Mechanics is that part of physics concerned with stuff that moves, from cannonballs to tennis balls, cars, rockets, and planets. Quantum mechanics is that part of physics which describes the motions of objects at molecular, atomic, and sub-atomic levels, such as photons and electrons. Although quantum mechanics is an extraordinarily successful scientific theory, on which […]
We learn in school science class that matter is not continuous, but discrete. As a few of the philosophers of ancient Greece once speculated nearly two-and-a-half thousand years ago, matter comes in “lumps.” If we dig around online we learn that we make paper by pressing together moist fibers derived from pulp. The pulp has an internal structure built from molecules (such as cellulose), and molecules are in turn constructed from atoms (carbon, oxygen, hydrogen).
Describing the very ‘beginning’ of the Universe is a bit of a problem. Quite simply, none of our scientific theories are up to the task. We attempt to understand the evolution of space and time and all the mass and energy within it by applying Albert Einstein’s general theory of relativity. This theory works extraordinarily well. But when we’re dealing with objects that start to approach the infinitesimally small – elementary particles such as quarks and electrons – we need to reach for a completely different structure, called quantum theory.
News broke in July 2015 that the Rosetta mission’s Philae lander had discovered 16 ‘carbon and nitrogen-rich’ organic compounds on Comet 67P/Churyumov-Gerasimenko. The news sparked renewed debates about whether the ‘prebiotic’ chemicals required for producing amino acids and nucleotides – the essential building blocks of all life forms – may have been delivered to Earth by cometary impacts.
Philosophers have long argued that sound, colour, taste, smell and touch, exist only in our minds. We have little basis for our assumption that these qualities represent reality as it really is. So, if we interpret the word ‘sound’ to mean a human experience, then the falling tree really is silent.