从声激波到光激波

From Sonic Shock Waves to Light Shock Waves

当超声速流通过物体时,可压缩流体动力学会造成激波。可以用非线性Schr dinger方程(NLSE)描述流体力学现象;用NLSE研究激波常有两种情况,一是航空工程中的声激波(SSW),二是非线性光纤技术中的光激波(LSW)。它们都是非线性光学的组成部分。回顾人类实现飞机以超声速飞行的历史,声障概念来源于线性小扰动理论中的密速方程ρ=ρ0[1-(v/c)^(2)]^(-1/2),它与狭义相对论(SR)中的质速方程相似。在奇点(v=c处)密度是无限大,当v>c将出现虚数。但在实际上,这些情况都不真实;简言之,虽然SSW是对飞机造成声障的原因,却不存在无限大密度。光障问题也如此,在奇点并没有无限大质量及无限大能量。……但是,对光障的研究并不表示超光速研究没有自身的特性,也不是说必须把它纳入空气动力学的框架中。正如飞机在空气中高速运动时会产生SSW,飞船在宇宙中高速航行时也会遇到LSW。但造成LSW的不是空气,而是新以太,即物理真空。已经有实验证明,这种真空环境会给动体造成阻力和摩擦,故飞船作高速运动时产生LSW是不可避免的。但在所谓奇点(v=c,β=1)并不会发生无限大质量和无限大能量,因此不可能对飞船加速到光速以上(v>c)构成障碍。

When supersonic flow passes through an object,compressible fluid dynamics can cause shock waves.The flow dynamics phenomena are described by the nonlinear Schr dinger equation(NLSE).There are two situations for studying shock waves with NLSE.One is the sonic shock waves(SSW)in aeronautical engineering,and the other is the light shock waves(LSW)in nonlinear optical fiber technology.They are all part of the Nonlinear Optics.When we look back on the history of realization on supersonic flight by airplane,the concept of sonic-barrier comes from the density-velocity equationρ=ρ0[1-(v/c)^(2)]^(-1/2) in linear small disturbance theory,which is similar to the mass-velocity equation in Special Relativity(SR),at the singular point v=c the density is infinite,when v>c the virtual value must appear.But in reality,these situations are not true.In short,although the SSW is the cause of sonic barrier to aircraft,there is no infinite density.The problem of light-barrier is also like this situation,there is no infinite mass and infinite energy at singular point.……However,such light barrier research does not mean that the superluminal research does not have its own characteristics,nor does it mean that it must be included in the aerodynamic framework.When the airplane moves at high speed in the atmosphere,the SSW can be generated.To be exactly the same,when the spacecraft moves at high speed in the universe,the LSW can be generated.But it is not the atmosphere that caused the LSW,but the new either,i.e.the physical vacuum.The experiment shows this vacuum environment can make construction and friction for a moving body,so it is inevitable to produce LSW when the spacecraft moves at high speed.But at the so called singurity point(v=c,β=1),it do not produce the infinitive mass and the infinitive energy,So it does not constitute an obstacle to the acceleration of the spacecraft above the speed of light(v>c).