Classical Physics Quotes & Sayings

The law of right-left symmetry was used in classical physics but was not of any great practical importance there. One reason for this derives from the fact that right-left symmetry is a discrete symmetry, unlike rotational symmetry, which is continuous. — Chen-Ning Yang

The brain does not own any direct copies of stuff in the world. There is no library of forms and ideas against which to compare the images of perception. Information is stored in a plastic way, allowing fantastic juxtapositions and leaps of imagination. Some chaos exists out there, and the brain seems to have more flexibility than classical physics in finding the order in it. — James Gleick

What really matters for me is ... the more active role of the observer in quantum physics ... According to quantum physics the observer has indeed a new relation to the physical events around him in comparison with the classical observer, who is merely a spectator. — Wolfgang Pauli

Scientific realism in classical (i.e. pre-quantum) physics has remained compatible with the naive realism of everyday thinking on the whole; whereas it has proven impossible to find any consistent way to visualize the world underlying quantum theory in terms of our pictures in the everyday world. The general conclusion is that in quantum theory naive realism, although necessary at the level of observations, fails at the microscopic level. — Ravi Gomatam

Modern physics has changed nothing in the great classical disciplines of, for instance, mechanics, optics, and heat. Only the conception of hitherto unexplored regions, formed prematurely from a knowledge of only certain parts of the world, has undergone a decisive transformation. This conception, however, is always decisive for the future course of research. — Werner Heisenberg

Certainly we do not need quantum mechanics for macroscopic objects, which are well described by classical physics - this is the reason why quantum mechanics seems so foreign to our everyday existence. — Alain Aspect

The physicist is familiar with the fact that the classical laws of physics are modified by quantum theory, especially at low temperature. There are many instances of this. Life seems to be one of them, a particularly striking one. Life seems to be orderly and lawful behaviour of matter, not based exclusively on its tendency to go over from order to disorder, but based partly on existing order that is kept up. — Erwin Schrodinger

Suppose we had some kind of device with particles moving with a certain definite symmetry, and suppose their movements were bilaterally symmetrical (fig. 20). Then, following the laws of physics, with all the movements and collisions, you could expect, and rightly, that if you look at the same picture later on it will still be bilaterally symmetrical. So there is a kind of conservation, the conservation of the symmetry character. This should be in the table, but it is not like a number that you measure, and we will discuss it in much more detail in the next lecture. The reason this is not very interesting in classical physics is because the times when there are such nicely symmetrical initial conditions are very rare, and it is therefore a not very important or practical conservation law. But — Richard Feynman

The only difference between causation and the value is that the word "cause" implies absolute certainty whereas the implied meaning of "value" is one of preference. In classical science it was supposed that the world always works in terms of absolute certainty and that "cause" is the more appropriate word to describe it. But in modern quantum physics all that is changed. Particles "prefer" to do what they do. An individual particle is not absolutely committed to one predictable behavior. What appears to be an absolute cause is just a very consistent pattern of preferences. — Robert M. Pirsig

Classical physics has been superseded by quantum theory: quantum theory is verified by experiments. Experiments must be described in terms of classical physics. — Carl Friedrich Von Weizsacker

Perhaps the main basis for the claim that quantum mechanics is weird is the existence of what Einstein called 'spooky action at a distance'. These effects are not only 'spooky' but are also absolutely impossible to achieve within the framework of classical physics. However, if the conception of the physical world is changed from one made out of tiny rock-like entities to a holistic global informational structure that represents tendencies to real events to occur, and in which the choice of which potentiality will be actualized in various places is in the hands of human agents, there is no spookiness about the occurring transfers of information. The postulated global informational structure called the quantum state of the universe is the 'spook' that does the job. But it does so in a completely specified and understandable way, and this renders it basically non-spooky. — Paul Davies

Turbulence is the most important unsolved problem of classical physics. — Richard P. Feynman

O. Hahn and F. Strassmann have discovered a new type of nuclear reaction, the splitting into two smaller nuclei of the nuclei of uranium and thorium under neutron bombardment. Thus they demonstrated the production of nuclei of barium, lanthanum, strontium, yttrium, and, more recently, of xenon and caesium. It can be shown by simple considerations that this type of nuclear reaction may be described in an essentially classical way like the fission of a liquid drop, and that the fission products must fly apart with kinetic energies of the order of hundred million electron-volts each. — Lise Meitner

The advantage of a quantum walk over a classical random walk can be appreciated by returning to our slow-moving drunk and imagining that the bar he leaves has sprung a leak and that water is pouring out of its door. — Jim Al-Khalili

The landed classes neglected technical education, taking refuge in classical studies; as late as 1930, for example, long after Ernest Rutherford at Cambridge had discovered the atomic nucleus and begun transmuting elements, the physics laboratory at Oxford had not been wired for electricity. Intellectual neglect technical education to this day.
[Describing C.P. Snow's observations on the neglect of technical education.] — Richard Rhodes

Dictionaries, manuals, grammars, study guides and topic notes, classical authors and the entire book trade in de Viris, Quintus-Curtius, Sallust, and Livy peacefully crumbled to dust on the shelves of the old Hachette publishing house; but introductions to mathematics, textbooks on civil engineering, mechanics, physics, chemistry, astronomy, courses in commerce, finance, industrial arts- whatever concerned the market tendencies of the day - sold by the millions of copies. — Jules Verne

A universe of classical particles is devoid of knowledge because the universe can only be itself and not a representation of something else. If the universe was only composed of classical particles, then there would only be physical properties but no meanings. The idea that we can have information about an object without becoming that object is central to all knowledge. — Ashish Dalela

Descartes, in his Third Meditation, said that God re-created the body at each successive moment. So that time was a form of sustenance. On earth time was marked by the sun and moon, by rotations that distinguished day from night, that had led to clocks and calendars. The present was a speck that kept blinking, brightening and diminishing, something neither alive nor dead. How long did it last? One second? Less? It was always in flux; in the time it took to consider it, it slipped away. In one of her notebooks from Calcutta were jottings in Udayan's hand, on the laws of classical physics. Newton's theory that time was an absolute entity, a stream flowing at a uniform rate of its own accord. Einstein's contribution, that time and space were intertwined. He'd described it in terms of particles, velocities. A system of relations among instantaneous events. Something called time — Jhumpa Lahiri

Thus it can be argued that quantum theory provides an opening for an idea of nature and of our role within it that is in general accord with certain religious concepts, but that, by contrast, is quite incompatible with the precepts of mechanistic deterministic classical physics. Thus the replacement of classical mechanics by quantum mechanics opens the door to religious possibilities that formerly were rationally excluded. — Paul Davies

Einstein does not remain attached to the classical principles, and when presented with a problem in physics he quickly envisages all of its possibilities. This leads immediately in his mind to the prediction of new phenomena which may one day be verified by experiment. — Henri Poincare

[About describing atomic models in the language of classical physics:]
We must be clear that when it comes to atoms, language can be used only as in poetry. The poet, too, is not nearly so concerned with describing facts as with creating images and establishing mental connections. — Niels Bohr

A consistent pursuit of classical physics forces a transformation in the very heart of that physics. — Werner Heisenberg

Given that the 'common sense' of many contemporary philosophers is shaped and supplemented by ideas from classical physics, the locus of most metaphysical discussions is an image of the world that sits unhappily between the manifest image and an out of date scientific image.11 — James Ladyman

We the undersigned, intend to establish an instruction and training institution which differs from the common elementary schools principally in that it will embrace, outside of (in addition to) the general and elementary curriculum, all branches of the classical high school, which are necessary for a true Christian and scientific education, such as: Religion, the Latin, Greek, Hebrew, German, French and English languages; History, Geography, Mathematics, Physics, natural history, Introduction to Philosophy, Music, and Drawing. — C.F.W. Walther

The deepest human intuition is not the immediate grasping of the classical-physics-type character of the external world. It is rather that one's own conscious subjective efforts can influence the experiences that follow. Any conception of nature that makes this deep intuition an illusion is counterintuitive. Any conception of reality that cannot explain how our conscious efforts influence our bodily actions is problematic. What is actually deeply intuitive is the continually reconfirmed fact that our conscious efforts can influence certain kinds of experiential feedback. A putatively rational scientific theory needs at the very least to explain this connection in a rational way to be in line with intuition. — Paul Davies

We live today in a world where most of the really important developments in everything from math and physics and astronomy to public policy and psychology and classical music are so extremely abstract and technically complex and context-dependent that it's next to impossible for the ordinary citizen to feel that they (the developments) have much relevance to her actual life. — David Foster Wallace

Quantum physics is one of the hardest things to understand intuitively, because essentially the whole point is that our classical picture is wrong. — Neil Turok

...quantum problems unseat many classical ideas about matter, causality, and change that biologists use, and that disruption in turn entails radical revisions to the ideas about the mechanism in evolution, in ways we don't yet acknowledge. — Ashish Dalela

In case you haven't noticed, they're moving a lot faster. I don't know about the laws of physics on your planet, but where I come from an object moving at subclass speed can't catch up to one running at starclass. But if you know something about turbines, thrusters and engines, quantum or classical physics that I've somehow missed, then please enlighten me.
- Caillen Dagan to Desideria Denarii — Sherrilyn Kenyon

As Sommerfeld said in his famous text "Spectral Lines and Atomic Constitution," on which a generation of physicists learned the subject, "In the fine structure constant e is the representative of the electron theory, h the appropriate representative of the quantum theory, c comes from relativity and characterizes it in contrast to classical theory. — Emilio Segre

The bridge between the electron and the other elementary particles is provided by the fine structure constant, a ~ 1/137, as manifested in the factor-of-137 spacings between the classical electron radius, electron Compton radius, and Bohr orbit radius. ... An a-quantized mass-generation grid extends accurately from the electron all the way to the top quark t, and leads to a corresponding a-quantized particle lifetime grid. — Malcolm H. Mac Gregor

In microphysics the observer interferes with the experiment in a way that can't be measured and that therefore can't be eliminated. No natural laws can be formulated, saying "such-and-such will happen in every case." All the microphysicist can say is "such-and-such is, according to statistical probability, likely to happen." This naturally represents a tremendous problem for our classical physical thinking. It requires a consideration, in a scientific experiment, of the mental outlook of the participant-observer: It could this be said that scientists can no longer hope to describe any aspects or qualities of outer objects in a completely independent, "objective" manner. — M.L. Von Franz

Perhaps the most energetic and persistent advocate of the claim that time is illusory is the British physicist Julian Barbour. Impressively, Barbour has managed to do interesting research in physics for decades now without any academic position, publishing dozens of papers in respected journals. He has supported himself in part by translating technical papers from Russian to English - in his spare time, tirelessly investigating the idea that time does not exist, constructing theoretical models of classical and quantum gravity in which time plays no fundamental role. — Anonymous

PROCESS PHILOSOPHY, a school greatly influenced by Alfred North Whitehead, holds that mind and brain are manifestations of a single reality, one that is in constant flux. It thus is compatible with classical Buddhist philosophy, which views clear and penetrating awareness of change and impermanence (anicca in Pali) as the essence of insight. Thus, as Whitehead put it, "The reality is the process," and it is a process made up of vital transient "drops of experience, complex, and interdependent." This view is strikingly consistent with recent developments in quantum physics. — Jeffrey M. Schwartz

A common refrain among theoretical physicists is that the fields of quantum field theory are the "real" entities while the particles they represent are images like the shadows in Plato's cave. As one who did experimental particle physics for forty years before retiring in 2000, I say, "Wait a minute!" No one has ever measured a quantum field, or even a classical electric, magnetic, or gravitational field. No one has ever measured a wavicle, the term used to describe the so-called wavelike properties of a particle. You always measure localized particles. The interference patterns you observe in sending light through slits are not seen in the measurements of individual photons, just in the statistical distributions of an ensemble of many photons. To me, it is the particle that comes closest to reality. But then, I cannot prove it is real either. — Victor J. Stenger

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