All religions try to explain away the things and events we try to contemplate through our five senses. To address the unknown religions offer us gods with supernatural powers. The commonalities in creation myths tell stories of the beginning of Earth and us that are far different from what scientific research and the geological record show.
The story science tells is far more intriguing than the words in Genesis or any other creationist text. Science tells us that our planet’s beginnings started more than 4.5 billion years ago. Then the Earth was a lumpy and growing protoplanet acquiring mass from numerous collisions with other bodies orbiting the young Sun. In time the mass became great enough for gravity to turn it into a spherical body. Every strike contributed to the planet’s spin and some likely caused the planet’s axis to tilt to where it lies today at a near 23.5-degree cant.
The material the early Earth collected from the Solar System included metals, carbon, water and gasses. Heavy elements like iron migrated from the surface sinking to the planet’s core. Iron has ferromagnetic properties. As the core and planet grew the interior heated up. A band of molten iron circled the solid core and its movement generated by the planet’s spin produced Earth’s protective magnetic field. Venus and Mars did not experience the same geological progress and hence the two sister planets don’t have a magnetic field as robust as Earth’s.
A spinning Earth created conditions for life to emerge. The axial tilt made seasons possible. The daily rhythm of the planet and seasonal variation influenced temperature, precipitation, and other critical environmental factors. These key characteristics played an important role in the emergence of life.
Scientists study the age and chemistry within the rocks that form Earth’s crust to piece together a picture of what the early Earth was like. It bears little resemblance to our world today where the atmosphere contains abundant amounts of oxygen. Earth’s early atmosphere was mostly carbon dioxide (CO2) with other gasses like methane (CH4) and water vapour (H2O) present.
Mars and Venus today both have atmospheres largely made up of CO2. Venus’s atmosphere is dense. Mars’s atmosphere is tenuous. Early Earth’s atmosphere was somewhere in between these two. The common ingredient in all three was the presence of carbon and it is the molecule that interacted with early Earth’s other chemistry to produce complex molecular compounds eventually leading to amino acids and double-helix, self-replicating DNA.
Whether life came from elsewhere in the Solar System, or spontaneously emerged remains a continuing debate. But rocks on Earth that date back 3.7 billion years are the first that we have found to contain fossilized remnants of microbes. These single-celled microbes formed sticky mats bound together by sand and secretions. In death, the mats mineralized to form hard, layered structures called stromatolites. Living stromatolite mats can be found on Earth today containing microbes. The microbes 3.7 billion years ago were anaerobic, that is, they thrived in an oxygen-free world. Anaerobic organisms are still with us today and can be found in the most hostile environments including our gut.
Life on Earth didn’t change much for the next 2 billion years as the Solar System settled into the pattern we see today, four small rocky planets circling close to the Sun, and four icy giant planets further out all in some form of harmonious synchronicity.
In Earth’s early history, the planet went through violent cataclysms as its crust fractured into plates that began drifting across the surface. The dynamic forces causing the planet’s physical changes made it a challenge for living things to thrive. Disruptions from cataclysmic events led to numerous extinctions and rebirths over 2 billion years. But at some point, relative stability ensued and the environment led to the emergence of cyanobacteria (see image below). This happened between 2.7 and 2.4 billion years ago.
Cyanobacteria may be a term unfamiliar to you. Blue-green algae is a cyanobacteria. What characterizes this form of life is its ability to harvest energy from sunlight which in combination with water produces sugars to support cellular metabolic processes.
When did cyanobacteria get this ability? A paper published this month in Nature describes evidence of photosynthesis in cyanobacteria fossils found in 1.73 to 1.78 billion-year-old rocks. These fossil bacteria exhibit structures called thylakoid membranes. Thylakoid membranes are where photosynthesis takes place. Before this discovery, the earliest known cyanobacteria fossils containing thylakoid membranes dated back 500 million years.
What’s the deal with thylakoids? They are found in chloroplasts, the specialized cells found in plants where photosynthesis occurs. A thylakoid membrane contains chlorophyll to capture solar energy and in the presence of water and CO2 convert it into sugar and oxygen.
Without cyanobacteria and thylakoids, the world would not have experienced the Great Oxidation Event when oxygen levels in the atmosphere and ocean began to rise. The event is marked by oxidated chemicals found in rocks laid down as sediments on ocean floors dating back well over a billion years. The paper describes the finding of thylakoid membranes in Australian fossils between 1.73 and 1.78 billion years old and in fossils in Canada between 900 million and 1.01 billion years old.
What was the Earth like at the time of the oxidation event? Imagine the world’s oceans covered by mats of blue-green algae blooms. Their life cycle and decomposition would have produced the same results seen in algae blooms today that cause life and death cycles as their decomposition robs the water of oxygen. The cycles of life and death back then would have made it difficult for new life forms to emerge.
In the 21st century, we have turned to neighbouring planets and the stars in the search for life elsewhere. Will its origin stories be the same as ours? Are the rovers on Mars equipped with tools to detect any kind of life or only life as we know it? The James Webb Telescope is powerful enough to sniff the atmosphere of exoplanets. Will the detection of oxygen and other life-friendly gasses on planets light-years away answer the question scientists have continued to ask, “Are we alone in the Universe?”
By understanding how life came to be here, we are not limited to the Earth in the present to make the call on the existence of life elsewhere or not. Earth had life 3.7 billion years ago in conditions we would never consider as amenable to its existence. Earth through time has witnessed dramatic changes to the life upon it. When we look beyond Earth for the conditions that could produce life elsewhere, our search criteria have broadened considerably by studying the planet’s past.
]]>When Cassini rendezvoused with Enceladus it discovered venting from the moon’s southern polar region back in 2005. Three subsequent passes happening from 2008 to 2009 confirmed that this wasn’t a one-time event. As the spacecraft flew through the ejected material, the onboard Cosmic Dust Analyzer analyzed the content. The plumes contained fine grains of ice and water vapour. The ice particles hit the spacecraft at speeds of between 6.5 and 17.5 kilometres (4 to 10.8 miles) per second. As they struck the ice vaporized. Electrical fields in the analyzer separated the chemical constituents.
What they found was that the composition was water. Enceladus was spewing liquid water with some of it freezing as it escaped from under the icy crust into the immediate space above the moon’s surface. Similar icy particles were found in Saturn’s E-ring, the faintest of the planet’s fabled rings, but also its most extensive. Scientists believe Enceladus is the source of much of the material populating the E-ring.
But it wasn’t just the icy particles and water vapour that was fascinating to the scientists following Cassini. In the water, they found organic compounds, the ingredients for amino acids which on Earth are believed to have been the precursors in the emergence of life. The chemistry in the water plumes venting from Enceladus included molecular compounds containing nitrogen and oxygen.
On Earth, we find similar compounds coming from ocean-floor hydrothermal vents. The speculation led scientists to believe Enceladus had an ocean beneath its icy crust with similar features to the hydrothermal vents on Earth. The analysis of the composition of the icy surfaces near where the venting is taking place on the moon indicates soluble organic compounds.
So what is likely happening on Enceladus, the whitest and brightest object in the Solar System, and the sixth largest moon in the Saturnian system, spanning 500 kilometres (310 miles) in diameter? How could such a tiny moon have so much going on beneath its surface? The little moon is so bright and white that it reflects more than 70% of the very diminished sunlight that reaches its surface.
The spectrometric readings from Cassini showed that the energy being produced at the moon’s south polar region was equivalent to 15.8 Gigawatts here on Earth. That is 2.6 times greater than all the hot springs and geysers at Yellowstone.
Enceladus’ composition includes an ice crust, an ocean below, and a rocky core. The heat energy Cassini measured is produced by a combination of radioactive decay from the moon’s core along with tidal forces exerted on it by Saturn and neighbouring moons. That heat energy causes the water to expand which then cracks through the icy surface and vents into space at a rate of 200 kilograms (441 pounds) per second.
So what we already know before I add another Enceladus surprise to the mix, is that the moon has water, organic compounds, amino acids, and sufficient heat to keep that water from freezing. These are all preconditions to the emergence of life here on Earth.
What’s the newest finding? In a paper appearing on December 14, 2023, in Nature Astronomy, scientists revealed that they have found hydrogen cyanide. This discovery has exobiologists excited because it is considered an essential molecule, the Swiss army knife of amino acid precursors. The interaction of hydrogen cyanide and water produces a starting reactant that is seen to have lead to the precursors of RNA and proteins. The hydrogen cyanide, therefore states the paper, could indicate the ability to “support extant microbial communities or drive complex organic synthesis leading to the origin of life.”
In other words, all the chemistry needed for life has been found on this little moon. It doesn’t mean life exists on Enceladus, but it sure makes it intriguing enough to consider a return to the moon with an orbiter and lander at sometime in the future.
]]>Charles Darwin described how natural selection (he didn’t use the word evolution until many later editions of his Origin of the Species) occurred leading to the emergence of new versions of species taking many generations and conceivably hundreds to thousands of years. What Darwin didn’t get right was how much time was needed for one or more new species to emerge.
Consider this. Several hundred thousand years ago many different human species lived on our planet. In the competition for food and the other necessities of life, Homo Sapiens emerged as the dominant species. Homo Sapiens’ dominance didn’t mean that Neanderthals, Denisovans, and earlier species like Homo Erectus didn’t live on, because they did. Today, the DNA of Neanderthals and Denisovans is in us. As climate change alters the appearance and behaviour of species around the planet, it is likely doing the same to us as we physically adapt to a hotter, drier world.
Although our ancestors first emerged in the tropics, we migrated to cooler areas of the planet over thousands of years and as we did our appearance changed. For those who moved closer to the poles, darker skin was no longer needed because sunlight was weaker. Even how fat in our bodies was stored and distributed changed in different environments. These variations didn’t turn Homo Sapiens into different species. Humans came up with the term race to identify the differences. But all of us on the planet today can produce offspring regardless of race which makes all of us Homo Sapiens.
Humans today have never been more homogenous. We can travel anywhere and interact with anyone. We live in artificial environments that air-condition us when it’s hot and heat us when it’s cold. Even with the current rate of global warming which by 2100 will make many areas of the planet increasingly inhospitable, we can carry our environment with us. If we remove the cocoon, however, the environment will once more assert itself and determine our evolutionary path.
Or we can go another way. Back in 2012, I wrote about an article I read that proposed it might be easier to re-engineer humans rather than try and stop global warming or, for that matter, population growth. Today through tools like CRISPR we can alter our DNA. It may be easier to change us than try to re-engineer the planet.
The new version of our Earth-based species could be smaller so that we would need less to eat in the face of fewer resources. We could alter our DNA to make us meat intolerant, turning humans into vegans which would free up land currently used for meat and dairy farming. We could make ourselves less reproductive to control population growth. We could make ourselves more altruistic and less warlike.
If we become spacefaring, we can alter our DNA to allow us to live in microgravity environments, or to make us more adaptable to living on Mars. The new versions of humans who leave Earth may become evolve into many new species designed for exotic environments, and no longer Homo Sapiens.
]]>The Anthropocene is a recent term that has been added to the geological record. It is an addendum to the Holocene which stretches back 10,000 years to the first appearance of organized human settlements and the beginning of the agricultural revolution. Anthropocene means the Age of Man. Not all earth scientists and geologists buy into the idea that the period defining the Anthropocene should be separate from the Holocene.
That’s where Crawford Lake’s varves come in. If you are not familiar with varves, they resemble tree rings producing a seasonal pattern in lake deposits. Each varve marks a deposition and a passage of time. And the varves at Crawford Lake are well preserved for study, showing what earth scientists call the Great Acceleration, a period that marks our human environmental impact beginning in the 20th century.
The area surrounding Crawford Lake was inhabited by indigenous people more than 600 years ago. There is evidence that suggests an agrarian settlement at that time. The planting of corn produced corn pollen grains which are evident in the varves. Later varve deposits see the disappearance of corn pollen indicating the site was abandoned a few decades after Europeans arrived in the Americas. Likely, European-introduced diseases wiped out most of the native population.
The annual cycle of varve deposits continued marking the passage of time. And by the early 1950s, something significant showed up. Earth scientists call it plutonium fallout signal from radioactive pollutants appearing in the lake sediments caused by fallout from the atmospheric testing of atomic bombs on Pacific island atolls occurring between 1950 and 1963. The varves contain radioactive traces and, state the earth scientists, mark the beginning of the Anthropocene. The point in time is preserved in the varves of Crawford Lake and has led to this small post-glacial lake being voted “the most suitable location of the proposed golden spike, a global reference in the Earth’s stratigraphic record indicating the start of a new geological unit of time.”
What makes Crawford Lake exceptional is the relatively undisturbed varve layers, resulting from little mixing of its water layers. States Josh Basseches, Director and CEO of Toronto’s Royal Ontario Museum: “If museum objects are stories, then the Crawford Lake sediment cores are epics — hundreds of years of geological change, written in earth and frozen in time. But they are also, more simply, a poignant reminder of humanity’s profound impact on our planet.”
In an article appearing last week in The Washington Post, it calls Crawford “a humble lake in a Canadian suburb.” The paper was one among many making the Anthropocene a headline story.
But others question the need to create a geological epoch called the Anthropocene. In an article that appeared in The Atlantic in 2019, Peter Brannen called it a vanity project. He noted, “Very little of our handiwork will survive the obliteration of the ages. If 100 million years can easily wear the Himalayas flat, what chance will San Francisco or New York have?”
He called the Anthropocene no more than “an interesting thought experiment” that “serves as a useful catalog of our junk” and stated that it served to “inflate humanity’s legacy on an ever-churning planet that will quickly destroy or conceal forever even our most awesome creations.”
Brannen made the case for a vanity project by comparing our existence to the legacy of the dinosaurs, an epoch that lasted 180 million years, 36,000 times longer than human-recorded history. He pointed out that despite the long geological record, dinosaurs left hardly any evidence of their existence. So much of what has been discovered has come from a few select sites. Yet dinosaurs thrived and evolved over millions of generations.
Brannen’s thought experiment reference is interesting. He wrote, “If, in the final 7,000 years of their reign, dinosaurs became hyperintelligent, built a civilization, started asteroid mining, and did so for centuries before forgetting to carry the one on an orbital calculation, thereby sending that famous valedictory six-mile space rock hurtling senselessly toward the Earth themselves—it would be virtually impossible to tell. All we do know is that an asteroid did hit and that the fossils in the millions of years afterward look very different than in the millions of years prior.” He noted that’s what 180 million years buys you in the fossil record. So maybe the revelation of Anthropocene, the Age of Man, is no more than an ego trip for our species. What do you think?
]]>NASA’s other active rover, Curiosity, has identified organic matter at its landing site, the Gale Crater, indicating the presence of the building blocks for life were at some point widely distributed across the Martian landscape.
But it is the presence of aromatic organic molecules at Jezero that has led to a conclusion that the conditions for life on Mars persisted for a long period, between 2.3 and 2.6 billion years. SHERLOC found three rock surfaces with organic molecules present, and when Perseverance used its drill, identified similar molecules 8 to 10 millimetres deep within collected rock samples. Four of these samples have been stored for pickup by the future Mars Sample Return mission still in the planning stages.
The Jezero Crater has produced an abundance of organic molecules by an order of magnitude over what has been found at Gale Crater so far, proving that NASA chose well to plant Perseverance there. Much of the rock from which the organic molecules have been detected is water-altered basalt with low amounts of ferrous oxide (FeO) embedded. This reinforces the hypothesis that where there is water, that’s where we likely will find organics and life.
The discoveries of organic molecules were found in concentration in two Jezero sites. The results appear in a published article appearing July 12, 2023, in Nature, which states that the “key building blocks for life may have been present over an extended period of time” and “two potentially habitable paleo-depositional settings in Jezero crater.”
How do we know the extent of time of up to 2.6 billion years when conditions for life existed? Because basalt is an igneous rock which makes it useful for doing accurate dating. That’s what makes Jezero such an incredible site because it contains a combination of sedimentary and igneous rocks with the latter highly suitable to accurately age. As a result, we know that the lake systems that formed in Jezero existed 3.8 to 3.6 billion Earth years ago. A Martian year is almost twice as long as an Earth year so in terms of Mars’ timeline, between 1.9 and 1.8 billion Martian years ago. The interaction between free-standing water and rock would have been a comfortable environment for Martian microbes to evolve.
Could there be another explanation for the organic compounds found in these Jezero rock samples? The organics could have been brought to Mars when comets and meteorites intersected its orbit. Or the existence of organic compounds could be from inorganic chemistry with chemicals on Mars interacting with carbon dioxide (CO2) which today makes up almost the entire atmosphere of the planet.
Would Mars have been a more hospitable place over up to 2.6 billion years back in time? One thing is for sure, Perseverance tells us it was because today, free-standing water cannot be found anywhere on the planet’s surface. For it to have flowed back then, the climate of the planet had to be far more benign.
Why did it change? The lack of a strong magnetic field similar to that on Earth may be one of the reasons the Martian surface today is inhospitable. Another reason may have to do with the planet’s mass, just not big enough to hold onto a thick atmosphere to protect the surface from cosmic and solar radiation.
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AI is more than a computer program that is capable of human-like language comprehension and communication. It is its data assimilation and ability to recognize patterns within billions of bits of information that makes it a powerful tool for the advancement of science.
Imagine you are a scientist researching a new cure for malignant lymphomas. Conventional means of doing research involve a comprehensive search of all papers previously published on the subject. In addition, the scientist can look at the newest papers posted on preprint servers. These latter ones would have yet to be peer-reviewed. A third search might compile a list of eminent scientists in the field with contact information for you to access as needed. But now you can ask an LLM to do all of those queries and deliver the information in less time than it will take you to read this article.
Schmidt anticipates that much of science can be automated creating what he calls “self-driving labs.” These robot-driven research facilities will conduct experiments which at the beginning will be devised by humans, but later by the AIs to produce publishable research results.
Schmidt doesn’t believe this will sideline scientists, but rather will open opportunities for more to join in including citizen scientists who today are already contributing to advancements in many fields.
Even peer review could become an activity better done by an AI than a human. A dispassionate, impartial assessment of research can be difficult to obtain because often the reviewers are known to the author who may favour their opinions. But an AI wouldn’t be burdened by human connections in looking at new hypotheses.
Already we are seeing AIs excel at some scientific tasks. One is protein folding. Back in 2013, I posted an article about FoldIt, a game created by scientists at the University of Washington to help understand protein structures and their role in diseases. It invited humans to play the game and come up with new ways to fold proteins and by doing this help find potential cures for diseases. In 2018, an AI named DeepMind took on protein folding leading to the creation of a new tool called AlphaFold. Tasked in competition with humans it solved 25 of 43 protein-folding problems compared to the second-place human finisher with only three. Since AlphaFold’s introduction, researchers at the University of Washington have come up with even more powerful AI protein folders. The latest is RoseTTAFold which concurrently can solve multiple protein-folding problems.
Reproducibility is another challenge for scientists. In a 2016 paper published in Nature, it quotes a survey of 1,576 researchers with more than 70% admitting they failed to reproduce published results from their experiments. I get in my inbox periodic reports from a site called Retraction Watch, which exposes bad science and scientists. But it only catches a small number of papers reporting unreproducible experiments. The vast majority slip by. And even the papers Retraction Watch catches continue to get cited by scientists doing new research. An AI tool would catch the unreproducible with Schmidt arguing it would create “a greater trust in science.”
Schmidt states that “AI is such a powerful tool because it allows humans to accomplish more with less: less time, less education, less equipment. But these capabilities make it a dangerous weapon in the wrong hands.” That’s why he is calling for well-informed regulation of AI tools and their use for the benefit of science and humanity. Exploiting AI’s potential and recognizing the potential perils of using it, Schmidt states will allow “us to combine information in novel ways and bring creativity and progress in the sciences to new heights.”
]]>While studying a protoplanetary disk it detected some interesting molecular chemistry – the precursor molecules needed to produce proteins and DNA. In other words, the JWST found the seeds of life circling a star far from our Solar
System.
The question of life originating in space has been argued for millennia. In the Western World, the first to propose life coming from space was the Greek philosopher, Anaxagoras, who almost 2,500 years ago hypothesized that the elemental stuff found among the stars bore the seeds of life. Even before Anaxagoras, Buddhist and Vedic philosophers expressed similar arguments.
The idea was revived in the 20th century, first by Svante Arrhenius in 1903. Today, Arrhenius is better remembered for his observations about increased carbon dioxide (CO2) in the atmosphere leading to climate change. He didn’t win much favour with the scientific community about climate change or his theory of life’s origins.
Another proponent of life from space was Fred Hoyle, a 20th-century British astronomer who proposed a theory called stellar nucleosynthesis. Later on, the name changed to panspermia.
I was a big fan of Hoyle as a young man interested in astronomy. I had several telescopes and was a member of the Royal Astronomical Society. I read Hoyle’s books about the origins of the Universe and later the origins of life. Hoyle believed in a steady-state theory of the Universe which was disproved by later observations supporting today’s inflationary model beginning with the Big Bang.
But Hoyle’s stellar nucleosynthesis may in the end prove to be right. He hypothesized that the Ort Cloud, sitting at the outer edge of our Solar System, was the likely source of life here. The Cloud, consisting of tens of thousands of small bodies circling our Sun in orbits lasting tens of thousands of years, is largely a carbon nursery where one can identify organic compounds that are almost indistinguishable from primitive bacteria. Disturbances within the Cloud that caused orbital changes, Hoyle believed, produced the comets that hurled themselves into the Inner Solar System. These comets, largely made up of carbon compounds and water ice rained down on the early Earth over 4 billion years ago. Many scientists today believe that the water in Earth’s oceans came from this cometary bombardment.
So how did the Ort Cloud become the nursery for life? Based on the JWST observations, the Ort Cloud was seeded from interstellar space. The protoplanetary disk circling a red dwarf star within the Orion Nebula could be one of billions of seeds of life nurseries producing carbon-based molecules. In this case, the JWST found a molecular compound called methyl cation (CH3+). It is deemed to be a significant building block for life’s origins because CH3+ interacts with a wide range of carbon molecules to create increasing complexity. Among those complex molecules could be the precursors of RNA and DNA. Previous to the JWST discovery, CH3+ had only been observed within the Solar System.
]]>I remember how hard it was to break Babe Ruth’s home run record of 60 in 154 games. That number stood the test of time until Roger Maris broke it with 61 in 1961. Maris did it in an extended 162-game season. Since Maris, others have surpassed 60 as well with the current record of 73 accomplished by Barry Bonds in baseball’s notorious “steroid-enhanced” era. That was done in 2001.
Over the years, the makeup of the baseball has purportedly changed although Major League Baseball denies this. An altered baseball was blamed for “the dead-ball era,” when too few home runs were hit. Now climate change is being cited as a home run performance enhancer.
A study at Dartmouth College claims that reduced air density caused by warmer temperatures is likely responsible for an additional 500 home runs above average since 2010. The study goes on to project an increase of 10% in home runs because of global warming by 2100.
Dartmouth has given this new baseball era the name “climate ball.” Their research was published on April 7, 2023, in the Bulletin of the American Meteorological Society. The research compiled data from 100,000 Major League Baseball games between 1962 and 2019, and 220,000 batted balls between 2015 and 2019 to come up with the hypothesis that global warming is changing how the ball takes flight attributable to reduced “gametime air density.” The study also notes that “without gameplay adaptations, future warming will intensify this effect alongside other climate impacts.”
The most recent surge in home runs per game occurred between 2015 and 2019. No steroids or doctored balls are involved. It’s all about changes to game-time temperatures. Past research has noted a correlation between the distance a baseball travels and gameday temperatures. But linking the increase in the number of home runs directly to rising temperatures meant having to rule out other potential associations. For instance, many new stadiums have been built in recent decades. Outfield dimensions have been altered, sometimes to make ballparks more pitcher or hitter-friendly. Many new ballparks have retractable roofs which change the airflow dynamics. Here in Toronto, the Rogers Centre, formerly known as Skydome, was the first of its kind to have a retractable roof.
The Dartmouth study only looked at open-air and retractable-roof stadiums. A 1 Celsius (1.8 Fahrenheit) increase in daytime temperature translates to a 1.96% increase in home runs. In terms of game time temperatures such as those played in the afternoon, the effect is larger with an increase of 2.4% while with night games 1.7%. Insignificant changes were noted in homerun statistics where stadiums were closed. There was nothing of note to separate home and away teams in terms of home runs hit under these varying conditions.
Other variables that the study mentions include warmer temperatures and the potential heat stress that can happen to pitchers. Could that be contributing factor to increased home runs? Can air density and temperature affect bat or pitch speeds?
Statcast data does show that the average increase in the number of fly balls per game correlates to the uptick in home runs. Right now the difference is small. But as atmospheric temperatures rise through the rest of the century the changes to air density that will also occur will produce more home runs. And each degree of atmospheric warming, states the study, will lead to approximately 95 additional home runs per season.
If all-day games were to be converted to night games, the number of additional home runs per season would be smaller. A season of only night games would cut the number by 15%. Adding more domes to stadiums would reduce the number further. Today, domed stadiums experience produce less than half of the home run totals seen in open stadiums.
And finally, the study cannot deal with all human factors including player conditioning changes, and altered pitching and defence strategies. Today’s top pitchers are consistently cracking 100-mile-per-hour speeds. Well-hit balls that come at you at 100 are likely to leave the bat at even greater speeds. And batters these days seem to be reaching for the fences with the angle of their swings, so it all adds up to an upswing in homerun counts.
I think this hypothesis needs further experimentation and greater parsing of the data to definitively be proven. What I like about it, however, is that it brings climate change into a baseball discussion, and maybe that gets more people aware of the unintended consequences of putting more greenhouse gasses into the atmosphere.
]]>If you think of DNA in correspondence terms, it writes instructions. RNA picks up the instructions and delivers them to a recipient in the cell. The instructions contain a recipe and what follows is the filling of it producing a protein molecule explicitly designed for the required task.
But before all of the above ever could have happened there had to be something with simpler chemistry. A research team at Rutgers University believes that what first emerged was probably a peptide containing the element nickel. They have named it Nickelback, not to be confused with a Canadian rock band of the same name. This Nickelback peptide consists of two bound nickel atoms which exhibit both stability and activity in terms of reacting with surrounding chemistry. Such a peptide is capable of redox reactions that transfer electrons from one chemical substance to another and is essential as the first stage on the way to life.
The Rutgers researchers believe that between 3.5 and 3.8 billion years ago, conditions in the water environment of early Earth led to the self-assembly of a pioneer peptide to become the precursor of proteins. With its emergence, metabolic processes began.
The evolutionary chain required a pre-protein before proteins could emerge. The Rutgers researchers believe that Nickelback or a similar peptide was probably the ancestor of all life on Earth. It conjectures that similar peptides could be what we need to be looking for on Mars for evidence of past and present life.
The Nickelback peptide (seen in the illustration below) consists of 13 amino acids binding two nickel ions. Nickel was abundant in the primordial oceans of Earth. A paper published on March 10th, in the journal Science Advances, describes why the inherent catalytic properties of nickel ended up producing molecular hydrogen with free protons and electrons and initiating a redox reaction.
Molecular hydrogen is an energy source for anaerobic microorganisms. Scientists believe that the first life to emerge on Earth was anaerobic. And for it to exist the chemistry needed to contain metalloenzymes of nickel or iron or both. The inherent catalytic properties of nickel reacting with surrounding amino acids and other organic chemistry would have led to a self-assembled peptide.
NASA’s search for evidence of past or present life on Mars has been seeking organic molecules and microfossils. When two Viking spacecraft landed on the Red Planet in 1976, the onboard experiments tested for evidence of organic chemical reactions. But with the Rutgers findings maybe what NASA should be looking for is simple peptide precursor biosignatures similar to Nickelback.
How NASA will find something as small as a peptide may come about by relying on artificial intelligence (AI) in the search for life. A current research project has been training an AI in the Atacama Desert in Chile to search for biosignatures. The reason to choose the Atacama is simple. It most resembles Mars on Earth, an extreme habitat. The AI using a convolutional neural network and machine learning is predicting where it could find DNA sequences. Maybe it should be looking for peptides instead.
]]>Before I switched my university major to Medieval and Islamic history, I was pursuing a degree in geophysics. Geophysics studies the Earth and its physical characteristics. Back then my teachers described the inner layers of our planet as follows: there was the lithosphere or Earth’s crust and beneath it lay the mantle, a viscous hot zone that was described as being like a moving conveyor belt of melted rock. Underneath the mantle lay the core, consisting of an outer shell of dense hot liquid iron surrounding a solid iron core.
That picture has changed since the late 1960s with new research using seismic data providing us with a much more detailed model of what lies beneath our feet. It appears now that the mantle doesn’t directly lie beneath the lithosphere. A layer called the asthenosphere is an interface lying between the crust and mantle.
The asthenosphere is a relatively soft boundary between the lithosphere and upper mantle. Junlin Hua, a postdoctoral fellow at the University of Texas – Austin is the lead author of a recently published paper appearing in the journal Nature Geoscience that describes the role the asthenosphere plays in Continental Drift. The paper notes the following:
The asthenosphere extends from 100 kilometres (approximately 60 miles) to 700 kilometres (450 miles) beneath the Earth’s surface. It is described as being malleable, in other words, soft but not necessarily molten. When heat from the mantle causes greater viscosity within the asthenosphere, the continental crustal plates are given the impetus to move. Mind you, the movement of crustal plates is measured in millimetres to centimetres per year where there is geological seismic activity. Earthquakes like the ones that Turkey just had are usually a result of the plates locking together and then releasing in response to physical changes within the asthenosphere.
The Earth has an outer and inner core. The core was first discovered by scientists in 1936. It lies 5,000 kilometres (3,100 miles) beneath the surface of the planet. Measuring 1,220 kilometres (760 miles) across, the core was a mystery until seismologists studying the waves created by earthquakes noted that when passing through the centre of the planet, they slowed down. Subsequently, seismic datasets accumulated over time have allowed researchers to discern subtle changes in speed and direction allowing them to discover the first two core layers and now the innermost.
A study from Australian National University is credited with discovering the innermost core. This solid iron-nickel sphere has anisotropic characteristics. Anisotropic means depending on the sampling angle of seismological data, noticeable changes in the crystalline structure of the metal alloy can be detected. The authors of the study believe this suggests “a significant global event from the past” in which changes occurred to the composition and dynamics of the planet’s interior.
The anisotropic characteristics of the innermost core may be behind the beginning of plate tectonics. The variability within the innermost core structure could have affected the heat flow from the interior to the outermost layers of the planet, ultimately altering the dynamics within the lithosphere.
In our Solar System, plate tectonics is believed to be unique to Earth. There is no evidence of crustal plates on the Moon, Mars, Mercury or Venus. Europa, one of Jupiter’s moons, experiences similar crustal movement but the cause is currents in the ocean that lies beneath the ice crust combined with the pull of Jupiter’s gravity. Jupiter and none of the other gas giant outer planets show evidence of having crustal plates.
So what do we know now about the role of Earth’s core in the dynamics of our planet?