The idea that force causes acceleration doesn't seem strange. This and other ideas of newtonian mechanics are consistent with our every day experience. But the ideas of relativity seem odd and more difficult to grasp. Discuss.

Physical sciences involve the systematic study natural world that mainly deals with inorganic compounds. One of the core categories of this field is physics which deals with the structure and interaction of individual atoms in this observable universe. Moreover, it is sub-categorized into classical and modern physics that mainly explain the behavior of particles on a macroscopic and a microscopic scale. However, the complexity and the routine applications involved in the concepts of both these branches describe the typicality to understand these areas of study. In general, classical physics refers to the physics developed before the 20th century and involve the laws and principles that well describe objects larger in size than an atom or a molecule. Furthermore, it employs a simplified approach by considering the quantities either conserved like the energy and momentum or constant such as mass, length and time. Consequently, the effect of the ideas presented in this branch can easily be felt in daily life, and, hence it is easily comprehensible. On the other hand, modern physics refers to those concepts of physics discovered in the earlier phases of the 20th century that reestablished the widely accepted theories of classical physics. It mostly applies to the nanoparticles and provides the relationships between the physical quantities, which includes the dilation theory as the speed of the object tends to the speed of light, quantum effects, and the inter-conversion of mass and energy. Subsequently, this inter-relationship between the quantities complexes out the mathematical models and the effects of the speed of light, which are negligible in routine activities, makes it difficult to apprehend. The researches these days focus more on establishing the concepts of the modern physics to make it relatively easier to understand that can be applied to everyday actions. Nevertheless, both these sets of ideas are crucial to study until a unified set of laws governing both the approaches of physics.