Physics is people's knowledge of the transformation of matter in life and natureRegularitySummary of.There should be two kinds of movement and transformation.One is the extension of early people's sense and vision, and the other is the extension of modern people's sense and visionInventionScientific instruments for observation and measurement, and the results of experiments.
Physics fromResearch angleDifferent views can be divided into micro and macro. Macro is to consider the overall effect directly without analyzing the single effect in the particle swarm, which has appeared in the earliest stage,MicrophysicsWith the development of technologyDevelopment theoryGradually improve.Secondly, physics is also a kind of intelligence.
just asThe nobel prize in physicsThe winner and German scientist Bohn said: "It is not so much because my published work contains anatural phenomenaIt is more because there is a natural phenomenonScientific thinkingMethodological basis. "The reason why physics is recognized as an important science is not only that it is important toobjective worldThe profound revelation of the law of the Chinese Academy of Sciences is also because it has formed a set of unique and effective ideological and methodological systems in the process of development and growth.Because of this, physics has becomeHuman intelligenceThe crystallization of civilization.
A large number of facts show that physical ideas and methods are not only valuable for physics itself, but also for the whole natural science, and evensocial sciencesHas made important contributions to its development.According to statistics, since the middle of the 20th centuryNobel Prize in ChemistryMore than half of the winners of biology and medicine awards, even economics awards, have backgrounds in physics——This means that they have learned wisdom from physics and succeeded in non physical fields.
For physics theory and experiment,physical quantityIt is consistent with the experimental law to define and measure the hypothesis selection, the mathematical development of theory, and the comparison between theory and experiment, which are the only goals of physical theory.
People can solve problems through such a combination, that is, prophecy guides scientific practice, which is not bigMaterialismThought is actually the purpose and structure of physical theory.
On the basis of constantly reflecting on the objective principle of non empiricism generated by metaphysics, physical theory can be judged by its own scientific terms.Instead of relying on their claims that they may belong to the philosophical school.At the beginning of the descriptionphysical propertyThe simple nature is selected in, and other properties are the imagination and combination of clustering.Through appropriatemeasuring methodAnd mathematical skills to further understand the original nature of things.The number of experiments selected has some corresponding relationship.One relationship can have many experiments corresponding to it, but one experiment cannot correspond to multiple relationships.In other words, a rule can be reflected in multiple experiments, but multiple experiments may not reflect only one rule.
For physics, the only truth is whether theoretical predictions are consistent with realityJudgment criteria。
Abstract: This paper reviews the history of physics development and discusses the direction of physics development in the 21st century.Maybe we should explore modernity from two aspectsPhysics revolutionOfBreakthrough: (1) Finding other forces than the four known forces in the objective world;(2) Pass the examinationrelativityandquantum mechanicsThe imperfection of the theoretical basis, redefining time and space, and establishing new theories.
The twentieth century is coming to an end, and the twenty-first century is coming to an endsocial developmentThe fastest century is the century with the fastest development of science and technology, and also the century with the fastest development of physics.In the past 100 years, a revolution in physics has taken place, with the establishment of relative properties and quantum mechanicsClassical physicsTo modern physics.After the 1920s and 1930s, modern physics has further developed vigorously in depth and breadth, resulting in a series of new disciplinesInterdisciplinary、Marginal discipline, humanMaterial worldWith a deeper understanding of the laws of physics, the theory of physics has reached a new height, and modern physics has reached a mature stage.
At the turn of this century, people naturally want to look forward to the development prospect of physics in the 21st century and explore the direction of future physics development.I'd like to talk about some of my views on this issue.First of all, let's review the development of physics at the turn of the last centuryCompareIt is very helpful to explore the development direction of physics in the 21st century.
1、 Historical review
At the end of the 19th century and the beginning of the 20th century,Classical physicsAll branches ofthermodynamicsandstatistical mechanicsEstablishment andmaxwellElectromagnetic field theoryClassical physics reached its peak with the establishment ofPhysical WorldA clear and complete picture that can almost perfectly explain all the observedphysical phenomenon。Due to the great achievements of classical physics, many physicists at that time came up with the idea that the building of physics has been built, the development of physics has basically been completed, and people's interpretation of the physical world has reached the end.Some basic and principled problems in physics have been solved, and what remains is the problem of further precision, that is, to make some additions and corrections in some details, so that the constants in the known formula can be measured more accurately.
However, at the end of the 19th century and the beginning of the 20th century, when physicists were celebrating the completion of the physics building, scientific experiments found manyClassical physicsUnexplainable facts.The first is the three major discoveries of physics at the turn of the century: electronX-rayandRadioactive phenomenonDiscovery of.Secondly, two "dark clouds" appeared in the clear sky of classical physics: the "zero result" andBlackbody radiationOf“Ultraviolet disaster”。These experimental results are related to the basic concepts of classical physics andfundamental theoryThere are sharp contradictions in classical physicstraditional ideasUnder the impact, classical physics has a "crisis".This led to a revolution in physics.Planck is inGerman Physical SocietyThe report on the results became the beginning of the revolution.[1]EinsteinEstablishing the theory of relativity;Heisenberg, Schrodinger and a group of other scientists founded quantum mechanics.Modern physics was born.
Comparing the current situation of physics development with that at the turn of the last century, we can see that there are similarities as well as differences between the two.
After the establishment of relativity and quantum mechanics, modern physics has reached a mature stage after more than 70 years of development.String theoryThe development of the view of material progress.The bricks that make up the material worldElementary particleBothCosmic stringVarious notes on the.[2]It is constantly producing and annihilating.[2]The diverse material world has becomeAll things are done according to the law, like a dream,Like dew or electricity, we should act accordingly.Physics steps intoCausal emptinessZen state.[2]So that human beings have an unprecedented understanding of the laws of the material world, and theories can explain everything knownphysical phenomenon。The edifice of modern physics has been built.In this regard, the current situation is very similar to that at the turn of the last century.Therefore, a few physicists believe that there will be no revolutionary progress in physics in the future. The fundamental problems and principles of physics have been solved. What they can do in the future is to develop modern physics in depth and breadth on the basis of existing theories, and make some supplements and amendments to existing theories.However, due to the historical experience of a hundred years ago, most physicists do not agree with this view. They believe that physics will have a breakthrough sooner or later.On the other hand, althoughMicrocosmandcosmologyThere are some physical phenomena in the field that cannot be explained by modern physics theories, but these contradictions are not so serious that it is necessary to completely reform the existing theories.In this regard,Classical physicsA "serious crisis" occurs;At the turn of this century, there is no "crisis" in modern physics.Therefore, modernPhysics revolutionThe conditions are not yet ripe.
The objective material world is hierarchical.Generally speaking, the system in each level is composed of a large number of small systems (belonging to the next level).In a sense, macro and micro are relative, and the macro system consists of a large number ofMicrosystemComposition.The material world is divided into many levels from micro to macro.The purpose of physics research includes: to explore the laws of motion at all levels and to explore the links between all levels.
Looking back at the development of physics in the twentieth century, we can see that it has progressed in three directions.In the 21st century, physics will continue to develop in these three directions.
(1) In the micro direction, Newton createdclassical mechanicsThe limitations of.In this direction, people have learnedNucleusFound a large number of basic particles and their operation rules, and establishedNuclear physicsandParticle physics, recognizing thathadronIs created byquarkConstitutive.There may be new progress in the future.But if we want to explore deeper phenomena, we must have much more powerful accelerators, which is a very difficult task. So I think it is difficult to make breakthroughs in this direction.
(2) Expand in the macro direction.1948 AmericanGamovThe theory of "Big Bang" was put forward, which did not attract attention at that time.In 1965, Penzias and Wilson of the United States observed the universeBackground radiationIn addition to other observation results, it provided strong evidence for the "Big Bang" theory. Since then, the "Big Bang" theory has been widely supportedKatsuhiko SatoAnd Gus of the United Statesinflationary theory 。After the 1980s, the BritishHawking[2,3] et al. began to discuss the creation of the universe, thinking that the universe was born from "nothing" and will continue to develop in this direction in the future.Basically,modern cosmology The continued development of the human race depends on the new results of observation farther away from the vast universe, which requires human beings to produce more thanhubble space telescope Space with much superior performance and various bandsAstronomical telescopeThis is a very difficult task.
The creation theory of the universe believes that the "Big Bang" theory is only an approximate description of the universe.becausecosmologyWhat we study is only the "universe" within the range that people can observe. The universe is infinite. There are countless "universes" outside our "universe". These universes are not unrelated and isolated, but affect and work with each other.Modern cosmology only studies our "universe" and only gets approximate results. If it extends their research to the beginning of the creation of the "universe" and the distant future, it will make more mistakes.
(3) Deeply explore the links between all levels.
This isStatistical PhysicsThe main contents of the study.In the 20th century, great achievements have been made in this field. First, non-equilibrium statistical physics has made great progress, and then“dissipationStructure "theorysynergeticsandCatastrophe theoryThen chaos theory and fractal theory developed one after another.Include these sub disciplinesnonlinear science Category of.It is believed that the development of nonlinear science has broad prospects in the 21st century.
The above development of physics is still within the framework of the existing basic theories of modern physics.How should the basic theories of physics develop in the next century?Some physicists are pursuing“Superunified theory”。In this respect, Einstein, Heisenberg and other scientists made great efforts to explore“Unified field theory”；Until 1967 and 1968WeinbergandPakistanOfSalamPropose unificationElectromagnetic forceandweak force"Weak electricity theory";At present, some physicists are exploring how to add strong“Grand unified theory”And plus the "super unified theory" that gravity unifies the four forces, whether their exploration can succeed is still uncertain.
EinsteinThe original exploration of "unified field theory" was based on his idea of "the unity of the physical world" [4], but he tried to explore for 30 years, and finally failed.according toDialectical materialismThe basic principle of "the material world is both unified and diversified".Let's not talk about pursuit“Superunified theory”Even if this theory is completed, it is not the end of the development of physics.Because "in the absolute overall development process of the universe, the development of each specific process is relativeAbsolute truthIn the long river ofDevelopment stageThe cognition of the concrete process of the theory only has relative truth.The sum of innumerable relative truths is absolute truth. ""People's understanding of truth in practice will never end."
How will the revolution of modern physics take place?There are two aspects worth retrying:
(1) There are not only four forces in the objective world.The fifth, sixth... where is the power?People don't know.First discovered in the futureThe fifth forceMay exist inLife phenomenonMedium.After the material forms the life body, its movement and change are really mysterious, and there are many problems that people do not knowlife sciencesUnderstanding ofAristotlePeople of the times have the same understanding of physics, so it is possible to make breakthroughs in this field.The intersection of physics and life science is a direction of the development of physics in the 21st century, which is related to the study of complexitynonlinear science Development of.
(2) Modern physics theory is justRelative truth, not absolute truth.The breakthrough of the modern physics revolution should be explored by reviewing the imperfection of the theoretical basis of modern physics. My views will be introduced in the next section.
3、 Is the theoretical basis of modern physics perfect?
Relativity and quantum mechanics are the two pillars of modern physics. Is the theoretical basis of these two pillars perfect
What about?People should think about this problem.
(1) Reflection on the Theory of Relativity
That yearEinsteinIt started from thinking about the speed of light and the essentials of timeSpecial relativity。Today, people should start from rethinking the concept of time and space to explore the breakthrough of modern physics revolution.Einstein founded the special theory of relativity from the lectureInertial frameOf two "events" at different locations inSimultaneityAt first, he stipulated to use light signals to correct two clocks at different locations to define "simultaneous", so that it can be naturally derivedLorentz transformation, resulting in aFour-dimensional space-time(x, y, z, ict) (c is the speed of light).Why did Einstein propose to use light signals to correct the clock instead of other signals?He did not explain this problem in his paper, which actually has profound implications.
Time and space areMaterial movementWe cannot talk about time and space without the physical mass movement. When we define space-time, we should explain what kind of movement space-time is.Modern physics believes thatAction at a distanceIt does not exist. The "event" at A affects the "event" at B and must be transmitted through a certain field. The transmission requires a certain time. The definition of time and space is closely related to this transmission speed.If this field iselectromagnetic field, thenElectromagnetic interactionThe speed of transmission is the speed of light.Therefore,EinsteinThe space-time defined is actually about the space-time of material movement caused by electromagnetic interaction, which is suitable for describing such movement.
Einstein applied his definition of time to all material movements, which in fact implied the following assumption:Gravitational interactionBut does gravitational interaction also travel at the speed of light?Let the transmission speed of gravitational interaction be c '.So far, no experimental facts have proved that c 'is equal to c.Einstein actually assumed c=c 'because of his world view of "the unity of the material world".I hold the view that "the material world is both unified and diversified"Electromagnetic forceAnd the strength of gravityOrder of magnitudeThere is too much difference between the two, so I believe that c 'may not be equal to c.Working sample, relating to the movement of matter caused by electromagnetic forceFour-dimensional space-time(x, y, z, ict) and spacetime (x ', y', z ', ic't') about the motion caused by gravity are different.If only one kind of interaction is involved in the researchEquation of motionThe form of is unchanged.For example,Einstein's gravitational field equationThe form of C is unchanged, just change the constant c to c '.If the problem studied involves two kinds of interactions, new theories need to be established.However, the first thing is to judge whether c 'and c are equal by experimental facts;If not, the value of c 'needs to be derived.
I began to form the above view more than 20 years ago. At that time, the measurement of gravitational waves was a hot spot of public attentionGreat expectations We hope that we can deduce whether c 'is equal to c from the experimental results.Regrettably, after long-term effortsGravitational waveThe experiment did not get a positive result, and then the work cooled down.The gravitational wave predicted according to Einstein's theory is weak. If the measurement sensitivity andAccuracyIf such weak gravitational waves should be detectable, the lack of positive results from long-term experiments seems to indicate the shortcomings of Einstein's theory.The problem should be considered from the perspective that c 'may not be equal to c. If there is a large difference between c' and c, it is possible to derive a result that the strength of gravitational waves is much weaker than that predicted according to Einstein's theory.
weak force, strength and gravityElectromagnetic forceThere are essential differences. The first two areShort-range force, the latter two areLong range force。Different interactions are realized by transmitting different media particles.Gravitational interactionThe sender of isGraviton；Electromagnetic interactionThe transmitter of is photon;The transmitter of weak interaction isGauge particle(except photons);The transmitter of strong interaction ismeson。Graviton and photonStatic massIs zero, according toEinsteinThe transmission speed of gravitational interaction and electromagnetic interaction is the speed of light.And the static state of the transfer particlesMass and energyTherefore, the transmission speed is varied.
In the study ofMaterial movementWhen defining the "simultaneity" of two "events" at different locations in the inertial system, should weak force or strong signal replace light signal?I am rightNuclear physicsandParticle physicsI'm a layman and don't want to rushAnswer this question。If you should useweak forceOr the strong signal replaces the light signal, so about the time and space of the movement of matter caused by the weak force or strong force andElectromagnetic forceSpace time of the motion caused by gravity (x, y, z, ict) and space time of the motion caused by gravity (x ',y’，z’，ic’t’）
There is a big difference.If the transmission speed of weak or strong interaction is c '', and c '' is not constant, but variable, then the space-time of motion caused by weak or strong interaction is (x '',y’’，z’’，Ic’’t’’），Time t '' and space (x '', y '', z '') will be functions of c '.However, it is likely that the problem should be considered in this way: for the space-time of motion caused by weak forces, the definition should be based onGauge particleThe speed of light c is replaced by the speed c1 when the static mass of is taken as zero.Because the "electric weak theory" combines weak forces withElectromagnetic forceIt is unified, so it is possible that c1=c, then the space-time of the motion caused by weak force and the space-time of the motion caused by electromagnetic force are the same (x, y, z, ict). The space-time of the motion caused by strong force should be defined asmesonThe speed c '' replaces the speed of light c, and c '' may not be equal to c.Then the space-time (x '', y '', z '', Ic ''t' ') of the motion caused by force is different from (x, y, z, ict) or (x',y’，z’，ic’t’）。No matter which of the above two considerations is correct, the space-time of the entire material world will be higher thanfour-dimensionalOfMultidimensional space-time。For aShort-range force(or just by force)Material movementIf space-time has a new meaning, it needs to establish new theories, that is to say, it needs to establish newQuantum field theory, newNuclear physicsAnd newParticle physicsEtc.If the research problem is clear andLong range forceIt also involves short-range force (especially strong force), so it is more necessary to establish a new theory.
(1) Reflection on Quantum Mechanics
From quantum mechanics to quantum field theory“Divergence difficulty”[6]。From 1946 to 1949, Japan'sChaoyong ZhenichiroFeynman andSchwengerThe "renormalization" method is proposed to overcome the "divergence difficulty".However, the theory of "reorganization" still has logical defects and has not completely overcome this difficulty.One of the basic reasons for "difficultly diverging" is that the "intrinsic" energy (static energy) of particles is calculated together with the motion energy and interaction energyDe Broglie waveAnisotropy when ν=0.
I am in a dilemma: if we adopt the traditionalDe Broglie relationship, we have to accept the unreasonable de Broglie Pochi;If we adopt the revised de Broglie relation, we must face the problem of making the new theory meet the theory of relativityCovariantThe problem of.Is there any other way to solve the problem?I think this problem may also be related to the definition of time and space.The definition of "Time Wide Man" in quantum mechanics theory is still essentiallydeterminismAndUncertainty principleIt is a basic law of the micro world, so time and space are not strictly determined, and the space-time essentials of determinism are no longer applicable.When the time or space interval is very small, the "before" and "after" concepts describing the order of events will lose their meaning.In addition, relevantMaterial movementCategory of.fuzzy mathematicsIt has developed quite maturelyMathematical toolsIt may be worth trying to use the definition of space and time in the micro world.
