In a spiral galaxy, the stars move in a circular motion around the galactic center, and the relation between velocity and the orbital radius is referred to as the rotation curve. Previous astronomical observation data indicate that the rotation curve is flat at the periphery of the galaxy, which completely dissatisfies Keplerian decline. Assuming…

When students of the of the physical sciences transition from school to university, they discover that knowledge of calculus is as vital as arithmetic, and that there is precious little useful information written without calculus. However, the lack of calculus in pre-university physics studies persists, especially in its application to the…