Thai Journal of Physics https://ph01.tci-thaijo.org/index.php/ThaiJPhys <p>Thai Journal of Physics is the official journal of Thai Physics Society</p> en-US siramas.k@cmu.ac.th (Dr. Siramas Komonjinda) thanida.chrs@gmail.com (Dr Thanida Charoensuk) Sat, 28 Jun 2025 06:05:00 +0700 OJS 3.3.0.8 http://blogs.law.harvard.edu/tech/rss 60 Classical Descriptions of Spin-2 Fields https://ph01.tci-thaijo.org/index.php/ThaiJPhys/article/view/260385 <p>In quantum theory, the photon and graviton are colloquially referred to as having spin <img id="output" src="https://latex.codecogs.com/svg.image?\pm&amp;space;" alt="equation" />ℏ and <img id="output" src="https://latex.codecogs.com/svg.image?\pm&amp;space;" alt="equation" />2ℏ, respectively.<sup>1</sup> Spin is associated with properties of the electromagnetic and gravitational fields related to their angular momentum or the way they transform under rotations. We review some of these properties and establish connections among them that explain the terms “spin 1” and “spin 2”. In particular, we show how helicity (a measure of how waves transform under rotations) is related to the eigentensors of Dirac’s infinitesimal rotation operator. We also examine systems emitting gravitational radiation to analyze the angular distribution of energy and angular momentum in circularly polarized plane waves and gain insight into the spin-2 nature of the gravitational field.</p> <p> </p> <p><strong>Keywords: </strong>Gravitational radiation, Angular momentum, Spin, Helicity</p> Daniel Abramson Copyright (c) 2025 Thai Journal of Physics https://ph01.tci-thaijo.org/index.php/ThaiJPhys/article/view/260385 Sat, 28 Jun 2025 00:00:00 +0700