Monthly Archives: September 2014

Descartes’ Famous Phrase: “I Think, Therefore I Am”

DescartesRené Descartes was an influential figure in the scientific revolution, and is considered to be the founder of modern philosophy. In 1637 Descartes wrote his well-known phrase: “I think, therefore I am.” He wrote this to rescue himself from doubt (the doubt of his own existence). He equated thinking with existing; therefore the awareness of his thoughts meant he was certain he existed. Descartes believed that the senses were unreliable, and ultimately, it was through the mind that one could arrive at the truth. Only reason could ascertain what was fundamentally true. He used examples such as: to the senses a stick in water appears to be bent, and the sun and the moon appear to be the same size.

The Evil Demon

For Descartes, doubt was central to his method of acquiring knowledge. He would tear down an idea through doubt and skepticism, and see if anything survived. His system has a likeness to the modern scientific method, as nothing is taken for granted. A hypothesis needs to be verified by tangible evidence in order to become accepted as knowledge.

He even went as far as imagining an evil demon, which created an illusion of the outside world and his own body. He concluded that if the deception was real, the fact that he was doubting his existence meant that someone was doing the doubting. Descartes concluded that the one thing he could know with absolute certainty was that he was thinking.

I Think…I Am

If we break up the phrase we see that Descartes’ statement is only a partial truth. To be aware of ones thoughts, there must be another dimension of consciousness apart from thought (something to witness the thoughts). The “I think” is separate from the “I am.” This was the insight of 20th century philosopher Jean-Paul Sartre when he examined Descartes’ statement.

To be thinking one must first be conscious. Although neuroscience is still trying to decipher the nature of consciousness, scientists are proceeding with the assumption that the secrets lie within the brain. Our experience is largely influenced by the activity in the brain. As it relates to consciousness, our thoughts are similar to our senses, as contributors to consciousness. Our thinking brain is a tool (a very valuable one), but it is not the totality of our existence.

The Power of Unconsciousness

There is still another level of existence that requires no thoughts or awareness. This is the unconscious processes that underlie all of existence, including ourselves. As familiar as conscious experience is to us and as complete as it feels, ultimate reality is much deeper. We generally accept that much of the world around us is without consciousness. For example, inanimate substances, plants, water, air, etc.

When it comes to humans (and animals to a lesser degree), we see ourselves as sentient beings. Yet consciousness emerges from a collection of unconscious processes. Focusing only on physiological functions, we can see how this works: we are unaware of our cells, blood, hearts, neurons, hormones, nerves and other bodily functions. Yet they all play a role in creating our experience. Clearly the brain has some critical input in regulating these activities, but that is mostly the unconscious brain.

It seems that Descartes’ conclusion was in effect describing the outer layer of self-awareness. Like an onion, the “I think” is the outer skin. The “I am” (consciousness beyond thought) is a deeper layer. And the core (unconscious life) is essentially the source that gives rise to experience, or as Descartes would have called it, existence. You could also say that Descartes was identifying solely with his thoughts. His sense of self was derived by his thinking mind, but he was much more than that.

 

References: Eckhart Tolle, A New Earth (New York: plume, 2006)

BBC Radio 4, In Our Time Philosophy: Cogito Ergo Sum (April 28, 2011)


 

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Darwin’s Theory of Evolution: The Best Idea Ever

Charles darwinCharles Darwin’s 1859 publication, On the Origin of Species, changed the way we look at biology forever. Its central idea, evolution by means of natural selection, explains how all life evolves. No single idea has ever explained so much. It stands apart from most, if not all, scientific discoveries in its outreach and simplicity. As with most great ideas, once grasped, one is inclined to ask: “Why didn’t anyone think of this before?”

Actually, others had similar ideas before Darwin, including fellow naturalist  Alfred Russel Wallace. Wallace had figured out that species evolve through natural selection and sent Darwin his version prior to Darwin’s landmark publication. In 1858 they jointly presented their work to the Linnean Society of London. But ultimately, it was Darwin’s detailed explanation in 1859 that history would recognize.

The Idea

Organisms evolve over time by means of natural selection. Each generation is tested by its environment; the traits that aid an organism to survive and reproduce will tend to be passed on to the next generation. Not necessarily all the time, but often enough or in greater numbers. Traits that are not useful will tend to be discarded when the organism that bears them fails to survive or reproduce.

Through this process survivors are copied with slight random variations, which are then tested many times over. In other words, survivors live longer and usually reproduce more, keeping their survival traits alive in the ensuing generations. Darwin wasn’t the first to suggest that organisms evolve from previous forms, but he provided the mechanism (natural selection).

Why is This Idea so Special?

  • Outreach: Natural selection provides an explanation for how all of life evolves. It accounts for microorganisms, plants, fish, insects, birds, animals and of course humans.
  • Simplicity: As oppose to other notable scientific ideas it can easily be understood by the general public. One does not need any technical science background to grasp the basics of this simple, yet elaborate idea.
  • A confidence boost for science: Before Darwin, few could have predicted that all life on earth could be explained by natural means. Ever since Darwin, few should doubt the power of science to explain just about everything else.
  •  Philosophical implications: Darwin compelled us to take a second look at our place in the world. Long-held beliefs that humans held a privileged position, separate from the other creatures, had to be re-evaluated.
Darwin's Tree of Life

Darwin’s Tree of Life

The Controversy

Darwin delayed the publication of his theory of evolution for about 17 years, because he feared a public backlash. And he was right in assuming that controversy would follow. His chief concern, I can only speculate, was probably religious. Natural selection can easily be viewed as taking god out of the creation business. If nature is shaping all of life, what is god left to do? Despite some criticism, his book drew worldwide interest. Even today evolution still gets some people upset. Why is such a profound idea so difficult for some? Let’s look at possible reasons why:

  • Religious : Evolution contradicts the bible’s account of creation; however, many people seem to have no problem squaring evolution with the bible. They either don’t really know what the bible says or they don’t take it literally. Whereas literal interpreters of the bible clearly see what evolution means for their faith. For them evolution is akin to a fatal blow.
  • Supernatural thinking: If one is inclined to believe that there exists a dimension outside the laws of nature, then anything is possible. Life can then be guided by a supernatural force. If that is the case, evolution is no longer required as an explanation.
  • Evolution is confused with natural selection: I suspect that some people think of evolution as simply gradual change over time. In terms of the cause, they can use their imagination. However, the key insight is the means by which change happens. Evolution is the process and natural selection is the mechanism.
  • Deep time: There is nothing in everyday experience that can prepare us for the time scales involved in evolution. Simple life emerged on earth (in the ocean to be exact) 3.8 billion years ago. And from there spread to all regions of the planet. That’s 38 million centuries for life to evolve to eventually create you and me. Given enough time, minor variations in each generation can result in changes that may be hard for some to grasp.          
  • Sometimes the truth hurts: There is no plan in evolution, no final destination that has to be achieved. Furthermore, human beings don’t hold any privileged position in the tree of life. Darwin described life as a family tree, with different species spreading in all directions. Life could no longer be seen as analogues to a ladder, with humans occupying the top rung.  

A Scientific Idea

Darwin’s idea was much more than a moment of insight. It was a scientific idea, a theory that he developed based on years of experience as a naturalist. As a young man Darwin sailed across the globe on the HMS Beagle. He accompanied Captain Robert FitzRoy on a 5 year journey, where Darwin collected a multitude of natural specimens and fossils. It is on this voyage, from 1831 to 1836, that Darwin gathered extensive evidence for his theory of evolution.

Darwin collected many fossils; some were from ancient sea creatures, which he found in mountainous regions. This was clear evidence that mountains moved over time—that a high altitude had once been under water. From a geological perspective the earth had changed slowing throughout the ages. This principle of gradual change over time was extended to include life forms. If the earth changed, life could also change.

Influential to forming his ideas, Darwin collected bird specimens (finches) from the Galapagos Islands in South America. He noticed that the shape of the finch’s beaks varied depending on the island they came from. Darwin reasoned that the finches all originated from a common ancestor, and had evolved different beaks. The finches had become isolated on separate islands, thus evolving differently to meet the demands of the local food supply.

These and other similar ideas got the wheels in motion for Darwin, showing him that species were not stable, that they can change dramatically over long periods of time. Some of the fossils he unearthed were from extinct species, distant ancestors that resembled species that were still living. He also examined different mammal skeletons and noticed they were all variations of a similar bone structure. Beyond his own ideas, Darwin corresponded with other naturalist around the world through letters, thus gathering piles of information.

It would eventually culminate in the publication of On the Origin of Species. Darwin surely struggled with the implications of his theory, as it would have been radical in Victorian England. Creationism was the overwhelming belief of the time; however, it became clear to Darwin that organisms where not created in their present form. Darwin must have been apprehensive upon the publication of his book. Nevertheless, he was guided by the overwhelming evidence he observed as a scientist. He had to accept what his scientific mind was telling him, regardless of the belief of the day. Darwin’s Theory of Evolution is a great scientific idea, and that is why it still stands today.

 

References: The Genius of Charles Darwin, The Science Foundation, https://www.youtube.com/watch?v=ptV9sNezEvk, Published on Jan 12, 2011.


 

Discovering the Nature of Gravity

Of course we all know what gravity is. It’s the force responsible for making objects fall, keeping our feet firmly planting on the ground, and maintaining the moon’s orbit around the earth. But by what mechanism does gravity accomplish these tasks? Surely there are no invisible strings of a master puppeteer. The full story behind understanding the force of gravity spans at least 400 years. Three giant steps have led to modern physics’ current picture.

Heliocentric Modle

 Step 1: The Copernican Revolution, Galileo and Kepler

Just before he died, in 1543, Nicolaus Copernicus published his famous work describing the heliocentric model of the universe. Although he had formulated his theory years earlier, he delayed publishing until the end of his life. This was probably because he feared criticism from contemporaries or retribution from the church. Placing the sun at the center of the known universe (as opposed to the earth) was a revolutionary idea for its time. This was a monumental leap in the early scientific age.

The idea that the earth moved went against common sense and intuition. In reality, whether the sun moved or the earth moved could not be determined by visual means. Sometimes science has to rely on other methods; in this case, the daily/monthly movements of the planets had to be charted and analyzed.

An object can only be said to be in motion in reference to something else. For example, if you are on a boat that is departing from a large dock, and you look to your side, you will see the dock moving. For an instant you will think that the dock is moving. Then you realize this can’t be true. You may feel the boat rocking or accelerating, but from a visual point of view you can’t tell which is moving.

Years later, Galileo adamantly supported Copernicus’ view and took the brunt of the attack from the church. He was sentenced to house arrest, where he spent the last decade of his life. Nevertheless, Galileo’s contribution to science extended much further than the celestial model. He was instrumental in establishing observation and experimentation as pillars of scientific reasoning. It was becoming clearly that there was order and predictability in nature, which was accessible to human analysis.

Johannes Kepler also lived in Galileo’s time, and he was able to calculate the motion of the planets using mathematics. His most famous work is known as the laws of planetary motion, a precursor to Newton’s laws. In the process he calculated that the orbits of the planets were not perfect circles as originally thought. But rather moved in elongated circles called ellipses. Although the movement of the celestial bodies were being charted in great detail, there was still no comprehensive theory of gravity.

 Step 2: Newton’s Insights

Newton's Cannon

Newton’s Cannon

Isaac Newton imagined a cannon perched on a mountain top and asked himself the following question: what would happen if cannon balls were fired at steadily increasing speeds? The first few balls would start out in a straight line and then fall to the earth in a curved trajectory. However, if he kept going, something peculiar would happen. The curved path of the cannon ball would eventually match the curvature of the earth. The cannon ball would be in perpetual free fall, and orbiting the earth.

This was the key insight. The same force that was responsible for maintaining the orbits of the moon and planets also caused an apple to fall from a tree. No one had thought of this before. At least if someone had, it did not become public knowledge.

Therefore, the story that Newton got his idea of gravity when an apple fell on his head may not be true. He could have been thinking about cannon balls. But having a cannon ball fall on his head does not make for an inspiring story. What followed was a mathematical unity of both the heavens and earth, his laws of motion and universal gravitation. In spite of Newton’s great achievements, he still had no clue what gravity actually was. It would take more than 200 years for someone to come up with the answer.

 Step 3: Einstein’s Imagination

Among many things, Albert Einstein was famous for his thought experiments. He imagined physical scenarios, which he tried to figure out what would happen and how it could be explained. Perhaps this is how he came up with his picture of gravity.

In 1915, ten years after his theory of special relativity, he published the theory of general relativity. As it relates to the actual cause of gravity, the answer is as counter intuitive as the earth moving through space. The gravitational effects are caused by the properties of space itself; just as Einstein had shown that time was flexible (in special relativity), space was also flexible.

It is the warping or curving of the fabric of space that make objects fall and maintain the orbits of celestial bodies. It is similar to the effect of a large rubber sheet (like a trampoline). If one were to place a large heavy ball at the center of the sheet, any smaller balls would be drawn to it by the warping of the sheet (caused by the heavy ball).

Warps in Space

Warps in Space

Orbits will be created when a balance is established between the motion of a body and the distortion of the spatial fabric. That’s it, distortions in space caused by massive bodies, not a pull or push is responsible for gravity. This theory goes beyond Einstein’s imagination; it has been confirmed by scientific observations. It took 400 years of investigation to understand the basic property of one of the most familiar forces on earth.

 

References: Richard Dawkins, The Magic of Reality

The Elegant Universe 1 of 3 Einstein’s Dream (Published on Jun 21, 2012) https://www.youtube.com/watch?v=UV_X2B5OK1I

Stephen Hawking’s Universe -101- Seeing is Believing (June 14, 2013) https://www.youtube.com/watch?v=5kgPxvJqvEA