评《观测与相对论》

《北京工业大学学报》本期"学术争鸣"栏目中的《观测与相对论:光速在爱因斯坦狭义相对论中为什么不变?》(以下简称《观测与相对论》),试图否定光速不变性原理,挑战爱因斯坦相对论!爱因斯坦是人类历史上最伟大的科学家。在物理学界,爱因斯犹如上帝一般地存在,而爱因斯坦相对论则犹如圣经一般。

From De Sitter Special Relativity and Snyder's Model to Complete Yang Model

The de Sitter special relativity on the Beltrami-de Sitter-spacetime and Snyder＇s model in the momentum space can be combined together with an IR-UV duality to get the complete Yang model at both classical and quantum levels, which are related by the proposed Killing quantization. It is actually a special relativity based on the principle of relativity of three universal constants （c, ρp, R）.

Special Theory of Relativity and the Intrinsicality of Spacetime Shape

In objection to one of Yuri Balashov＇s defenses of perdurantism, Matthew Davidson claims that, according to the special theory of relativity, both 3-dimensional and 4-dimensional shapes are nonintrinsic, i.e., they are relative to reference frames. The author argues that 3-dimensional and 4-dimensional spatial shapes are indeed nonintrinsic, but shapes in 3-dimensional and 4-dimensional spacetime are intrinsic according to the special theory of relativity. This follows from the special relativity theory＇s claim that spacetime intervals or distances in any n-dimensional spacetime are invariant, unlike spatial distances.

Matter （Pudgalastikaya or Pudgala） in Jain Philosophy

Pudgalastikaya is one of the six constituent dravyas of loka in Jainism and is the only substance that is sense perceptible. The sense attributes ofpudgala are colour, taste, smell, and touch properties which become the basis of its diversity of forms and structures. The smallest constituent of pudgala is paramanu; the other forms are its combinations. The combination ofparmanus forms various states of the matter. The paper describes different types of combinations and modes, rules for combinations and properties of aggregates known as vargana. Some varganas associate with the soul and form various types of bodies of organisms and others exist as forms of matter in loka （universe）. The paramanu defines the smallest units of energy, space, time, and sense quality ofpudgala. Pudgala exists in visible and invisible forms but anything that is visible is definitely pudgala. Pudgala is classified in various ways; one of them is on the basis of touch property and there are pudgalas having two touches, four touches, and eight touches, each class having some specific character that differentiates them in respect of stability and motion. Pudgala is also classified as living, prayoga-parinat, and non-living, visrasa-parinat. The living matter existing as bodies of organisms exhibits some properties that are not found in non-living matter. Modem science has no such distinction which has become a cause of confusion in recognizing the existence of soul. The description of body remains incomplete without considering the presence of soul in the body. In modem terms, aparamanu is a vibrating and moving charge that is bosonic in character. The two-touch and four-touch pudgala do not appear to follow the speed limits prescribed by Special Theory of Relativity. Jain canonical works describe two types of motions sparshad type and asparshad type and these determine the motions of different class ofpudgala and soul. Jain philosophy describes the dynamics and motion ofparmanu in detail. The paper describes the Jain concepts of matter in detail and compares with the modem concepts to highlight the strength of Jain views. Modem science has explored the properties and behavior of matter in great detail but still there are many concepts that Jain philosophy has to offer.

An Historical Inquiry on Geometry in Relativity： Reflections on Early Relationship Geometry-Physics （Part Two）

In order to present an historical discussion on spherical geometry in relativity between the 19th-20th centuries, the current research divided into two parts-papers is presented. Part I： Reflections on geometry-physics relationship is an excursus focusing on the role played by geometry in history and its relationship with physics. Part II： Reflections on Late Relationship Geometry-Physics is an epistemological investigation on the history of the foundations of geometry in special relativity focusing in S4（0, x, y, z, O. In this sense, the two parts are complementary. By considering the large literature, we decided to present the main and basic accredited references, maybe useful for very young scholars, as well.

The Influence of Particle Interactions on the Existence of Quantum Particles Properties

We propose a novel model, based on two postulates, which provide new perspective on the fundamental forces using special and general relativity concepts. Many studies address the relations between the particles and the space time manifold, and the latter＇s physical structure, whether it is Continuous or Discrete. In the proposed model the properties of the particles are classical in the sense of general relativity, whereas their quantum properties are arises due to the experiments.

Foundation of Graduate Study in Mechanical EngineeringmAdvanced Dynamics

Dynamics is the foundation of undergraduate study in mechanical engineering. If you are good in dynamics, you will be good on all other courses. Advanced dynamics is the foundation for graduate study. The author taught advanced dynamics for more than ten years, this is the author＇s observation. Why it is so？ Because the course of advanced dynamics covers usually many mathematical fundamentals such as vectors, tensors, matrices and rotation operators; principles and applications in dynamics from particle dynamics to rigid body motion, from small oscillation to vibration of systems with multiple degrees of freedom, the author＇s course covers also special relativity theory. They are very innovative. And they set the foundation for the study of all the graduate courses. Science is always in progress, dynamics is in the same form. Just say a few examples to illustrate the frontier of dynamics： missile shooting missile is important in our defense, the author covered this as an example in particle dynamics. Space ship travels from Earth to Mars is another example. Several rotational motions with different axes can be combined to one through the use of rotation operator. This is important because it usually can save time. All these examples will be included in this paper in some details.

雾都孤儿

我相信,灾难在人类中间激发出一种难以名状的力量,且将整个种族凝聚到了一起,以一种惊人一致的步调和坚不可摧的精神力量直面灾难。然而我很怀疑,宇宙是否在乎这一切。

Delta Shocks and Vacuum States in Vanishing Pressure Limits of Solutions to the Relativistic Euler Equations

The Riemann problems for the Euler system of conservation laws of energy and momentum in special relativity as pressure vanishes are considered. The Riemann solutions for the pressureless relativistic Euler equations are obtained constructively. There are two kinds of solutions, the one involves delta shock wave and the other involves vacuum. The authors prove that these two kinds of solutions are the limits of the solutions as pressure vanishes in the Euler system of conservation laws of energy and momentum in special relativity.

Conversion potential energy and its application to thermodynamic optimization

In general,heat transfers can be classified into two categories according to the purposes of object heating or cooling and the heat to work conversion.Recently,a new physical quantity,entransy(or potential energy),was proposed to describe the ability of heat transfer with the former purpose.This paper addresses the concept of potential energy in terms of the heat transfer processes for the latter purpose,named the conversion potential energy.The physical meaning of this newly introduced concept is the potential energy for the heat to work conversion stored in the equivalent mass of heat(thermomass) derived on the basis of the Einstein's special theory of relativity.The dissipation of conversion potential energy occurs during the real irreversible heat to work conversion processes as a measure of the conversion irreversibility.Finally,a heat to work conversion problem of a heat exchanger group is provided to show that the minimum conversion potential energy dissipation rate can be used as an optimization criterion for the heat transfer performance with the purpose of the heat to work conversion.

One Electron Atom in Special Relativity with de Sitter Space-Time Symmetry

The de Sitter invariant Special Relativity （dS-SR） is SR with constant curvature, and a natural extension of usual Einstein SR （E-SR）. In this paper, we solve the dS-SR Dirac equation of Hydrogen by means of the adiabatic approach and the quasi-stationary perturbation calculations of QM. Hydrogen atom is located in the light cone of the Universe. FRW metric and ACDM cosmological model are used to discuss this issue. To the atom, effects of de Sitter space-time geometry described by Beltrami metric are taken into account. The dS-SR Dirac equation turns out to be a time dependent quantum Hamiltonian system. We reveal that： （i） The fundamental physics constants me, h, e variate adiabatically along with cosmologic time in dS-SR QM framework. But the fine-structure constant α≡ - e^2/（hc） keeps to be invariant; （ii） （2s^1/2 - 2p^1/2）-splitting due to dS-SR QM effects： By means of perturbation theory, that splitting △E（z） are calculated analytically, which belongs to O（1/R^2）-physics of dS-SR QM. Numerically, we find that when ｜R｜ = {103 Gly, 104 Gly, 105 Gly}, and z = {1, or 2}, the AE（z） 〉〉 1 （Lamb shift）. This indicates that for these cases the hyperfine structure effects due to QED could be ignored, and the dS-SR fine structure effects are dominant. This effect could be used to determine the universal constant R in dS-SR, and be thought as a new physics beyond E-SR.

The deformation of Poincar subgroups concerning very special relativity

We investigate here various kinds of semi-product subgroups of Poincar6 group in the scheme of Cohen-Glashow＇s very special relativity along the deformation approach by Gibbons- Gomis-Pope. For each proper Poincar6 subgroup which is a semi-product of proper lorentz group with the spacetime translation group T（4）, we investigate all possible deformations and obtain all the possible natural representations inherited from the 5 - d representation of Poincar6 group. We find from the obtained natural representation that rotation operation may have additional accompanied scale transformation when the original Lorentz subgroup is deformed and the boost operation gets the additional accompanied scale transformation in all the deformation cases. The additional accompanied scale transformation has a strong constrain on the possible invariant metric function of the corresponding geometry and the field theories in the spacetime with the corresponding geometry.

Editorial

This issue of Science China Physics, Mechanics ＆ Astronomy celebrates the Centenary of Einstein＇s General Theory of Rela- tivity, which changed the way humanity understood the concepts of space, time and matter. Prior to 1915 Einstein had intro- duced his theory of Special Relativity, and Minkowski had introduced the spacetime metric. General Relativity overthrew the Newtonian idea that space, time and matter were independent, replacing it with the idea that space, time and matter are inex- tricably linked. Within a year of the publication of General Relativity came Schwartzchild＇s exact solution of Einstein＇s field equations which describes the spacetime structure of black holes. In 1916 and 1918 Einstein showed that his theory predicted the existence of gravitational waves. Within 7 years, in 1922, Friedmann published a solution for Einstein＇s field equations applied to a homogeneous universe, uncovering the basic physics of Big Bang cosmology.

Axiomatization of Special Relativity in First Order Logic

The axiomatization of physical theories is a fundamental issue of science. The first-order axiomatic system SpecR el for special relativity proposed recently by Andr′eka et al. is not enough to explain all the main results in the theory, including the twin paradox and energy-mass relation. In this paper, from a four-dimensional spacetime perspective, we introduce the concepts of world-line, proper time and four-momentum to our axiomatic system SpecR el^+. Then we introduce an axiom of mass(Ax Mass) and take four-momentum conservation as an axiom(Ax CFM)in SpecR el^+. It turns out that the twin paradox and energy-mass relation can be derived from SpecR el+logically. Hence,as an extension of SpecR el, SpecR el^+is a suitable first-order axiomatic system to describe the kinematics and dynamics of special relativity.