real in the ontological meaning of the word, but only to the links between phenomena." Bernard d'Espagnat, born 22 August 1921.

"... very often the laws derived by physicists from a large number of observations are not rigorous, but approximate." Augustin Louis Cauchy, born 21 August 1789.

"... mathematicians progress only by doubt, through humble and constant attempts to impinge on the immense domain of the unknown." Leopold Infeld, born 20 August 1898.

"Mathematical physics represents the purest image that the view of nature may generate in the human mind; this image presents all the character of the product of art;..." Théophile de Donder, born 19 August 1872.

"Acid rain is a short-hand term that covers a set of highly complex and controversial environmental problems. It is a subject in which emotive and political judgements tend to obscure the underlying scientific issues which are fairly easily stated but poorly understood." Basil John Mason, born 18 August 1923.

"... the progress of science still depends on "a few people of vision"." Lewis M. Branscomb, born 17 August 1926.

"For many things we can find substitutes, but there is not now, nor will there ever be, a substitute for creative thought." Crawford Greenewalt, born 16 August 1902.

Physics Quote of the Day (August 9 - August 15)

"It is proper to submit periodically to a very searching examination, principles that we have come to assume without any more discussion." Louis de Broglie, born 15 August 1892.

"The agreement of this law with nature will be better seen by the repetition of experiments than by a long explanation." Hans Christian Ørsted, born 14 August 1777.

"It is very difficult for us, placed as we have been from earliest childhood in a condition of training, to say what would have been our feelings had such training never taken place." George Gabriel Stokes, born 13 August 1819.

"I am very astonished that the scientific picture of the real world around me is deficient. It gives a lot of factual information, puts all our experience in a magnificently consistent order, but it is ghastly silent about all and sundry that is really near to our heart, that really matters to us." Erwin Schrödinger, born 12 August 1887.

"I like teaching and the contact with young minds keeps one on one's toes." Aaron Klug, born 11 August 1926.

"There are many examples in physics showing that higher precision revealed new phenomena, inspired new ideas, or confirmed or dethroned well-established theories." Wolfgang Paul, born 10 August 1913.

"Theoretical chemistry is a peculiar subject. It is based on an equation that can hardly ever be solved." William Fowler, born 9 August 1911.

Physics Quote of the Day (August 2 - August 8)

"It seems clear that the present quantum mechanics is not in its final form." Paul Dirac, born 8 August 1902.

"The laws of classical mechanics represent a mathematical idealization and should not be assumed to correspond to the real laws of nature." Léon Brillouin, born 7 August 1889.

"You must develop one all-important ability—being able to enlist the help of other people. You have to reach a state where others want to help you. This includes giving credit...which will come back to you a hundredfold. Your reputation stems from what people say when you’re not present." Cecil H. Green, born 6 August 1900.

"We need to go back to the discovery, to posing a question, to having a hypothesis and having kids know that they can discover the answers and can peal away a layer." Shirley Jackson, born 5 August 1946.

"... an undercurrent of thought was going on in my mind which gave at last a result, whereof it is not too much to say that I felt at once the importance. An electric circuit seemed to close; and a spark flashed forth the herald (as I foresaw immediately) of many long years to come of definitely directed thought and work by myself, if spared, and, at all events, on the part of others if I should even be allowed to live long enough distinctly to communicate the discovery." William Rowan Hamilton, born 4 August 1805.

"Getting up any cliff is like a physics problem -- you just got to hold on, try everything, and stick with it." Marlan Scully, born 3 August 1939.

"Knowledge once gained casts a light beyond its own immediate boundaries." John Tyndall, born 2 August 1820.

Physics Quote of the Day (July 26 - August 1)

"If there's one thing to do, it's to engage in education." Georges Charpak, born 1 August 1924.

"... the physicist who states a law of nature with the aid of a mathematical formula is abstracting a real feature of a real material world, even if he has to speak of numbers, vectors, tensors, state-functions, or whatever to make the abstraction." Hilary Putnam, born 31 July 1926.

"In our time of ever-increasing specialization, there is a tendency to concern ourselves with relatively narrow scientific problems. The broad foundations of our present-day scientific knowledge and its historical development tend to be forgotten too often. This is an unfortunate trend, not only because our horizon becomes rather limited and our perspective somewhat distorted, but also because there are many valuable lessons to be learned in looking back over the years during which the basic concepts and the fundamental laws of a particular scientific discipline were first formulated." Emil Wolf, born 30 July 1922.

"I think physicists are the Peter Pans of the human race. They never grow up and they keep their curiosity." Isidor Rabi, born 29 July 1898.

"It's a fantastically specialized universe, but how in the world did it happen?" Charles Hard Townes, born 28 July 1915.

"In the hands of Science and indomitable energy, results the most gigantic and absorbing may be wrought out by skilful combinations of acknowledged data and the simplest means." George Airy, born 27 July 1801.

"Scientists need to exchange ideas in an informal place." Ronnie Kosloff, born 26 July 1948.

Physics Quote of the Day (July 19 - July 25)

"Science and everyday life cannot and should not be separated." Rosalind Franklin, born 25 July 1920.

"Individuals with any of a very broad spectrum of intellectual attributes can contribute to science." Roland W. Schmitt, born 24 July 1923.

"Science is competitive, aggressive, demanding. It is also imaginative, inspiring, uplifting." Vera Rubin, born 23 July 1928.

"All our suffering comes from a deficiency to stand up for our beliefs." Heinz Barwich, born 22 July 1911.

"Resolution of conflict, easing of stress must come from the penetration into many groups of wide and common interests which, by a process of dilution, will weaken other groups often artificially maintained." John H. Manley, born 21 July 1907.

"Doing physics is much more enjoyable than just learning it. Maybe 'doing it' is the right way of learning, at least as far as I am concerned." Gerd Binnig, born 20 July 1947.

"Quantum theory was split up into dialects. Different people describe the same experiences in remarkably different languages. This is confusing even to physicists." David Finkelstein, born 19 July 1929.

Physics Quote of the Day (July 12 - July 18)

"Only when they must choose between competing theories do scientists behave like philosophers." Thomas Kuhn, born 18 July 1922.

"Nature always uses the simplest means to accomplish its effects." Pierre Louis Moreau de Maupertuis, born 17 July 1698.

"How quick are we to learn, that is, to imitate what others have done or thought before. And how slow to understand, that is, to see the deeper connections. Slowest of all, however, are we in inventing new connections or even applying old ideas in a new field." Frits Zernike, born 16 July 1888.

"We can start measuring only when we know what to measure: qualitative observation has to precede quantitative measurement, and by making experimental arrangements for quantitative measurements we may even eliminate the possibility of new phenomena appearing." Hendrik Casimir, born 15 July 1922.

"... some general method, capable of being employed in every case, is still wanting." George Green, born 14 July 1793.

"Our words are built on the objects of our experience. They have acquired their effectiveness by adapting themselves to the occurrences of our everyday world. But when we approach realities of another scale, these words can become obstacles." Hubert Reeves, born 13 July 1932.

"In fact, there really is not a new law of nature. It was all in the theory to begin with but nobody worked it out." Willis Lamb, born 12 July 1913.

Physics Quote of the Day (July 5 - July 11)

"I did all the problems a little different from the rest of the class." Samuel Goudsmit, born 11 July 1902.

"The scientific man does not aim at an immediate result." Nikola Tesla, born 10 July 1856.

"There are many modes of thinking about the world around us and our place in it. I like to consider all the angles from which we might gain perspective on our amazing universe and the nature of existence." John Archibald Wheeler, born 9 July 1911.

"Creativity makes life valuable." Igor Tamm, born 8 July 1895.

"If history has a lesson, it is that the "winner take all" attitude deprives one of the pleasures of being the heir to the best of different traditions, even while avoiding their intolerance against each other." László Tisza, born 7 July 1907.

"The standard model longs for the Higgs particle in order to be a sound theory." Jos Engelen, born 6 July 1950.

"If you really want to contribute to our theoretical understanding of physical laws - and it is an exciting experience if you succeed! - there are many things you need to know. First of all, be serious about it!" Gerardus 't Hooft, born 5 July 1946.

Physics Quote of the Day (June 28 - July 4)

"It is almost instinctive in science to accept contrary views, because disagreeing gives you guidance to experimental tests of ideas - your own and those offered by others…." Frederick Seitz, born 4 July 1911.

"As the world rapidly becomes a civilization of machines, the masters of machines will increasingly be the ones in control of the world." John Howard Dellinger, born 3 July 1886.

"You should look at all the experimental information at hand, not only the most relevant, and be prepared to make conjectures if that helps." Hans Bethe, born 2 July 1906.

"One has to do something new in order to see something new." Georg Christoph Lichtenberg, born 1 July 1742.

"Each of us has had his own peculiar training, his own personal contact with the mighty ones of the immediate past; and this forms as it were a telescopic tube determining limits to our field of vision." Cargill Gilston Knott, born 30 June 1856.

"Ever since quantum phenomena became definitely recognized many attempts were made to picture their mechanism." Boris Podolsky, born 29 June 1896.

"Does not any analysis of measurement require concepts more fundamental than measurement?" John Stewart Bell, born 28 June 1928.

Physics Quote of the Day (June 21 - June 27)

"Great physics does not automatically imply complicated mathematics!" Martinus Veltman, born 27 June 1931.

"The life and soul of science is its practical application." William Thomson, Lord Kelvin, born 26 June 1924.

"If they can, in their proposals, write the word nano, the chances for funding increase." Alexei Alexeyevich Abrikosov, born 25 June 1928.

"The experimenter dealing with nature faces an outside and often hard world. Natures' curriculum cannot be changed." Martin Perl, born 24 June 1927.

"If you can’t reduce a difficult engineering problem to just one 8-1/2 x 11-inch sheet of paper, you will probably never understand it." Ralph Brazelton Peck, born 23 June 1912.

"To understand is to marvel." Larkin Kerwin, born 22 June 1924.

"That which can affect our senses in any manner whatever, is termed matter." Siméon Denis Poisson, born 21 June 1781.

Physics Quote of the Day (June 14 - June 20)

"Physics does not ask which is better: the proton or neutron, baryon or lepton, helium or neon, the conductor or insulator. These are simply properties of nature. Rather, physics asks: “Why?”" Isaac Abella, born 20 June 1934.

"To make light of philosophy is to be a true philosopher." Blaise Pascal, born 19 June 1623.

"We certainly don't yet know all the answers. But the universe is about to be pried open." Lisa Randall, born 18 June 1962.

"To stop short in any research that bids fair to widen the gates of knowledge, to recoil from fear of difficulty or adverse criticism, is to bring reproach on science." William Crookes, born 17 June 1832.

"... self-study, in a sense of learning by yourself without anybody teaching you anything, has an enormous value." Robert P. Kraft, born 16 June 1927.

"The main difficulty to popularize quantum physics is that we do not really know how to make images of it in our world. In this sense it is really counterintuitive." Alain Aspect, born 15 June 1947.

"On graduating from the school, a studious young man who would withstand the tedium and monotony of his duties has no choice but to lose himself in some branch of science or literature completely irrelevant to his assignment." Charles de Coulomb, born 14 June 1736.

Physics Quote of the Day (June 7 - June 13)

"The experimental verification of the mathematical results therefore is no evidence for or against the peculiar doctrines of this theory." James Clerk Maxwell, born 13 June 1831.

"In the labs, the young make things move, and the older ones follow like parents evolving with their children." Catherine Bréchignac, born 12 June 1946.

"Each time the discovery of new facts, the reversal or extension of accepted theories, reminded us that science is never finished." Charles Fabry, born 11 June 1867.

"... if the aim of physical theories is to explain experimental laws, theoretical physics is not an autonomous science; it is subordinate to metaphysics." Pierre Duhem, born 10 June 1861.

"In mesoscopic physics, you really need to build up intuition, because it is not the world you know." Carlo Beenakker, born 9 June 1960.

"The Web does not just connect machines, it connects people." Tim Berners-Lee, born 8 June 1955.

"... the more accurate the calculations became, the more the concepts tended to vanish into thin air." Robert S. Mulliken, born 7 June 1896.

Feynman and what comes next...

As you may be aware of, I am a Feynman aficionado:

1. My scientific motto is a (not so famous) quote of Feynman: "All we do is draw little arrows on a piece of paper - that's all!"
2. My Twitter visual profile is dedicated to him.
3. I love viewing videos of his lectures or his interviews.
4. I regularly go across his written works.
5. I've spotted errata in his Physics Lectures, volume III (Quantum mechanics), most of them typo, but some substantial errors.

Curiously, I discovered him relatively late. When I followed quantum mechanics courses at university (somewhere between 1985 and 1989), my courses didn't refer to his lectures. I consider that as a missing. It was only after I took time to dig deeper into the quantum foundations (after 1996) that I came across his works. Reading his works was so enlightening for my comprehension of the fundamental laws of nature, that there are pieces that I could read tens of times and each time I would learn new things. Or better said: approach known things from a new point of view.

Feynman is deservedly one of the most quoted people (at the Selected Pages section of Wikiquote, he figures along with people like Aristotle, Buddha, Confucius, Einstein, Jesus or Shakespeare...). His words are inspiring and often explain physical truths in plain language, comprehensible to the layman. As for all quotes, there is a caveat: they must not be seen as an absolute truth. Or as Feynman stated it himself: Learn from science that you must doubt the experts.

Very early I was skeptic about one of Feynman's most famous quotes: nobody understands quantum mechanics. This is often requoted in a more or less transformed way (for example Dawkins' version: "If you think you understand quantum mechanics, you don't understand quantum mechanics"). Does this quote have a general and definitive value of truth? Or was it just that Feynman didn't know of anyone who could explain quantum mechanics in an understandable common sense way?

Chapter 1 of Feynman's quantum lectures gives some insight in the reasons of his belief that nobody understands quantum mechanics: "We choose to examine a phenomenon which is impossible, absolutely impossible, to explain in any classical way, and which has in it the heart of quantum mechanics." He goes on to describe the double-slit experiment (with electrons), showing that it is impossible to think of waves alone or of bullets alone (such explanations have been taken over by popular media like that given by "Granddaddy of all Quantum Weirdness"). And Feynman concludes with "No one has found any machinery behind the law. No one can explain any more than we have just explained. No one will give you any deeper representation of the situation." These are terrible sentences when repeated to hundreds of thousands, maybe millions of physics students since 1965. They mark a halt for any further investigation of the subject.

Fortunately, there are inventive unconventional physicists. There were already deeper theoretical representations given by physicists like De Broglie or David Bohm, showing how a particle may be directed by a guiding wave and thus yield all the experimental results of the double slit experiment, but this had never been put to proof during their lifetime with an experimental model.

Today, I think I can safely say that the quote "nobody understands quantum mechanics" is experimentally outdated. Couder and Fort, two French physicists, experimented with bouncing droplets on a liquid subtract and discovered that they exhibited quantum behaviour, without looking for any quantum analogy:

• droplet travelling in its wave,
• diffraction and interference patterns of travelling droplets similar to photon and electron diffraction patterns,
• attraction and repulsion of droplets embedded in their waves,
• symmetric and anti-symmetric orbital motion of droplets.

Visuals presented by Couder are breathtaking. Even if you don't understand french, I highly recommend watching bouncing droplets orbiting around each other (for example at 25:35 of his 2006 presentation).

An upcoming paper of Couder's group in Physical Review Letters even suggests a quantum tunneling analogy with ordinary droplets: "Unpredictable tunneling of a classical wave-particle association", by A. Eddi, E. Fort, F. Moisy, and Y. Couder.

So today, Feynman's defeatist words about nobody understanding quantum mechanics are outdated. Please, experimental physicists, go ahead, be inventive and focus on experiments where ordinary macroscopic individual particles simulate quantum behaviour, polarization, bosonic and fermionic behaviour, inward bound forces, entanglement, quantum erasure, coupling of ordinary particles to their pilot-wave fields (gravitation, electromagnetism). Because all these quantum phenomena may be rationally understood with the help of experimental models. It's just a matter of inventivity. And we "will find someday that, after all, it isn't as horrible as it looks." ~ Feynman's Epilogue to his Lectures on Physics.