The new era of modern physics began near the end of:

Explanation

The late 19th century marks the beginning of the new era of modern physics. This period saw the formulation of classical electromagnetic theory by James Clerk Maxwell, the development of thermodynamics, and the groundbreaking work of physicists like Michael Faraday. However, the true turning point came with the advent of quantum mechanics and the theory of relativity in the early 20th century, initiated by physicists such as Max Planck, Albert Einstein, Niels Bohr, and others.