大学物理 ›› 2025, Vol. 44 ›› Issue (2): 45-.doi: 10.16854/j.cnki.1000-0712.240395

• 教学讨论 • 上一篇    下一篇

用Stirling公式严格证明玻尔兹曼对热二律的微观解释

李元昌,刘玉龙,刘鹏,吕勇军,李军刚   

  1. 北京理工大学物理学系,北京100081
  • 收稿日期:2024-08-27 修回日期:2024-09-27 出版日期:2025-04-18 发布日期:2025-04-28
  • 作者简介:李元昌(1982—),男,北京理工大学物理学院教授,博士,主要从事热学教学和凝聚态物质的计算研究工作.
  • 基金资助:
    2023年北京高等教育本科教学改革创新项目;教育部高等学校物理学类专业教学指导委员会2023年热学课程教学研究会项目(JZW23RX11);国家自然科学基金(12074034)资助

Understanding the Boltzmann microscopic interpretation of the second law of  thermodynamics from the Stirling formula

LI Yuanchang,LIU Yulong,LIU Peng,LV Yongjun,LI Jungang#br#   

  1. School of Physics,Beijing Institute of Technology,Beijing 100081,China
  • Received:2024-08-27 Revised:2024-09-27 Online:2025-04-18 Published:2025-04-28

摘要: 本文利用Stirling公式的精确形式严格求解了N个气体分子在一长方形容器中左、右两半分布的热力学概率问题,定量验证了玻尔兹曼对热力学第二定律微观本质的统计解释. 结果显示占微观态总数95%的态分布在平衡态附近±N的区间,即,相对涨落与N呈1/N的标度关系. 本文讨论了常用的Stirling近似引发的困惑和谬误.

关键词: 热力学第二定律, Stirling公式, 玻尔兹曼熵, 热力学概率

Abstract:  In this work,the thermodynamic probability problem of N gas molecules distributed in the left and right halves of a rectangular container is rigorously solved using the exact form of Stirlings formula,which quantitatively verifies Boltzmanns statistical interpretation of the microscopic nature of the second law of thermodynamics. It is shown that 95% of the total microscopic states are distributed in the ±Ninterval near the equilibrium state,i.e.,the relative fluctuations are 1/Nwith respect to N. Confusion and errors caused by the common Stirling approximation are discussed.

Key words: the second law of thermodynamics, Stirling formula, Boltzmann entropy, thermodynamic probability