The swan was seen as a traditional symbol of beauty and grace in ancient Greece, and was sacred to Aphrodite. The swan was also sacred to Apollo, the god of music (among other things), in Greek mythology. At the time, the people believed that the swan sang a sweet and beautiful song when people died.
For example, in case of monatomic gas it is just a kinetic energy of motion of atoms of gas as measured in the reference frame of the center of mass of gas. In case of molecules in the gas rotational and vibrational energy is involved.
An object that has motion-whether it is vertical or horizontal motion-has kinetic energy. There are many forms of kinetic energy-vibrational (the energy due to vibrational motion), rotational (the energy due to rotational motion), and translational (the energy due to motion from one location to another).