Sunday, March 30, 2008
Byzantium: The Surprising Life of a Medieval Empire
by Judith Herrin
$19.77 in the Hansisgreat Store
This is an extraordinary new book on a fascinating and little understood part of history: the Byzantine Empire.
In the fifth century, Europe experienced the fall of the Roman Empire. The western empire collapsed into hundreds of tiny, independent countries and entered the system of feudalism which characterized the Middle Ages. The eastern empire, however, stayed together in one big piece, called the Later Roman or Byzantine Empire.
Among other things, the Byzantines were essential to the spread of Christianity. Indeed, their capital city of Constantinople was filled with the most lavish cathedrals, centuries before western Europeans abandoned paganism. Construction on Hagia Sophia (pictured) was completed almost 1000 years before Columbus discovered America. It remains a breathtaking masterpiece of medieval architecture.
Their eastern border was shared with the Persian Empire, and great portions of their territory were soon invaded by the mighty nations of Islam. Without this first line of defense, Christendom probably would not have survived the Middle Ages into modern times.
Some of the leaders are really magnificent. Their first emperor, Constantine the Great, is most famous for his conversion to Christianity. His reasons for doing so may surprise you.
Others were not so lovable or revered. Consider the emperor Phocas (602 - 610), whose fondness for torture would cast a sinister shadow over the next several centuries.
The Empire endured from 330 - 1453, so obviously there's too much information to explain here with any degree of competence. Suffice it to say that Byzantium is one of the great stories of the Middle Ages, and it seems to represent a giant dark patch in most peoples' knowledge of history.
It's a very exciting story: loaded with war, intrigue, disaster, and redemption. You'll se people at their worst and at their absolute best. Dr. Herrin does an amazing job of condensing an overwhelming amount of material into one short, easy to read volume.
Truth is often stranger than fiction. Here's some non-fiction that reads like Star Wars, yet informs like the lengthiest, driest textbook. An A+ from me!
Posted by Hansisgreat at 11:07 PM
Saturday, March 29, 2008
Tonight is a special night for fans of these chemistry posts. These are three of the most important and interesting elements, and some of the earliest discovered and used by man. They have biological uses for all plants and animals, in fact life couldn't exist without them. We also use them in our culture for electricity, machinery, our money, and thousands of other things.
Let's give it up for...
Atomic Symbol: Ni
Atomic Number: 28
Much of the nickel that is mined here on Earth arrived here in the form of giant meteorites, hundreds of millions of years ago. One example is in Ontario, Canada. It is estimated to weigh 200 million tons, and supplies about 30% of the world's demand for nickel. Annual production exceeds 500,000 tons and it will last for at least 150 more years.
One remarkable alloy of the metal is nickel aluminide (Ni3Al), which has a unique property at high temperatures. It is six times stronger than stainless steel, and it gets stronger as it gets hotter. At 500oC it is twice as strong as it is at room temperature.
Another curious alloy is nitinol (55% nickel, 45% titanium), which has the ability to "remember" a previous shape that it had. Eyeglass frames made from nitinol can be bent and jump back into shape when released.
Atomic Symbol: Cu
Atomic Number: 29
Copper beads have been excavated in Northern Iraq that were more than 10,000 years old. It was by far the earliest metal worked by man because of its low melting point.
Bronze is nine parts copper and one part tin. Adding a small amount of tin makes the alloy harder and also makes it possible to give it a sharp edge. Cultures who made this discovery moved out of the Stone Age into the so-called Bronze Age, beginning around 3000 BC.
Some of the ancient uses of bronze were spectacular. The Colossus at Rhodes was a bronze statue that was 35 meters high, but was destroyed in an earthquake only 50 years after being completed.
The blood of the octopus is blue because it relies on a blue copper compound to carry its oxygen, whereas most creatures rely on the deep red iron compound hemoglobin. Both seem to do the job equally well.
Atomic Symbol: Zn
Atomic Number: 30
The German Chemist Andreas Marggraf was the first to identify it as an element in 1746, but zinc had been known and used for centuries before that date. Strabo (66 BC - AD 24) mentions an ore from Cyprus that, when refined, resembled "mock silver", and that could be mixed with copper to produce brass.
Zinc oxide is mixed with plant oils in calamine lotion, and as a sun-blocker against damaging UV rays which can cause skin cancer.
Zinc sheets have often used in roofing, most famously in Paris where they created the attractive roofscapes which inspired many paintings. Zinc roofing has a long life, and may function for over 100 years without maintenance.
My posts on the previous elements are available here.
An exceptional book of reference on the subject is Nature's Building Blocks: An A-Z Guide to the Elements, by John Emsley. This and other fine volumes available through the Hansisgreat Store.
Posted by Hansisgreat at 10:30 PM
Thursday, March 27, 2008
Modern cosmology considers the Big Questions of how the Universe was created and how it will all end.
In 1658, and Irish bishop named James Ussher reconstructed a chronology of the Universe based on the information in the Bible (considered the standard method at the time). His calculations placed the date of creation on 23 October, 4004 BC.
Modern scientists like Charles Darwin suggested a very different possibility for the development of life on Earth. His theories suggested that the Universe must be far older than anyone had previously considered. Natural Selection and Plate Tectonics both involve very gradual changes which occurred over millions or billions of years.
Most scientists now believe that the Universe began with a Big Bang. Most people are somewhat familiar with this idea. All matter and energy was once compressed into an infinitely small dot called a singularity. Intense heat and pressure caused a massive explosion which cooled and expanded to form the Heaven and the Earth.
Time and Space were created along with the Universe, so there was no "before" the Big Bang. Scientists think they know what happened after the Big Bang, except for the first millionth of a second. During this period, called Planck Time, fundamental forces and the laws of physics were still forming.
The temperature at the Big Bang was roughly ten trillion trillion times hotter than the core of our Sun.
The most important evidence suggesting the Big Bang was discovered by Edwin Hubble. Using modern telescopes, he noticed that other galaxies seemed to be moving away from Earth. This is true no matter what direction you look in: they're all moving away from us, suggesting that the Universe is expanding. Extrapolating backward over billions of years, he theorized that all matter and energy must have once been contained in a very tiny space.
Astronomers believe that the Universe came into being between 12 and 15 billion years ago. A small amount of tv static is actually created by radiation left over from the Big Bang, which has taken countless billions of years to reach Earth.
Perhaps a billion years after the instant of creation, gas clouds formed giving birth to the first stars. Five billion years ago our Sun was born and the Solar System began forming. Earth became a planet about four and a half billion years ago.
There are an awful lot of good books on astronomy and the origins of the Universe. Two of the best are The Short History of Nearly Everything, by Bill Bryson and Don't Know Much About the Universe, by Kenneth C. Davis. Both do an incredible job of explaining very complicated material in a way that's interesting and easy to follow.
Posted by Hansisgreat at 9:14 PM
Wednesday, March 26, 2008
The Blue Star, by Tony Earley
$16.13 in the Hansisgreat Store
This is the sequel to Jim the Boy, a novel which was popular a few years ago about a naive farm boy raised by his mother and uncles in rural North Carolina. It's set as American small towns are getting electric power, running water, and becoming industrialized.
In The Blue star, Jim is a senior in high school. It's the oldest story in the world: torn between two lovers, feeling like a fool. He's been involved romantically with a young lady named Norma, a childhood friend with whom he seems to be on the fast track to marriage.
Enter the lovely and seductive Chrissie, a half Cherokee girl from the other side of town. Just looking at her hair from his classroom desk is enough to give Jim dizzy spells as he falls head over heels for the chick everyone insists is all wrong for him.
Mostly, this is a novel about growing up and facing the often scary consequences of the adult world. Jim gives Chrissie a ride home as she experiences female complications, and quickly learns that there's a dark side to his raven haired beauty.
His best friend gets a teenage girl pregnant (yes, they did have unwed teenage mothers in those days), and he comes to terms with the death of a rival boy who's killed at
the beginning of World War II.
The war is probably the most interesting theme in the book. We never see any military action in remote Aliceville, North Carolina, yet even here the fighting taints everything that happens to these simple, peaceful people.
Jim is completely adorable from beginning to end. He tells girls that he loves them without truly considering the consequences of what that implies. He means well, of course, he's just horny and not well schooled in such matters. He's also a bit of a hothead, but adolescence is emotional so this is to be expected.
Living on a small farm in the good old days is often said to have been a simpler life. The Blue Star is a novel of how such people in fact did have intricate lives full of complex problems. Still waters run deep. This book is quiet and unassuming, with surprising depth of emotion from characters who bear their suffering silently and do what they must.
Reading this book felt like a quiet summer evening when we were young, lying outdoors and looking up at the stars.
Posted by Hansisgreat at 6:43 PM