This paper introduces the first question of the theoretical examination of the 54th International Physics Olympiad. The question is set against the background of global warming due to the greenhouse effect, and it examines the energy balance in blackbody radiation and heat conduction. The question is divided into two parts: the first part focuses on the distribution of radiant energy in blackbody radiation; the second part addresses the balance of energy under reflection and absorption. The question involves modern physics (blackbody radiation), energy transfer in thermodynamics, and the Fabry-Perot effect similar to that seen in multi-beam interference in optics.

This paper introduces the third question of the theoretical examination in the 24th Asian Physics Olympiad. The question is about the observation and energy calculation of quasars, including initial experimental observations and theoretical modeling calculations. The question is divided into six parts, covering a variety of topics from optics, modern physics, and electromagnetism. The content of this question is broad, with moderate difficulty, and its distinctive feature is the good integration of experimental observation and theoretical calculation. Therefore, a detailed introduction and solution are provided here.

This paper introduces the second question of the theoretical examination of the 54th International Physics Olympiad. The question is set against the background of ion trapping and atomic cooling, discussing the fundamental models of these two important applications and guiding the derivation of some significant conclusions. The question is divided into two parts: the first part focuses on the Paul Trap model in ion trapping, with an emphasis on the dynamic equilibrium achieved by charged particles under the modulation of a high-frequency electric field, which leads to their confinement. The second part involves the use of atomic absorption of light, utilizing the Doppler effect to create differential absorption of light on either side of the atom, resulting in momentum transfer and subsequent deceleration and cooling of the atom. The theoretical model presented in the question is clear, the guided inferences are reasonable, and it requires a certain level of computational and approximation skills.