Living in a Medium-Size World

The human experience is limited by the range of our senses. We can only see, hear, touch, smell and taste so much. Our sensory input is the result of the world directly around us, and that is what we perceive as reality. Humans have evolved to intuitively deal with the medium-size world. Hidden from us are the microscopic realm and the large-scale universe. In addition, we are not well equipped to deal with things moving at light speed and extreme time scales (sometimes called deep time).

universe-telescopeTo a large extent modern science has advanced due to decoding the small-size world and the large-size world. The current picture of the universe is defined by technologies that probe realities beyond the human senses. Scientists have come to the realization that human intuition is deceptive in understanding how the universe works. For example: the behavior of atoms, the formation of stars and galaxies, the speed of light, and the evolutionary timeline. This creates a gap between knowledge and perception, which demands a stretch of imagination to bridge the gap. It may even be wise to expect that new scientific discoveries will be counter-intuitive, just like many significant discoveries from the past.

 Some People Can’t Go There

Why are some people able to digest objective scientific information, while others can’t get beyond their subjective experience? In other words, to expand our world view we need to look outside ourselves. An individual’s life experience is by far too small a sample size to make any meaningful conclusions, particularly when examining some of life’s big questions. There is tremendous variety in life experiences, both in time and geography.

Before modern science the earth was viewed as the center of existence; humans were the focal point of all life and the universe. Now the message is clear that humans occupy a planet that is a tiny part of a much grander scheme. Human life is also a brief existence in an epic evolutionary tale of innumerable life forms. An appreciation of the modern scientific view requires we look beyond our direct experience and consider a reality foreign to ourselves. It is a challenging mental and emotional exercise to honestly look at life from a truly universal perspective.

Albert Einstein was a revolutionary thinker and well-known for his thought experiments. It was by first imagining physical scenarios that he came up with his great insights. He is quoted as saying:

“The true sign of intelligence is not knowledge but imagination.” and “Logic will get you from A to B. Imagination will take you everywhere.”

A Miss-Match Between Intuition and Reality

If we had to find candidates for the most influential and revolutionary scientific theory of all time, at a minimum the list would include: Newton, Darwin, Einstein and the quantum theory scientists. These three individuals and the group of scientists that formulated quantum theory have created the foundation of modern science. Newton’s ideas describe the physics of our everyday reality. Einstein worked out the precise laws of space, time and the large-scale universe. Quantum physics describes the atomic and subatomic realm. And Darwin’s theory of evolution is the cornerstone for studying all life.

quantum-universeAn interesting angle with these landmark ideas is that they are all counter-intuitive. These theories are defined by hidden realities that required great minds and creative techniques to uncover. It is not clear whether others could have come up with similar discoveries; however, I think that few thought along those lines. In the early years of science, knowledge of the world was limited to the human senses. The idea that to accurately describe our world required a leap beyond the sensory experience of the medium-size world must have been revolutionary. Today, scientists and philosophers have come to accept theories based on evidence, even if it goes against common sense.

Before Newton no one had considered that the same force was responsible for controlling the orbits of the planets and falling objects on earth. Space and time were believed to be absolute and unchanging before Einstein showed that they were flexible. Life was clearly designed by God (each species set apart in its present form) before Darwin unveiled the mechanism of natural selection as a powerful creator. And in several ways quantum theory is the most bizarre of scientific theories; For instance, even those that work with quantum mechanics can’t explain why light behaves as both a particle and a wave.

If these examples are too abstract for you, consider the deceptive everyday observation of the sun traveling across the sky. In medieval times it was thought to be heretical to suggest anything other than the sun moving around a stationary earth. And today, if we go by our senses alone we would reach the same conclusion. The earth moves, it spins and orbits the sun, but we don’t feel it. To take it a step further, if the sun actually orbited the earth, it would still look exactly the same. How many other things about our world do we get wrong by overlooking scientific facts? This could be due to ignorance, oversight, or possibly by over rating subjective experience.

Evolution is the Big One

charles-darwinDarwin clearly knew the implications of his theory of evolution; perhaps that is why he waited a couple of decades to publish. Evolution, properly understood, solved the great mystery of life’s propagation and overthrew centuries of beliefs. In terms of its philosophical implications, evolution is the most life-altering scientific idea. Yet, it is still not universally accepted or understood. If I was only exposed to one scientific idea, I would pick evolution; it has the farthest reach and most deeply influences us.

We don’t need to know how atoms work or how galaxies form to function in everyday life. Common sense and intuition will serve us well enough in most situations. Understanding evolution is debatable; I think it is very valuable in understanding human behavior and how our lives unfold (not to mention the natural world).

If we neglect thinking in evolutionary terms we can easily be led astray. Take for example the vibrant colors of flowers: We could assume that the flowers are meant for the enjoyment of human observers (designed for our benefit). But we are only bystanders, which have stumbled upon a deeper truth. The colorful flowers have attracted pollinators over long periods of time, allowing seeds to spread. Nature favors brightly colored flowers over duller colors, because they are more noticeable to birds and insects. Generation after generation the colorful flowers have the advantage. It is not about us, it’s about the insects and the flowers. Nevertheless, we are here and can still enjoy the flowers.

The point I am trying to make is that the deeper questions of our lives need a deeper view. We can’t tackle profound questions with the same reasoning that we use to bake a cake or change a tire; a leap of imagination is required. Although we can’t think about the mysteries of life and the universe all of the time, for those that are philosophically inclined, we cannot help but think about it some of the time. Be forewarned that surface impressions are usually not the whole story.

 

References: Brainy Quote, 2001-2016. http://www.brainyquote.com/quotes/authors/a/albert_einstein.html


 

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What is Emergence?

emergenceEmergence is a general term that refers to a characteristic of complex systems. Typically, emergence is the result of a process, where smaller ingredients act together to form a larger pattern. The resulting emergent properties tend to be very different from the properties of the smaller components. We have all heard it expressed in everyday language: “The whole is greater than the sum of its parts.” The quote has been credited to Aristotle.

So the idea is not new, and like many ideas it has been refined and expanded on over time. The concept of emergence has been applied to a wide range of behaviors and structures (both living and nonliving). It seems to happen everywhere, giving the impression that it’s a fundamental property of nature. Therefore, is it inevitable that complex interactions eventually lead to new phenomena? 

An emergent property may be difficult to spot, because emergence is intertwined with our everyday world. At the scale of our experience the underlying causes for our observations are subtle and not always obvious. When something new or unexpected arises, and when order or organization comes about, it’s a good sign that emergence is involved.

Examples of Emergence

  • Solids, Liquids and Gases: All the states of matter for a given compound, such as water, emerge from the same fundamental particles. The different properties of air, water and ice result from changes in the arrangement of the particles. In this case, temperature is the key factor for the phase transitions of water. 
  • Ocean Waves: Individual water molecules make up water droplets. A single droplet cannot make a wave, but countless droplets (with help from environmental conditions) can move together and create ocean waves.
  • Ant Colonies: An ant has limited intelligence. The key to their evolutionary successes is their ability to work together. The communication and interconnections between the ants result in an overall intelligence of the colony, which far exceeds the intelligence of a single ant. Their survival needs can only be attained as a group.
  • Flock of Birds: As birds fly in flocks they move about in patterns. The patterns are mesmerizing to watch as they constantly change. These patterns are surely unplanned and no single bird is in charge. The patterns emerge as a result of birds following simple rules. The flock is moving in a general direction, and each bird stays close to other birds, but far enough to avoid a collision.
  • Movement of Crowds: Humans moving in crowds is an emergent property similar to the birds. No one is controlling the movement of people on city streets or gatherings at large events. Pedestrians are following each other and obeying general rules. Each person reacts to the people around them and their environment.
  • Consciousness: This is perhaps the most impressive example of emergence. Although neuroscience has identified brain functions as the cause of consciousness, the mechanisms tell use very little about what consciousness actually is. Connections of neurons in the brain are physical processes, and yet we experience consciousness as nonphysical. And how does self-awareness emerge from processes that are not self-aware (as far as we know)?

Who or What is in Control?

flock-of-birdsWith our human organizations we are accustomed to having a person or group in charge. It is a follow the leader mentality. This structure is rarely questioned, as it is the foundation of governments, religions, business entities and most organizations. We do, however, question the competency of the leaders at times. Nevertheless, the point is that nature operates differently. Most of the time, there is nothing in control; order and complexity emerges from the interactions of all the individual parts.

In my book, The Landscape of Reality, I introduced a term to describe how the universe/nature creates and organizes. I called it self-creation, and summarized it in the following manner:

“… a universe that can create itself is unplanned and the result of countless contributing factors… In addition to creating the components of the universe, self-creation applies to the unfolding of events. In that sense, self-creation can also be viewed as all the conditions that create a given moment of reality.”

ocean-wavesMy idea of self-creation is closely related to emergence, but there is a difference. Emergence refers to an integral part of an all-encompassing process called self-creation. Generally, the emergent properties occur at the level we most identify with and experience. Broken down into its finer ingredients, the world around us is composed of different arrangements of atoms; all biology is controlled by the complex system of DNA and genes. Scientists have an extensive understanding of physics, chemistry and genetics, as well as many other specialized fields. Science can make progress by studying things in isolation; however, the behavior of the whole is still somewhat mysterious. Interactions of simple individual parts, lead to large-scale complexity and organization.

One of the fascinations with emergence is that the large-scale structures look nothing like the structures of the finer scales. And if one were to examine the ingredients, the net result would reveal a surprising outcome. Whether you look at the micro scale or the macro scale, emergence is counter intuitive. But it seems that nature is able to self-create in multiple ways, without anyone or anything in control.

 

References: Systems Theory: 8 Emergence, Complexity Academy, Published on Mar 5, 2015, https://www.youtube.com/watch?v=pooxD8XF5Uw

NOVA science NOW: 34 – Emergence, aranial, Published on Aug 9, 2012, https://www.youtube.com/watch?v=aEaZHWXmbRw


 

Evolution in a Deck of Cards

dnaFor some people the process of evolution is a difficult concept to grasp. For sure, evolution is a counter-intuitive idea. We don’t experience evolution in our daily lives. It only makes sense when we look beyond the surface of things; evolutionary concepts require a long-term view. Perhaps the biggest stumbling block towards understanding evolution is the disconnection between our lives and the evolutionary timeline. If we compared the history of the Earth to the length of a person’s arm, all of human history could be wiped out with a single stroke of a nail file.

Still, despite much scientific evidence for evolution, many people are not convinced. They may look for supernatural explanations for the existence of life, or conclude the question is beyond human understanding. How is it possible that all life evolved from single cell organisms? How did even a single cell evolve? And how did life diversify into millions of species? To get a grasp for evolution we need to shift our attention from the finished product to the process.

Evolution is indeed a process, which is ongoing. And it has no finished product in mind. Evolution can be defined as gradual changes and development over time. However, there is a mechanism that generates those changes, which Darwin called natural selection. Perhaps Darwin’s greatest insight was recognizing the power of natural selection. It is similar to an algorithm, because nature selects positive survival and reproductive traits. It also discards negative survival and reproductive traits. The process is cumulative and continuous from generation to generation. Once the process began improvements to life were inevitable, even though specific outcomes were not guaranteed.

The Card Game

deck-of-cardsAs a thought experiment we can use the analogy of a card game to show how natural selection works. The analogy is not perfect, because there are subtleties in evolution that are more complicated. The exercise is meant to provide a simple analogy for natural selection.

Although it was not known in Darwin’s time, we now understand that life is controlled by genetic information. Essentially, it is genes that are passed on through the generations. In our analogy it is more useful to view the cards as genes, and a hand of cards as a group of genes (or an individual life form). The game has 4 basic ground rules:

1) The deck of cards represents the gene pool: We need to assume multiple decks, because the same genes exist simultaneously in other individuals and are copied many times over. Each card carries information, which may or may not survive each reshuffling. For example, the 5 of spades is one gene and the 10 of harts is another gene.

2) The shuffling symbolizes the generations: Every time the cards are shuffled and handed out, it’s like a new generation. The cards are always being rearranged in different combinations.

3) The players act as natural environments: The players select which cards they want to keep. Just like nature favors different genes in different environments, each player will select different card combinations. In our game some players are playing poker, others cribbage and others bridge. For example, the poker player represents a specific environment, such as an ocean.

4) The goal of the game is to collect the best hand possible: Every player keeps the cards they want, and discards the ones they don’t want. The poker players will collect different card arrangements than the bridge players. But all the cards come from the same card pool. This selection process is done with every deal.

Stable Arrangements

For natural selection to work the process had to work in the primordial period. The creation of life on earth probably did not start in an instant of time. It is more likely that the building blocks (atoms and molecules) were assembling for a long time; nature was favoring stable patterns. Richard Dawkins points out in The Selfish Gene:

“The earliest form of natural selection was simply a selection of stable forms and a rejection of unstable ones.”

microscopic-lifeJust like today, things that last are stable arrangements of atoms (whether living or nonliving). Consequently, life began in a fuzzy period where forms were interacting and assembling. At some point the forms acquired the ability to replicate (with occasional errors). The errors are necessary for evolution; this would be like randomly adding new cards to the deck (like a 15 of diamonds). Eventually, simplicity grew into increased complexity; small patterns grew into larger patterns. This is also what happens with the game of cards.

Exact patterns would be difficult to recognize in the first few hands. Nevertheless, there would still be cards that are more desirable than others. Generally, an ace or a face card is better than a numbered card. But there are exceptions, which depends on the type of game and the combination of cards. With each reshuffling patterns will emerge, where eventually an onlooker could identify the game each player is playing. This is analogous to the time when stable patterns would be recognized and classified as organic life (that’s if someone where watching).

Reshuffling the Deck

We can now see how the process of reshuffling the deck, selecting and discarding the cards would work. It would not take too many hands to achieve almost perfection. Each player would select for their specific game, just like nature selects for its specific environment. All the hands would contain some of the same cards, but in different combinations. Nature mixes the genes in the same way.

cards-in-rowsThe power of natural selection is the continual selection and discarding process, which occurs at unfathomable timescales. Successful genes are kept from generation to generation, random gene mutations are added, and remixed in endless combinations. Only the best of the best survive the process. That is why an after-the-fact view of evolution can be deceiving. Incredible order can emerge without a design and a planned outcome.

Our card game never ends; the players are always looking to make improvements, no matter how small. Many poker players will end up with a Royal Flush (the best possible hand). Bridge hands will end up with every card of the same suit or all aces and face cards. This is where our analogy doesn’t quite measure up. In real life the environments constantly change, which drives evolution to adjust. It’s like occasionally changing some rules to each card game, which will force the players to change their hands.

I hope this thought experiment helps to conceptualize how evolution can accomplish a seemingly daunting task. The basics of natural selection are only a starting point towards understanding evolution. Evolution is a messy process of trial and error, an incalculable amount of trials and errors, which muddies the water. Yet the time involved is critical to the process (more than 3 billion years).

Knowledge of evolution is fundamental towards understanding all life on earth. The life sciences could not progress without it. Our own bodies function as a result of evolution and much of human behavior has evolutionary roots. It has been said that, “Evolution is not something you believe in; either you understand it, or you don’t.”

 

References: Richard Dawkins, The Selfish Gene (Oxford: Oxford University Press, First published 1976, Second edition 1989, 30th anniversary edition 2006).


 

Why is The Earth a Life-Sustaining Planet?

landscape-at-sunsetWhat has allowed the earth to maintain stable conditions that are favorable for life? To answer this question we need to look at our planet’s history, and ask why the earth has been habitable for almost 4 billion years. This is an extremely long time, and probably the time needed for intelligent life to evolve. Scientists have second-hand evidence to go by, like entering a crime scene after the fact. But there is plenty of evidence to reconstruct the major historical events of our planet; this comes from a wide range of scientific fields.

The earth is the home of all life that we know about, possibly the only home humans will ever have. However, given enough time, it is possible that much like ancient sailors settled new lands, spaceships will cross space to new worlds. Up until now we should consider ourselves very fortunate that our planet has maintained the conditions necessary for life. For sure, the earth has gone through dramatic changes in its lifespan, but not significant enough to snuff out life. Let us examine a number of plausible reasons why a life-friendly earth has endured for so long:

The Goldilocks Zone

The earth’s location in relation to the sun has been called the ‘Goldilocks Zone’ or ‘Habitable Zone,’ because it is just the right distance from the sun to support life. Specifically, the temperature on earth is within a range that allows for water to flow (life as we know it needs liquid water). The right location is the starting point for a living world.

It is possible that life could exist with other chemicals that are liquids at other temperatures. For example, it has been suggested the liquid methane at extremely cold temperature could support life, such as the lakes of Titan (Saturn’s largest moon). But this is speculative, and that form of life would be unfamiliar to us. Nevertheless, finding evidence for liquid water on other worlds is challenging, as Goldilocks Zones are hard to come by. Although over 2 thousands exoplanets (planets outside our solar system) have been discovered, planets in habitable zones are rare.

The Solar System

solar-system-planetsThe earth is in constant motion and in relation with other celestial bodies in the solar system. Somewhat like a mobile hanging above a baby’s crib, all the bodies have influence on the system. In addition to a habitable zone, a long-term stable system is necessary. At least, the overall effects of the celestial bodies must stabilize the movement and climate of one body (like the earth). Here are 4 earth-friendly characteristics of our solar system:

  1. Earth’s Tilt: The earth is tilted at an angle of 23.5 degrees away from the plane of the elliptical orbit. The tilt gives us our seasons, which allows a greater surface to attract heat from the sun. Without seasons, only the region around the equator would be habitable. This would have drastically changed life on the planet?
  2. The Sun: The sun is 4.5 billion years old and will live for another 5 billion years. Some stars only live for a few million years. For complex life to evolve it takes several billion years, therefore a long-lived sun is needed.
  3. The Moon: The earth-moon system seems to have attained a stable relationship. The moon is just the right size to help prevent a chaotic wobble of the earth’s axis. The moon also aids in creating larger tides, which is thought to have played a role in transitioning life from water to land. And the speed of the earth’s spin has slowed over time due to the moons presence, thus moderating climate extremes.
  4. The Gas Giants: Jupiter and Saturn are the largest of the outer planets. Their orbits outside the earth’s orbit have protected the earth from large impacts. In the early development of the solar system, there were many large moving objects. The gas giants are believed to have ejected some of the large debris out of the system, and aided the inner planets to form sooner. And who knows how many potential collisions with the earth were absorbed by the gas giants.

Climate Stability

It is remarkable that the earth has maintained a stable climate for billions of years. I mean stable in the sense that the climate has not varied enough to wipe out life. Since life has appeared the earth has gone through a number of ice ages and periods of intense warming. Average temperatures may have varied by as much as 100 degrees C. But for reasons only partially understood, the climate has always returned to moderate levels.

Factors controlling the temperature have fluctuated throughout planetary history, such as: the heat generated by the sun, the earth’s heat absorption rate, and the amount of greenhouse gases that trap heat in. Could there be a regulating effect or cancelling-out effect that has prevented a runaway process? The earth has avoided irreversible climate change, unlike our two cosmic neighbors (Venus is to hot and Mars is to cold). Currently the average global temperature is about 15 degrees C.

Moderate and Gradual Change

Changes to the climate and environment are essential for the evolution of life, provided that the changes are moderate and gradual. Evolution is a multi-generational process, in which individuals that are better suited to their environments survive longer and reproduce. Beneficial genes are passed on to future generations; however, what constitutes beneficial genes is unstable, because the earth is constantly changing.

As a result of moderate and gradual changes species evolve into other species. If the planet was unchanging, the earliest life forms would not have evolved into more complex forms. On the other hand, if the changes were too drastic life could not have adapted successfully. Earth’s history shows that environmental changes have caused some species to go extinct, while others have evolved and branched out into new species.

The Gaia Hypothesis

James Lovelock, a NASA chemist in the sixties, proposed the Gaia Hypothesis when he was searching for life on other planets. While comparing the atmospheres of Earth, Mars and Venus he noticed that the earth was chemically in a state of flux. Conversely, Mars and Venus were chemically unchanging and predominately composed of carbon dioxide. The fact that the earth’s atmosphere was an active mixture of gases and still retained its overall composition, suggested some form of planetary regulation. His conclusion was that life regulated the atmosphere by its many processes.

earthLovelock expanded the Gaia Hypothesis (also called Gaia Theory) to include the whole biosphere (climate, rocks, oceans, biology, etc.) and described the earth as a self-regulating system. In other words, the earth acted as one organism. Gaia was controversial as a scientific hypothesis when first proposed. The main objection was evolutionary theory, as organisms are not believed to act in concert with their environment (sometimes supportive and sometimes destructive). The argument against Gaia Theory was that organisms would somehow have to communicate with each other, and act altruistically towards the planet. This was impossible.

Lovelock’s counter-argument was that Gaia was not intentionally achieved, yet that natural selection was critical in shaping the regulatory patterns of the planet. Gaia did not need a controlling center; it was a consequence of natural selection. Nevertheless, loosely applied it points to life processes as being critical in creating and maintaining living conditions. Over time Lovelock’s idea gained more popularity as evidence grew for an ever more interconnected and interdependent biosphere.

It could be that natural selection allows life to adapt to whatever conditions arise, giving the impression of Gaia. Or possibly, that long-term climate and atmospheric stability is in large part due to the existence of life.

Good Luck

It could be that the earth is a rare and unique planet, which has benefited from an extraordinary amount of good luck. Evidence for planets outside our solar system is mounting. There are a number of earth-like candidates, but the odds are stacked against finding a place just like earth. This does not mean that other earths don’t exist, just that they would be extremely far away. Paradoxically, the unfathomable size of the universe could mean that life is both rare and plentiful.

Anthropic reasoning would suggest that the earth has endured through a long succession of fortunate events. Intelligent observes are the result of anthropic selection, of which other lifeless worlds have no one to observe them. If events had not worked out just right for us, we wouldn’t be here. Still, it is difficult to comprehend the many unlikely phases of earth’s evolution. For example:

  1. The emergence of life.
  2. Multi-cellular life.
  3. Atmospheric transformation from carbon dioxide rich to available oxygen.
  4. Life moving from water to land.
  5. The rise of consciousness and intelligence.

These examples are major thresholds that were crossed, yet countless other variables could have changed the course of history. Life could have taken a completely different direction, even to the point of total extinction. Obviously, this has not happened, either from cosmic events or global catastrophes. When life began there was no guarantee that it would survive for nearly 4 billion years. And the specific circumstances that led to human beings were even more tenuous. We should consider ourselves very lucky to be here, on such a special planet.

 

References: David Waltham, Lucky Planet (New York: Basic Books, 2014).

Beautiful Minds – James Lovelock – The Gaia Hypothesis / Gaia Theory, Published on Sep. 12, 2013.

Life on Earth Can Thank Its Lucky Stars for Jupiter and Saturn, By Sarah Lewin, Staff Writer | January 12, 2016 07:30 am ET, http://www.space.com/31577-earth-life-jupiter-saturn-giant-impacts.html

What Makes Earth So Perfect for Life? Dec 13, 2012 03:00 AM ET, http://news.discovery.com/human/life/life-on-earth-121019.htm.


Photosynthesis: The Breath of Life

large-leafPhotosynthesis is a chemical process, by which plants, algae and some bacteria convert solar energy into chemical energy. Basically, the organisms take in carbon dioxide and water, and use sunlight to make glucose, thus releasing oxygen as a by-product. The organisms are able to make their own food (glucose) by capturing sunlight. Other elements, such as nitrogen, phosphorous and magnesium are also needed to complete the process.

Sunlight provides the energy needed to transfer electrons from water molecules, an essential part of the process. The electrons are extracted from water molecules and passed along a chain, and finally forced onto carbon dioxide to make sugars. Photosynthetic organisms are called autotrophs. People and animals cannot photosynthesize; they are called heterotrophs. Today, plants are the most familiar form of autotrophs, but they were not the inventors of photosynthesis.

It Started Way Back

The evolution of photosynthesis is believed to have stared about 3.4 billion years ago. It was developed by primitive bacteria, first using elements such as hydrogen, sulfur and organic acids. These early bacteria manufactured food without using water, and did not produce oxygen (a process called anoxygenic photosynthesis). This was, however, an important development in the evolution of life.

algaeAround 2 billion years ago, a variant form of photosynthesis emerged. These bacteria lived in the ocean, used water as electron donors, and the release of oxygen into the atmosphere was the result (oxygenic photosynthesis). Photosynthesis was one of the most important developments in earth’s history. Learning to use sunlight to produce food took advantage of an endless supply of energy.

The introduction of free oxygen into the atmosphere was a game changer for all life. For some microbial life that existed then, oxygen was a toxin; this led to a significant extinction event. However, it opened up new opportunities for complex life to evolve, which it did. Oxygenating the atmosphere was an extremely slow process, as it took in the range of 1 billion years before complex life emerged.

How Did Plants Acquire the Ability to Photosynthesize?

Inside the cells of plants there is a separate compartment called the chloroplast. The chloroplast contains the green-colored pigment chlorophyll, which absorbs blue and red light. These are the wavelengths used in photosynthesis. The green wavelengths are deflected out, and that is why plants look green to us. In the chloroplast a number of complex interactions occur to produce food for the plant cell.

The chloroplast originated from primitive bacteria. In fact, in an earlier period chloroplast were bacteria, which eventually formed a symbiotic relationship with more complex cells. This relationship was the beginning of plant life on earth. It seems that the complex cells took advantage of the bacteria in order to get a free lunch. However, there was probably a benefit for the bacteria as well, perhaps the protection of an outer membrane or some other survival advantage.

The Ultimate Recycling Project

Photosynthetic organisms are the original source of oxygen and food for other life forms. If not for plants, there wouldn’t be any food for animals to eat. So the food chain in any ecosystem begins with photosynthesis. The food chain starts with plants, which are consumed by herbivores; the chain continues with carnivores and omnivores.

athmosphereThe earth’s atmosphere contains 20.95% oxygen and .039% carbon dioxide. The remainder is mostly nitrogen (78.09%). What concerns us here is the oxygen/carbon dioxide relationship. Most of the oxygen is provided by terrestrial green plants and microscopic phytoplankton in the ocean (they consume carbon dioxide and release oxygen). Non-photosynthetic organisms, like humans, animals and fish do the opposite (they breathe in oxygen and breathe out carbon dioxide).

Oxygen and carbon dioxide are continually recycled into the air. Life as a whole has evolved to function with the present mix of oxygen and carbon dioxide. What we don’t know is how delicate the balance is and if human carbon emissions will drastically change the balance. Scientists know that the atmosphere has changed significantly over evolutionary time; the result being the extinction of some species and the evolution of other species.

Given that life has created and maintained the atmosphere for billions of years, it will no doubt continue to do so. Life as a whole is safe. The questions for humans are: What are the long-term implications of releasing more carbon dioxide in the atmosphere? Which species will adapt successfully? And whether the atmosphere is changing in a direction that is less favorable for us?

 

References: In Our Time: Science, Photosynthesis, May 14, 2014.

livescience, What is Photosyhthesis? by Aparna Vidyasagar, July 31, 2015. http://www.livescience.com/51720-photosynthesis.html

Earth and Sky, How much do oceans add to world’s oxygen? June 8, 2015. http://earthsky.org/earth/how-much-do-oceans-add-to-worlds-oxygen


 

Is Anything Possible?

You’ve heard it before: ‘anything is possible.’ I have also, but how much truth is there in this statement? On the surface it sounds OK; it’s usually used in a positive tone (but not always) and it’s open to seemingly unlimited possibilities. What could be wrong with that? Hold on just a minute until we look a little deeper.

highway-at-nightIs anything really possible? And can we determine when something becomes impossible? If a person losses a hand, it won’t grow back. A conventional air plane will not fly without wings. Pure water will not freeze if the temperature is above 0 degrees Celsius. So there you have it, anything is not possible. I don’t think this is a big revelation. People who say that ‘anything is possible’ know that it isn’t true. So why do they say it? We all go through life with insufficient knowledge, it’s just part of being human. I believe what people are really thinking is: many things are possible, or they don’t know what’s possible.

Nature’s Regularities

‘I don’t know what’s possible’ doesn’t sound quite as positive as ‘anything is possible.’ So maybe that’s why the word anything is so often used. Despite our limited knowledge, there lies one fundamental truth which determines what is possible and what isn’t. This truth is related to the following question: What does the loss of a hand, an airplane not being able to fly and water not freezing have in common? On the surface they seem totally unrelated; however, they share a subtle and profound relationship. I’ll get back to this later but first a little back ground.

There are reasons why some things are possible and others impossible and they are fundamentally the same reasons. It has to do with the way the world works (in fact the entire universe). There exist regularities in nature, both seen and unseen. Some of these regularities would have been known in ancient times simply by observing nature. For example, the ancients were aware of the conditions needed to make fire and how to put it out. They learned how to grow food by observing how crops responded to the seasons and so on. Early humans had a rudimentary understanding of what might be possible. They achieved this with varying degrees of success by observing nature’s regularities. However, they lacked an appreciation of what was behind the observed regularities. A deeper understanding would come about later.

The Scientific Revolution of the 15th and 16th hundreds is the unofficial line of demarcation of modern science. This is when scientists began deciphering the laws that govern nature. The laws of nature are fundamental to the regularities we observe. For the first time nature could be explained by a series of scientific laws rather than superstition, conjecture or a few rules of thumb. For instance, seen phenomena such as the motion of objects were explained by Newton’s laws of motion. Perhaps even more ground breaking is that eventually parts of the unseen world could also be explained by scientific laws. For Example, quantum laws of the early 19th hundreds, of which several scientists were involved, explained the workings of atomic and sub-atomic particles.

Out of the Ordinary

In everyday experience people often use the ‘anything is possible’ line as a positive projection into the future. They are usually thinking about the trajectory of one’s life and the numerous untapped possibilities. In this context they are referring to ordinary events in human affairs. Ordinary in the sense that one doesn’t had to believe in anything outside the established laws of nature to account for what might unfold.

ghostSome people consider other ideas, which fall into a totally different category. These ideas are sometimes called paranormal or supernatural, but personally I dislike both those terms. The reason being, that some of these concepts diminish the established laws of nature. The simplest way I can convey what kind of ideas I mean is to begin with a list. The following is just from the top of my head and much more could apply: alien visitations, ghost stories, miraculous healings, near-death experiences, psychic readings and so on. With this list, one should ask: how do the laws of nature fit in these schemes?

Let’s look into one of the possibilities listed above. With alien visitations for instance, one has to consider such things as a life-sustaining planet and the distance the aliens would have to travel. A little understanding of the laws of nature can give us clues as to how seriously we should consider a claim. We know that other than Earth, there is no complex life in our Solar System. So our star system is out.

The nearest star system is a three star system call Alpha Centauri, of which Proxima is the closest (about 4.24 light years away). On the surface this doesn’t sound all that far away. However, if we consider present technologies, it would take anywhere from 19,000 to 76,000 years to make the trip. The wide range in estimates has to do with which technologies would ultimately prove viable for such a trip. We should also consider the possibility that the proposed aliens would have to come from much farther away.

rocketIn short, in an absolute best case scenario, there would have to exist a life-sustaining planet where intelligent life evolved and its inhabitants developed far superior technology. Not an impossibility, but a long shot. The determining factor is the limits imposed by the laws of physics. The limits in this case are distance and how fast a spaceship can travel. Keep in mind that no matter how advanced a technology may be it cannot overcome the laws of physics. Considering the distances involved, it seems unlikely that we have been visited by aliens.

Pure and Simple

Now back to my earlier question: about the loss of a hand, an airplane unable to fly and water not freezing. All three are determined by the laws of nature; specifically, the limits of biology, physics and chemistry. And that’s not only true for these three scenarios but for any proposed idea. That’s right, any proposed idea. That being said, it needs to be mentioned that our understanding of the laws of nature are likely incomplete and currently serve as our best representation of reality. Nevertheless, whether we are talking about everyday experience or the fantastic, the laws of nature run the show. Whether the answer lies within the scope of our knowledge or not; it all boils down to one simple truth: anything which is in principle allowed by the laws of nature is possible and anything which is not allowed by the laws of nature is impossible!

 

References: Universe Today, How Long Would it Take to Travel to the Nearest Star?, Sept 6, 2016 by Matt Williams. http://www.universetoday.com/15403/how-long-would-it-take-to-travel-to-the-nearest-star/


 

Evaluating Ideas

 

good ideaHow can we tell if an idea is a good one, or if a claim is true or false? When should we take a theory seriously or discard it? In an information age it is not always easy to separate the wheat from the chaff. One can find conformation on-line for just about any idea. When we are growing up, we tend to believe just about anything. For the most part, we accept what adults and authorities are telling us. We are also less likely to question what we read, what’s on television or the internet. However, at some point we have to grow up, and part of growing up is evaluating the validity of ideas.

How Can We Know What’s True?

scale 2Unfortunately there is no fail safe method that will always give us the right answer. That being said, there are modes of thinking that are more likely to get at the truth, or something close to it. A scientist would almost certainly evoke the scientific method as the best course of action. The empirical approach has proven effective at getting to the bottom of things. However, for the general public the scientific method is not always applicable. In everyday experience we are often faced with making assessments on the fly, or even if we have plenty of time to contemplate an idea, we are still left to our own devices. We don’t necessarily have access to the tools of science. It needs to be said nonetheless, that in some cases we can use established scientific knowledge as part of the evaluating process.

Idea Evaluation Checklist

ideas check listLife situations often demands that we buy in or reject certain ideas or claims. In everyday experience we need a way of moving forward, even though in most cases we can’t apply the scientific method. For what it’s worth, I present to you my idea evaluation check list. This list can be applied to a variety of ideas, claims or theories. It consists of 10 questions one might consider:

  1. Where does the preponderance of the evidence point to? This is a pros and cons way of looking at a situation. In other words, the evidence for vs. the evidence against.
  2. Is there a plausible explanation for how a proposed idea works? Here I am not suggesting that we need prof, but a sound explanation that makes sense on the surface. Such an explanation gives us some degree of confidence in an idea.
  3. Can this in principle be a shared experience? Can the idea proposed be tested or experienced by others?
  4. How reliable is the source? It is impossible for an individual to test or challenge everything. By necessity we must accept information from outside sources. Therefore, reliability of the source becomes important.
  5.  Do I want this to be true? If you want something to be true; a red flag should immediately be raised. In these cases one must be extra vigilant, not to let wishful thinking get in the way of sound judgement.
  6. Is the strength of the idea threatened by new information? If an idea can’t absorb new information, then it is substantially weaken. The knowledge base is constantly evolving. For that reason, some ideas need to be re-evaluated or even discarded as we learn more about the world.
  7. Can the idea be defended if challenged? Plain and simple, if you can’t defend your idea, why hold on to it?
  8. Is this how the world normally works? Does the idea comply with your understanding of the world? Or does your thinking need to be compartmentalized in order to make room for the idea?
  9. Are you confusing coincidence with causation? Just because two events happen in sequence, it does not automatically mean that one caused the other. A clear link between cause and effect needs to be established (beyond just A happened before B). Many false claims gain momentum because of this confusion.
  10. Does it ring true? On its own this is not enough, but if you need to tip the scale one way or the other, resort to what your gut is telling you.

So there you have it, my check list. Of course it is arbitrary; one could alter it and still come up with something as good or better. Nonetheless, I think that an exercise such as this one encourages critical thinking. Our world view is largely arrived at by what kind of ideas we accept or reject. What follows is: what we believe, what we don’t believe, and how we live our lives.

 

References: Michael Shermer: Baloney Detection Kit, Richard Dawkins Foundation for Reason & Science, Published on June 5, 2014.  https://www.youtube.com/watch?v=aNSHZG9blQQ


 

Interpreting Chance and Probabilities

mixed up cardsMuch of our lives are affected by random events; however, we are not fully aware of them. How could we, there is just too much randomness to keep track of. Despite our best efforts to reach our goals, we can’t eliminate the role of chance and unpredictability. We know that randomness exist, but to what extent? That is when a keen understanding of probabilities can be helpful. Calculating probabilities can determine a course of action and set realistic expectations for outcomes.

The insurance business is built on probabilities, which predict how often unforeseen events occur. That is, unforeseen for one particular individual, but almost a certainty for someone in a large group of people. For example: houses will burn down, cars will crash and people will die unexpectedly; we just don’t know who and where. Unfortunately, insurance cannot protect us from something bad happening (even the things we buy insurance for).

We like to think that we are in control of our lives. We tend to focus on intentions and give credence to willful actions or direct causes. Most of the time, when something works out for us we are eager to take credit. When something does not work out, we find fault by blaming ourselves or others. But I don’t think it’s that simple; success or failure is partly the result of chance (maybe as much as effort). Chance, however, does not mean that all outcomes have an equally chance of happening. Some outcomes are more probable than others, and sometimes it can be calculated.

How Do We Quantify Chance

Although there are many unnoticed causes that we cannot quantify, there are situations when we can calculate chance. For example, a coin toss, the role of a die, and the dealing of playing cards. In simple situations, intuition is a reasonable guide. Simple mathematics instantly reveals the odds: There is a 1 in 2 chance of a coin landing on heads. There is a 1 in 6 chance of a die showing a six. There is a 1 in 52 chance of a turning over the ace of spade.

Problems arise when situations get more complicated. For instance, how many different possible outcomes are there for a 7 game series between 2 sports teams? From one team’s perspective, one outcome could be: win, win, loss, loss, win, loss and win. Like most probability questions, it can be calculated, but the answer is not immediately obvious. Assuming that all 7 games are played, there are 128 possible outcomes. In reality the outcomes are less, because after one team wins 4 games the series is over.

In fact, intuition is usually misleading. Why is that? 1) Humans are good at recognizing patterns, and often find patterns when there are none. 2) We tend to give more weight to recent events and stronger memories. 3) We are bias and notice what we look for. 4) Short-term results don’t always match actual probabilities, which will show up in larger sample sizes. The following are examples of how scrutinizing randomness can reveal surprising results:

The Gamblers Fallacy

Imagine you are trying to predict the outcome of a coin toss. You toss the coin 5 times and it turns up heads every time. On the sixth toss, would you be inclined to call tails? Or with a number of people predicting the next toss, would there be more calls for tails than heads? If the answer is yes to any of these questions, someone has fallen victim to the gamblers fallacy.

The gamblers fallacy is the mistaken belief that if something happens more often than normal in a time period, it will happen less often in the future. It’s a belief that odds will even out, which is true in the long run; however, it will not bear out in the short run. That’s the difference between the Law of Small Numbers and The Law of Large Numbers. Although the odds of a coin toss are 50/50, a small sample size will often show a large dependency in heads and tails (The Law of Small Numbers applies). Conversely, a large number of tosses will come out very close to 50/50 (The Law of Large Numbers applies). For odds to accurately reflect reality there needs to be many events. A run of consecutive heads in no way changes the odds for the next toss.

In the coin toss scenario each result is independent from each other. Therefore, the odds of getting six heads in a row are 1 in 64. It’s also the same odds of getting 5 heads and 1 tails (in that exact order). This means that no matter how many times you toss, the odds are always 50/50 on the next toss. This is important, because the gamblers fallacy does not apply in dependent events. That’s when one result truly influences a future result. For example, when an ace turns up in a game of black jack, then there is less chance of an ace showing up on the next card. By removing an ace from the deck there are fewer aces left and the odds are really less of drawing another ace. As long as the cards are not reshuffled, your intuition of expecting cards that have not shown up would be correct.

The Monty Hall Problem

Let’s Make a Deal was a popular TV game show, which air in 1963 and ran for many years. The host was Monty Hall, and here is the problem: Monty Hall gave a contestant a choice, pick 1 of 3 doors. Behind one door was a valuable prize, and behind the other two was something far less valuable. Let’s say the contestant was playing to win a car. After the contestant picked a door (for example door #1), the host (who knew where the car was) opened one of the two remaining doors. Monty always opened a door with a dud prize (for example door #2).

Monty Hall ProblemThis is the point when the Monty Hall Problem arose. He gave the contestant the choice to change his/her mind. Should the contestant stick with door #1, or pick door #3. Without careful analysis, it seems that it makes no difference. Both door #1 and door #3 have an equal chance of winning the car. However, that is incorrect. The probability of winning is twice as high if the choice is switched.

The reasoning is very simple, yet it eludes many people. With the original choice, the odds are 1 in 3 that the car is behind the chosen door. That means that it’s 2 in 3 that the car is behind one of the other doors. When the host opens one of the dud doors (which he already knows has a dud prize), he is giving new information. He has eliminated one of the bad options. Therefore, there is a 2 in 3 chance of winning the car by switching doors (for example door #3), but only a 1 in 3 chance of winning by staying put.

We can exaggerate the game by imagining 100 doors. The contestant chooses 1 door and the host opens 98 doors without revealing the car. Remember that the host knows where the car is. The obvious choice here is to make the switch. There is only a 1 in 100 chance that the first choice is correct. That means that there is a 99 in 100 chance of winning the prize by switching doors.

Sharing a Birthday

birthday cakeIf you are hosting a party, what is the likelihood that two people will share the same birthday? Worded another way, how many people need to show up for the odds to be higher than 50%? Once again, intuition is shaky. One would think that the number would be quite high, as there are 365 days in a year. The answer is surprisingly low: just 23 guests will give a better than even chance of two people sharing a birthday.

The reason is that there are many possible combinations in which people can share a birthday. Each guest is not limited to matching a specific date on the calendar. Every arriving guest has the chance of matching a birthday with all the people already at the party. By the time it gets to 23 people, every guest has 22 chances of sharing a birthday with another guest.

My three examples above are fairly straight forward. Life is not as simple. Although we tend to feel responsible for the events in our lives, we should not underestimate the role of chance. Of all the possible outcomes, we don’t know how each day will turn out. We clearly can’t predict what will happen in life; however, there are isolated situations when information can help us determine the most probable outcomes. We need to figure out which facts apply and which facts do not apply. And unless we think it through, we can easily be fooled by surface information. Probabilistic thinking requires that at times we set our emotions and intuitions aside and let the numbers take over. Sometimes the numbers will reveal surprising results.

 

References: Leonard Mlodinow, The Drunkard’s Walk, (New York: Pantheon Books, 2008).


 

The Moon: Our First Satellite

moonWhen one thinks of a satellite it is usually in the form of a man-made object orbiting the Earth. However, by definition a satellite is a moon, planet or machine which orbits a planet or a star. From our vantage point here on Earth, the Moon is the predominant satellite. Long before Sputnik 1 (the first man-made satellite launched by the Soviet Union) the Moon was our one and only satellite.   

Long, Long Ago

When the Solar System first formed it consisted of a star surrounded by a disk of gas. Eventually this gas gathered into dust, rocks, asteroids and finally planets. Each planet also had its own disk of gas, which in turn would follow a similar process. Some of the debris was pulled into the planets, but not all. Over time some of the gas eventually turned into moons. Some moons could have formed independently from their host planet, and later were captured by gravity as they drifted through space.

Our Moon is believed to have been created by a different manner. The early Solar System was a very violent and chaotic place. As planets and moons were born, they were bombarded by asteroids and small planets. The Moon’s many craters is clear evidence of this early chaotic period. In the 1970s a theory was proposed: about 4.5 billion years ago the Moon was formed by a gigantic collision between the early Earth and another planet. Recently a new theory has surfaced which tweaks the original 70s theory. I’ll begin with the established theory first, then get back to the revised theory later.

earth moon collisionThe original theory states that a mars-size planet on a similar orbit as Earth struck the Earth on an angle. The collision created the Moon and quite possibly the tilt of the Earth’s axis of 23 degrees. This rouge planet is sometimes referred to as Theia, named after the mother of the ancient Greek moon goddess, Selene. The impact generated intense heat in both planets. The Earth absorbed part of Theia along with her heavy iron core, the lighter rocky material ended up in a ring around Earth’s orbit. From this debris our first satellite would from. Interestingly, the Moon may have been intact after only several decades. Over billions of years both bodies cooled, but not entirely; the Earth still has a largely molten core. The smaller Moon may have completely cooled or perhaps still retains a tiny molten core.

 Evidence for the ‘Giant Impact Theory’ (70s theory)

  • The Moon is large for a satellite in comparison to the size of the Earth. Most moons are much smaller in ratio to the planet they orbit. Models for how moons are usually formed place a limit on how big a moon can be in relation to its host planet. Our Moon appears to be too big to have formed by surrounding gas in the early solar system or captured by the Earth’s gravity.
  • By examining the surfaces of both Mercury and Mars we are able to see what the early solar system must have been like. Virtually unchanged for about 4 billion years, these planets are dotted with craters. Some of which are as large as six hundred miles wide. The Earth has no such markers due to climate and erosion, but by deduction, we can assume that the early Earth was also hit by large objects (such as Theia).
  • In six trips to the Moon the Apollo astronauts collected rock samples and for the first time they were able to see what the Moon was made of. Remarkably, the Moon samples were found to have a similar chemistry to Earth. This discovery is in line with a Theia and Earth collision. Such an event would have blasted parts of the Earth into space which coalesced with bits of Theia to form the Moon.
  • The impact hypothesis was also put to the test with computer simulations. The impact suggested, was applied to software that recreated the conditions of the early Solar System. After running several simulations of a Mars-size object colliding with the Earth at the angle predicted, everything worked. The end result was the Earth/Moon system we have today.

The ‘big Whack’ (new theory)

This is where the new revised theory comes in; modern computer simulations suggest a much more intense collision at a significantly sharper angle. Such an intense impact would have vaporized Theia and much of the Earth. This  accounts for why the Earth and Moon are so similar in their chemistry. In fact, new research is finding increasing chemical similarity. This points to a much more violent impact which would have thoroughly mixed both bodies before they separated.

Also, the impact forced the Earth to spin much faster (about once every 2 hours) and tilt as much 60 to 80 degrees on its rotational axis. The Earth’s present rotational tilt of 23 degrees is though to have been arrived at later by complex interactions with the Moon and the Sun. Another interesting fact, which the original theory left unexplained, is the 5 degree tilt of the Moon’s orbital plane. The Moon’s orbit is tilted 5 degrees in relation to the Earth’s orbit around the Sun. The Earth orbits the Sun on what is called the ecliptic plane; this plane is where most bodies orbit the sun. The early Moon’s orbit is though to have matched the severe tilt of the Earth and did not transition smoothly to match the ecliptic plane. The revised theory proposes that the 5 degree orbital tilt of the Moon is but a relic of a much steeper orbital tilt from the distant past.

A Match Made in Heaven?

earth and moonThe two prominent heavenly bodies are the Sun and the Moon. Much of the Sun’s influence on the Earth is clearly recognizable; the Moon, however, affects us in more subtle ways. The warmth of the Sun (or lack of it on some days) is an everyday experience. In ancient times the Sun was worshiped by some cultures as godlike. It would have been clear then, as it is now, that without the Sun the Earth would be void of heat and most likely without life.

As it turns out the Moon’s presence might also be fundamental to life. However, for a large part of human history the Moon remained mysterious. Today scientists speculate that the Moon may have contributed to life in various ways. What follows are plausible explanations for how our Moon influenced life:

  • When the Moon was first formed it was much closer to the Earth than it is today. It is still receding by a minuscule amount every year. Over 4 billion years ago the Moon exerted a greater gravitational pull on the Earth, which may have set plate tectonics in motion. Plate tectonics are believed to be necessary for a living planet.
  • Shortly after the Earth’s post impact formation it rotated about once every 5 hours (70’s theory) or once every 2 hours (new theory). Either way, the Moon’s presents gradually slowed down the Earth’s rotation, diminishing the severity of the weather. The Moon may also have stabilized the earth’s rotation on its axis.
  • Nocturnal animals behave differently at various times during the monthly lunar circle, depending on the brightness of the Moon. If not for the influence from varying moon light, who knows how the course of evolution would have been altered.
  •   The greatest influence the Moon has on the earth is in generating tides. This would have allowed life from the ocean (where life began) to spend short intervals of time on land. This may have provided the ideal training ground for life to gradually adapt to the land.

ocean tidesThe Earth and the Moon have been united by gravity for over 4 billion years. It is hard to know for sure what the Earth would be like without the Moon. Would there be life? If so, what would it look like? Nevertheless, if there was no Moon and life did manage to evolve, it would almost certainly be different.

 

References: Jim LeBans, The Quirks & Quarks Guide to Space.

Did We Need The Moon For Life? Fraser Cain, Published on Nov 20, 2015, https://www.youtube.com/watch?v=KulEmr7X1HM

Origin of the Moon, tonyweston9, Uploaded on Nov 27, 2008, https://www.youtube.com/watch?v=m8P5ujNwEwM

What is a Satellite? Dan Stillman, Feb 12, 2014, http://www.nasa.gov/audience/forstudents/k-4/stories/nasa-knows/what-is-a-satellite-k4.html

Scientists propose new theory about how Earth got its moon, By Sheena Goodyear, CBC news, Posted: Nov 1, 2016. http://www.cbc.ca/news/technology/moon-theory-1.3830623

Violent Impact That Created Moon Mixed Lunar and Earth Rocks, By Charles Q. Choi, Space.com Contributor | January 28, 2016 02:28pm ET. http://www.space.com/31763-moon-creating-impact-mixed-lunar-earth-rocks.html

Did Early Earth Spin On Its Side? Monday, October 31 2016. http://www.seti.org/seti-institute/press-release/did-early-earth-spin-its-side

New Model Explains the Moon’s Weird Orbit, October 31, 2016, http://cmns.umd.edu/news-events/features/3680


 

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).