Special Relativity Study Materials

Light cone (Image Credit: Wikimedia Commons)

Introduction:

One of the greatest triumphs of Maxwell's electromagnetic theory (c. 1864) was the explanation of light as an electromagnetic wave. But a question arises; Waves in what? In conformity with the mechanistic view of nature then prevailing, it seemed imperative to postulate the existence of a medium—the ether—which would serve as a carrier for these waves. This led to the most urgent physical problem of the time: the detection of the earth's motion through the ether.

One of the many experiments were devised for this purpose. Michelson and Morley (1887), looked for a directional variation in the velocity of light on Earth. Fizeau (1860), Mascart (1872), and later Lord Rayleigh (1902), looked for an expected effect of the earth's motion on the refractive index of certain dielectrics. And Trouton and Noble (1903) tried to detect an expected tendency of a charged plate capacitor to face the 'ether drift'. All of them failed. The facile explanation that the earth might drag the ether along with it only led to other difficulties with the observed aberration of starlight, and could not resolve the problem. 

Herpetology: Study Materials on Amphibians and Reptiles

Panther Chameleon (Furcifer pardalis), endemic to Madagascar.
Image courtesy link

-by Aaron S. Johnson

Introduction:

Herpetology is the zoological study of amphibians (frogs, toads, salamanders, newts, caecilians [legless amphibians]) and reptiles (turtles/tortoises, snakes, lizards, amphisbaenians [non-snake, legless squamate clade], crocodilians, tuataras).  A herpetologist is an expert in amphibian and reptile behavior, diet, ecology, taxonomy, physiology, anatomy, evolution, health, conservation, and husbandry.

Amphibians have been around for over 370 million years (m.y.) and reptiles for 310-320 m.y.  Amphibians are the descendants of a fishlike ancestor, whereas reptiles descended from a common amphibianlike ancestor.  Together, reptiles and amphibians are collectively known as "herps" and are the common ancestors of birds and mammals.  

Herps may be ectotherms, but they are voracious eaters of everything humans consider as "pests" and carriers of disease, e.g. insects, arachnids, slugs, rodents.  Needless to say, world ecological systems would collapse without them.  With the decline of amphibians and reptiles due to herbicides, pesticides, pet trade, destruction of the environment, climate change, invasive species, and pathogenic microbes, the importance of these creatures have grown ever more apparent.  Accordingly, modern herpetologists should have expertise in microbiology, chemistry, climatology, conservation, and even business administration, communications, and sociology in order to professionally problem solve as difficult issues arise. 

Study Materials on Classical Electrodynamics

Introduction:

Mechanics tells us how a system will behave when subjected to a given force. There are four forces in nature known (presently) to us. If we arrange them in order of decreasing strength, they would be:

1. Strong nuclear force
2. Electromagnetic force
3. Weak nuclear force, and
4. Gravitational force

We have often thought about questions, like: Where is friction? Where is the "normal" force that keeps us from falling through the floor? Where are the chemical forces that bind molecules together? Where is the force of impact between two billiard balls? The answer is that all these forces are electromagnetic.

Quantum Mechanics Study Materials

Image Courtesy : http://bit.ly/1nxAvAM

Introduction:

Our description of the physical world is dynamic in nature and undergoes frequent change. At any given time, we summarize our knowledge of natural phenomena by means of certain laws. These laws adequately describe the phenomenon studied up to that time, to an accuracy then attainable. As time passes, we enlarge the domain of observation and improve the accuracy of measurement. As we do so, we constantly check to see if the laws continue to be valid. Those laws who do remain valid gain in stature, and those who do not are abandoned in favor of new ones that do. 

In this changing picture, the laws of classical mechanics formulated by Galileo, Newton, and later by Euler, Lagrange, Hamilton, Jacobi, and others, remained unaltered for almost three centuries. The expanding domain of classical physics met its first obstacles around the beginning of 20th century. The obstruction came on two fronts: at large velocities and small (atomic) scales. The problem of large velocities was successfully solved by Einstein, who gave us relativistic mechanics, while Bohr, Heisenberg, Schrödinger, Dirac, Born, et al.—solved the problems of small-scale physics. Quantum mechanics brings with it not only improved numerical predictions for the microscopic world, but also conceptual changes that rock the very foundations of classical thought. With that being said, we present to all of you the necessary lecture notes, lecture videos, etc., found in the WWW domain to study/learn quantum mechanics. 

Classical Mechanics Study Materials

Introduction: 

Classical Mechanics is a subdomain of Classical physics. Classical mechanics is the study of the motion of the bodies (including the special case in which bodies remain at rest) in accordance with the general principles first enunciated by Sir Isaac Newton. Classical mechanics was the first branch of physics to be discovered, and is the foundation upon which all other branches of physics are built. Moreover, classical mechanics has many important applications in other areas of science, such as Astronomy (e.g., celestial mechanics), Chemistry (e.g., the dynamics of molecular collisions), Geology (e.g., the propagation of seismic waves, generated by earthquakes, through the Earth's crust), and Engineering (e.g., the equilibrium and stability of structures).

Classical mechanics is also of great significance outside the realm of science. After all, the sequence of events leading to the discovery of classical mechanics— starting with the ground-breaking work of Copernicus, continuing with the researches of Galileo, Kepler, and Descartes, and culminating in the monumental achievements of Newton—involved the complete overthrow of the Aristotelian picture of the Universe, which had previously prevailed for more than a millennium, and its replacement by a recognizably modern picture in which humankind no longer played a privileged role.

With that being said, we present you the necessary lecture notes and videos, found in the WWW domain to study/learn classical mechanics.