Bob Doyle

Bob Doyle

Both astronomy and chemistry had false starts: astronomy as astrology and chemistry as alchemy.

Astrology asserted that the positions of the stars and planets ruled human destiny while alchemy maintained that by combining certain substances one could produce a “philosopher’s stone” that could transmute base or common metals into gold.

These two pseudo-sciences were pursued for thousands of years, yet they yielded valuable insights into nature.

Astrology focused on the precise relative positions of the sun, moon and planets relative to the stars of the zodiac. Astronomical observations by Tycho Brahe allowed Johannes Kepler to determine the actual paths of the planets around the sun.

Decades later, Isaac Newton was able to derive Kepler’s laws of planetary motion. These laws have allowed NASA and other space agencies to send probes to orbit remote planets and determine the compositions of other planet’s atmospheres.

Alchemy started out with unproven beliefs about the nature of matter. The most prevalent idea was that there were five elements: air, fire, water, earth and ether.

Many properties of matter could be explained by philosophers by the first four elements we could sense: the motion of sky bodies was due to their being made of ether (quintessence), a substance that was eternal and could only move circularly.

Chemistry is the science of the transformation of matter. The discovery of fire from lightning strikes or striking flint against each other led to a way of clearing out brushes and flushing out game, tenderizing the flesh of animals and plants that could be more easily digested by cooking.

The earliest pigments were used in painting in caves in South Africa 70,000 to 100,000 years ago. Kilns for making pottery first appeared about 6000 BC. Clay was used to make bricks using ovens which would be much stronger than those baked in sunlight.

Ancient Egyptians used a variety of pigments, dyes and metals for their paintings and cosmetics. Their pigments used cobalt, lead and copper. Gold was connected with the sun, iron with Mars, copper with Venus and lead with Saturn. Lead compounds were used heavily in black eye shadow.

As early as the 16th century BC, Egyptians had furnaces hot enough to make glass. The Egyptians were accomplished in pharmaceuticals. Their medicines were based on lead and antimony.

Better known is the Egyptian art of mummification. Egyptians first extracted the mummy’s brains through their nostrils. Key internal organs were removed (heart, liver, intestines) and stored in jars.

They used natron, which absorbs water and acts as an antibiotic. They also used sodium carbonates, raising the pH of treated flesh and retarding bacterial growth. The dried corpses were coated with pitch and tars, then wrapped in linen. In this way, mummies can stay unchanged for thousands of years.

Six metals have been known since prehistory. They are gold, silver, tin, copper, lead and iron. The first evidence of working with copper is a copper smelting site in Serbia from 5500 BC. (Smelting heats the ores to high temperature and removes the oxides.)

It took centuries before it was realized that by mixing copper with arsenic or tin makes a harder alloy — bronze. Bronze became used in making tools and weapons. The widespread use of bronze brought the Stone Age to an end.

The Bronze Age began about the fifth millennium (5000-4000) BC in the Middle East, India and China. Bronze containing tin was first used around 4500 BC in Serbia. Ores containing these two metals are not found in the same region, so both metals had to smelted first, transported and then mixed together while molten.

The discovery of iron ores marked the end of the Bronze Age and the beginning of the Iron Age between 1200 BC and 600 BC. Iron melts at a much higher temperature (1538 C or 2800 F) than other metals so charcoal had to be used. Despite this difficulty, the Bronze Age gave way to the Iron Age.

SKY SIGHTS IN THE COMING WEEK:Dawn begins just before 6 a.m., sunrise is 6:56 a.m., mid-day is 11:59 a.m., sunset is 5:02 p.m. and dusk ends about 6 p.m. Daily sunlight lasts 10 hours and six minutes.

The bright planet Jupiter sets about 7 p.m. The planet Saturn in the southwest at dusk sets about 9 p.m.

Bob Doyle, professor emeritus at Frostburg State University, invites any readers comments and questions. E-mail him at rdoyle@frostburg.edu. He is available as a speaker on his column topics.

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