Pioneers of Science and Earth's Internal Dynamics

Pioneers of Physics and Astronomy

• Isaac Newton: Universal gravitation. His first law demonstrates the laws that govern motion in dynamics on Earth.
• Stephen Hawking: Related the principles of the theory of relativity with the Big Bang and black holes; he also contributed to quantum theory.
• Karl Popper: Author of The Logic of Scientific Research.
• Alexander Fleming: Discovered penicillin and lysozyme by serendipity.
• Tycho Brahe: Created new astronomical tables. He discovered that asteroids (comets) were not weather phenomena but celestial bodies. He conducted studies on the refraction of light and proposed a theory of the Sun and Moon orbiting the Earth, while other planets orbit the Sun.
• Giordano Bruno: Promoted heliocentrism and the infinity of the universe.
• Nicolaus Copernicus: Heliocentrism; considered the founder of modern astronomy.
• Johannes Kepler: A key figure in the scientific revolution and collaborator of Tycho Brahe. He created Kepler's Laws to explain movement in the heliocentric system.
• Galileo Galilei: Improved the telescope and conducted astronomical observations. He formulated the First Law of Motion and is known as the "father of modern astronomy," the "father of modern physics," and the "father of science."

Foundations of Modern Geology

• Charles Lyell: Founder of modern geology and one of the most prominent representatives of uniformitarianism and gradualism.
• James Hutton: The first formulator of the theories of uniformitarianism and volcanism; he is considered the father of modern geology.
• Arthur Holmes: A pioneer in geochronology.
• Harry Hess: One of the "founding fathers" of the theory of plate tectonics.
• Alfred Wegener: A German scientist who developed the theory of continental drift.
• J. Tuzo Wilson: One of the principal authors of the final formulation of plate tectonics and the development of the theory of the Wilson Supercontinent cycle, thanks to his pioneering argument on transform faults.
• Frederick Vine: One of the major contributors to the theory of plate tectonics.

The Formation of the Solar System

Planetesimals: According to Carl von Weizsäcker and Gerard Kuiper, the solar system formed from gas and dust from a Milky Way nebula approximately 4.5 billion years ago.

Seismic Waves and Earth's Interior

• P-waves (Primary): These have a faster rate than S-waves. They are the first detected during an earthquake and can travel through all materials.
• S-waves (Secondary): These are slower than P-waves and are detected afterward. They can only cross solid materials.

Earth's Discontinuities

The Mohorovičić (Moho) discontinuity separates the crust from the mantle and responds to changes in composition between layers. In the oceanic crust, it is less than 30 km deep, while in some continental areas and great mountain ranges, it is more than 70 km deep. The Repetti discontinuity separates the upper mantle from the lower mantle. The Gutenberg discontinuity separates the mantle from the core and, simultaneously, the mesosphere from the endosphere. This discontinuity reflects significant changes in composition and physical state. Other minor discontinuities are seen at depths of 700 km and 5,150 km. The Wiechert discontinuity is the boundary between the external and internal endosphere, corresponding to an important change in the physical state of these layers.

Tectonic Plate Boundaries

Boundaries include transform, convergent, and divergent types:

• Andean: Oceanic crust with continental crust (LC).
• Island Arc: Oceanic crust with oceanic crust.
• Alpine: Continental crust (LC) with continental crust (LC).