MODERN MODERN PHYSICSPHYSICS

PhysicsPhysicsThe natural science which investigates the The natural science which investigates the nature and behavior of physical concepts nature and behavior of physical concepts or phenomena, including mass, matter, or phenomena, including mass, matter, motion, and charge as well as corollary motion, and charge as well as corollary observations derived from these observations derived from these examinations, such as energy, force, examinations, such as energy, force, space, and time.space, and time.

NEWTONIANNEWTONIAN MECHANICSMECHANICS

Sir Isaac Newton Sir Isaac Newton (1642-1727) (1642-1727) formulated the mathematics for the universal law of gravitation and determined the nature of light.

The Newtonian SynthesisThe Newtonian Synthesis

Newton’s Newton’s Principia Principia MathematicaMathematica (1687) (1687) stated the laws of stated the laws of motion, the universal motion, the universal law of gravitation, and law of gravitation, and a derivation of a derivation of Kepler’s laws for the Kepler’s laws for the motion of planets.motion of planets.

Newton’s Three Laws of the Motion of Newton’s Three Laws of the Motion of Matter formed the basis of classical Matter formed the basis of classical mechanics.mechanics.

a body remains in a state of rest or continues its a body remains in a state of rest or continues its motion in a straight line unless impelled to change by motion in a straight line unless impelled to change by forces impressed on itforces impressed on it

acceleration: the change in a motion of a body is acceleration: the change in a motion of a body is proportional to the forces acting upon itproportional to the forces acting upon it

for every action, there is an equal and opposite for every action, there is an equal and opposite reactionreaction

Newton’s personal copy of the first edition of Newton’s personal copy of the first edition of Principia Principia MathematicaMathematica with handwritten corrections for the second with handwritten corrections for the second edition.edition.

Modern PhysicsModern Physics

post-Newtonian developments in physicspost-Newtonian developments in physicsclassical physical descriptions of classical physical descriptions of

phenomena are lackingphenomena are lackingclassical physics, for example, could not classical physics, for example, could not

accurately explain the question of black accurately explain the question of black body radiationbody radiation

scientists sought a more accurate, scientists sought a more accurate, ‘modern’ description of physics ‘modern’ description of physics

Newtonian mechanicsNewtonian mechanics (based on universal absolutes)

versusversus quantum mechanics quantum mechanics

(based on universal probabilities)

Development, growth, and Development, growth, and evolution of physical science: evolution of physical science:

from order (Scientific Revolution, The Enlightenment, and Age of

Reason) to chaos (Age of Anxiety; World War I, II; breakdown and disintegration of the Enlightenment Order)

Max PlanckMax PlanckConsidered by some to be the father of quantum mechanics deriving from his initial work on the problem of black body radiation, the formulation of Planck’s constant, and the articulation of Planck’s law of radiation; not all physicists cite Planck as the “founder” of quantum mechanics; some credit Albert Einstein as the founder of modern physics

Max Planck worked on the problem Max Planck worked on the problem of describing black body radiationof describing black body radiation

Quantum MechanicsQuantum MechanicsQuantum mechanics involve principles derived from attempts to describe physical nature, or physical systems, at an atomic, or microscopic, scale; from these explorations, physicists observe both particle-like and wave-like behaviors of matter and radiation

Modern physicists attempted to Modern physicists attempted to predict the behavior of quantum predict the behavior of quantum material (atoms, molecules, material (atoms, molecules, photons, electrons, and other photons, electrons, and other subatomic particles) in terms of subatomic particles) in terms of probabilities whereas classical probabilities whereas classical physicists predict certainties.physicists predict certainties.

Albert Einstein: Albert Einstein: Theory of RelativityTheory of Relativity

E = MC2

Werner Heisenberg: Principle of Werner Heisenberg: Principle of Uncertainty, or IndeterminacyUncertainty, or Indeterminacy

Erwin SchrödingerErwin Schrödinger Schrödinger equation is an equation that describes how the quantum state of a physical system changes in time. It is as central to quantum mechanics as Newton’s laws are to classical physics.

Schrödinger's CatSchrödinger's Cat:: Dead or Alive?Dead or Alive?

idea of entanglement: does the condition or state of the cat inside of the box depend on the observer? or, is the cat independent of the observer?

Niels BohrNiels Bohr

Principle of complementarity:items can be analyzed separately as having contradictory properties (particle-like or wave-like)

Unified Field TheoryUnified Field Theory The unified field theory is an attempt to reconcile the

infinite with the intimate mathematically.

A type of field theory that allows all of the fundamental forces between elementary particles to be written in terms of a single field. There is no accepted unified field theory yet, and this remains an open line of research.

A Theory of Everything is closely related to unified field theory, but differs by not requiring the basis of nature to be fields, and also attempts to explain all physical constants of nature.

chaos = unpredictabilitychaos = unpredictability

The Butterfly EffectThe Butterfly Effectsmall variations of the initial conditions of a dynamical system may produce large variations in the long term behavior of the system

observer effectobserver effect

Does the act of observation alter or Does the act of observation alter or change the phenomena being change the phenomena being observed?observed?

refers to changes that the act of observation refers to changes that the act of observation make on the phenomenon observed; often the make on the phenomenon observed; often the result of instruments that, by necessity, alter the result of instruments that, by necessity, alter the state of what they measure in some manner; the state of what they measure in some manner; the effect can be observed in the domain of physicseffect can be observed in the domain of physics

OCCAM’S RAZOROCCAM’S RAZOR

the simplest answer is the best answer; named after the 14th c. Franciscan friar, William of Ockham (Latin: lex parsimoniae); also, law of parsimony, law of economy, law of succinctness; parsimony was an important principle in Einstein’s formulation of special relativity; Occam’s razor is a metaphysical (or, heuristic) preference, not a logical or scientific principle

Karl Popper’s Karl Popper’s concept of falsifiabilityconcept of falsifiability

falsifiabilityfalsifiability: (also, : (also, refutability); Karl refutability); Karl Popper’s assertion Popper’s assertion that a hypothesis, that a hypothesis, proposition, or proposition, or theory is scientific theory is scientific only if it is only if it is falsifiablefalsifiable

entropyentropy: measurement of : measurement of the disorder of a systemthe disorder of a system

Rudolf Clausius originated the concept of entropy.

phase transitionphase transition:: transformation of a thermodynamic system from one phase to another; at phase-transition point, physical properties may undergo abrupt change; for example, volume of the two phases may be vastly different; imagine transition of liquid water into vapor at boiling point; in common usage, the term is used to denote transitions between states (solid, liquid, gas) of matter; comparable to tipping point

thermodynamicsthermodynamics:: conversion of heat energy into other forms (esp. chemical, electronic, and mechanical); historically, thermodynamics developed out of need to increase the efficiency of early steam engines

1890s-vintage triple-expansion marine engine that powered the SS Christopher Columbus

The Manhattan ProjectThe Manhattan Project(formal, Manhattan Engineer District, or MED)

project to develop the first nuclear weapon by project to develop the first nuclear weapon by the United States, Canada, and the United the United States, Canada, and the United Kingdom during World War II; from 1942 to 1946 Kingdom during World War II; from 1942 to 1946 the U.S. Army Corps of Engineers under the the U.S. Army Corps of Engineers under the administration of General Leslie R. Groves; administration of General Leslie R. Groves; scientific research was led by J. Robert scientific research was led by J. Robert Oppenheimer and included many other Oppenheimer and included many other prominent scientists such as Niels Bohr; a prominent scientists such as Niels Bohr; a research team led by Enrico Fermi achieved the research team led by Enrico Fermi achieved the first man-made nuclear chain reaction in 1942, first man-made nuclear chain reaction in 1942, and in 1945 the world's first nuclear explosion and in 1945 the world's first nuclear explosion was detonated at Trinity site; MED maintained was detonated at Trinity site; MED maintained control over U.S. weapons production until the control over U.S. weapons production until the formation of the Atomic Energy Commission in formation of the Atomic Energy Commission in January, 1947January, 1947

The mushroom cloud (r) over Nagasaki, Japan after the detonation of “Fat Man,” a gravity bomb (l), on August 9, 1945.

practical impact of modern physics and quantum mechanics: atom bombs; nuclear energy and power plants; advances in molecular and chemical biology; observation and description of DNA/RNA; space exploration; X-ray lasers, compact disc players, and bar code readers; transistors, computers and many, many other developments.

Francis Crick, who along with James D. Watson co-discovered the molecular structure of DNA, was influenced by the work of physicist Erwin Schrödinger.

Source: Diagram, map, and photo from The Press of Atlantic City (April 9, 2009)

Nuclear energy: “The nation's oldest nuclear power plant…Oyster Creek Nuclear Generating Station…generates enough electricity to power 600,000 homes a year. It provides 9 percent of New Jersey's electricity. Oyster Creek's boiling-water reactor is considered obsolete by today's standards. It went online December 1, 1967.” [Source: Wayne Parry, “Oldest US nuclear plant gets a new 20-year license.” (April 8, 2009), Associated Press.]

Fermi ParadoxFermi Paradoxapparent contradiction between high estimates of the probability of the existence of extraterrestial civilizations and the lack of evidence for, or contact with, such civilizations; named after atomic physicist Enrico Fermi who worked on the Manhattan Project

Two-dimensional projection of a three-dimensional analogy of space-time curvature described in General Relativity.