Article archive

The Beginnings of Life

02/11/2013 08:38
What are the origins of life on Earth? How did things go from non-living to living, from something that could not reproduce to something that could? How can a collection of inanimate atoms become animate? How did organic molecules achieve a high enough level of complexity to be considered as...

The Big Bang and the Big Crunch

02/11/2013 08:37
Most scientists now believe that we live in a finite expanding universe which has not existed forever, and that all the matter, energy and space in the universe was once squeezed into an infinitesimally small volume, which erupted in a cataclysmic "explosion" which has become known as the Big Bang....

Black Holes and Wromholes

02/11/2013 08:35
Black holes are a phenomenon predicted by Albert Einstein's General Theory of Relativity, which was published in 1916. In fact, the idea of a black hole was proposed as early as 1783 by the amateur British astronomer John Michell (and independently by the Frenchman Pierre-Simon Laplace in 1795)....

Cosmological Theories Through History

02/11/2013 08:34
"Cosmos" is just another word for universe, and "cosmology" is the study of the origin, evolution and fate of the universe. Some of the best minds in history - both philosophers and scientists - have applied themselves to an understanding of just what the universe is and where it came from,...

Spin and the Pauli Exclusion Principle

02/11/2013 08:33
To return to the property of spin of fundamental particles, mentioned briefly in the previous section, spin can perhaps be most easily thought of as a rotation of particles around their own axis, although this is in fact something of a simplification, and in reality it is impossible to tell whether...

Superposition, Interference and Decoherence

02/11/2013 08:31
In the same way as it is possible in the everyday world to get big rolling waves in the sea with tiny ripples superimposed on them, it is also possible in the sub-atomic world for a combination or superposition of waves to exist. [Read more] ...  

Probability Waves and Complementarity

02/11/2013 08:30
The acceptance of light as composed of particles (or photons) led to another shocking realization. For example, if light shines on an imperfectly transparent sheet of glass, it may happen that 95% of the light transmits through the glass while 5% is reflected back. This makes perfect sense if light...

Nonlocality and Entanglement

02/11/2013 08:29
Another of the remarkable features of the microscopic world prescribed by quantum theory is the idea of nonlocality, what Albert Einstein rather dismissively called “spooky actions at a distance”. This was first described in the “EPR papers” of Einstein, Boris Podolsky and Nathan Rosen in 1935, and...

Quantum Tunnelling and the Uncertainty Principle

02/11/2013 08:27
One of the consequences of light having a wave-like aspect is exemplified by its apparent ability to jump gaps. For instance, light penetrating through a block of glass at a shallow angle is effectively trapped within the glass by the barrier of air at the far side, unless a second glass block is...

Wave-Particle Duality

02/11/2013 08:26
The earliest steps in the development of quantum physics arose from the investigation into something as mundane as why metal glows red when hot. The great German physicist Max Planck had been studying the problem of black body radiation in the late 1890s. [Read more] ...  
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