Modern Physics: Quantum Mechanics and Relativity

• Physics examines matter, its parts, motion, behavior through space and time, and related energy and force entities.

Modern Physics

• Modern physics includes advances from the early 20th century onward.
• Encompasses quantum mechanics and Einsteinian relativity.
• Includes quantum mechanics, special relativity, and general relativity.
• Quantum mechanics studies matter and energy at atomic and subatomic levels.
• Special relativity studies the relationship between space and time.
• General relativity studies gravity as the curvature of spacetime.
• Modern physics has led to technologies like lasers, semiconductors, and medical imaging.
• It tests classical physics in extreme conditions like high speeds, strong gravity, and microscopic scales.
• Wave-particle duality is a concept where particles act like waves and vice versa.
• The Heisenberg uncertainty principle states that position and momentum cannot be known with perfect accuracy at the same time.

Ray Optics

• Ray optics (geometrical optics) describes light using rays.
• It's an approximation when light's wavelength is smaller than the objects it hits.
• Reflection is when light bounces off a surface.
• The law of reflection: the angle of incidence equals the angle of reflection.
• Refraction is when light bends passing from one medium to another.
• Snell's law: n1sin(θ1) = n2sin(θ2), links incidence and refraction angles with refractive indices of the media.
• Lenses use refraction to focus or diverge light.
• Convex lenses converge light, while concave lenses diverge light.
• Focal length is the distance from the lens to where parallel rays converge (or diverge from).
• Optical instruments like telescopes and microscopes use lenses to magnify images.
• Total internal reflection: light from a denser medium to a rarer medium hits the interface at an angle greater than the critical angle.
• Fiber optics use total internal reflection to transmit light over distances.

Electrostatics

• Electrostatics studies electric charges at rest.
• Electric charge is a basic property of matter, in positive and negative forms.
• Like charges repel; opposite charges attract.
• Coulomb's law: F = k * (q1 * q2) / r^2, quantifies the force between two point charges, where k is Coulomb's constant, q1 and q2 are the charges, and r is the distance.
• The electric field is the force per unit charge on a test charge.
• Electric field lines show the electric field's direction and strength, originating from positive charges and ending on negative charges.
• Electric potential (voltage) is the electric potential energy per unit charge.
• Potential difference is the work to move a unit charge between two points.
• Capacitance is a system's ability to store electric charge.
• A capacitor has two conductive plates separated by an insulator (dielectric).
• Capacitance C = Q / V, where Q is the charge stored and V is the voltage.
• Energy is stored in a capacitor via charge separation.
• Dielectrics increase capacitance and prevent electrical breakdown.
• Materials are classified based on their ability to permit the flow of electrons.
• Conductors allow electrons to move easily, while insulators do not.
• Semiconductors have intermediate conductivity.

Explore modern physics, including quantum mechanics and Einsteinian relativity. Delve into matter and energy at atomic levels and the relationship between space and time. Discover how these concepts revolutionized technologies.