目前光子质量的实验上限是：1.2×10^(-54)Kg，见今年三月份的论文：J. Luo（罗俊）, L. C. Tu, Z. K. Hu and E. J. Luan, Phys. Rev. Lett. {\bf 90} (2003) 081801.

光子质量实验可以分为两类：一类基于Ampere-Maxwell-Proca equation，另一类基于Lagrangian (or Hamiltonian) density of electromagnetically interacting system。无论是哪类实验都有三个特点：装置庞大；要在特殊条件下做实验（如山洞里面，山壁要厚大40米以上，如罗俊实验，Phys. Rev. Lett. {\bf 90} (2003) 081801）；数据处理需要用计算机，很耗时间。

请问，这位冯劲松先生还能在西安会议讲台上演示他的实验装置？？？？再请问他得到的光子质量实验上限是多少？比1.2×10^(-54)Kg大还是小？如果是比1.2×10^(-54)Kg大，那么他什么意义都没有。

以下是近三十年有关于光子质量实验的论文：
 \bibitem{Feinberg} G. Feinberg, Nature {\bf 166} (1969) 879.

\bibitem{Williams} E. R. Williams, J. E. Faller and H. A. Hill, Phys. Rev.
Lett. {\bf 26} (1971) 721.

\bibitem{Goldhaber} A. S. Goldhaberand, M. M. Nieto, Rev. Mod.
Phys. {\bf 43} (1971) 277.

\bibitem{Barrow} J. D. Barrow and R. R. Burman, Nature {\bf 307} (1984) 14.

\bibitem{Davis} L. Davis, A. S. Goldhaber and M. M. Nieto, Phys.
Rev. Let. {\bf 35} (1975) 1402.

\bibitem{Gintsburg} M. A. Gintsburg, Sov. Astron. {\bf 7} (1964) 536.

\bibitem{Chernikov} M. A. Chernikov, C. J. Gerber and H. R. Ott, Phys. Rev. Lett. {\bf 68} (1992) 3383.

\bibitem{Fischbach} E. Fischbach, H. Kloor, R. A. Langel, {\it et al.}, Phys. Rev. Lett. {\bf 73} (1994) 514.

\bibitem{Lakes} R. Lakes, Phys. Rev. Lett. {\bf 80} (1998) 1826.

\bibitem{Schaefer} B. E. Schaefer, Phys.
Rev. Let. {\bf 82} (1999) 4964.

\bibitem{Luo} J. Luo, L. C. Tu, Z. K. Hu and E. J. Luan, Phys. Rev. Lett. {\bf 90}
 (2003) 081801.

以下是本人对以上10篇论文结果的文献综述：

During the last three decades, photon rest mass problem captured
special attention of many investigators who have reported several
experimental upper limits on the photon mass $m_{\gamma}$ by using
various
methods\cite{Feinberg,Williams,Goldhaber,Barrow,Davis,Gintsburg,Chernikov,Fischbach,Lakes}.
Since the radiation from pulsars and/or certain explosive
astrophysical events at high redshift can be used to place the
severe limits on both the fractional variation ($\triangle c/c$)
in the speed of light with frequency and the photon rest
mass\cite{Schaefer}, in 1969 Feinberg analyzed the data obtained
in the detection of the sharply defined radio and optical pulses
from pulsars and indicated that the rest mass of a real photon is
less than $10^{-47}$ Kg\cite{Feinberg}. Goldhaber {\it et al.}
discussed the method used to set a limit on the photon rest mass
({\it e.g.}, sensitive techniques which test Coulomb's law and its
analog in magnetostatics) and showed that the laboratory tests of
Coulomb's law\cite{Williams} gave an upper limit on photon rest
mass of $2\times 10^{-50}$ Kg and the constant ``external''
magnetic field experiment at the Earth's surface obtained a limit
$m_{\gamma}\leq 4\times 10^{-51}$ Kg\cite{Goldhaber}. The
experiments of Pioneer-10 measurement of Jovian magnetic
field\cite{Davis} and hydromagnetic wave in the Earth's
magnetosphere and solar wind\cite{Gintsburg} derived an upper
limit on $m_{\gamma}$ of about $10^{-52}$ Kg. In 1992 Chernokov
{\it et al.} suggested a new method to set an upper limit on the
photon mass at low temperature ($1.24$ K) based on a null test of
Amp\`{e}re's law and their experiment resulted in an upper limit
about $10^{-48}$ Kg\cite{Chernikov}. Fischbach {\it et al.}
investigated a new geometric limit on the photon rest mass which
was derived from an analysis of satellite measurements of the
Earth's magnetic field. The order of magnitude of the upper limit
on $m_{\gamma}$ obtained by Fischbach {\it et al.} was $10^{-51}$
Kg\cite{Fischbach}. In 1998, Lakes reported that their
experimental approach based on a toroid Cavendish balance which
was used to evaluate the product of photon rest mass squared and
the ambient cosmic magnetic vector potential gave an upper limit
on $m_{\gamma}$ of about $4\times 10^{-52}$ Kg\cite{Lakes}. More
recently, Luo {\it et al.} obtained the most new upper limit on
photon rest mass of $1.2\times 10^{-54}$ Kg by means of {\it
rotating torsion balance} experiment\cite{Luo}.

Although both Luo {\it et al.}'s experimental scheme and their
obtained results are excellent and impressive, here we have a
supplement to their results, since our evaluation shows that the
{\it photon effective rest mass} due to the {\it self-induced
charge currents}\cite{Ho,Scr} in the environmental dilute plasma
({\it e.g.}, the muon ($\mu$) component and alpha-particles in the
secondary cosmic ray flux) is just the {\it same} order of
magnitude\cite{Shen} as Luo's obtained upper limit on photon mass.

In addition, it is worthwhile to point out that there are two main
classes of experiments to detect photon rest mass based on the
Amp\`{e}re-Maxwell-Proca equation and the Lagrangian (or
Hamiltonian) density of electromagnetically interacting system,
respectively. The torsion balance experiments\cite{Lakes,Luo}
considered here fall into the latter class ({\it i.e.}, based on
the electromagnetic Lagrangian and Hamiltonian density).        
                            

本人关于光子质量的工作：
罗俊实验（J. Luo（罗俊）, L. C. Tu, Z. K. Hu and E. J. Luan, Phys. Rev. Lett. {\bf 90} (2003) 081801）证明目前光子质量的实验上限是：1.2×10^(-54)Kg。

我通过研究次级宇宙射线中谬子稀薄等离子体的self-induced charge current效应，计算得到谬子的自极化附加给光子的有效质量是（0.3到1）×10^(-54)Kg，即与罗俊实验的数据处于同一个数量级。这说明了：未来的测量光子质量实验需要预先排除次级宇宙射线中谬子稀薄等离子体的self-induced charge current效应，这样才能测量到光子内禀质量。