The discovery of water on Mars has been claimed so often that I’d forgive anyone for being skeptical about the latest announcement. Frozen water, ice, has been proven on Mars in many places, there are lots of ancient canyons hundreds of kilometres long that must have been carved by rivers, and much smaller gullies that are evidently much younger.
The alignment of both the Sun and the Earth with another planet in the Solar System is a rare event, which we are seldom able to observe in a lifetime. The Sun-Venus-Earth alignment for example only takes place once every 105.5 or 121.5 years. Similarly, the next Sun-Earth-Mars alignment will only occur in 2084. But on 5 January 2014, we were lucky enough to witness one such rare event: the alignment of the Sun, Earth, and Jupiter. Much to our surprise, we saw a new physical effect never observed before.
Many people have heard of Pyrite, most-commonly referred to as fool’s gold, but far less people know about pyrite’s cultural significance or its prevalence throughout history. From American mining lore to Greek philosophy and medieval poetry, pyrite appears throughout our past, and continues to influence our lives today.
The great German physicist Max Planck once said, “However many specialties science may split into, it remains fundamentally an indivisible whole.” He declared that the divisions and subdivisions of scientific disciplines were “not based on the nature of things.”
How can an element be lost? Scientists, and the general public, have always thought of them as being found, or discovered. However, more elements have been “undiscovered” than discovered, more “lost” than found.
One of the most interesting developments in the history of chemistry has been the way in which theories of valency have evolved over the years. We are rapidly approaching the centenary of G.N. Lewis’ 1916 article in which he proposed the simple idea that a covalent bond consists of a shared pair of electrons.
The history of modern Crystallography is intertwined with the great discoveries’ of William Lawrence Bragg (WLB), still renowned to be the youngest Nobel Prize in Physics. Bragg received news of his Nobel Prize on the 14th November 1915 in the midst of the carnage of the Great War. This was to be shared with his father William Henry Bragg (WHB), and WHB and WLB are to date the only father and son team to be jointly awarded the Nobel Prize.
In the same way as a jungle harbours several species of birds and mammals, the stellar (or almost stellar) zoo also offers a variety of objects with different sizes, masses, temperatures, ages, and other physical properties. On the one hand, there are huge massive stars that easily overshadow one as the Sun. On the other, there are less graceful, but still very interesting inhabitants: small low-mass stars or objects that come out of the stellar classification. These last objects are called “brown dwarfs”.
For some people, recent images of the Rosetta space program have been slightly disappointing. We expected to see the nucleus of the Churyumov-Gerasimenko comet as a brilliantly shining body. Instead, images from Rosetta are as black as a lump of coal. Galileo Galilei would be among those not to share this sense of disappointment.
In 1980, Walter Alvarez and his group at the University of California, Berkeley, discovered a thin layer of clay in the geologic record, which contained an anomalous amount of the rare element iridium. They proposed that the iridium-rich layer was evidence of a massive comet hitting the Earth 66 million years ago, at the time of the extinction of the dinosaurs. The Alvarez group suggested that the global iridium-rich layer formed as fallout from an intense dust cloud raised by the impact event.
Light occupies a central place in our understanding of the world both as a means by which we locate ourselves in nature and as a thing that inspires our imagination. Light is what enables us to see things, and thus to navigate our surroundings. It is also a primary means by which we learn about the world – light beams carry information about the constituents of the universe, from distant stars and galaxies to the cells in our bodies to individual atoms and molecules.
American consumers have increased their purchases of artisanal foods in recent years. Grant McCracken, an anthropologist who reports on American culture and business, identifies ten concepts that the artisanal movement is composed of and driven by. These include preferences for things that are handmade, on the human scale, relatively raw and untransformed, unbranded, personalized […]
The business of condensed-matter physics is to explain why the world appears as it does to our naked eyes. This is a field lacking the glamour of high-energy physics or the poetry of astrophysics. The general public is quick to forget that smartphones owe much to the manipulation of electron herds in the Silicon Forest and the quantum theory of solids.
One of the central concepts in chemistry consists in the electronic configuration of atoms. This is equally true of chemical education as it is in professional chemistry and research. If one knows how the electrons in an atom are arranged, especially in the outermost shells, one immediately understands many properties of an atom…
In the popular imagination, science proceeds with great leaps of discovery — new planets, new cures, new elements. In reality, though, science is a long, grueling process of trial and error, in which tantalizing false discoveries constantly arise and vanish on further examination. These failures can teach us as much — or more — than its successes.
The periodic system, which Dmittri Ivanovich Mendeleev presented to the science community in the fall of 1870, is a well-established tool frequently used in both pedagogical and research settings today. However, early reception of Mendeleev’s periodic system, particularly from 1870 through 1930, was mixed.