Newtonian and Quantum
There are two kinds of natural science. They are biology and chemistry. Sub branches include astronomy, physics, and earth science.
Different kinds of engineering.
The "two" kinds of energy are real and vector energy. Mot accounting for the two kinds of energy is the cause of current confusion in physics. Newton and Einstein missed the two kinds of energy real and vector. The gravitational energy is E= -mu/r + mcV. The first kind of energy Newton got the real or potential energy -mu/r. The unaccounted for energy is the "vector" energy mcV. The vector energy is the source of "dark energy" and myriad mysteries in cosmology. The Universe has two kinds of numbers, real numbers and vector numbers. This gives two kinds of energy, and two kinds of forces ,etc,etc,etc. Quaternions are the answer to the "two kinds" of energy, "reals and vectors" or quaternions!
Science studies Chemistry,Physics and Biology.
The two types (branches) of science are social science (anthropology, psychology, sociology, etc.) and natural science (physics, biology, physiology, astronomy, etc.)
Theoretical and applied physics are two most common classifications.
There are two main branches of pure physics. These are quantum physics and applied physics and they both focus on different aspects of physics.
there are two kinds in every person.
The Two kinds of Solution are:SolventSolute
physical and biological physics
classical physics and (Quantum or modern) Physics
It consists of chemistry, biology, physics, materials science, and engineering.