Further Confirmation of the Big Bang

The Big Bang / BBC Science

The Big Bang / BBC Science

And it all started with a Big Bang…

Everyone knows our universe began with a Big Bang.  Actually, it is probably more accurate to say that approximately 13.8 billion years we know that what we can observe seemed to have underwent a significant phase transition, which directly led to the creation of all known matter and energy, and perhaps led to the existence of space and time itself.  But we don’t know that the Big Bang was the start of everything there is.  We don’t know whether there are other areas of our universe that existed pre-Big Bang.  And perhaps more importantly, we don’t know what caused the Big Bang itself.

However, I definitely don’t want to undersell how powerful a theory the Big Bang theory is.  The Big Bang theory is the central, guiding theory in all cosmology, and can explain nearly every aspect of the universe we observe.  That is quite an ambitious and successful theory by any measure.  And last month the Big Bang theory got a big boost by a team of international researchers that massively strengthened one of the four observational pillars of the Big Bang.

For everyone who doesn’t know, the four observational pillars of the Big Bang are:

  1. Expansion of the fabric of space
  2. Cosmic Background Radiation
  3. Abundance of light elements
  4. Galactic evolution and distribution

The observed expansion of spacetime itself is crucial to supporting the idea that our observed universe started with a Big Bang.  All galaxies are rushing apart from each other.  The further apart two galaxies are, the further apart they are rushing apart.  This expansion has been ongoing since the beginning of spacetime itself.  We can extrapolate expansion rates into the past, and with help from Einstein’s theory of general relativity, we can get an estimate on the conditions of the early universe.

The Cosmic Background Radiation (CBR) is equally important to understanding the Big Bang as the expansion of spacetime.  Discovered in the 1960s, the CBR is empirical confirmation that the universe was once in a primordial state with no galaxies or stars.  It is actually a snapshot of time approximately 380,000 years post-bang when the universe had just started to form atoms and photons were first able to roam freely.  This period in the universe’s development was predicted by the general theory of relativity, and thus is a fantastic example of the predictive power of the theory.

The fourth pillar (we’ll get to the third after!) is also important.  We now know that galaxies have evolved in a quite straightforward direction of time.  As the universe expanded gravity pulled slightly unevenly distributed matter into larger and larger clumps.  First gravity sculpted clouds of hydrogen.  Then young galaxies.  Then super clusters of galaxies.  Today the largest structures in the universe are galaxies connected like giant cosmic filaments.  Our universe as a giant web of matter (that is admittedly being ripped further and further apart).

Finally, the third pillar: the abundance of light elements.  For a while chemists wondered how we could possibly explain why 99% of the universe was composed of the lightest elements: hydrogen, helium, and lithium.  Stars are chemical factories, but the known process of thermonuclear fusion predicts that there should be a higher percentage of heavier elements than observed.  The only way we can explain the observed abundance of light elements is if the universe was once as hot and dense as a star for a short period of time.  If this was the case we should suspect that the universe in this state would have only been able to produce the lightest elements, which would explain why they are so abundant.

Wait… that is what the Big Bang theory predicts!  Perfect!  This phenomenon is called “Big Bang nucleosynthesis“.  But there is a problem.  Scientists have shown that the Big Bang theory roughly accounts for the amount of hydrogen and helium observed.  Over the past few decades astronomers have observed that there are two times the amount of two Lithium isotopes (Li-6 and Li-7) than Big Bang nucleosynthesis could account for.  This is a major problem that cosmologists have been working to resolve now for over twenty years.  Some scientists suspected that there could be pre-galactic fusion cores that we don’t have the technology to observe yet.  Some thought there was a big enough discrepancy in observations to that justify re-working the Big Bang theory itself.

However, last month the aforementioned Big Bang pillar-reinforcing study demonstrated that the problem was technological.  The authors claim that the observed over-abundance of lithium was due to poor observational quality in the past.  In their study, utilizing the powerful W.M. Keck Observatory’s 10-meter telescope, they completely reconciled the Big Bang theory with the observed abundance of lithium.

As a result, the pillars are stronger than ever.  Our universe, at least what we can observe of it, started with Big Bang.  Future studies related to reinforcing the pillar of the Big Bang will now be focused on observing the first stars and galaxies in our universe’s history.  In order to do that, astronomers will have to wait for the James Webb Space Telescope, which is the planned successor of Hubble and is scheduled to launch in 2018.

What do you think of this scientific development?  Let Cadell know on Twitter!

Into The Microscopic

Technology has allowed humanity to extend its vision to scales of reality that our ancestors could have never imagined. Ever more advanced telescopes are allowing us to see the birth pangs of the universe and the formation of the very first large scale objects. In contrast, ever more advanced microscopes are allowing us to see the very structure of all normal matter. It seems like scientists are in a race to see who can see further and deeper faster; and there may not be an “end” or “bottom” in either direction.

few days ago an epic milestone into new realities was reached when a team of physicists captured the first ever image of a hydrogen atom’s orbital structure. This was done using a quantum microscope, which should help physicists better understand the way atoms behave and interact.

Below is a ode to the microscopic. I have assembled images we have taken of objects at ever-decreasing size. The purpose of this exercise is to realize that at every scale of reality there is beauty and new wonder. Every scale of reality seems to be like a world unto itself, just like we imagine our “middle world” to be. Enjoy!

Largest known bacteria (0.001 m) (Image Credit / teachoceanscience.net)

Largest known bacteria (0.001 m) (Image Credit / teachoceanscience.net)

Human egg (0.0001 m) (Image Credit / thetimes.co.uk)

Human egg (0.0001 m) (Image Credit / thetimes.co.uk)

Cell nucleus (0.00001 m) (Image Credit / wikipedia.org)

Cell nucleus (0.00001 m) (Image Credit / wikipedia.org)

X Chromosome (0.000001 m) (Image Credit / scienceclarified.com)

X Chromosome (0.000001 m) (Image Credit / scienceclarified.com)

AIDS Virus (0.0000001 m) (Image Credit / science.nationalgeographic.com)

AIDS Virus (0.0000001 m) (Image Credit / science.nationalgeographic.com)

Hydrogen Atom's Electron Orbital (0.00000000001 m) (Image Credit / i09.com)

Hydrogen Atom’s Electron Orbital (0.00000000001 m) (Image Credit / i09.com)

Also, this is fun.

What do you think of the first picture of an electron orbital?  Let Cadell know on Twitter!






The Largest Living Systems


For anyone who studies evolution, it is important to realize that there are characteristic evolutionary patterns. For example, evolution tends towards greater complexity (although not always). Evolution also has a variable speed (which is often contingent on the environment). And a study recently published in PNAS indicates that evolutionary processes generally select for species-level living systems with universal size distribution. Science Daily summarized the importance of this universal size distribution well:

Flocks of birds, schools of fish, and groups of any other living organisms might have a mathematical function in common [… researchers] showed that for each species studied, body sizes were distributed according to the same mathematical expression, where the only unknown is the average size of the species in an ecosystem.

For the researchers of this study, these apparent universal size distribution may be useful for understanding how systems of living matter operate. However, this study made me think of the role of size in evolutionary processes. Specifically, what causes different living systems to evolve different sizes? And what living system has evolved the largest overall size?

The role of size in evolutionary processes has always been a contentious issue for evolutionary theorists. Central to the issue of size has been the idea that natural selection tends to drive the evolution of larger and larger overall size, regardless of whether the living system is a bacterium, a hydra, or a chimp. This observed trend has been labeled Cope’s rule after Edward Cope, a 19th century paleontologist who first proposed the trend. The late evolutionary theorist Stephen J. Gould disregarded Cope’s rule as a “psychological artifact”, however recent studies have provided empirical evidence to support the general pattern.

Paleontologist Joel Kingsolver supports the idea that evolution tends to favour large body size, stating that:

In 80 percent of the studies, there’s consistent selection favouring larger size.

Disappointingly, the theory to explain this pattern is still underdeveloped. In fact, Kingsolver contends that there may not be any universal driver of larger body size:

My guess is that it’s a mix of particular reasons for particular speices. You may be able to make through lean times better than someone who’s smaller. Females that are larger are able to produce more eggs. If males are competing for females, larger size is often favoured.

Paleontologist and science blogger Brian Switek echoed a similar perspective recently in an article about large dinosaur body size:

The evolutionary driving forces behind the evolution of truly huge body size are not clear, and likely differed from one group to the next.

Although evolutionary theory explaining the drive behind selection for larger body is underdeveloped, we do have a better idea of proximate determinants of body size. For example, many theorists have demonstrated that mode of locomotion and reproduction are both important factors either constraining or enabling large body size.

As Brian Switek discussed at length recently, the monstrous sauropod infraorder was able to “sidestep” the costs and risks that constrain mammalian size by “externalizing birth and development.” The size distribution of sauropods dwarfed the size distribution of all other known terrestrial organisms to ever exist.

So of these supermassive sauropods, what species holds the title of largest? The answer to this question was far more difficult to find than I originally thought. Michael Stevens from VSauce recently claimed that Giraffatitan was the largest known “with certainty of a complete skeleton”. Estimates of Giraffatitan come from one skeletal sample, and was thought to be 72-74 feet in length and weigh ~30-40 tons. Compare that to the largest known African elephant which weighed ~12 tons.

However, there is general consensus in the paleontological community that there were larger sauropods than Giraffatitan. Thankfully, I had some help from Brian Switek to better understand the contemporary debate:



According to Switek Argentinosaurus and Supersaurus
are the leading contenders for heavyweights in the dinosaur world. The longest known of these giants was a Supersaurus that is estimated to be 108-111 feet long. The heaviest was a Argentinosaurus estimated to have weighed 73 tons. They were the giants of the gigantic sauropoda order.


But we can’t forget about a living clade of animals that has experienced an explosive increase in size distribution: cetaceans. The largest (by far) of our mammalian cousins is the blue whale. And the blue whale is not just a contender for largest living animal, they are also contenders for largest animal of all time. In fact, in terms of absolute weight, it doesn’t appear to be close at all. Whereas Argentinosaurus weighed 73 tons, the largest known blue whale weighed over 200 tons! More than double the weight of the largest known dinosaur! But to be fair, blue whales don’t have to worry as much about the crushing weight of Earth’s gravity. The battle is much closer when we compare length: Supersaurus was between 108-111 feet and the largest known blue whale was ~110 feet.


Blue whale Balaenoptera musculus = heaviest of all time?

The SV-POW paleontology blogger team made a brilliant point that we should suspect that Supersaurus was on average longer than blue whales because we are comparing with biased sample sizes:

A huge sample of blue whales included none longer than 110 feet, while our comparatively pathetic sample of sauropods has already turned in one animal (Supersaurus) that may have just edged that out, and another (A. fragillimus) that – assuming it was really as big as we think – blows it out of the water.

In case you were wondering, A. fragillimus is estimated to have been between 130-200 feet long! It completely blows my mind that a terrestrial organism can reach those sizes on our planet (just imagine how big they would have been if they had evolved on a planet the size of Mars!).


The red image represents A. fragillimus, potentially the longest organism ever

In case you were wondering, no primate species has ever been a contender for largest living system. The primate order is comparatively small, with the largest contemporary species (gorillas) weighing between 300-400 lbs (or about 0.15-0.2 tons!). Even if we consider extinct species, no primate has ever even been a contender for largest land mammal. The largest, Gigantopithecus, weighed approximately 1,200 lbs (or about 0.6 tons). Of course, I think Gigantopithecus is aptly named (and I think sympatric populations of Homo erectus would agree); but they are only aptly named in comparison to our relatively puny order. Primate size has probably always been constrained by underdeveloped quadrupedalism and selection for long-term infant dependence.


Reconstruction of Homo erectus and Gigantopithecus in Southeast Asia

However, it is interesting to know that all species body sizes (from prokaryotes to sauropods) are distributed according to a potentially universal power law. This universal describes how ecology influences average species size, while genetics contains variability around that average. In the future, I’ll be interested to see whether evolutionary theorists can better describe the adaptive pressures selecting for larger size. It is useful to have a grasp on the proximate causes of body size, but the ultimate causes will be necessary to better describe how living systems develop over time.

What do you think about the evolution of large size?  Let Cadell know on Twitter!

Also posted via Svbtle:

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Earth-Like Planets

The search for an Earth analogue is heating up. And although we may have to wait for the James Webb Space Telescope to see another Earth, indirect methods are bringing us closer and closer to finding an Earth-like exoplanet every month. These findings are also bringing us closer to estimating the number of Earth-like planets in the Milky Way (e.g., study 12).

The latest research, and for some the most exciting, was the discovery of Kepler-62e. Kepler-62e is a planet located approximately 1,200 light years away from Earth in the Kepler-62 star system. This system is composed of a smaller and cooler star than our Sun, and is accompanied by five known planets, two of which are rocky worlds in the stars habitable zone.


From the limited data available to astronomers at this point in the detection process, Kepler-62e has been touted as the “most Earth-like” planet known to date. In fact, by utilizing the Earth Similarity Index (ESI) equation Kepler-62e scores a 0.82 (scale: 0-1.0). That score matches the unconfirmed exoplanet candidate Gliese 581 g (Figure 1).


Figure 1 – Current Potential Habitable Exoplanets

ESI is calculated using data on the mean radius, bulk density, escape velocity, and surface temperature of an exoplanet. In the popular science media a high ESI (~0.80-1.00) is code for “Earth-sized planet within the habitable zone.” In essence that is what everyone means when they say “Earth-like.” But a growing number of scientists, myself included, are beginning to realize that we are getting way ahead of ourselves. At the moment we have no way of understanding an exoplanet’s geophysical history, present state, or the dynamics of the entire star system. Astronomer Phil Plait recently tempered enthusiasm re: Kepler-62e by stating there are too many unknowns to call it Earth-like yet:

Kepler-62e could have a thick CO2-laden blanket of air, making its surface temperature completely uninhabitable, like Venus. Or it might not. We just don’t know yet, and won’t for quite some time.

In short, more data on Kepler-62e could radically alter its ESI number from 0.82 to 0.44! And that is not even factoring in data on how a radically different solar system would affect Kepler-62e’s development and present state.

This frequent, and perhaps cavalier, use of the term “Earth-like” has caused some astronomers concern. Astrobiologist Caleb Scharf recently forced us to consider what is meant by “Earth-like” when used in the context of exoplanet discovery:

Utterance of [Earth-like] can evoke all sorts of images. It may make us think of oceans, beaches, mountains, deserts, forests, fluffy clouds, fluffy bunnies, warm summers, snowy winters, the local pub, or the fabulous hubbub of the local souk. But this is typically far from the meaning attached by scientists. It can simply indicate a planet with a rocky surface, rather than a world with a thick gaseous envelope. It can mean a world that is roughly the same mass and density as Earth. It can mean a planet orbiting a star like the Sun. Or it can just mean that we got bored of saying things like ‘a two-Earth mass object in a close to a circular orbit around a roughly 4 billion year old main-sequence star that is similar in mass to the Sun’.

For me, Scharf adequately articulates the complexity in this galactic search. He also reminds me that we still must be humbled by what we can’t know at this point in time. Our estimates on the number of Earth-like worlds are going to be in constant flux this century because our data will be imperfect. All we need to do is remind ourselves of Earth’s history to know our current data are insufficient to label an exoplanet “Earth-like”. Despite the fact that our planet’s orbit and size have been relatively static, it has gone through phases (and will go through future phases) that we would consider inhospitable.

On a final note, we must also remember that our planet has the current temperature, chemical composition, and general climate it does because of the biosphere. Life, as far as we know, creates an “Earth-like” world. So perhaps, moving forward, the term “Earth-like” should be reserved for planets that we can tell are operating in a Gaia-like way. By that I mean that we should only call a planet Earth-like if the light elements (e.g., carbon, nitrogen, sulphur, and nitrogen) are being dominated and controlled by biology.

What do you think about our search for another Earth?  Let Cadell know on Twitter!

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We Are Not Aquatic Apes


Anthropology is a subject that has attracted its fair share of anti-intellectual theorists before. These anti-intellectuals are scientists from other areas of scientific inquiry that attempt to propose their own theories about who we are and where we came from despite having no formal anthropological training. Consequently, these people are usually a massive headache because they have no idea what they are talking about. Dr. Jonathan Marks did a great job elucidating why anthropology may attract this type of anti-intellectualism in a recent podcast I did with him.

Either way, I woke up yesterday to an infuriating article published in the Guardian: Big brains, no fur, sinuses… are these clues to our ancestors’ lives as ‘aquatic apes’? The article gave an international platform to several scientists that support the Aquatic Ape Hypothesis/Theory (AAH/T). This hypothesis proposes that there was a, as yet unidentified, aquatic phase of human evolution causing our ancestors to develop bipedalism, big brains, subcutaneous fat, sinuses, and lack of fur. Supporters of the AAH believe that these features are all indicative of an ancestral past spent living primarily in deep creeks, river banks, and the sea.

But there is one major problem: there is no evidence to support it. No evidence is usually a problem in science. No ancestral hominids have ever been found that lived in an aquatic environment.

The theory was first developed in 1960 by Sir Alister Hardy. Since then its supporters have generally been from biology. The AAH has received little to no serious consideration from the anthropological community. And nor should it. Paleontologist Chris Stringer accurately acknowledged in the Guardian article that:

[T]he whole aquatic ape package includes attributes that appeared at very different times in our evolution. If they were all the result of our lives in watery environments, we would have to have spent millions of years there and there is no evidence for this – not to mention crocodiles and other creatures would made the water a very dangerous place.

These are all very important points. If the AAH is valid we would have spent millions of years in a watery environment and we should suspect all features of the “aquatic ape package” to have evolved together, not at separate times. But this is not what paleoanthropology has taught us about our past. We know that our hominid ancestors lived primarily in woodlands 6 million years ago, and primarily in savanna landscapes 3 million years ago. Furthermore, two of the most important features that the AAH attempts to explain, bipedalism and encephalization, developed millions of years apart from each other.

Paleoanthropologist John Hawks has previously deconstructed why no anthropologists take the AAH seriously. He accurately pointed out that the AAH’s single assumption does not explain why we retained these “aquatic characteristics”:

Certainly it makes sense that hominids would develop new anatomies to adapt to such an alien [aquatic] environment. But once those hominids returned to land, forsaking their aquatic homeland, the same features that were adaptive in the water would now be maladaptive on land. What would prevent those hominids from reverting to the features of their land-based ancestors, as well as nearly every other medium-sized land mammal? More than simple phylogenetic inertia is required to explain this, since the very reasons that the aquatic ape theory rejects the savanna model would apply to the descendants of the aquatic apes when they moved to the savanna. […] It leaves the Aquatic Ape Theory explaining nothing whatsoever about the evolution of the hominids. This is why professional anthropologists reject the theory.

And yet anti-intellectuals still get a credible platform to spout nonsense about our aquatic past. Perhaps I could contain my disappointment if it all remained academic. However, ecologist Dr. Michael Crawford claims that our brain growth was solely because our aquatic ancestors had a diet rich in Docosahexaenoic acid (DHA), which is found in seafood. So he then makes the dangerous (and ridiculous) argument that:

[W]ithout a high DHA diet from seafood we could not have developed our big brains. We got smart from eating fish and living in water. More to the point, we now face a world in which sources of DHA – our fish stocks – are threatened. That has crucial consequences for our species. Without plentiful DHA, we face a future of increased mental illness and intellectual deterioration. We need to face up to that urgently. That is the real lesson of the aquatic ape theory.

Using an unsupported theory of human encephalization to claim that lack of fish in someone’s diet will lead to mental illness and intellectual deterioration is just anti-intellectual pseudoscience. Considering how far evolutionary theory has progressed in the past few decades, it is disappointing to see these scientists employ it so poorly. The Aquatic Ape Hypothesis is nothing more than an unsupported adaptive story. It has not been supported by evidence, and I find it highly unlikely that it ever will be.

In 2009, John Hawks thought the AAH fit the description of pseudoscience. In 2013, it still fits the description. We have never been aquatic apes.

What do you think of the AAH?  Let Cadell know on Twitter!

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Underselling Science

As anyone who consistently reads The Ratchet could tell you, I am an atheist.  I am not necessarily a militant atheist, but I believe it is important to critique religious belief.  Over the years I have made a point to observe how prominent atheists engage with believers, and the public in general.  Throughout this time, one issue has become particularly worrisome.  Atheists tend to undersell how much the scientific way of knowing has been able to reveal about our origins.  To illustrate this point, I have three specific examples:

Example 1: Richard Dawkins on The O’Reilly Factor (2007)

Bill O’Reilly: “You guys [scientists] can’t tell me how it all got here.”

Richard Dawkins: “We are working on it.”

Example 2: Richard Dawkins on The O’Reilly Factor (2009)

Bill O’Reilly: “You guys still haven’t figured out how it all began.”

Richard Dawkins: “There is a great deal that science hasn’t worked out, and we don’t know how it all began.”

Example 3: Penn Jillette on Piers Morgan (2011)

Piers Morgan: “I never here an atheist give me any answers: how did we get here?  And what happens at the end of our lives? […] How do you think we got here?

Penn Jillette: “I don’t know.”

The Problem

If prominent atheists are going to go on talk shows to espouse their position on religion and religious institutions, they have to adequately explain to the public why their scientific inquiry has led them to become non-religious.  It is not acceptable to appear confused or uninformed when it comes to the origin of the Universe, the Earth, life or humanity.  In fact, this does a great injustice to the work of countless scientists in various areas of inquiry.  More importantly, it leads the scientifically illiterate to believe that there are no deep or meaningful answers about life in science.  If I ever had the chance to answer a question similar to the questions Dawkins and Jillette encountered, I know exactly what I would say:

“Throughout the modern era of scientific inquiry, scientists in nearly every subfield have helped us better understand our place within the Universe, and consequently, have helped us piece together the narrative of ‘how we got here’.  Currently, we know that the Universe came into existence 13.7 billion years ago.  After its initial expansion the Universe eventually cooled enough to allow the formation of the first subatomic particles.  These subatomic particles eventually combined, creating the first elements: hydrogen and helium.  Within two billion years, large networks of galaxies composed of stars had coalesced from giant clouds of these elements.  At this time the Universe had the same amount of mass, but was considerably smaller.  As a consequence, the first galaxies were composed of massive stars that lived shorter lives than most stars in existence today.  These first generation stars forged more complex elements in their cores via the strong nuclear force.  This led to the development of second and third generation galaxies and stars with planets and complex chemistry.  One of these galaxies was the Milky Way, our home galaxy.  One of these stars was Sol, our Sun.  Approximately five billion years ago, an accretion disc of gas and rock formed around our early star, and eventually produced the planets, asteroids, and meteorites that became our solar system.  In the beginning, Earth was a chaotic and inhospitable place.  It took one billion years for Earth too cool down, but once it did, the first single-celled organisms formed from complex, self-replicating organic compounds that are still present elsewhere in our solar system today.  Simple single-celled organisms based on deoxyribonucleic acid (DNA) dominated our planet for the first two billion years.  Around 1.9 billion years ago these single-celled organisms started to develop complex internal structures, and shortly after (1.7 billion years ago), many lineages started to form the first multicellular organisms.  Increasingly complex life forms formed after this period, leading to the first vertebrates (525 million years ago) and the first plants (450 million years ago).  In between 500-65 million years ago the Earth was dominated by several different orders of plants and animals.  Most notably, dinosaurs dominated the biosphere between 200-65 million years ago until the Cretaceous-Paleogene extincton event.  After this event mammals flourished by exploiting niches formerly occupied by dinosaurs.  One order of mammal, known as primates, became exceptionally successful by exploiting an arboreal niche.  They developed opposable thumbs, large brains, as well as binocular and colour vision.  Over time, several different clades of primates diversified in the tropics of Asia, Africa and South America, producing monkeys and apes.  Approximately six to eight million years ago one of these apes adapted to a terrestrial life in East Africa, eventually starting the hominid lineage.  Between two million and 200,000 thousand years ago, several species of hominid existed and experienced a dramatic expansion of brain size.  They also developed the world’s first known tool technologies.  Around 200,000 years ago, the first modern humans emerged in East Africa, and began to spread throughout the rest of Africa, Asia, Australia, Europe, and the Americas between 70,000-10,000 thousand years ago.  These first modern humans replaced all other species of hominid, accelerated the pace of technological evolution, and created first known examples of art.  After this period, several groups of humans started to transition from a nomadic hunter-gatherer existence to a settled agricultural existence.  The first cities formed, trade networks expanded, writing developed, animals and plants were domesticated, and technological evolution continued to accelerate.  This transition was largely concentrated in Eurasia, but also occurred to varying degrees in the Americas, and Africa.  Over the next few thousand years, humans continued to organize themselves in increasingly complex political entities.  Several multi-continental empires developed throughout Eurasia, Africa and the Americas.  However, the next large transition occurred 250 years ago when the global economy became dominated by societies based on industrial-driven production.  In the modern era humans have become increasingly interconnected, forming a global community divided up into independent nation states.  That is the condensed version of what science has discovered about ‘how we got here.’”

I know that Dawkins or Jillette wouldn’t have been given enough time to tell that entire story, but some version of explaining what science has learned about our origins would be far better than saying that scientists are “working on it” or “I don’t know.”  Scientists aren’t “working on it”, they have pretty much figured out most of it.  And saying “I don’t know” is just preposterous.  Atheists are not doing the non-religious movement any good by insinuating that scientists have little to say about “how we got here.”  By communicating in this way, they are certainly not going to convince any religious individuals that there are real answers in the scientific understanding of our origins.  So I have one important request for any atheist, or non-religious individual, who will be in this position in the future: please do not make the mistake of underselling what scientists know about our origins.  We know a great deal about how we got here.  The story of our origins is more incredible than any of our early myths.  Finally, our true origin story is also important for everyone to know because it will help us understand the structure of the Universe.  It will help us understand how things change over time, and consequently how we may change in the future.  That message is worth spreading to the world.

“Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works.”

— Carl Sagan

Top Science Discoveries of 2012

science disc

This is my personal top 25 discoveries and stories from the world of science this year.  In terms of criteria I wanted to make a list of what I thought was interesting or important.  I also wanted to try and equally represent discoveries in the environmental, physical, life, and social sciences.  I purposefully left out more applied scientific discoveries in health and technology.  This is because it is hard for me to quantify their importance next to more theoretical and conceptual breakthroughs.  There were also a lot of interesting discoveries that I had to leave off the list.  I debated making a list of the top 50 discoveries, but this project took me a very long time as it is.  Its purpose is to be thought-provoking, inspire a broad interest in science, and give people a snapshot of what the world’s best researchers are discovering about our Universe!

25. Mapping Earliest Complex Human Societies


A new system has been developed to help understand early human settlement patterns.  This system utilizes computers to scour satellite images for telltale clues of human habitation, like soil discolorations and the distinctive mounding that results from the collapse of mud-brick homes.  This method was first applied this year by a team of archaeologists in a 23,000 square kilometer area of northeastern Syria.  The images revealed 9,000 possible ancient settlements between 7,000 and 8,000 years old.  These data were staggering and will help archaeologists understand an area of the world where the first complex human societies emerged in greater detail.  At the moment archaeologists only have small-scale understandings of the ancient world.  However, with these new techniques we may be able to understand the ancient world on large, complex scales.  Consequently, we may gain a new understanding of how humans made the first transition from hunting and gathering to settled agricultural city-states.


Mapping patterns of long-term settlement in Northern Mesopotamia at a large scale

24. Record Minimum Arctic Sea Ice


Arctic sea ice extent has been shrinking consistently since satellite records have been tracking it over the past 30 years.  This year represented the start of what climatologists are calling “uncharted territory”.  In 2012, the record for lowest extent of Arctic sea ice coverage was broken three times.  The previous record was broken on the 18th of Septemeber 2007, when the Arctic sea ice extent low was 4.17 million square kilometers.  In 2012, Arctic sea extent was 4.10 million square kilometers on 26th of August, below four million square kilometers on the 4th of September, and reached the now record low of 3.41 million square kilometers later in September.  This is almost one million square kilometers less than the previous record and is 50% lower than the 1979-2000 average Arctic sea ice extent.  At current rates, climatologists now expect no Arctic sea ice by the 2030s.


Record minimum for Arctic sea ice

23. First Objects Temporally Cloaked


Scientists developed spatial cloaking earlier this century.  However, now researchers have developed a device that can hide events in time, or “temporal cloaking”.  The device does this by speeding up and slowing down different parts of a light beam and then putting them back together.  As a result, the event would become “hidden in time”.  At the moment, this technology can only hide events for 40 trillionths of a second (0.00012), which is a time frame impossible to directly impact human actions.  In the future, the ability to cloak events in both time and space simultaneously may be improved to the point where events and spaces can be hidden on the scale of seconds and minutes.  Combining the ability to cloak events both spatially and temporally is theoretically possible.  Likewise, extending the current timeframe and spatial scale of cloaking ability is also possible.


Demonstration of temporal cloaking

22. XNA Compounds Demonstrate Evolution


In the emerging field of astrobiology, researchers are attempting to understand if life elsewhere could be based on a host of alternative nucleic acids other than the ones that compose RNA and DNA.  Synthetic biologists seem to have proven it is likely that life could be based on a number of different nucleic acids.  The team showed that artificial molecules can be made to pass genes onto their descendants by focusing on XNA’s (xeno-nucleic acids).  XNA’s are based on different sugars than RNA and DNA, but even with a different sugar backbone, XNA can mimic many of DNA’s properties.  This evidence suggests that XNA’s (or other forms of DNA) could form the basis of life on other planets or moons, where different conditions lead to different types of chemistry than found on Earth.  Perhaps most importantly, this research makes it even more likely that some moons in our solar system with different chemistry to Earth (e.g., Titan, Europa) may host complex life.

21. Origins of Indo-European Language Family Linked to Farming


There are currently two competing hypotheses for the emergence of the Indo-European language family, which is the most widespread language family in the world.  The history of this language family is relatively clear over the past 2,000 years because these languages have been written consistently and the history of their peoples is understood as a result.  However, it is less clear when these language families emerged.  At the moment the majority view is that the language family emerged in Ukraine 6,000 years ago, and the minority view is that it emerged in Anatolia between 8,000-9,000 years ago.  Researchers from the Max Planck Institute attempted to better understand this emergence by applying a Bayesian phylogenetic approaches to model the expansion of the family and test the two hypotheses.  This analysis revealed that the minority view is likely correct.  It appears as though the Indo-European language family first emerged in Anatolia between 8,000-9,000 years ago.  This means that the spread of the Indo-European language family is likely connected to the emergence of farming and the societies that first adapted to a farming lifestyle in central Eurasia.


Mapping the Origins and Expansion of the Indo-European Language Family

20. Star Formation 1/30th of its Peak


The first-generation stars born after the Big Bang were massive and short-lived by today’s standards.  These early stars produced the complexity of elements found in third-generation stars and solar systems like ours.  However, the stars in the present day Universe are much smaller and longer-lived than their predecessors.  Understanding this cosmic evolution is key to understanding its future development.  In order to better understand this evolution astronomers wanted to assess whether star formation rate over cosmic time was stable, increasing, or decreasing.  A team of international researchers collected information on star-forming regions of galaxies at different distances.  Using this data the team was able to determine that star formation was at its highest rate 11 billion years ago, and is 1/30th of its peak in contemporary times.  If this decline continues, 95% of the stars that will ever be created in the Universe have already been born.  This is because stars today are lasting billions of years longer than their predecessors and are exploding their gaseous material into an ever-expanding Universe.  This means fewer stellar nurseries will form in the future.  These data help scientists better understand how our Universe has evolved and how it will be structured billions and trillions of years from now.

19. Lichen Survive Mars-like Environment


Scientists have debated for decades whether Mars may be host to microbial life.  Although no indigenous Martian life has been discovered, research this year demonstrated that it is theoretically possible.  A team of researchers exposed lichen (Circinaria gyrosa) to Mars-like conditions at the German Aerospace Center’s Mars Simulation Laboratory for 34 days.  The lichen were subjected to the same conditions that they would have experienced if they were placed on Mars.  The researchers discovered that these lichen adapted fairly easily to the environment, but were most successful at surviving in small cracks within the simulated Martian soil.  It is believed that these areas allowed the lichen to avoid harsh radiation.  This experiment revealed that fairly complex life could still exist on Mars.  It is known that Mars had a much more hospitable environment billions of years ago.  If life arose during this time period, there may still be indigenous life forms on Mars in present day niches that resemble areas that the lichen adapted to in the simulated environment.  This research also shows that life is extremely adaptable, even to extremely harsh conditions, and indicates that life could theoretically survive in others areas of the solar system.


The resistance of the lichen Circinaria gyrosa (nom. Provis.) towards simulated Mars conditions – a model test for the survival capacity of an eukaryotic extremophile

18. 100-km, 3-Billion-Year Old Impact Crater Discovered


There have been several massive asteroid and meteor impacts in Earth’s natural history.  However, a team of scientists in Greenland discovered one of the largest and oldest.  The team that made the discovery has been methodically piecing together the key evidence of this impact over the past three years.  It took so long to understand what caused the geological structures observed in western Greenland because the impact occurred three billion years ago.  Scientists had previously thought that it would be impossible to find evidence of such an impact from this epoch due to geological processes like erosion.  However, this impact was so large and intense that the shock wave penetrated deeper into the crust than any other known crater.  The impact itself was around 100 kilometers in size and would have completely reshaped the evolution of the early Earth’s climate and life.  Future research will be needed to understand how these processes were affected.


Oldest Known Meteorite Impact Uncovered

17. Lethally Hot Temperatures During Early Triassic


Earth suffered a major mass extinction called the end-Permian event 252 million years ago.  However, scientists were always unable to answer why it took 5 million years for life to recover from that mass extinction event.  Palaeoclimatologists in 2012 revealed why: the Earth became “lethally” hot.  The end-Permian die off killed almost all of the Earth’s plants, and without any plants to consume carbon dioxide, the Earth experienced a runaway greenhouse effect.  Researchers discovered that at its worst, oceans reached 104 degrees Fahrenheit (compare that with contemporary oceans that are 77-86 degrees).  Over this time period the Earth was virtually life-less.  This study also shows how our planet reacts to a climate with unbalanced levels of carbon dioxide, a greenhouse gas that is currently driving up average global temperature every year.


Lethally Hot Temperatures During the Early Triassic Greenhouse

16. Pleistocene Plant Blooms Again


We got a little closer to Jurassic Park in 2012.  A team of scientists brought a 30,000 year-old Siberian Pleistocene plant (Silene stenophylla) back to life.  This is by far the oldest plant brought back to life; 2,000 year-old date palm seeds held the previous record.  The scientists claim that the seeds of the Pleistocene plant were in permafrost for the entire period of time, which acted as a giant freezer, leaving them undisturbed and unthawed.  This research represents a landmark discovery that biological material can be revived after laying dormant for tens of thousands of years, and may be an important development in the quest to revive other species, including species that are currently extinct.


Regeneration of whole fertile plants from 30,000-y-old fruit tissue in Siberian permafrost

15. Dark Matter Scaffolding Directly Detected


Dark matter is thought to make up 83 per cent of matter in the universe, yet until 2012, astronomers had never directly detected its existence.  In July a team of researchers announced that they had directly detected dark matter between two galactic clusters Abell 222 and Abell 223.  The discovery came as a surprise to the science community, which did not expect dark matter to be directly detected until future advancements in telescope technology were made.  The team made the discovery after analyzing the light of more than 40,000 background galaxies to determine the percentage of unseen mass holding Abell 222 and Abell 223 together.  Astronomers have said that this research is a resounding confirmation of standard theory of structure formation in the universe.  Future research and improved telescope technology should give astronomers more opportunities to study the structure of dark matter in the universe.


A filament of dark matter between two clusters of galaxies

14. Super Volcanoes May Be Predictable


Supervolcanoes are extremely rare, but extremely devastating events for the Earth’s climate and biosphere.  Research into the nature of supervolcanic eruptions has revealed some startling and terrifying results.  However, volcanologists main concern has been trying to devise a way to predict when the next supervolcanic eruption would occur.  New results from an international study this year may have revealed how much time we would have to prepare for such an event.  By studying the crystals in pumice rock from the Santori site, researchers realized that magma was growing within the caldera underneath the volcano for decades.  This new discovery should help volcanologists predict a supervolcanic eruption decades in advance, as opposed to weeks or months in advance.  Some tell tale signs would be rapid caldera chamber build up, increased rock deformation, and increased gas emission to the surface.  Our species biggest challenge now becomes trying to understand what we would do to prepare for such an event.


Decadal to monthly timescales of magma transfer and reservoir growth at a caldera volcano

13. Human-Caused Megafaunal Extinctions During Quaternary


Scientists have long-debated about the cause of Quaternary megafaunal extinctions in Eurasia, Australia, and the Americas.  This debate frequently centers around climate change or anthropogenic overkill as the main cause.  However, several research papers this year seemed to strongly indicate that anthropogenic overkill was the main cause of megafaunal extinctions throughout the world.  Research studying environmental change in Australia over 130,000 years concluded that human presence disrupted ecological equilibrium, not climate change.  Other researchers studying geographic ranges of over 150 animals in North America, attempted to understand whether extinctions disproportionately effected taxa with small geographic ranges.  They found that the extinction event did not preferentially impact taxa with small geographic ranges, but did preferentially impact taxa with large body size.  This is also consistent with the anthropogenic overkill hypothesis.  Furthermore, theoretical research was also used to integrate our understanding of Neanderthal extinction into the larger Quaternary megafaunal extinction events.  These studies have important implications for contextualizing contemporary extinction events, and predicting our future impact on the biosphere.


The Aftermath of Megafaunal Extinction: Ecosystem Transformation in Pleistocene Australia

The Quaternary megafaunal extinction and the fate of Neanderthals: An integrative working hypothesis

Range sizes and shifts of North American Pleistocene mammals are not consistent with a climatic explanation for extinction

12. Oldest Galaxy Discovered


Astronomers are constantly improving our understanding of the early universe by utilizing new technologies and methods.  As a consequence, our knowledge of the Universe in its infancy keeps improving.  Before 2012, astronomers had little knowledge of the “cosmic dawn” a period between 400-600 million years ago.  This year, we gained a better understanding of this period when a family of the oldest galaxies were discovered.  The oldest of these galaxies was UDFj-39546284, which formed approximately 380 million years after the Big Bang.  This galaxy, along with its surrounding galaxies, which formed between 400-600 million years ago, have indicated that the first galaxies formed gradually, as opposed to suddenly.


The Abundance of Star-Forming Galaxies in the Redshift Range 8.5 to 12: New Results From The 2012 Hubble Ultra Deep Field Campaign

11. Denisovan Genome Decoded


Until recently, most scientists thought that there were only two species of humans (i.e., modern humans and Neanderthals) living in Eurasia in the Upper Palaeolithic (50 – 10 thousand years ago).  However, over the past decade several finds have indicated that there were several more.  Svante Paabo and his colleagues at the Max Planck Institute (MPI) of Evolutionary Anthropology have revealed further proof of this fact with genetics.  They sequenced the genome from the bones of an individual that had been found in Denisova Cave in southern Siberia.  The results indicated that the individual was not a modern human or a Neanderthal.  The new species has been named Denisovans.  Together with Neanderthals, Denisovans are the closest extinct relatives of modern humans.  It is likely that all three species knew of each others existence and may have even lived together in what is today Siberia.  Future genomic comparative studies should help scientists uncover important genetic differences that contributed to the development of modern human culture and technology.


A High Coverage Denisovan Genome

advanced apes logo

10. Secret to Hydra Immortality Revealed


Scientists have known for several years that the polyp Hydra displayed signs of negligible senescence.  It appears as though this animal can only die from predation or disease.  One of the ways in which the Hydra can do this is because of continuous proliferation of stem cells.  This year, researchers in Germany gained a better understanding of this process, and believe their findings have relevance to ageing in humans.  They identified the gene FoxO, which is known to play a role in ageing, and they genetically modified three groups of Hydra.  One group had normal FoxO levels, one group had inactivated FoxO, and one group had enhanced FoxO levels.  They were able to show that the Hydra with inactive FoxO started to have severe complications with their immune systems.  Many of these complications mirrored immune system dysfunction that is seen in elderly humans.  The team concluded that FoxO plays a critical role in ageing, and that immune system function and stem cell proliferation may be the key to prolonging the human lifespan as well.


FoxO is a critical regulator of stem cell maintenance in immortal Hydra

9. Earth-sized and Habitable Zone Exoplanet Detection


The search for “another Earth” continued this year, with phenomenal results.  Before 2012 astronomers had detected over 800 planets, but none of them were Earth-sized or within the habitable zone of their host star.  That changed this year.  In the first month of 2012 astronomers identified three of the smallest planets ever detected (smallest was Mars-sized).  However, all three planets orbited their host star as closely as Mercury orbits our Sun, making them way too hot to be Earth-like candidates.  Later in the year astronomers made two more significant finds: an Earth-sized planet in the closest solar system to ours (Alpha Centauri), and a “super-Earth” within the habitable zone of its host star.  The Earth-sized planet in Alpha Centauri orbits very closely to its host star, but demonstrated astronomer’s ability to detect Earth-sized planets and suggested that Earth-sized planets were relatively common.  The “super-Earth” discovered is only 42 light-years away and is thought to be a candidate for life because it may be covered in liquid water.  More interesting news from exoplanet detections was made this December when astronomers announced the possible discovery of an Earth-sized planet within the habitable zone of Tau Ceti (12 light-years away).  If confirmed, this would become the number one candidate for the discovery of “another Earth” and also a potential hot-spot for complex life in the universe.


NASA’s Kepler Mission Finds Three Smallest Exoplanets

Earth-size planet found orbiting the star system next door

Another Earth Just 12 Light-Years Away?

8. Crucial Milestone for Quantum Teleportation


Teleportation is no longer just science fiction…  at least at the atomic scale.  Scientists have been teleporting photons for several years now.  However, scientists from the University of Waterloo recently broke a new teleportation distance record with significance for the future of teleportation.  They successfully achieved quantum teleportation over 143 km distance from the Canary Islands to the islands of La Palma and Tenerife.  This distance is significant because that is the minimum distance between the ground and orbiting satellites.  Once full-scale networked quantum computing exists, quantum teleportation could allow for secure communication.  The next goals for the research team is to start quantum teleporting upwards.


Quantum teleportation over 143 kilometers using active feed-forward

7. “Ratcheting” Separates Humans From Other Primates


Sir Isaac Newton famously stated that we “stand on the shoulders of giants”, insinuating that humans are able to accomplish deep scientific understanding, create rich artistic traditions, and build sophisticated technology because our culture becomes increasingly complex.  We build on the cultural achievements of the generations that came before us.  However, a study in 2012 provided strong evidence indicating that this is absent in other species, even our closest relatives.  Researchers compared the ability of human children, chimpanzees and capuchin monkeys to solve a complex puzzle box with three different stages.  In order to solve the puzzle box (and acquire a food reward) the individuals would have to cooperate and teach each other in order to accomplish progressively higher-level solutions at each stage.  All human children were able to accomplish these tasks, however no chimpanzee or capuchin groups were able to exhibit the behaviour necessary to complete the task.  This led primatologist Victoria Horner to conclude: “if cumulative culture does exist in other species, it is extremely rare.”


Identification of the Social and Cognitive Processes Underlying Human Cumulative Culture

6. Next Ice Age Offset by Human Fossil Fuel Consumption


A study from the environmental sciences this year provided significant evidence that the next scheduled Ice Age would occur 1,500 years from now, if we had left fossil fuels in the ground.  This study, although it can be interpreted positively, demonstrates just how dramatically humans are changing climate on a global scale.  The researchers claimed that even if we stopped burning fossil fuels immediately, the next Ice Age would already be averted.  The researchers were able to calculate when the next Ice Age would have occurred by comparing the Earth’s pre-industrial climate to past interglacial phases over the past few million years.  Ice Age and interglacial cycles occur in distinct patterns known as Milankovitch cycles.  These cycles are caused by subtle variations in the Earth’s orbit that take tens of thousands of years to change.  If we stop burning fossil fuels by 2100 the Earth should experience its next Ice Age approximately 120,000 years from now.


Determining the natural length of the current interglacial

5. Final Great Ape Genomes Decoded


Before 2012, humans, chimpanzees, and orangutans had their complete genomes decoded.  This year two separate European research groups decoded the gorilla and bonobo genomes.  Researchers at Cambridge decoded the gorilla genome.  The results indicated that gorillas share 98% of our DNA and diverged from the human/chimp/bonobo lineage 10 million years ago.  Although these numbers weren’t major shocks, the speciation date was earlier than had previously been thought.  Researchers at the Max Planck Institute (MPI) for Evolutionary Anthropology decoded the bonobo genome shortly later in the year.  Their genome revealed that only 4 amino acids per 1,000 within their DNA sequence differed from chimpanzees.  Using these data researchers were able to pin point the chimp/bonobo divergence to 1 million years ago.  Now researchers at MPI are going to try to understand more about the human/chimp/bonobo common ancestor by comparing all three species genomes in greater detail.


Insights into hominid evolution from the gorilla genome sequence

The bonobo genome compared with the chimpanzee and human genomes

4. First Model Simulation of Observable Universe

This year a team of French researchers used CURIE, a new supercomputer, to create the first ever computer model simulation of the entire observable universe from the Big Bang to the present (a distance equivalent to 90 billion light years).  The super computer created this simulation by following the evolution of 550 billion particles as part of a project called Deus: full universe run.  The results from these simulations allowed the researchers to a) estimate the total number of galaxy clusters with a mass larger than hundred thousand billion solar masses (144 million), and b) discover that the first of these galaxy clusters developed around 2 billion years after the Big Bang.  Their data also revealed that the largest massive cluster in the observable universe weighs 15 quadrillion (15 thousand trillion) solar masses.  In the future, data from this simulation will help cosmologists understand the imprint dark energy leaves on cosmic structures and how dark energy can be inferred from observing distributions of matter.


First-ever model simulation of the structuring of the observable universe

3. Planets Around Stars: Rule, Not Exception

exoplanets upside down

A long-term astronomy study this year suggested exoplanets outnumber stars by a large margin in our galaxy.  Their results revealed that each of the 100 billion or so stars in our galaxy hosts 1.6 planets on average.  Most of these planets are likely to be low mass, indicating that there may be hundreds of millions of small/rocky planets like Earth.  This study was based on statistical extrapolation and provided considerable evidence that stars with a gravitationally bound planetary system is the rule, rather than the exception.  The data was collected between 2002-2007 with earth-based telescopes using gravitational microlensing.  Gravitational microlensing is a more reliable approach to uncover hidden extrasolar worlds because other popular methods (e.g., photometry, radial velocity) are biased towards finding stars that orbit closely to their parent star.  This made statistically extrapolating the number of planets in the Milky Way based off of the data collected in this study more accurate.  Although it is now estimated that there are around 160 billion planets in our galaxy, the number of total planets is likely double that because of the recent discovery of nomad planets (planets without a host star).



In early September our understanding of the human genome was increased substantially with the coordinated publication of 30 research papers produced by the research consortium Encyclopedia of DNA Elements (ENCODE).  Before their publication we understood how small sections of DNA — genes — coded for important chemicals and proteins in our body.  However, that was only 2% of the entire human genome; the rest was thought to be ‘junk DNA’.  Researchers revealed that 80% have our genome does have a function, but further research will be needed to elucidate exactly what it does.  Most aspects of this part of the human genome is information that is coded to be ‘on’ or ‘off’ during certain times in our lives.  Medical professionals hope that we will be able to use this information to understand how these ‘on/off’ switches can be modified to prevent diseases, improve overall health, and slow the ageing process.


ENCODE-funded Publications

1. Discovery of the Higgs Boson


On July 4th, CERN rocked the world of physics with the discovery of the Higgs boson, the last of the elementary particles in the Standard Model of physics.  The Higgs can explain why particles acquire mass and why the electromagnetic force and the weak force are divided.  Although it is still unclear whether the boson was exactly what the Standard Model predicted 40 years ago, the discovery is sure to define the entire subject for the foreseeable future, and open up the possibility of “new” physics.  Perhaps most importantly, this discovery allows physicists to make a pitch for a new next-generation collider that would work as a “Higgs factory” and enable the possibility for a theory to unify quantum mechanisms and the theory of general relativity.


Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC

Combined search for the Standard Model Higgs boson using up to 4.9 fb-1 of pp collision data with the ATLAS detector at the LHC