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In the 1860s the formula for making pressed glassware changed. Manganese was substituted for lead to act as a stabilizer and to make the glass brighter and clearer. Nearly every major American glass manufacturer used manganese dioxide for such a purpose until 1915, when industrial chemists realized that selenium made for a better stabilizing/clarifying agent.
Because of the nature of manganese, the glassware manufactured during the late nineteenth century has some unique properties. Original manganese glassware glows brightly under a blacklight (although vaseline glass, glass tinted yellow with uranium does the same thing). When exposed to the sun over the years, as in a bright kitchen or a window, manganese glass takes on a slight amethyst purple cast. Glass objects with a faint hint of sun purple betray their provenance, but they also lose some value–since antiques dealers regard the effect as “discoloration”.
However, some people became obsessed by the sun purple effect and put their antique glassware outside for months in order for it to fully turn cloudy purple in the sunlight. This “solarized” glassware could then be sold to novice antiques collectors (often with a little card explaining “sun-purpling”). Dealers realized that the causative factor behind the color change was ultraviolet radiation, and so instead of putting glass outside they exposed it to radiation from UV sterilizers (a common anti-microbial tool in bio labs and hospitals). As you read this, somewhere out there is a room full of ornate glass pitchers, sugar dishes, and goblets being irradiated with blistering ultraviolet waves!
Seasoned glass dealers are aghast at the practice, which leaves everything a murky washed-out pale purple. Additionally there is glass currently being deliberately manufactured to resemble the manganese purple solarized glass. To confuse the issue even further, there is also glass manufactured in a robust shade of purple (for people who like purple) which is named “amethyst” glass.
A day ago an international team of stellar physicists announced that the sun’s surface is covered with thousands of searing hot plasma super tornadoes each of which is the size of a large continent on Earth. Using a combination of a space telescope and a ground telescope, researchers discovered that each of these plasma vortexes spins at velocities up to 14,500 kilometers (9,000 miles) an hour.
The mystery of why the corona of the sun is 300 times hotter than the star’s surface has long vexed scientists. The surface of the sun is a balmy 5,526 degrees Celsius (9,980 Fahrenheit), while temperatures in the corona peaks 2 million degrees Celsius (3.5 million Fahrenheit). The discovery of these giant fast-moving storms provides a new mechanism by which heat is transferred through the sun’s atmosphere and ejected into the corona. Energy locked in the powerful magnetic vortexes is effectively self-insulated and does not heat the solar photosphere and chromosphere as much as the corona (where the storms widen and dissipate).
Sven Wedemeyer-Böhm, a Norwegian scientist working on the team was quick to stress that the tornadoes are likely one of several complicated energy transfer mechanisms by which heat reaches the solar corona. However it seems that there are more than 11,000 of these huge plasma tornadoes on the solar surface at any given time.
Welcome to Egypt week at Ferrebeekeeper! All of this week’s posts will share an Egyptian theme. To start out Egypt week, we cast our gaze deep into the underworld beneath the Nile and the burning desert. The dark river passages beneath the world are said to be the home of the principle ancient Egyptian god of chaos, the great serpent Apep (AKA Apopis or Apophis).
According to myth, the sun god Ra carried the sun across the heavens on a mystical solar boat every day. Then every evening Ra returned from west to east via an unseen river path through the underworld. As night covered the world and the sun god struggled to return to the farthest point in the east in time for sunrise, the great serpent would appear from the dark waters to attack the boat.
Apep would try with all of his might to devour the sun in the manner than a serpent eats an egg. Some myths maintain that Apep was the sun god before Ra and wanted the sun back out of dynastic bitterness. In other sources the great demon is not ascribed with a back story and is only a huge snake who wants to eat the sun. Sources agree that Apep was not so much worshiped as “worshiped against.” Many prayers and liturgies from ancient Egypt are magical incantations to help the gods stave off attacks by the huge poisonous snake.
Ra was assisted in fighting off the nightly attack by an unlikely figure, the powerful god Set–a fratricidal maniac with the head of an unknown animal (who doubles as the god of evil and the desert). Whatever Set’s other faults might be, lack of vigilance against giant chaos serpents was not among them. In several passages from ancient literature, Set is heard to boast about his prowess and bravery in making sure the sun gets past the serpent in order to rise on time. The spirits of the devout who had passed to the next life could also help out by rowing the beautiful boat. In later Egyptian myth, the battle goddess Bastet would also assist Ra and Set in fighting the demon.
Of course despite the best intentions of the gods, Apep would occasionally get the upper hand and temporarily run off with the sun. Such (rare) days were marked by storm and overcast skies. Additionally the wily snake demon would sometimes leave the underworld and try to devour the sun as it gloriously made its way across the heavens. According to Egyptian superstition, these occasional daytime attacks were responsible for solar eclipses. Fortunately Ra and the other protectors of the sun could always rely on a reservoir of spiritual energy to drive back the snake (helping the gods defeat Apep was one of the purposes of worship in ancient Eypt). Because of the power of prayer, Apep, dreadful demon snake of the underworld, never did succeed in devouring the sun.
Shamash was the Mesopotamian deity of the sun. To the Akkadians, Assyrians, and the Babylonians he was synonymous with justice, generosity, and salvation. However there was a second solar deity in the Mesopotamian pantheon, Nergal, who was not associated with such positive aspects of existence. Nergal was the child of Enlil, god of the wind, who was exiled from earth for raping Ninlin, the goddess of the open fields. Ninlin followed Enlil into exile and gave birth to their son Nergal in the underworld (Sumerian myth-makers should be ashamed of the sexism of this story). Nergal’s dark origins foreshadowed his nature. Unlike Shamash, who represented the life giving power of the sun and divine justice, Nergal was only associated with certain phases of the sun. To quote Wikipedia “Portrayed in hymns and myths as a god of war and pestilence, Nergal seems to represent the sun of noontime and of the summer solstice that brings destruction, high summer being the dead season in the Mesopotamian annual cycle.”
As a god of plague, drought, fire, and insufferable heat, Nergal quickly came to be associated with death and the underworld. He was portrayed either as a powerful man bearing a sickle-sword and a mace, or as a lion with a man’s head.
Although he was a terrible god of destruction, the main myth we have about Nergal is romantic in nature. Mesopotamian scholars have discovered and translated a poetic epic recounting Nergal’s tempestuous courtship of the dark goddess Ereshkigal (the queen of the underworld, who once gave Ishtar such a wretched time). After a passionate tryst, Nergal left Ereshkigal, who thereafter was overwhelmed by passionate longing for further intimacy. Hearing of her unhappiness and realizing how much he in turn missed her, Nergal abandoned his place in the heavens and traveled down through the seven gates of hell to rejoin Ereshkigal. The two death gods then shared a bed for seven days and seven nights before marrying and jointly sharing rule of the underworld (it’s a happy story!).
Despite the felicity of his connubial circumstances, to the people of Mesopotamia, Nergal represented the unpredictability of mortal life and early unnatural death. He was worshiped, particularly at his chief temple located at Cuthah (a smaller city just northeast of Babylon) but his cult was far from the most popular. Unlike many other Babylonian deities, Nergal was mentioned in the Bible (2 Kings 17:30) and his name has therefore found a place among the demons and boogeymen of Christianity. If you search for “Nergal” on the internet you are likely to find the picture of a heavy metal singer from Poland dressed up in gothic makeup!
Yesterday NASA’s spacecraft MESSENGER entered orbit around Mercury, the least explored of the Solar system’s rocky inner planets. This is the first time a spacecraft has been in orbit around Mercury and it represents a tremendous engineering achievement. Since gravity becomes more intense the closer one comes to the sun, Messenger had to slingshot back and forth among the inner planets for some time in order to accomplish the tricky feat. The spacecraft had to undertake a 4.9 billion mile (about 7.9-billion kilometer) journey to enter orbit around the closest planet to the sun. Of course that hefty mileage only is equal to 0.00083 light years!
Having survived the grueling trip, the spaceship must now carry out its mission in the blistering bath of solar radiation. To survive next to the star, Messenger is equipped with a large sun visor which prevents the little craft from frying like a quail egg.
Messenger will try to determine the planet’s mineralogical composition and learn about its geological history (the surface of Mercury is reckoned to be one of the oldest in the solar system). The robot probe will fully map Mercury and analyze the planet’s composition. Like Earth (but unlike Mars and Venus) Mercury has an internal magnetic field. Additionally, the tiny world is incredibly dense. In order to learn more about the planet’s core Messenger will measure the extent to which the planet wobbles on its rotational axis. Studying the partially molten interior of Mercury should provide clues about how the planet formed which will help us better understand the creation of all planets (especially in conjunction with the flood of data regarding exoplanets which we are beginning to receive).
Since the craft will be trying to learn the secrets of Mercury’s molten interior, it is worth reflecting on the deity whom the planet is named after. Although he was worshipped as a messenger, a herald, and a god of commerce, the Greco Roman god Hermes/Mercury was also quietly worshipped as a god of the underworld. The Greeks and Romans regarded him as a psychopomp who guided souls down to Hades with his magical staff. Because (like the somewhat similar African traveling god Eshu) Hermes was able to go anywhere at will he was one of the only entities in the Greco Roman pantheon free to enter and leave the underworld.
Although we are not capable like Mercury of going everywhere at our whim, I think it is a tremendous accomplishment to navigate a robot spacecraft into broiling orbit around the innermost planet. That we are using the craft to learn the secrets of the fiery underworld of the swift planet seems like a fitting tribute to the god who was slayer of Argus, giver of charms, messenger, schemer, luck bringer, and patron of travelers and wayfarers (even those voyaging to their last end or to places the ancients could never dream of).
Three days ago, on August 1st, 2010, a great mass of plasma was ejected from the sun. The cloud of protons and electrons reached earth last night where it collided with the planet’s magnetic field to produce a series of spectacular aurora lights. Because of the strength of the coronal flare, the dancing streamers of red and green fire were visible across much of the temperate part of earth and not just near the poles. A second coronal mass ejection is due to arrive tonight. These are the first big coronal flares which have headed towards earth for quite a while so, unless you are a jaded Inuit or world-weary arctic explorer, you should keep an eye towards the nearest pole.
The sun is entering an active portion of its eleven/twelve year sunspot activity. The peak year is projected to be in 2013. Solar activity was mild throughout the twentieth century, but our star has not always been so quiescent. At 11:18 AM on September 1st, 1859, a British astronomer, Richard Carrington, was observing a projection of the sun on a yellow glass and illustrating the sunspots he saw. Suddenly, in the midst of a great boiling mass of spots, two kidney shaped points of light formed and grew intensely bright. Here, halfway down the page, is Carrington’s hilariously Victorian description of the event taken from NASA’s website.
Carrington was the first to directly witness a coronal mass ejection, when the sun’s opposing magnetic fields rip great hunks of plasma into space. After traveling 93 million miles, the particles from the 1859 ejection created spectacular aurora lights visible as far south as the Caribbean. Blood colored light shone across the night skies of the world. The solar storm played havoc with telegraph wires and the telecommunication system of the day was rendered completely unusable. Parts of the system burst into flame. Keep in mind this was 1859 so telecommunications consisted of ponies, men with semaphores, and a handful of telegraph wires. If a storm of such magnitude struck today, it would fry our communication satellites like chicken livers and do horrible, horrible unspeakable things to our electric and fiber optics grids. From beryllium deposits in polar ice cores we know that solar storms of the magnitude of 1859 are rare. They usually occur once every five centuries or so. However the sun is famously unpredictable.
These days we do not have an Englishman sitting in a study looking at a bright circle on a straw-colored sheet (or maybe we do, but he is unimportant and rather silly). Humankind now has a fleet of spacecraft which continuously monitor the sun (perhaps you might take a moment to reflect on how remarkable that sentence is). Here is movie taken by the Transition Region and Coronal Explorer (TRACE) of a coronal mass ejection which occurred in 2001. The sun is behind the opaque dot in the middle. Notice how the exotic radiation from the flare’s peak addles the craft’s movie making ability.