The Anthropic Principle

the astronomerWhy are we here? This is perhaps the most fundamental philosophical question. One can imagine contemplating this question at any time in human history. Many stories have been inspired by this question, usually taking the form of myths, or religious and spiritual traditions. Today, ‘why are we here’ is also a scientific question. The anthropic principle arose as a response to the question of human existence. The idea was first proposed in 1973 by theoretical astrophysicist Brandon Carter. Since then it has been expanded and stated in several forms.

What is the Anthropic Principle?

The word anthropic is defined by the Merriam-Webster online dictionary as: “Of or relating to human beings or the period of their existence on Earth.” That’s a start. For simplicity I will stick close to Brandon Carter’s original formulation, which he expressed as two variants. I will paraphrase based on the description from a few sources:

  1. The Weak Anthropic Principle refers to our special location in the universe (both in time and space), which is conducive to our existence. The fact that we can observe the universe means that planet Earth must have the conditions necessary for our existence.
  2. The Strong Anthropic Principle refers to the fundamental laws of physics, which are precisely set for our existence. The strong principle takes into account the properties of the universe as a whole.

The Burden of Proof

habitable zoneIn a vast universe it is not surprising that a planet, like the Earth, has a special location (usually called a habitable zone or a Goldilocks zone). The specific laws of the universe needed for human life are more difficult to explain (usually called fine tuning). Using a legal metaphor, the strong anthropic principle has a greater burden of proof than the weak anthropic principle. In this case, burden of proof is a figure of speech, because the anthropic principle is as much a philosophical idea as a scientific one. 

In The Grand Design, Stephen Hawking and Leonard Mlodinow describe the weak anthropic principle as an environmental factor. They write:

“Environmental coincidences are easy to understand because ours is only one cosmic habitat among many that exist in the universe, and we obviously must exist in a habitat that supports life”

The strong anthropic principle is all-encompassing and generally more controversial. Hawkings and Mlodinow go on:

“The strong anthropic principle suggests that the fact that we exist imposes constraints not just on our environment but on the possible form and content of the laws of nature themselves”

Stating the Obvious or a Profound Insight

Is the anthropic principle a satisfying explanation? On the surface, it seems like an obvious statement that explains very little. But as I reflect on the idea, I am not so sure. Maybe it is suggesting something profound. Perhaps the answer to why we are here is simple: it could not be otherwise.

Lawrence KraussFor example, Lawrence Krauss provides an anthropic interpretation to one of the universe’s properties. In the book, A Universe from Nothing, he examines the relationship between the energy density of matter and the energy density of empty space. Yes, space has energy and it can be measured. The density of matter in the universe can also be measured. It turns out that now is the only time in cosmic history that both values are comparable. That’s a curious result.

The universe has been expanding since the big bang, and as it expands the density of matter decreases. Matter gets diluted as galaxies get farther apart from each other. Meanwhile the energy in empty space remains constant (there is nothing to dilute or increase in empty space). Therefore at the time galaxies formed the density of matter was greater than the energy in empty space. That’s a good thing, because the gravitational effect of matter was dominant, which allowed matter to come together.

However, if the values for matter and energy had been comparable at the epoch of galaxy formation, galaxies would not have formed. Empty space exerts a repulsive force, which would have canceled out normal attractive gravity. Matter would not have clumped together. Krauss writes in A Universe from Nothing:

“But if galaxies hadn’t formed, then stars wouldn’t have formed. And if stars hadn’t formed, planets wouldn’t have formed. And if planets hadn’t formed, then astronomers wouldn’t have formed!”

It seems highly coincidental that the energy values for matter and space are roughly equal now, but they could not have equalized too much earlier. Otherwise, no one would be here to observe it. Similarly, if one of a number of physical properties were slightly different, we would also not be here. That’s when anthropic reasoning steps in: An observer must observe the conditions of the universe that allows the observer to exist.

astronomersMaybe a change of perspective is needed: Instead of focusing on our present circumstances and looking back, we can look at the evolution of the universe. Life is a latecomer to the process, of which an incalculable series of events occurred. Our existence is the result of all that came before. Although it does appear that the universe was made for us, it is in fact, the universe that made us. We were formed from the conditions that were set long before conscious beings could observe any of it.

Is Physics an Environmental Science?

The traditional approach of physics is to discover and understand the universe we live in. The fundamental laws and the values for the constants of nature are consistent throughout the observable universe. The physical laws discovered on Earth can be applied to the universe as a whole. But there can only be one exact set of laws and history that allow for our existence. That’s unless our universe is not the only one.

For some, recent scientific evidence is suggesting that there are many universes (a multiverse). Others point out that inferring a multiverse is not science; because by definition other universes cannot be observed directly (they would exist outside our observable universe). If we apply the strong anthropic principle to the multiverse theme, it does partly explain the exact parameters of our universe.

If the cosmos is populated with many universes, possibly infinite universes, then the laws of physics could be purely random. They would simply emerge as an environmental consequence. Some physicists have compared the multiverse to a foam of bubbles (each bubble representing a universe). The laws could be different in every bubble of an endless cosmic foam. Some bubble universes could be similar to ours, others vastly different.

Of course, this is a hypothetical argument. Nevertheless, if we could observe every universe in a multiverse, every single one would be finely tuned for its own existence. Anthropic reasoning would state that there is nothing special about our universe. In all the non-life generating universes there is no one to observe them, in ours there is. It’s that simple. Obviously, the anthropic principle (inferring a multiverse or not) is not a proven argument, but it’s one of many possible answers to the question: Why are we here?

 

References: Stephen W. Hawking and Leonard Mlodinow, The Grand Design (New York: Bantam Books, 2010), 155.

Lawrence M. Krauss, A Universe from Nothing (New York: Free Press, 2012).


 

How Could We Discover Alien Life in The Universe?

exoplanetOf all the so-called big questions, perhaps none inspires more curiosity than the following: Is there life elsewhere in the universe? The question leads to many other questions, speculations, possibilities and impossibilities. In recent years science has made tremendous progress towards understanding the universe, both in what is out there and how it came to be. The number of stars and galaxies is enormous, and we now know that many stars have planetary systems (nearly 2000 exoplanets have been discovered). Some planets outside our solar system are believed to be earth-like, in size, composition and location in relation to their host star.

Recent discoveries have shown that other locations in the universe may have conditions similar to Earth. Our galaxy, the Sun and the Earth are not unique. That said, the Earth supports life due to a series of coincidences that may be unique. Still an unimaginably large cosmos presents many opportunities for life-giving conditions to align. This means that the possibility for alien life may be greater than once thought. There seems to be 3 ways in which humans could discover extraterrestrials: 1) Searching the universe for life. 2) Sending signals in outer space so aliens could intercept them. 3) Aliens discovering us. Let us examine these possibilities a little further:

Searching the Universe for Life

mars roverNumerous unmanned space probes have explored our Solar System. The firsts space probes to visit other planets were launched in the sixties, even before the first lunar landing. By the seventies probes were reaching the outer planets, and in 2015, New Horizons made its historic Pluto flyby (the farthest planet when I was in school). Several rovers have landed on Mars, transmitting images and analyzing soil samples (the first successful mission was in 1976). Presently, the rovers Opportunity and Curiosity are still operating on Mars.

Scientists have discovered much about the composition of the planets and their moons, including evidence for liquid water. A few moons of Jupiter and Saturn are believed to contain oceans of liquid water beneath their icy surfaces. And in October 2015, NASA made the announcement that liquid water flows on Mars. A number of conditions are necessary for life to exist, but liquid water is a must for all known life on Earth (the starting line in the search for life). At least if life exists somewhere without water, it would be to foreign for us to imagine.

If there is alien life in our Solar System, it would be simple life and probably microbial; but what about intelligent life? How far do we have to look? The Solar System is merely our cosmic neighborhood.

In 1995, the first exoplanet was discovered and many more followed. The existence of the planets is inferred by studying minor changes in starlight, which are caused by the presence of planets; however, the distances involved are immense. The closet star system is Alpha Centauri (a 3 star system), which is 4.25 light years away. By comparison it takes about 8 minutes for the Sun’s light to reach the earth. The Milky Way alone is 100,000 to 120,000 light years in diameter, and contains over 200 billion stars. Beyond our home galaxy, there are over 100 billion galaxies in the observable universe.

By numbers alone, it seems that the opportunities for extraterrestrial life are endless. But the odds against discovering alien life seem equally as great. At this time indirect evidence is all we have. For example: exoplanets that may be located in habitable zones or distant regions that have chemical compositions similar to our Solar System. Maybe all we will find is information or signals which have to be decoded, and conclusive evidence may never be found.

Sending Signals in Outer Space

Humans have been inadvertently sending signals to the universe since the first radio and television broadcasts. By now the signals have reached thousands of star systems. However, they travel as electromagnetic waves and will go undetected unless someone has an appropriate receiver at the other end. Even if the signals have crossed advanced civilizations, what are the chances that they have built earth-like technology? There is also the evolutionary timeline to consider. Could some civilizations be too early in their development, or could others have long gone extinct?

Attempts were made to purposefully send messages to outer space. In 2008, the Beatles song “Across the Universe” was broadcasted towards Polaris (the North Star). But even traveling at light speed the signal will take over 300 years to reach its destination. And if we get a reply, it will take another 300 years.

voyager 1The space probes Pioneer 10, Pioneer 11, Voyager 1 and Voyager 2 have completed their missions exploring the planets, and have left the Solar System (speeding away indefinitely). They all contain time capsules, with information about humans and our location in the universe. Incidentally, the well-known image of the pale blue dot was taken by Voyager 1 as it left our Solar System; a snapshot of the earth from 6 billion miles away.

Sending space probes into interstellar space solves one problem, but creates another. On the one hand they are concrete objects (not like radio waves), on the other hand they travel much slower than radio waves. For example, the nearest star system is 4 light years away (that’s 4 years for a radio signal). By comparison, it will take 70,000 years for the space probes to travel the same distance. Either way, the odds appear slim that our messages will ever be noticed.

Aliens Discovering Us

alienIt is possible that aliens have already discovered the Earth; they may even have tried to communicate with us. Some people believe that aliens have visited the Earth, but for a logically minded person the stories are far-fetched. From a scientific perspective, there is no evidence to support such claims. Everything scientists know about space travel makes alien visitations practically impossible. The distances are simply too great; it would take hundreds of generations to make the voyage (unless aliens have lifespans of a 1,000 years or use teleportation and wormholes, though we shouldn’t believe everything we see in Star Trek).

The most likely form of alien contact would be indirect, such as something moving at light speed, like an electromagnetic wave. An alien space probe sent many years ago would be a possibility, however, it would be a tremendous stroke of luck to pass anywhere near the Earth. Then again, it depends on how many probes are out there. The odds of being found or finding something is proportional to how many are looking. Therefore, we don’t know if humans are the only species looking to the stars for life.

A Numbers Game

By studying the light spectrum of distant galaxies, astronomers have discovered that the chemistry of the universe is similar throughout. In addition, at the largest of scales the universe has evolved basically the same everywhere. The Earth has intelligent life because of a series of fortunate events (fortunate for us); it could also have occurred elsewhere. Or maybe a very different form of life evolved due to totally different circumstances.

For example, take the Earth’s distance from the Sun as one of many specific variables. The Earth is about 93 million miles from the sun, just the right distance to allow for liquid water. To appreciate how precise the location is, the change from summer to winter is caused by a 23.5 degree tilt of the earth’s axis. As the Earth orbits the sun it either tilts towards (in summer) or away (in winter) from the sun. That’s it. Of course the northern and southern hemispheres have their seasons in reverse relation to each other.

So is the existence of life simply a numbers game? Given the unimaginable size of the universe, is it inevitable that conditions will be just right somewhere else? With the number of planets that likely exist, even if the odds for life were a billion to one, there would still be life on a billion planets. If I had to make a call, I think the odds are good that there is life elsewhere in the universe. However, the odds are slim that we will ever discover it. The distances involved present challenges that may be too much to overcome.

 

References: Big Picture Science: Life in Space, April 20, 2015.

Big Picture Science: How to Talk to Aliens, January 12, 2015.

Universe Today: 10 Facts About the Milky Way, by Matt Williams, http://www.universetoday.com/22285/facts-about-the-milky-way/ December 3, 2014.

Universe Today: What is the Closest Star, by Fraser Cain, http://www.universetoday.com/102920/what-is-the-closest-star/ June 14, 2013.


 

The Agricultural Revolution

For much of human history foraging for food was the norm. For nearly 200,000 years people lived on what they could find in their natural environment. This meant gathering food from the land and hunting wild animals. This way of life meant that relatively small groups of people were subject to what their environment could provide. They could either find sustenance in one area or move as needed. If their present location was insufficient in resources, they could follow migration patterns of wild animals or look for more naturally fertile areas.

What Changed?

Agriculture originated in about 9,000 BC. What follows is a brief time line of the early stages of agriculture:

  • Around 9,000 BC agriculture begins east of the Mediterranean in the place known as the Fertile Crescent. Relatively close by agriculture also appears in the Nile Valley. Wheat is the crop of choice in these regions.
  • Then in about 6,000 BC there is evidence of rice farming in China, and in Papua New Guinea they are growing yam and taro.
  •   After a few thousand years in roughly 2,000 BC framing pops up in scattered regions of the world: In West Africa sorghum and millet are being harvested, South America is cultivating potatoes and Central America is now growing maize and squash.

Ancient agricultureInterestingly, most of the plants that feed humans today were domesticated before the first century. From these initial regions framing would continue to spread around the globe. Why did humans change their way of life after so many years of foraging? One factor worth considering is that agriculture developed independently in unconnected parts of the world. What could account for this fact? It happens that the beginning of agriculture coincides with the end of the last ice age. This was a global phenomenon; as regions warmed framing became possible.

Another factor was increasing population. In a scarcely populated planet it would have been much easier to find fresh areas to forage even if some distance had to be covered. As population grew it became more difficult to keep up with rival groups coveting the same lands. At this point, the best option was to settle in one area and farm. Once this happened population continued to grow and villages sprang up.

Settling down had an exponential effect on population; mainly because woman no longer needed to travel with children. As you can imagine, all this was a gradual process. The earth warmed over time and not all people adopted framing at once. Around 10,000 BC the earth had somewhere between 5 to 8 million foragers; by the first century only 1 to 2 million people were foragers and farmers consisted of 250 million people. With the adoption of agriculture a threshold in human development had been reached.

The Birth of Civilization

Adopting agriculture initiated a huge shift in how humans lived. When groups of people made the decision to settle in one region, a whole series of events followed. Along with agriculture came the domestication of animals; the most docile and fattest species were chosen. These animals could be used for their skin, fur, meat, milk and eggs. Some farm animals were also valuable for labor. Perhaps land that could not be harvested before could now be plowed with the aid of domesticated animals.

old farmhouseOnce villagers became dependent on agriculture for sustenance, they now had something very valuable to protect. Their lives depended on farm land, animals, and crops. The notions of property, state, law and quite possibly economics can be traced back to the early agrarian villages. What’s more, in time the shift to agriculture made cities and empires possible. With the first crops came questions that did not previously exist. Who manages the land, animals and crops? How will the area be protected from other humans and pests? If there was a surplus of food, should it be traded and who acquired the wealth?

Not All its Cracked up to be   

farmerIn most cases development come with a cost; the adoption of agriculture was no exception. As you can imagine, the life of foragers was probably not an easy existence. However, it does not mean that early farmers had an easy time of it. Framing with primitive tools was hard work and as societies emerged a hierarchy was created. This usually meant that a large group of people toiled for the benefit of the higher class. I can’t help but think that if it were not for agriculture, would slavery have existed in the same way? And let’s not forget the fate of farm animals, who in effect, have been enslaved for thousands of years. At the hands of humans, some of these animals have been subjected to cruelties too numerous to mention.

Along with farming came villages and cities. Larger groups of people living in close proximity were more susceptible to disease than in the past. At a time when little was known about infectious disease, the early agrarian societies had to deal with sickness that could spread like never before. Also vulnerable was the food supply itself. Now dependent on a successful harvest, what then if crops failed? They could stock pile grain if there was a surplus, but a succession of poor growing seasons could mean starvation. Still today we celebrate Thanksgiving at harvest time, because a good harvest meant so much for so long.

Even if growing seasons were stellar, the invaluable farm land needed to be protected. War was a natural consequence of agriculture because territory became more valuable than ever before. Think for a moment of how many wars have been fought over territory. The idea of controlling or owning land was a game changer in human behavior, and not always for the best.

 A New Way of Thinking About the Future   

Looking ahead and planning is something we all do without much thought. Thinking about the future is virtually a necessity in the modern world. The life of foragers would have been far more present oriented. They would have likely consumed most of the meat they hunted on a particular day, saving only a little extra. Their foraging needs would have been best served by picking daily. There is no better preservative than nature. The food supply was out there, in the wild. Realistically, how far ahead could they really plan for?

Agriculture made it necessary for humans to foresee into the future (more so than before). Cultivating land, planting and harvesting are future oriented endeavors. Working for a pay off several months down the road requires planning. From the moment humans began the ambitious task of farming, our lives were destined to become more complicated. Farming led to civilizations; which entails governments, laws, economics and a multitude of complications. On the other hand, this future mind-set has allowed us to progress far beyond what the early farmers could have ever imagined. Nevertheless, it was their venture into agriculture which started the ball rolling on a path to civilization.

 

References: Yuval Noah Harari, Sapiens (Canada: Signal Books, an imprint of McClelland & Stewart, 2014).

Why Was Agriculture So Important? | Big History Project, Published on May 19, 2014, https://www.youtube.com/watch?v=Hx6-m510hjU.

Mankind: The Story of All of Us: Birth of Farming | History, Published on Dec 2, 2012, https://www.youtube.com/watch?v=bhzQFIZuNFY.


 

The Evolutionary Arms Race

Evolution is guided by an intense competition for survival. When one individual or species gains an advantage, natural selection will cause competitors to catch up. Because there is always competition, over time species are pushed to improve, and a stable balance is generally established. It would be more economical for all to keep things as is, but that’s not how it works. Evolution requires change, and change is continual. An evolutionary arms race is an unavoidable consequence of evolution. To see how this works let’s look at a few examples:

The Tree Canopy

tree canopyHave you ever wondered why mature trees in a forest are roughly the same height. Given the fact that there is tremendous diversity in nature, why not have trees of various heights. Although different species can naturally grow to different heights, they are not found in the same forest environment. The reason is due to a race upward for sunlight. All the trees in a forest are competing for solar energy.

Forests could easily have been populated by low growing trees, at an energy cost savings for all. But nature has selected the trees that gained a competitive advantage (those that grew a little taller). The other trees were forced to keep pace or be left behind. Trees have evolved to grow higher because competing trees were also reaching for sunlight. Individual trees compete with their own species and also with other species. It does not matter whether it’s an individual or an entire species, those that cannot keep pace will not be successful at passing on their genes. In The Greatest Show on Earth, Richard Dawkins writes:

“In fact, what we actually see is a forest in which each tree species evolved through natural selection favouring individual trees that out-competed rival individual trees, whether of their own or another species.”

Of course, this was a slow process that was played out over evolutionary time and at the genetic level. Genes favorable for growing tall trees were passed on, because the trees that contained them were more likely to survive and seed the next generation. This competition continued for millions of years until an optimal height was achieved. There is a limit to the amount of energy a tree can divert towards growth, and a limit to the height a tree’s structure can support. Eventually the forest settled at a maximum height, when it was no longer an evolutionary advantage to grown higher.

Running Speed of Predator and Prey

predator and preyThe relationship between predator and prey is a complicated one, with each trying to outwit the other. Both predator and prey will evolve their own skill set. Some traits are specific for catching prey, while others are specific for avoiding predators. But there is an overlap as some traits are shared. For example, let’s consider the running speed of animals, which is just one of many skills needed by both sides. Running speed is valuable for both predator and prey.

Predators like cheetahs have evolved to run faster and faster, while gazelles (their prey), have also evolved to run faster. The end result being that neither gains ground. Richard Dawkins explains:

“Natural selection drives predator species to become ever better at catching prey, and it simultaneously drives prey species to become ever better at escaping them. Predators and prey are engaged in an evolutionary arms race, run in evolutionary time.”

Running speed is important, but it is part of a delicate balance with other important traits: such as endurance, strength and eyesight. The evolutionary winners will be those that get the balance right, yet running speed will be in the mix. Although less obvious, it is just as important for an individual to outrun individuals from the same species. For instance, a gazelle which runs slightly faster than the average gazelle will escape the predator at the expense of the slower gazelles. The fastest gazelle in the herd will be favored just as much as the overall speed of the herd.

Bacteria, Viruses and Human Defenses

In the two examples listed above (the tree canopy and the running speed of predator and prey), evolution acted at the subconscious level. No conscious agent designed any particular trait. The arms race was fought by natural selection. Because of our knowledge of viruses and bacteria, another level of the arms race is added. That is, the production of vaccines and antibiotics.

The Influenza Virus and Vaccines: In 1918 the Spanish Flu was responsible for the death of about 50 million people (the worst pandemic in world history). The pandemic struck in the last year of World War 1. The world war was critical in spreading the disease as masses of soldiers moved across the globe. The poor living conditions and ill-health of the solders may also have contributed. Pandemics have reoccurred throughout history, and experts caution that it could happen again. Different strains of the flu still come around every year. Today, much progress has been made in developing vaccines, which along with sanitation is our best defense against viruses.

influenza virusViruses attack the human body by invading cells. The immune system produces antibodies that fight off the virus. Therefore, a specific virus can only infect a host body once. However, viruses evolve very fast and are inaccurate replicators. As a result they evolve into different strains that can evade the human immune system. Viruses are not trying to change; they change because of chance mutations. The ones that are resistant to antibodies populate. It may appear that viruses are attempting to outsmart the immune system, but they simply evolve through the process of natural selection in their environment.

An arms race between viruses and their host is ongoing. Each year experts predict which strains of influenza will be dominant, and they product vaccines in accordance. It is an educated guest, which sometimes they get right and sometimes they don’t. Except for particularly dangerous strains, such as the H1N1 pandemic in 2009, it is debatable whether wide-scale vaccinations for the flu are effective or necessary.

The arms race will surely continue. We have the natural competition between viruses and antibodies, and the additional armament of vaccines. The speed in which viruses replicate and evolve insures that they are here to stay. Humans are faced with every-changing viruses, which we have to keep pace.

Bacteria and Antibiotics: Common bacterial infections for today’s standards were often fatal in the past, but thanks to antibiotics are now easily treatable. Antibiotics can kill bacteria inside a human body, however it kills good bacteria as well as bad bacteria. Good and bad are subjective descriptions based on their influence on humans. Bacteria are single cell organisms that have evolved to live in symbiotic relationships with humans (bacteria cells in the body outnumber human cells). The beneficial bacteria will defend its turf against invading bacteria, and thus can be considered as part of the immune system.

bacteriaAlthough the antibiotics are engineered to target the invaders, they are not perfect and they kill some of the symbiotic bacteria. Because antibiotics have been widely used, this has changed the balance of bacteria that dwell in humans. The effects of these changes is not clear, but there is evidence it can contribute to some diseases.

When an antibiotic is used to treat an infection it does not kill all the invading bacteria. And similar to viruses, the bacteria develop resistance to the antibiotic. The surviving bacteria will multiply and evolve until that specific antibiotic becomes ineffective. New antibiotics need to be developed in order to keep up. Even though a patient is cured, surviving bacteria can still spread to other people. Once again, the battle is similar. Unwanted bacteria verses beneficial bacteria and human ingenuity. The arms race is on with no end in sight.

 

References: Richard Dawkins, The Greatest Show on Earth (New York: Free Press, 2009), 380, 381.

Big Picture Science, Skeptic Check: Evolutionary Arms Race (June 22, 2015).


 

The Scientific Revolution

On July 20, 1969, the first humans landed on the surface of the moon. This was an incredible achievement. The Apollo spacecrafts were guided by technology that had less computing power than a modern smartphone. The equations used to plot the course to the moon were devised by Isaac Newton in the 1600s. The lunar landing is a milestone that links the Scientific Revolution of the 15th and 16th hundreds and 20th century science. For science to have progressed this far, it had to be rescued from centuries of insignificance.

The Scientific Revolution refers to an era when mankind developed the methods that led to our modern scientific view. Ancient Greece started the scientific process, and then it stalled during the Middle Ages when human progress remained at a standstill. The Scientific Revolution occurred mainly in Europe, and it coincides with the Age of Enlightenment. This was an age of reason, when individuals searched for truth by their own means. The revolutionary scientists (natural philosophers) did not blindly accept old ideas; they came to their own conclusions.

Breaking the Spell of Tradition

middle age cathedralFor much of human history, tradition was the authority. The rules were set by the state or the religion of the time and they were strictly enforced. During the Middle Ages the Catholic Church was the unquestioned intellectual authority. Free expression of ideas was not tolerated and the main source of knowledge was church doctrine. This not only applied to spiritual matters, but also to nature and the universe.

Progress was not deemed to be possible by human methods. Only God had the power to intervene and change the direction of human life. The goal of the church was to maintain the ideals outlined in scripture, and not to question whether new ways could make life better. I suspect that a large portion of society had accepted their lot in life; however, some free thinkers questioned the authority of tradition. A new way of thinking about humankind’s ability and responsibility for directing life began. This was the impetus for the Scientific Revolution.

The Methods and Mathematics of Galileo and Newton

Galileo died in 1642, the same year that Newton was born. These two men were probably the most influential scientists of the Scientific Revolution. Both men have been called “the father of science.” This may be an oversimplification of history, as there was surely a movement, which many contributed to the scientific cause. Nevertheless, Galileo and Newton stand out with both their discoveries, and their methods.

If relying on old books and tradition was not sufficient, a new way was needed to understand the world. Galileo came before Newton: Galileo established observation and experiment as the pillars of science. In order to determine if something was true, it had to be tested. Even the senses were considered unreliable in some cases. He also used mathematics to calculate the motion of objects. The idea that nature could be described using numbers was revolutionary. The scientific method had taken root.

Galileo & chruchGalileo’s confrontation with the church is well-known and is an iconic turning point in history. For 1500 years the church supported an earth-centered model of the universe; it was considered heresy to challenge this view. In 1632, Galileo published his most famous work, Dialogue Concerning the Two Chief World Systems. He wrote a dialogue showing both sides (earth-centered model and sun-centered model) hoping it would avoid church censorship. However, it was clear that Galileo supported Copernicus’ model from an earlier publication in 1543. This model placed the sun stationary at the center, with the earth, planets and stars orbiting the sun. The church banded the book and sentenced Galileo to house arrest, where he spent the last decade of his life.

Galileo came to his conclusion because the evidence led him to do so. Truth was not a matter of faith, belief or tradition. Ultimately, objective evidence was the determining factor. Using a telescope, which he built, he observed 4 moons orbiting Jupiter. This was proof that not every celestial body circled the earth. He also observed the phases of Venus (similar to lunar phases). The phases were caused by Venus’ orbit around the sun inside the Earth’s orbit. He concluded that the Copernican Model of the universe was the correct model. Galileo was right, and the world eventually agreed with him.

NewtonIf there was any doubt that science could explain the world, by the time Isaac Newton was done it had been dispelled. According to some present scientists, Newton was the most brilliant scientist that ever lived. In 1687, he published the Principia Mathematica, where he disclosed his law of universal gravitation and the three laws of motion. With Newton’s laws one could calculate the motion of objects in both the heavens and the earth, including the trajectory of a spaceship flying to the moon. For Newton, God’s hand was present in the laws of nature.

Although not as publicized, Newton also made influential discoveries in optics. He discovered that white light is a mixture of the different colors of the rainbow. White light can be spread out into a spectrum of colors. This phenomenon would prove to be critical in charting the universe a few centuries later. We now know a tremendous amount about the large-scale universe because scientists can decode light. Information can be extracted from the light of distant galaxies. This is done by studying the fine details of the spectrum.

Galileo, Newton and the revolutionary scientists showed that the book of nature was accessible to human understanding. And the avenue was the scientific method and mathematics. This was just the beginning, as Newton realized:

“I was like a boy playing on the sea-shore, and diverting myself now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.”

Transforming the World

The early scientists were like the pioneers that sailed to discover the New World. The explorers were trying to claim and settle new lands, but they could not predict the types of civilizations that would follow. Similarly, the initial goal of science was to understand how nature worked. The applied sciences would come later. Newton never imagined that his equations would be used to place a man on the moon. The physicists of the early 1900s that studied the atom did not foresee the internet and smartphones.

telescpoeThe first step was to discover the laws that governed the universe. Then gradually it became apparent that nature could be manipulated for man’s benefit. Science had a say in the philosophical questions by challenging long-held beliefs, but it also changed humanity’s way of life. In the last 500 years the world has seen more changes than any other time period. This is mainly due to the Scientific Revolution and the Industrial and Technological Revolutions that followed.

 

References: Yuval Noah Harari, Sapiens (Canada: Signal Books an imprint of MeClelland & Stewart, 2014).

Brainy Quote, http://www.brainyquote.com/quotes/authors/i/isaac_newton.html, 2001-2015 BrainyQuote, June 14, 2015.

Sparknotes, http://www.sparknotes.com/history/european/scientificrevolution/context.html, 2015 SparkNotes LLC, June 14, 2015.

Nova – Galileo’s Battle for the Heavens (PBS Documentary, https://www.youtube.com/watch?v=VnEH9rbrIkk, Published on Sept. 30, 2014.

Secret Life of Issac Newton (HD) – New Full Documentary, https://www.youtube.com/watch?v=YPRV1h3CGQk, Published on June 9, 2014.


 

The Birth of Science

ancient greeceThe origin of science is generally credited to the ancient Greeks, starting around 500 BC. There were surely other civilizations that applied scientific thinking, as cultures often evolve similar methods independently. It is well-known that other cultures tracked the motion of the stars and natural cycles. For example, Stonehenge and the Pyramids at Giza are aligned according to solar alignments at specific times of the year. In order to build these and other ancient sites, some fairly advanced technology would have been required. It is also possible that some discoveries and knowledge have been lost through the ages. One can conceive a number of ways this could happen, such as poor documentation, political strife, religious suppression and various conflicts.

What to Make of Cause and Effect?

For much of ancient history, there were essentially no recognizable patterns in nature. No cause and effect mechanisms could be discerned from the random and chaotic events that surrounded humans. Gods were assumed to be in control of nature, and humans could gain favor or disapproval from the Gods. When the Gods were pleased people experienced fine weather, peace, plentiful food and health. When the Gods were displeased people suffered from disease, war, famine and natural disasters. The only form of cause and effect that they considered was how their actions appealed to the Gods.

The birth of science occurred when patterns in nature began to be recognized and attributed to natural laws. This was a huge shift in thinking, which considered explanations outside the realm of the Gods. The idea that the world could be explained by physical principles (partly accessible to humans) has had a long an arduous road. It is easy to see how this would have met resistance, as it has to this day in some circles. Nevertheless, the Greeks were the first to systematically document ideas that resembled modern science.

The Seeds of Science

The classical period in Greece is famous for influencing the development of western civilizations, including scientific thought. The region of Ionia, a colony of Greece located across the Aegean Sea, was the birthplace of Greek science. Thales is believed to be the first person to accurately predict a solar eclipse, one that occurred in 585 BC. It is uncertain whether he actually made this prediction, but the fact that this story exist shows that the Ionians were thinking scientifically.

greek mathThe Pythagorean Theorem also originates from Ionia, stating the mathematical relationship between the three sides of a right triangle (the square of the hypotenuse is equal to the sum of the square of the other two sides); the theorem is named after Pythagoras. He is also credited for having calculated the relationship between the length of a string and the specific sound it makes in a musical instrument. Archimedes discovered laws governing levers, buoyancy and light reflection. And perhaps the greatest insight came from Democritus, who proposed the existence of atoms as the fundamental particle of matter. Democritus reasoned that if you cut an object into piece, there would be a limit to the process. The word atom means “uncuttable.”

The Greeks developed some advanced concepts in geometry, which was their main form of mathematics. Other disciplines such as algebra, trigonometry and calculus, would only come many years later. Science being still in its infancy, they made little headway in describing actual natural phenomena using mathematics. Today, mathematics can be viewed as the language of science, as it is the cornerstone of many scientific theories.

The Absence of a Scientific Method

PhilosophersThe early scientists were as much philosophers as anything else. In fact, the term scientist was only coined in the 1800s (previously they were called natural philosophers). The Greeks’ method for describing patterns and principles in nature was mainly through reasoning. In other words, they had the idea that natural laws existed, but had not yet devised a method for testing them. Either they did not see it necessary to provide experimental evidence for their conclusions, or they believed it was fundamentally beyond their capabilities to do so. Or maybe they thought it was sufficient to understand the world by reason alone.

Although the Greeks were developing scientific ideas, there were disagreements, specifically because there was no way to settle conflicting ideas. According to Stephen Hawking and Leonard Mlodinow in The Grand Design:

“So if one scholar claimed an atom moved in a straight line until it collided with a second atom and another scholar claimed it moved in a straight line until it bumped into a cyclops, there was no objective way to settle the argument”

Clearly the cyclops is an exaggeration to make a point. But the fact is that explanations about the physical world were a matter of opinion, and based on an individual’s line of reasoning. There was no objective truth. Aristotle saw little need to test his theories. His approach was focused on why nature behaved in certain ways, rather than how nature behaved as it did. The term natural philosopher was fitting for the time.

Even though predictable patterns were being noticed, an idea persisted that nature had intentions. It was up to man to figure out what those intentions were, or what rules nature followed. There seemed to be an uneasy relationship between physical reality and some form of higher power. Perhaps they were trying to replace the Gods as an explanation for the world, but they had not yet achieved the means.

Modern science is done by observation and experimentation. Any scientific theory is only validated when data shows that a prediction about nature is indeed true. Modern science tries to understand how things happen, and gives little attention to why things happen. In ancient times the scientific method had not yet been devised, and there were no clear road maps that showed scientists the way forward. In his book, To Explain the World, theoretical physicist and Nobel Prize winner, Steven Weinberg comments on the mindset of early scientists:

“It is not only that our predecessors did not know what we know about the world – more important, they did not have anything like our ideas of what there was to know about the world, and how to learn it.”

If this was true about scientists of past centuries, it was especially true during Classical Greece. From a standstill, ancient Greece broke the inertia and set the wheels in motion towards scientific discovery. Given rudimentary mathematics and insufficient tools for making precise measurements and observations, their insights were impressive. However, much of their ideas lay dormant for centuries following the fall of the Greek and Roman Empires, only to be revived or rediscovered later. The scientific torch would be picked up at the turn of the first millennium in the Middle East, and continued 500 years after that in Europe (it has become known as the Scientific Revolution).

 

References: Stephen W. Hawking and Leonard Mlodinow, The Grand Design (New York: Bantam Books, 2010), 22.

Steven Weinberg, To Explain the World (New York: HarperCollins Publishers, 2015).

What the Ancients Knew – Greece (Published on Dec 30, 2012), https://www.youtube.com/watch?v=nJRFLXBlsmA


Memes that Make the World

dnaMemes are the cultural equivalence of biological genes. The term meme was coined by Richard Dawkins in the 1976 publication of The Selfish Gene. The premise behind The Selfish Gene is that Darwinian natural selection acts at the level of genes; ultimately, it is genes that guide evolution by controlling the traits in bodies that contain the genes. In order for natural selection to work, there needs to be something like DNA and genes in which information is replicated. There also requires some copying errors so that small variations can occur from one generation to the next. Memes also fit that description.  Memes are ideas that survive in human brains, and similar to genes they can be copied and passed on.

There are many different types of memes: for example, songs, hairstyles, phrases, beliefs, words and manners. In today’s world the word meme has become popular on the internet. Whenever we here that something has “gone viral,” it is often referred to as a meme. In most cases the meme is something trivial, such as a piece of music, a surprising story or a silly video. It spreads rapidly, but usually it will not last very long. However, other memes have a far greater impact on society, and become part of cultural evolution. Or you could say that the memes guide cultural evolution, much like “the selfish genes.”

The Meme Codes

Language may be the key ingredient that allows memes to spread. Like a DNA code, language is also coded information. It comes in the form of letters and words. Speech is one variation of language, which is surely copied, but written language is even more stable as a replicating code.

We can all recall numerous instances when an event is passed from one story-teller to another. In most cases the details in the story changes until we have conflicting accounts. The information is transferred from one individual brain to another, but memories are not perfect and the copies are not exact. However, written language can exchange hands without the story being altered. The stories still have to resonate in people’s brains and the interpretations will vary, but the fidelity of the written word is higher than the spoken word.

Music is another meme that has two routes of transition. 1) Tunes are passed on by hearing the sounds and attempting to duplicate them. If a tune sounds appealing there is a higher chance it will be copied. As time passes the tune will change a bit. 2) Music can also be written in sheet music using mostly symbols. Like written language, the written music will remain close to the original form. One piano player following a sheet music may sound slightly different from another player. But as the song is played by many piano players it will not change significantly.

MathematicsMathematics is a meme of numbers, symbols and diagrams. It is more accurately copied than language, because there is less ways it can be altered. 2 plus 2 will always equal 4. There is an order in mathematics that is self-correcting, although concepts evolve over time with new applications. Language, music and mathematics are coded information that are replicated and evolve in human brains.

Marching on Through the Generations

The idea of generations is different for memes than it is for genes. A different generation for a gene is an offspring, which will carry some of the same genes. For memes, there is a double meaning for a generation. A meme can be passed on from person to person in a single day, or survive for many years. For instance, I tell you an idea, and you share it with someone else. That’s 3 generations, from me to you to someone else. In this scenario the meme could evolve like microbes, where mutations can occur in a matter of days or weeks. The idea will spread quickly, but each person could add to it or leaves something out; these would be mutations of the original idea.

There are also memes that are handed down in the traditional sense of generations, that is, from a father to a son. These memes are long-lasting and could become cultural norms or traditions. For example, holidays are memes that have survived for many years. In many cases the original customs and purposes behind the holidays are lost or changed (at least by some people). Still the celebrations continue and millions of people observe the holidays. Do we know why the colors of Christmas are red and green, or why the Easter Bunny gives out eggs, or why children get candies at Halloween?

Memes Working Together

Similar to a single gene, a single meme has a minor impact. Genes are effective when they combine with other cooperative genes. Memes also combine with compatible memes and also compete with other memes for attention in human brains. One could think of different ideas as a meme pool, which people select (consciously or subconsciously). The memes that work well together will be more likely to be copied. A meme-complex could be copied because it benefits society, but it could also be copied because it aids the propagation of itself. It is not a guarantee that humans will make the best possible choices; there are equal reasons to believe that we will choose unwisely.

football stadiumA sport is an example of a well-established meme-complex. The North American culture is fascinated with sports on a daily basis. Many play sports at local venues; many more watch sports at stadiums and on televisions. What memes could be working together? How about this list: (memes for running, throwing and catching), (memes for competing, winning and losing), (memes for watching, cheering and analyzing). Any stable and self-replicating cultural norm will consist of mutually beneficial memes.

History-Making Memes

Recorded human history is a story of culture. The ideas that populations believed in mass, whether real or imagined, has fueled the events of history. The most influential ideas (memes) have won out over other ideas. Not always because they were better ideas, but because they were more effective at spreading from brain to brain. Historian Yuval Harari writes in Sapiens: A Brief History of Humankind:

… history’s choices are not made for the benefit of humans… There is no proof that cultures that are beneficial to humans must inexorably succeed and spread, while less beneficial cultures disappear.

Religion symbolsThe cultural enterprises that have dominated human life contain large numbers of memes. Such examples are: religion, war, agriculture, kingdoms, art, music, politics, nationalism and science. No one can tell if the history-making memes (or meme-complexes) took the best course of action for humanity. Some did and others did not. Nevertheless, they had the attributes to enter human brains and to be imitated. Our modern culture is formed by memes with the same qualities as the historical memes. That is, copying fidelity, with variation, and wide-spread selection from the meme pool.

 

References: Yuval Noah Harari, Sapiens: A Brief History of Humankind (Canada: Signal Books, an imprint of McClelland & Stewart, 2014).

Richard Dawkins, The Selfish Gene (Oxford: Oxford University Press, 30th anniversary edition, 2006).

Richard Dawkins | Memes | Oxford Union, Published on Feb. 26, 2014. 

Susan Blackmore sobre memes e “temes” – TED Legendado, Published on Jul. 13, 2013.


Why do Leaves Change Colors in the Fall?

Road in fallFor many years I have enjoyed the fall colors, yet without knowing exactly why the leaves change colors. People have given me a number of one-line explanations, such as: It is because of cooler temperatures. It is caused by lack of sunlight. The fall colors are already in the leaves, but are covered up in the summer by the green color. At some point I became curious enough to look it up. It turns out that I had received a collection of partial answers, and the fall colors are due to more than one cause.

The Colors

Eastern Canada and the northeastern United States have ideal conditions for brilliant fall colors. The colors of the leaves in deciduous trees turn to variations of yellow, red, orange and brown. The different colors are produced by different pigments in the leaves, which become dominant when the green color fades.

orange leavesDuring the growing season the leaves produce chlorophyll, which is responsible for the normal green color. The production of chlorophyll is part of the chemical process of photosynthesis. This is the process that converts sunlight into energy the tree needs to grow. When the fall arrives the daylight hours get shorter and this decreases the production of chlorophyll, until it will eventually stop altogether.

Yellow pigments, called carotenoids, have been produced throughout the growing season, but in smaller amounts than the green pigment. When the green color dissipates the yellow becomes visible. The red color comes to the leaves later in the season, mostly being produced in the autumn. The pigment name for red in trees is anthocyanins. When these pigments are lacking, other pigments called tannins can affect the leaf color. Tannins are mainly responsible for the brown colors.

Variations in Color and Intensity

The 4 pigments (chlorophyll, carotenoids, anthocyanins and tannins) can be present in various amounts. Therefore leaves are not always pure green, yellow, red or brown; they can be a mixture of more than one color. For example, when the yellow and red pigments are dominant the leaves will appear orange; there is no single pigment that will produce orange.

Different species naturally produce specific pigments, which will keep the colors of the same species fairly consistent from tree to tree and year to year. That being said, each autumn the climate is slightly different. Changes in sunlight and temperature will result in varying amounts of pigments, thus affecting the fall colors.

red orange leavesThe yellow pigments are always present in the leaves and this will keep the yellow colors fairy consistent. However, red pigment production is whether dependent. Falls that have warm sunny days and cool nights (but above freezing) will result in the most spectacular red and orange colors.

So, if you have noticed that some years the fall colors are more vibrant, it is not your imagination. In those years the conditions were probably ideal. Nevertheless, having some knowledge as to why the leaves change can deepen the enjoyment of the fall colors. Combined with the crisp cool air and generally low humidity, autumn is my favorite time of year. But as it is with many of nature’s spectacles, it does not last for very long. My suggestion is to get out, take a walk or a drive and simply observe.

References: USDA Forest Service, Why Leaves Change Color, http://www.na.fs.fed.us/fhp/pubs/leaves/leaves.shtm, July 7, 2011.

ESF, Why Leaves Change Color, http://www.esf.edu/pubprog/brochure/leaves/leaves.htm, 2015.

Why do Leaves Change Colors in the Fall? https://www.youtube.com/watch?v=AeypaiIoMPI, Uploaded on October 20, 2009.


 

Free Will: A Great Paradox

In the modern world we are faced with an almost unlimited amount of choices. We all make numerous decisions each day, whether we are aware of it or not. Many of our choices are relatively insignificant, such as: What will we wear today? What will we eat for breakfast? Will we stop at a coffee shop on our way to work? Then there are more important decisions we might tackle at work, depending on our occupation and position. Outside of work leisure time opens up another series of choices.

fork in the roadThen there are the big decisions, which can alter the course of one’s life. Good or bad outcomes often follow based on the decisions we take. For example: The partner we choose, the career we pursue and unforeseen events that will force us to choose the next path. As the saying goes: “When you reach a fork in the road, take it.”

An Introduction to So-Called Decision-Making 

Can we account for the decisions we make? Of course it is easy to rationalize why we do what we do, but what’s behind a decision? Most of us feel that our decisions are ours alone. But is that true? First let us look at different types of decisions (or perceived decisions).

  • Instinctual: There are actions we take that could be perceived as decisions but in reality aren’t. They are actions that are basically reactions to the outside world. For instance, if we cross the street and a car is racing at us, we will get out-of-the-way. Or if a ball is thrown at our face we will try to catch it with our hand.
  • Appetites: My favorite pie is pumpkin pie. As a dinner guest I am sometimes offered a choice of pies. If pumpkin is on the list, I will always choose it. I may have a gene that makes pumpkin pie taste better to me than other pies. Therefore, is my choice of pie actually a decision or a mere consequence of my genes?
  • Desires: Much of our life journey is a response to desires we can’t account for. These include career choices, sexual attraction, hobbies, leisure activities and more. We simply do not know why we are interested, or pushed in the directions we are. Our desires are a complex mix of genetics and cultural conditioning.
  • Contemplative: This is the slow pros and cons type of decision-making, when we take the time to weigh our options before we choose. For example, let’s say we are shopping for a new car. We will look at different models and probably tests drive a few vehicles. Weighing quality and cost we come to a final decision on a new car.

Of the four examples above, the last listed (contemplative) looks and feels most like a true decision. The other three fall more in a grey area where one can’t be sure how much decision-making is involved. As you will see later, even the contemplative type may not be what it appears to be at first glance. That brings to the table the idea of free will.

Free Will

free willWhat do we mean when we say free will? Free will is the idea that we have the ability to make decisions independent of our genetics and conditioning. Another way to think about free will is the belief that we could have done differently than we did in a given circumstance. And likely, the only way we could have done differently, is if we were different at the time. That is, if our genetics and conditioning were different.

We are who we are due to a long series of events not of our choosing. To account for the actions we take, one has to consider evolutionary history. The human brain (presumably key to decision-making) is a product of evolution and each unique brain is genetically based. Also parenting and social conditioning have a significant effect on human development and behavior. One could even conclude that in order to have free will the universe would have to be different.

The Universe on a Pool Table

Let’s do a simple thought experiment. A pool table is used as a model for the universe. In this experiment only one shot is considered (the break). The table represents all of space and the fundamental forces. The billiard balls act as the particles (atoms, sub-atomic particles and so on). The cue stick is the force behind the big bang. At the break, the cue ball is struck and from that point on everything else follows.

pool ballsAs an observer one has to wait and see how the balls will collide and bounce around, but it can only turn out one way. It was all determined by the brake and the way the table was setup. The movement of the billiard balls are a consequence of the characteristics of the balls, the break and the nature of the table. One could say that it is a closed system; after the initial conditions nothing can intervene in the process.

Now let’s look at the actual universe. The big bang created spacetime, the fundamental forces and particles. All the particles behave as a consequence of the conditions at the big bang (the break) and the acting forces. Can anything after the initial conditions intervene in how the universe unfolds? The universe is also a closed system, it just happens to be unimaginably larger that a pool table. We should be mindful not to confuse our ignorance of the future with the prospect of altering it.

A Game of Dice

What I just described is a deterministic picture of the universe. It is sometimes referred to as the Newtonian view or classical physics. Here the universe unfolds like clockwork. If the present conditions are known, then the laws of physics can be applied either forward or backwards in time with great accuracy. Nevertheless, it needs to be mentioned that another set of physical laws described by quantum mechanics seems to contradict the classical picture.

At the scale of the atom randomness is introduced and outcomes can only be predicted in terms of probabilities. There is no sure way to determine what a single sub-atomic particle will do. Only if a sufficient number of identical experiments are run, will the aggregate of outcomes reflect the assigned probabilities. So what we are left with is a deterministic framework at the large-scale and a probabilistic understanding for the small-scale.

Some people believe that quantum mechanics seems to erode determinism and opens the door for free will. However, I would argue that randomness and probabilities doesn’t get us any closer to free will. If the universe is essentially deterministic, or on occasion tosses a dice, how does any of this grant us free will? Whether classical or quantum laws apply, the universe is presumably still subject to those laws, and so are we.

The Great Paradox

 Does something change when consciousness arises?  Conscious beings are made of the same kind of particles that permeate the universe. There is no reason to think that brains are any different. If our thinking faculties are caused by natural forces acting on particles in our brain, how can we conclude that our decisions are ours alone?

To examine this question let’s do another thought experiment. Let’s say you are asked to name the first city that comes to your mind. After a few seconds of reflection you say Rome. Can you account for why you did not think of Paris, or any one of hundreds of other possible cities? Even if you were given a little more time and asked to choose a city, you would still be limited to a list that your mind could produce. It would appear to me that we fundamentally do not choose our thoughts, they simply arise. How can we get to free will if we don’t choose our thoughts? I suppose one could make the argument that from a collection of thoughts that do arise, we can then choose and that constitutes free will. However, that would mean that our decisions are influenced by a stream of thoughts that our conscious mind does not produce.

Scientifically and Philosophically, the idea that we have free will makes little sense. Some people realize this, but if we adopted this principle on mass, it could be the collapse of society as we know it. The idea of free will touches everything we do. Without free will (or we could call it personal responsibility) everything about our society would change. We would have to rethink our justice system, religions, morality and relationships. Nevertheless, if we all agreed that decisions are caused rather than made, it would undoubtedly lead to a more compassionate world. We would probably still have to hold people accountable for their behavior, but we would be less inclined to be judgmental, angry or resentful.

From a personal decision-making stand point, without free will, we would also be easier on ourselves for perceived bad decisions that often lead to regret. This we can do right now, regardless of how society at large thinks about free will. Nevertheless, going forward we are confronted with an unavoidable paradox. How can we possibly go through the normal decision-making process without the feeling that we are in control? And there lies the great paradox. Even if one accepts that free will is an illusion, I don’t see any other reasonable choice (a choice that is fundamentally not ours) than to live as if we have it.

 

References: Sam Harris on “Free Will”, Published on March 27, 2012https://www.youtube.com/watch?v=pCofmZlC72g.

Free Will — What Sam Harris Gets Right and Wrong, Published on April 10, 2013, https://www.youtube.com/watch?v=8pJXt3LclcY


 

The Paradox of Wave-Particle Duality

blue light beam The wave-particle duality of light and other subatomic particles, such as electrons, is a central concept in quantum mechanics. The idea that light and elementary particles have both wave-like and particle-like properties is just one of a number of strange quantum realities. The quantum revolution, which began at the turn of the 20th century, has transformed our world from a technological standpoint. A century later the quantum laws underpin our modern technology. But scientists that were probing the atom in the early 1900s were simply trying to understand the nature of reality at the smallest scales. The challenges proved to be immense, mind-boggling and paradoxical. Wave-particle duality is one paradox that is still not completely understood.

The Photoelectric Effect

Albert Einstein is most famously known for the theories of special relativity, general relativity and the equation E=MC². However, in 1905 he won the Nobel Prize for his explanation of the photoelectric effect. Before Einstein, light was generally thought to behave like a wave, similar to a water wave. But there were some unsolved questions regarding properties of different colored light. Specifically, the ability of ultra-violet light to remove an electric charge from a metal plate (a phenomenon not observed with red light).

Photoelectric Effect

Photoelectric Effect

Einstein proposed that light was composed of packets of energy called quanta (later known as photon). These particles of light acted like miniature billiard balls, knocking the electrons off the metal plate. According to Einstein, the particles from the red light carried low energy, because red light has a low-frequency. Conversely, the higher frequency ultra-violet light contains higher energy particles, which were able to dislodge the electrons from the metal plate. With the analogy of the billiard balls, it was like the ultra-violet particles were heavier than the red light particles. Therefore, the heavy particles of light were able to knock off the electrons, while the lite particles could not.

Einstein’s explanation of the photoelectric effect showed that light was made up of individual particles. It opened the doorway to a new branch of physics. Although Einstein played a key role in the foundation of quantum physics, he never accepted the implications that the theory would eventually bear out. The idea that the quantum world was ruled by uncertainty, did not sit well with him. Einstein supported the classical view of physics, where precise predictions and conclusions could be made. Referring to the probabilistic foundation of quantum mechanics, Einstein said: “God does not play dice.”

 The Double-Slit Experiment

The discovery of the wave-particle duality of light was only the beginning of the paradoxes that would later emerge. A simple experiment, known as the double-slit experiment would overthrow any common sense notion of the quantum realm. The experiment worked as follows: An electron gun was set up to fire an electron beam through a barrier with two open slits. A full screen was placed a small distance behind the barrier. One would expect that the electrons that go through the slits would strike the background screen and produce two bands. However, the outcome showed not two, but a number of bands across the length of the screen; a striped pattern emerged.

Double-Slit Experiment

Double-slit Experiment

The electrons were behaving like a wave; the stripes were consistent with an interference pattern. This had already been observed in water waves. For instance, when two ripples in a pond meet they interfere with each other, causing the similar interference pattern that was observed with the electrons. Water is composed of individual molecules and together they combine to form a wave. Similarly, the electrons were exhibiting both wave-like and particle-like properties (this was also observed in light).

If this was not strange enough, the next step of the experiment would reveal a greater paradox. When the electron gun was allowed to fire one electron at a time, the screen in the back would eventually show the same striped pattern. How could single electrons produce an interference pattern? To point out how strange that was: it was like a single electron was passing through both slits at the same time, or like each electron was carrying information from the wave as it was passing through the slits.

Explaining the Impossible

Niels BohrDanish physicist Niels Bohr, one of the founders of quantum mechanics provided a possible explanation. It is known as the Copenhagen Interpretation. According to Bohr, the electrons that travel from the gun to the screen cannot be viewed as single point particles, but rather as a probability wave. In other words, an electron exists only as a spectrum of possibilities when it travels. It carries with it every possible path from the gun to the screen, including passing through the two slits at the same time. Only when it strikes the screen is the electron forced to take an exact position.

In this view, each electron will strike the screen at a different point, however, with a sufficient number of electrons the striped pattern will emerge on the screen. Whether the electrons are traveling in a continuous beam or as single travelers, the outcome will produce an interference pattern. Even if it is not completely understood, wave-particle duality is a fundamental property of the quantum world.

It is safe to say that Einstein and Bohr disagreed as to what is ultimately responsible for quantum uncertainty. For Bohr it was enough to apply a workable mathematical framework (based on probabilities), but for Einstein there must have been an undiscovered classical principle guiding the process. A century after Einstein and Bohr there is still no classical physical principle (one that agrees with common sense) that explains the uncertainty of quantum mechanics. However unsatisfying, it seems that Bohr’s explanation of the double-slit experiment is still as good as we have. Nevertheless, Bohr realized the gap between quantum mechanics and everyday experience, he said: “If quantum mechanics hasn’t profoundly shocked you, you haven’t understood it yet.”

In time, Bohr’s approach would lead to a revolution in technology. Even if exact outcomes cannot be known, physicists can calculate probabilities that will allow electronic devises to work. Similar to the double-slit experiment, even if the path of each individual electron cannot be known, the overall pattern can be predicted. Today, computers, mobile phones and GPS devices operate based on quantum mechanics.

 

References: The Secrets of Quantum Physics Episode 1 Einstein’s Nightmare BBC Documentary 2014. Published on Feb 28, 2015. https://www.youtube.com/watch?v=uV8oSgMhS54

Brainy Quote, 2001-2015. http://www.brainyquote.com/quotes/authors/n/niels_bohr.html

Brian Greene, The Fabric of the Cosmos.