I was looking at the pictures and I had this idea, what is it that I like about these pictures and Chinese trigram elements? It is that they represent nature and science is the study of nature so I decided to find a scientific photo to represent every taeguek element.

Scientific Meanings

1. Heaven and Light. Heaven is a rainbow, the water vapor in the air after it rains are like prisms because they break (refract) the light into its component colors. Vapor is cloudy and a prism is sharp but both are able to break light because they have a refraction index which is greater than that of air.
2. Joyfulness. Is the frog in this picture just being serious and stern or is he mad? I can't tell the difference.
3. Fire and Sun. The sun uses nuclear fusion to create energy. Fusion involves merging two nuclei to form one and this involves the nuclear shell, which was described by Dr. Maria Goeppert-Mayer. Dr. Goeppert-Meyer won the Nobel Prize in physics for her nuclear shell model of atomic nuclei. She described the spin orbit coupling of the nuclear shell structure as waltzing in a room. There is not much biographical information about her, but I think she must have had firsthand experience with waltzing in order to use it accurately as a metaphor.
4. Thunder. Lightning is due to an electrical (electrostatic) discharge between a cloud and the ground or between two clouds. The clouds and or earth are ionized, that means that the ions in the air (or ground) are separated into positive and negative ions (charges, cations and anions respectively). When the two bodies come into contact, the ions lose their charge, that is, electicity is discharged. The discharge is an emission of electrons which emit light when they propagate. Thunder lacks a conclusive physical explanation.
5. Wind. When you go swimming, you will often notice that even if the sand it too hot, the water is cooler and in general, water is always much cooler than land. Land can change its temperature more quickly. It heats up faster and loses its heat energy faster because it has a lower heat capacity than water. Water does not change its temperature so quickly (higher heat capacity), it remains the same temperature longer. So at night, the land cools off quickly and the water remains at about the same temperature. When this happens, the air above the land is cooler and the air above the water is warmer. The cooler air over the land sinks (convection) and the warmer air over the water rises resulting in a wind, more specifically a land breeze.
6. Water. Spherical waves. Only two types of waves, pressure waves and electromagnetic waves constitute most of classical wave phenonema such as sound and optics and if you understand wave mechanics, you will understand the majority of physical phenonema. Probably if you want to study physics, you should become a surfer first and learn to describe the motion of the ocean waves. I'm only half joking, you would probably be able to understand fundamental wave concepts such as amplitude and frequency better if you had a concrete example.
7. Mountain. Mountains are mostly formed by continental plate movement.
8. Earth. The earth is one of nine planets. The planets should move in a straight line when there is no other force (Newton's first law) but they revolve around the sun because of the gravitational attraction pulling them into a curve.