Day: January 23, 2017

At some point in history there had to be one initial crucial step that separated humans from the other animals in our journey to becoming the dominant species on this planet.  I will call that point the beginning of science and label it by humans ability to control fire. The ability to control fire was a turning point in human evolution.

The Benefits of Controlling Fire

Sometime in our ancestor’s very ancient past, and certainly by 400,000 years ago, fire came under human control.  By this time the archeological record is full of heat altered artifacts. Control of fire in human evolution was beneficial for a variety of novel reasons. These benefits include:

1. Provided protection from predators and assisted in hunting prey.
2. Provided warmth which allowed people to live in cooler regions of the planet
3. Assisted in tool making
4. Ceremonial usages
5. Allowed people to see at night
6. Provided us with the ability to cook food
7. Provided groups with a “nest” – the campsite

Protection from predators and used in hunting prey

In the struggle for survival, fire was used both defensively and offensively. Fire can be used as a deterrent because it often scares away animals. Additionally, there is evidence that first accidental and then controlled fires were used to scorch large areas of land for food. During the blaze many animals inevitably perished in the inferno. Our early humans ancestors could then walk in and “fire harvest” many of the small animals and eggs for food. These large scale fires would also create chance cooking, a prequel of intentional cooking as it led to the food being more easily digestible. Fires would also cause larger animals to flee out into the open making them easier to kill.

Fire provides warmth

Humans are well adapted to living in warmer climates but are much less well adapted to living in colder regions. The obvious reason is that we have lost much of the hair on our body. Without fur we needed another way to stay warm. Staying close to a fire allows us to survive during cooler nights and in cooler regions during the winter season.

Fire assists in tool-making

Fire allowed the forging of tools. The is evidence that Neanderthals used fire in shaping wood tools. Although wood from hundreds of thousands of years ago would not last to the present day it is likely that our ancestors would have done the same. Stone and bones last much longer than wood. There is evidence for deliberate heat altered stone and bone artifacts as far back as 1,000,000 years ago in caves across Africa. The artifacts would have been used for weapons such as a spear, or a digging stick for a food gatherer.

Fire in ceremonial usage

The raw power of fire would have been inspiring to our ancient ancestors. There is evidence that it was used in ceremonials services of sacrifices, offerings, or devotion. We still see candles displayed in many ceremonies today.

Night vision

Controlling fire allowed people to see at night. Being able to see at night adds to the time that people can be productive. It also meant people could travel much more safely at night.

Cooking food

Cooking food may have been a significant step in leading humans to the top of the food chain and even to increasing brain size, although hominid brain size was increasing before cooked food became common in early humans.  In any case, what is indisputable is that cooking food killed the parasites that infested food, allowing for easier digestion. This enabled our human ancestors to make due with smaller teeth and shorter intestines.  It is hypothesized that a smaller intestine was the factor in allowing for a larger, jumbo brain of sapiens and Neanderthals, since both the brain and the digestive tract are two are the largest energy consuming organ systems in the body.  By shortening the digestive tract it enabled the energy economy of the body to devote more resources to a jumbo human brain.

The campsite

The campsite is also believed to have functioned as a “nest” for our ancestors and therefore played a pivotal role in the evolution of our sociability.  All animals that exhibit sociability have a nest, which allow for a common place for the species to gather and stay at. Evidence of campsites exists from about 400,000 – 300,000 years ago in varying sizes and contexts.

Control of fire was a turning point in human evolution. The process happened gradually through increasing interaction with natural fires. Accidentally cooked meat provided a new sources of calories and protein that was easily digestible. A fortuitously shaped burnt stone in the shape of a sharp point would have been used for hunting or digging. Eventually our ancestors learned to control fire and made these things deliberately. We used the power of fire to forge the metals that made our tools and building structures. The benefits to our species of fire use cannot be overstated in the physical, social, and cultural realms.

Continue reading more about the exciting history of science!

The invention of the telescope in 1608 by Dutch spectacle makers provided the tool need to transform astronomy.  Word spread fast of this new invention.  By April 1609 one could be purchased in eyeglass shops in Paris.  Later that same year it spread into Italy, where word of it came to Galileo Galilei.  Galileo did not actually see a telescope, but based on its description he went ahead with the task of creating his own.  He vastly improved the instrument allowing for some of the most revolutionary and groundbreaking discoveries in the history of science.

It didn’t take very long for Galileo to make his discoveries known. Published by Galileo on March 13, 1610, Sidereus Nuncius (or Starry Messenger) revealed to the world his observations as he viewed the night sky through his improved telescope.  These new revelations changed how we viewed the composition of the universe and our place among the cosmos and heavens.  The came in direct contradiction with Aristotelian cosmology, Ptolemaic astronomy, and the most significantly the theological teachings of the Roman Catholic Church. The evidence presented in the book sided more with the Copernican System of the universe, placing the Sun at the center of the Solar System.

The Starry Messenger and its Findings

Let’s take a look at some of the profound observations and conclusions of The Starry Messenger: 

• Craters and Mountains on the Moon:  Galileo’s observations showed mountain and valleys present on the moon.  He could even estimate the height of the mountains  based on the length of their shadows.  These observations contradicted the accepted wisdom of Aristotle and the cosmology of Ptolemy that taught that the moon and other heavenly bodies were perfect spheres.  It proved there could be other worlds similar to Earth.
• The Discovery of Four of Jupiter’s Moons:  Galileo noticed four points of light following and orbiting around Jupiter, which he deduced as moons.  This further reinforced that the Earth is not the center of everything.
• Many additional stars in the night sky:  Galileo was able to observe hundreds of stars behind the stars visible by the naked eye.  This showed unequivocally that the stars were not fixed and that the universe was far larger than most people had previously imagined.

Galileo also made some other startling discoveries around this time that were not published in his book.  These observations included:

• Sunspots: Galileo observed many dark spots on the Sun that moved and changed over time.  He was able to see that the Sun itself was rotating. 
• The Phases of Venus:  The order of phases and changes in diameter of Venus proved conclusively that Venus orbited the Sun.  This proved that the Earth is not the center of the universe and that the Sun was also a center of motion.

The publication of this book began the process of upending the long held ideas of Aristotelian cosmology and Ptolemaic astronomy by providing evidence for heliocentrism and the Copernican System.  Clearly the Earth was not the center of the universe.   Clearly the revered heavenly bodies were not perfect spheres.  Clearly the universe was far larger than anyone had previously imagined.  These discoveries quickly made Galileo famous across Europe.  Indeed, he seeked fame. He dedicated the four satellites orbiting Jupiter to Cosimo de Medici II, Grand Duke of Tuscany, naming them the “Medicean Stars” after Cosimo’s family name. But the fame coupled with his arrogant personality also also brought him enemies.  It marked the beginning of his famous troubles with the Catholic Church as heliocentrism was at the time in direct conflict with Christian theology. 

In 1616 Galileo was called before Cardinal Robert Bellarmine and warned to cease his teachings of heliocentrism.  It was determined at this meeting that the Sun being placed at the center of the universe was heretical and that mobility of the Earth was in contrast to theology. For a time Galileo stayed away from teaching and promoting the Copernican System. However eight years later Galileo published a book defending the Copernican System titled A Dialogue on the Two Chief World Systems.  This work further infuriated Church as it seemed to mock the Pope as a simpleton and in 1633 Galileo was brought before the Roman Inquisition to stand trial for his supposed heresies.  Threatened with torture and ridicule, Galileo was ultimately forced to plead guilty and spent the rest of his life on house arrest at his villa near Florence.  Only centuries later, in 1992, was Galileo finally vindicated by the Catholic Church when Pope John Paul II officially declared him innocent. 

Continue reading more about the exciting history of science!