Scienceandsf -A Blog Published by Robert A. Lawler – Page 52 – Discussions of Topics Related to Science and Science Fiction

Paleontology News for July 2018

Since my last post (11July18) was a review of the new dinosaur movie Jurassic World: Fallen Kingdom I thought this might be a good time to discuss several items of interest in the field of paleontology. Since T-rex is one of the heroes of the Jurassic Park franchise, well at least to me, I’ll start with a recent discover about them.

The word dinosaur itself means ‘terrible lizard’ and the first scientists who studied their fossil bones did actually think of them as simply enormous lizards. Over the last two hundred years we’ve learned a great deal about just how different dinosaurs are from other types of reptiles and now a new study takes us another step further by examining dinosaur’s tongues.

Most representations of dinosaurs, including those in Jurassic Park, show dinosaurs as having tongues similar to those of lizards, long, only attached at the back and therefore able to stick out, pretty much the way ours do, see image below.

Old View of the Dinosaur Tongue (Credit: Spencer Wright)

According to Julia Clarke, professor of vertebrate paleontology at the University of Texas at Austin and co-author of the study however dinosaurs probably had a tongue more like those of the crocodiles and alligators. A tongue that was firmly attached to the bottom of the mouth along its entire length and one would be completely unable to stick outside of the mouth, see image below.

Dinosaur Tongue were actually more like those of a Crocodile (Credit: Shutterstock)

Since the soft parts of dinosaurs, such as tongues rarely survive the study based the study’s conclusions are based on an examination of the bones in the mouths of dinosaurs, in particular the hyoid bones that anchor and support the tongue. What the researchers found was that the short hyoid bones of dinosaurs more closely resembled the hyoid bones of the crocodilians rather than the hyoid bones of the lizards. So it turns out that we may have still been incorrectly thinking of dinosaurs as just big lizards.

One of the best known types of dinosaurs are the huge sauropods, the long necked, long tailed behemoths who were without doubt the largest animals ever to walk on Earth. Our modern whales may be as large but of course they swim in the ocean. See image of a brachiosaurus below.

The Brachiosaurus (Credit: Todd Marshall)

Now paleontologists working in Argentina have unearthed what they consider to be earliest known member of the sauropod group, and animal that they have named Ingentia prima. As might be expected for a very early member of a group I. prima looks a good bit different, see image below.

The Early Sauropod Igentia prima (Credit: The New York Times)

Comparing I. Prima to the brachiosaurus it’s easy to see that I. prima’s neck is a good bit shorter and while the legs of the brachiosaurus strongly resemble those of an elephant the legs of I. prima look more like those of theropod dinosaurs. To me the rear legs look a bit like the legs of T-rex.

I. prima lived during the Triassic period, about 215 million years ago, not long after the very first recognizable dinosaur evolved. While smaller than its later descents at an estimated ten tons and nearly ten meters in length I. prima was probably the biggest creature in the world at that time.

Paleontologists have long known that the huge sauropods evolved from much smaller, two legged dinosaurs and I. prima still shows some evidence of that two legged past. Researchers hope that further study of I. prima’s bones will give them further insight into how the sauropod group of dinosaurs evolved.

These studies are just two more examples of how, piece by piece, paleontologists are filling in the gaps in our knowledge of the history of life on Earth.

Movie Review: Jurassic World, Fallen Kingdom

Anyone who is even an occasional reader of this blog knows that I love Dinosaurs, always have. I’ve also always loved monster movies, probably because many of them (Godzilla, Gorgo) were take offs on dinosaurs. I freely admit that when I was a kid I dragged my dad to more than a few lousy movies because they had dinosaurs or something that resembled a dinosaur in them.

So as you might imagine I had to go see the latest edition of the Jurassic Park franchise Jurassic World: Fallen Kingdom starring Chris Pratt and Bryce Dallas Howard. I’ve seen all of the Jurassic Park movies and even if the plots are convoluted, the characters rather one-dimensional and the endings really just a setup for the next movie in the franchise, they’ve got dinosaurs!!

Jurassic World Fallen Kingdom (Credit: Amblin Entertainment)

So let me start by discussing the parts of Fallen Kingdom that I liked. First of all I’ve always like the way the Jurassic Park series has included some animatronic dinosaurs rather then just relying on CGI. In the dinosaur movies I saw as a kid the actors could never actually interact with the dinosaurs because they were actually guys in rubber suits like Godzilla, or small claymation figures like in ‘King Kong’ or they were blown up film of real life small lizards as in ‘The Lost World’. Either way it looked hokey to even a dinosaur loving kid like me.

Another good part of fallen Kingdom is the two stars, Chris Pratt and Bryce Dallas Howard, both of whom are easy to like and who seem to like each other, which is good because half of the movie is them interacting. In fact my favourite scene in Fallen Kingdom is when Pratt and Howard are trapped inside a shipping container with a sedated T-rex who starts to wake up. Here we have the two principals acting together and with something that, even if it isn’t really alive, still looks like a dinosaur, one they can touch and which can touch them back! Pratt and Howard are acting to a real thing, not just acting to a green screen on to which the computer guys will add a dinosaur.

Bryce Dallas Howard (Left) and Chris Pratt (Right) posing with T-rex (Credit: Daily Wire)

Now if you think that sounds like I’m not a fan of CGI, you’re mostly right. I think that too much CGI starts to look more like a cartoon than anything else. Now I know that sometimes the producers have no choice, the things that they want to show simply don’t exist. Still, the less CGI, the more special effects consist of real objects, the better as far as I’m concerned. And that’s the way Amblin Entertainment, the studio that produces the Jurassic Park franchise, does things!

Sedated T-rex (Credit: Amblin Entertainment)

Now just a few criticisms. The movie is really two stories combined, and not too well. In the first story a volcano on the island where the dinos are is about to erupt, killing them all. So a rescue is setup. The second story concerns that fact that the people who rescued the dinos are badies! Ho hum!

Also, in Jurassic World Fallen Kingdom James Cromwell plays Benjamin Lockwood, a partner to Richard Attenborough’s John Hammond from the original Jurassic Park. Obviously they wanted Attenborough’s original character but Attenborough had died since Jurassic Park so they created a new, virtually identical character out of nowhere who doesn’t really do much anyway. They really should have gone with a completely different character.

Still, Jurassic World Fallen Kingdom is an entertaining thrill ride, which is what any summer blockbuster is supposed to be. But best of all, it’s got Dinosaurs!!!

What is causing the Massive Die off of Bats in the Eastern United States?

For many years, one of my favourite things to do on a summer’s evening was to watch for the bat’s to come out about a half an hour after the Sun went down. To be honest I usually combined this with some backyard stargazing, but still the bats were certainly fun to watch. One of the most interesting parts was the timing, the bats always appeared just a few minutes after the last bird flew to its roost, never before, and never more than ten minutes after.

Over the last few years however my nocturnal flying friends have disappeared, along with millions of other bats throughout eastern North America and the cause has been identified as an epidemic of the fungus Pseudogymnoascus destructans, commonly know as White Nose Syndrome. The first image below shows a Little Brown Bat, Myotis lucifugus, that has been infected by white nose syndrome while the second shows the fungus itself.

Bat Infected with White Nose Syndrome (Credit: Marvin Moriarty / USFWS)

Fungus Pseudogymnoascus destructans (Credit: Gudrun Wibbelt et al)

Now P. destructans causes harm to bats in several different ways. The most obvious symptom is the fungal growth and lesions around the mouth and on the wings which inhibit the bat’s ability to eat and fly. The fungus is also known to infect the lungs causing respiratory distress.

However it is actually thought that White Nose Syndrome does its greatest harm by interfering with a bat’s winter hibernation. You see during hibernation bats, and other mammals as well, lower their body temperature in order to stretch body fat reserves throughout the winter. The fungus however prevents the bats from entering the torpor stage of hibernation, where the body temperature goes lower, and therefore the animals literally starve to death while trying to hibernate.

P. destructans was first spotted in a cave in New York state back in 2006 and has since spread to 33 states in the U.S. along with 5 provinces of Canada. The effect of the disease has been devastating with a decline of more than 90% in the bat population of caves where the fungus has been for over four years. By 2012, that’s six years ago now, 5-7 million bats are thought to have perished! The image below shows that areas of North American where White Nose Syndrome has been identified.

Present Extent of White Nose Syndrome in North America (Credit: Enwebb)

So where did White Nose Syndrome come from, how did it get here? The answer is simple, Europe. The fungus P. destructans has been known to infect European bats for decades but it seems that the European bats have acquired at least a partial immunity to the disease. It looks as if this is yet another example of a disease whose original population has evolved to survive, leaping into a related population with no immunity and causing a devastating epidemic. Well know examples of this phenomenon are smallpox among the Native Americans and Measles among the Hawaiian Islanders. And I’m afraid that once again Human Beings are probably the transmitters of the disease because it appears that people who like to explore caves, known as spelunking, can get the fungus on their clothing, which can then be passed to other caves they visit, even caves on different continents.

Spelunking, people having fun in a Cave (Credit: Phys.Org)

Now I know some of you are saying, who cares about bats? They’re icky anyway! Well remember that bats eat insects, a lot of insects and without bats we’re going to have a lot more destructive, disease carrying insects around! In fact the Forest Service estimates that 1.1 million kilograms of insects will go uneaten. That’s a lot of bugs eating our crops and spreading germs that infect people!

At the moment there is no known way of fighting White Nose Syndrome. There is research underway but only a little. There’s not a lot of funding to combat bat diseases. So, barring a providential discovery we can only hope that, like their European cousins, American bats will acquire the immunity to survive White Nose Syndrome.

Astronomers take First Ever Images of Planet being Formed around nearby Star, and how do Planets Form anyway.

By a strange coincidence, it was in 1633 CE, that the French Philosopher René Descartes first began to ponder how the Solar System was formed. Coincidence, because that was the very year that Galileo was tried by the Inquisition for supporting the theory that the Sun, and not the Earth stood in the center of the Universe.

Like Galileo, Descartes accepted Copernicus’ hypothesis that the Earth was a planet that circled around the Sun and not the Sun that circled the Earth. The Copernican picture of all of the planets orbiting around the Sun as if in a whirlpool led Descartes to speculate that originally the Solar System had formed from a vortex of swirling particles which condensed into the Sun and the planets.

Because Newton had not yet discovered his theory of Gravity, Descartes had no idea what had caused the condensation and because of his own fear of the Inquisition his ideas were only published after his death in 1664. Nevertheless Descartes basic idea of a rotating cloud that condenses turned out to be basically correct.

In was more than a century later in 1796 that the French Mathematician Pierre-Simon Laplace first attempted to construct a detailed model of how planetary systems formed. In addition to Newton’s theories Laplace also benefited from the observations of 18th century astronomers like Charles Messier and William Herschel who had discovered a large number of fuzzy, swirling ‘nebula’, in the night sky. To Laplace these nebula were Solar Systems in the process of formation, baby stars and planets. The images below show two of these ‘nebula’ the Andromeda (Messier Catalog M31) and the Triangulum (M33).

Triangulum Galaxy M33 (Credit: Space.com)

Unfortunately it turned out that many of those ‘baby solar systems’, in particular Andromeda and Triangulum were actually found to be other galaxies!!! Vast, huge collections of billions of stars. Other physicists soon discovered other problems with Laplace’s ideas as well so work on planetary formation stalled for about a century.

The Astronomer Forest Moulton in 1900 discovered one interesting fact about the Solar System that any theory of planetary formation must account for. It is simply that, while the Sun contains 99.8% of all of the mass in the Solar System, the planets contain 99% of the angular momentum. Throughout the early 20th century this simple fact became the downfall of several theories of how the planets formed.

It wasn’t until 1972 that the Soviet astronomer Victor Safronov revived the nebula theory of Laplace with his Solar Nebula Disk Model (SNDM). Safronov and his model received considerable attention when several young stars, such as Beta Pictoris, were found to be surrounded by disks of cool dust exactly as predicted by the (SNDM) theory.

Further observations by space telescopes such as the Infrared Astronomical Satellite and of course the Hubble Space Telescope have succeeded in discovering enormous ‘cosmic nurseries’ such as the Orion nebula (M42) and the famous ‘pillars of creation’ in the Eagle nebula (M16). See images below.

Pillars of Creation inside the Eagle Nebula M (Credit: ESA, Hubble)

Now astronomers using the Very Large Telescope at The European Southern Observatory have succeeded in looking deep into one of the disks of gas and dust that surround a baby star to see a baby planet in the act of forming. The baby planet is orbiting around a young orange dwarf star named PDS 70 at a distance from Earth of 370 Light Years. Looking at the image below the planet is the bright blog to the lower right of the black dot. The dot itself is a mask inserted in the telescope used to eliminate the light of the dwarf star which would otherwise overwhelm the faint light of the proto-planet.

PDS 70 Image showing Proto-Planet (Credit: Spacepage)

Astronomers at the Max Planck Institute who conducted the research had discovered a protoplanetary disk around PDS 70 back in 2012 which led them to attempt to image the proto-planet itself. Based upon their data the team, led by astronomer Miriam Keppler, estimate that the planet is about two to three times the mass of Jupiter orbiting its star at a distance of three billion kilometers, about the distance between Uranus and the sun.

Science works best when there is a strong back and forth between theory and observation / experiment. Our theories of planetary formation improve with every new observation while the new theories give the astronomers a better idea of what to look for in the sky!

Space news for June 2018.

Some really out of this world stories have taken place this past month. I think I’ll start with Jupiter, the king of the planets.

NASA’s Juno spacecraft has been studying Jupiter for over a year now, traveling on a highly elliptical polar orbit. That means part of its orbit passes very close above the planet’s poles while other parts of the orbit are at a much greater distance from Jupiter. The image below shows how a highly elliptic orbit works.

Highly Elliptical Orbit (Credit: Wikipedia)

One of the interesting aspects of the Juno mission is that NASA is releasing the raw images taken by the spacecraft’s cameras online and allowing citizen scientists to combine and enhance the images. Whether or not these amateur astronomers make any major discoveries they have certainly already produced some wonderfully artistic views of the planet. The image below, which rivals the best work of any avant garde painter, is the work of two such citizen scientists, Gerald Eichstädt and Seán Doran.

Jupiter Gas Clouds as Seen by Juno Spacecraft (Credit: Gerald Eichstadt, Sean Doran )

The Juno spacecraft is also helping to solve some long standing mysteries of the Solar Systems largest planet. For example, it’s been known for decades that lightning occurred in the planet’s atmosphere, some of which was far more powerful than any lightning here on Earth. Well, based on data sent back by Juno, the scientists at NASA have discovered that, while the lightning on Jupiter is generated in much the same way that it is on Earth, nevertheless the lightning on Jupiter is concentrated around the poles rather than being spread around the planet as it is on our planet. The image below shows a composite of many images of lightning captured by the Juno spacecraft.

Lightning on Jupiter (Credit: NASA, JPL)

Another spacecraft, the Japanese probe Hayabusa-2 has arrived at its destination the asteroid Ryugu after a 300 million kilometer journey that began back in December 2014. It didn’t take long for the Hayabusa-2 to make a major discovery for the asteroid has a very peculiar shape, that of a diamond, see image below.

Asteroid Ryugu (Credit: JAXA, University of Tokyo)

The spacecraft is expected to touch down onto the asteroid’s surface in an attempt to gather some material which is scheduled to be returned to Earth in late 2020. Hopefully that means that the spacecraft’s revealing of the asteroid’s shape is just the first in what will be a long series of discoveries.

Now you may remember that the Cassini spacecraft made its final plunge into Saturn’s atmosphere last September (See my post of 13September2017). However the data sent back by Cassini during it’s 13 years of exploring the ringed planet is still being analyzed so the spacecraft hasn’t finished making discoveries just yet.

One of the last maneuvers Cassini made before its final plunge was to actually pass through some of the material being ejected into space by the geysers it had earlier discovered on the moon Enceladus. These geysers are believed to be liquid water that was heated by the tidal friction between the moon, the planet Saturn and the larger moon Titan. (Much the same thing is believed to happen on Jupiter’s moon Europa) The image below, taken by Cassini, shows the geysers.

Geysers erupting on Saturn’s Moon Enceladus (Credit: New Scientist)

Now NASA has announced that their scientists have found evidence of complex organic molecules in the material Cassini passed through. This discovery increases dramatically the chances that some form of life may exist in an ocean under the protective ice cover enveloping the moon.

Finally Space X just seems to keep on adding on to their long string of space successes. Today’s launch of a Falcon 9 rocket with its Dragon capsule not only marked the beginning of Space X’s 15th resupply mission to the International Space Station (ISS) but was also a reuse of both the Falcon 9’s first stage and the Dragon capsule. Indeed the booster first stage had be used only ten weeks ago to launch NASA’s Transiting Exoplanet Survey Satellite (See my post of 28April2018) making this the fastest turnaround of a reusable first stage ever. The image below shows the launch of the Falcon 9 / Dragon capsule.

Space X launch of 29 June 2018 (Credit: Daily Express)

To date Space X has succeeded in recovering 25 Falcon 9 first stages and has reflown 14 of them in the company’s effort to reduce the cost of space travel by developing reusable launch vehicles and capsules. Space X did not attempt to land the Falcon 9 first stage after today’s launch however because the company is phasing out its ‘block 4’ design in favour of the new ‘block 5’ boosters which are optimized for reuse.

Also, in just a few months, Space X is scheduled to conduct the initial, unmanned test flight of what will become its crewed Dragon capsule. I can’t wait for that!

Chemists Develop Technique to Recover Early Photographic Images that have been Degraded over Time, and a bit about the History of Photography.

Nowadays most of us carry a camera with us wherever we go. The cheap little digital cameras in our phones can capture images that are often superior to the images taken 50 years ago by professionals using the best equipment of their time. It’s hard to imagine that photography is only a little more than 200 years old and that it was once a very difficult combination of art and science.

The word camera itself is Latin for room and really applies to the box which light can only enter through a pinhole opening. Such a device is known as a ‘Camera Obscura’ and way back in ancient China it was found that the light coming through the pinhole would project an inverted image on the opposite side of the box. See the image below for a diagram of the operation of a Camera Obscura.

How a Camera Obscura Works (Credit: Public Domain)

It was in the year 1800 that Thomas Wedgwood attempted to capture the image in a Camera Obscura by means of a sheet of paper that had been soaked with the light sensitive chemical silver-nitrate. Wedgwood did succeed in making a shadowy image however the silver-nitrate was so unstable that the image faded after only a few days.

It was the Frenchman Nice’phore Nie’pce who placed a lens where the pinhole had been and produced the earliest surviving photograph in 1826. Known as ‘The View from the Window at Le Gras’ the image took several days exposure to complete, that’s how much light was needed to alter the silver nitrate. The image of “The View from the Window at Le Gras’ is below.

The Earliest Surviving Photograph (Credit: Public Domain)

Obviously photographs that required hours or even days to produce were not going to be a big commercial success. It wasn’t until 1839 when Louis Daguerre discovered a way to make the images formed by using silver halides permanent that photography became more than just a science experiment. Daguerreotypes as they were known were produced in the thousands with many historical and artistic firsts. These include the first photographs of world leaders, see the earliest known photo of Abraham Lincoln below, and the first photograph of a Solar Eclipse, taken on July 28, 1851 and also shown below.

Earliest Photograph of Abraham Lincoln (Credit: Public Domain)

First Photograph of a Solar Eclipse (Credit: Public Domain)

Even Daguerreotypes fade in time however, and today some of the oldest known photographs are so degraded that their images are all but lost. Lost that is, except for the work of researchers at Western University and the National Gallery of Canada. Led by Madalena Kozachuk, a Ph.D. student at Western’s Department of Chemistry the researchers used rapid-scanning micro-X-ray fluorescence to measure the Daguerreotype’s remaining mercury, used in the development of the image after exposure.

By making a point by point measurement, taking eight hours to complete, Kozachuk succeeded in restoring the images. Looking at the side by side comparison below of a Daguerreotype of an unknown woman it is easy to see how well the process works.

Original (left) and Restored Photo of a Woman (Credit: Madalena Kozachuk)

There are thousands of Daguerreotypes stored in libraries around the world; the National Gallery of Canada itself has over 2,700. Madalena Kozachuk’s technique allow enable conservators to bring back some of our earliest photographic history.

Think about that the next time you pull out your smartphone and start snapping some selfies!

Unusual Form of Chlorophyll found to produce Photosynthesis using Infrared Light.

We all know the basic facts about photosynthesis, or at least we all think we do. Plants use the chemical chlorophyll to absorb sunlight and use its energy to turn carbon dioxide and water into sugar. This chemical process is called photosynthesis and is the main source of food for all life on Earth. At the same time photosynthesis also produces oxygen as a by-product. So for us animals photosynthesis provides both the food we eat as well as the oxygen we breath. Oh, and chlorophyll is also the reason plants are green. See image below of plant cells, the green blobs are called chloroplasts where the chlorophyll is concentrated.

Chlorophyll in Plant Cells (Credit: Wikipedia)

As you might guess, chlorophyll is a rather complicated chemical and not surprisingly there are several variant forms of the chemical. Looking at the chemical diagram below for chlorophyll-a the most common form, the roundish structure on the right hand side is called the chlorin magnesium ligand, which is shared by all forms of the chemical.

Chemical Diagram of Chlorophyll (Credit: Wikipedia)

Biochemists have identified six other slight, yet still distinct variant form of chlorophyll. These are labeled chlorophyll-b through -f with two different c’s, -c1 and -c2. Each of these variant chlorophylls absorbs different wavelengths of visible light more or less efficiently than the others with Chlorophyll-a generally being the most efficient, which is why it is by far the most common type. The image below shows the absorption efficiency versus wavelength for chlorophyll-a and chlorophyll-b.

Absorption Comparison of Chlorophyll-a vs. Chlorophyll-b (Credit: Wikipedia)

Of course there are wavelengths of light that are outside the visible spectrum. Infrared light is one of these and researchers have now discovered that chlorophyll-f is particularly good at using the energy of infrared light in what is being called ‘a new kind of photosynthesis’. In fact, under low light conditions photosynthesis using chlorophyll-f becomes dominant in certain species of cyanobacteria and blur-green algae.

These bacteria and algae are examples of life in extreme conditions, many live deep underwater in the boiling hot volcanic springs of Yellowstone or similar hostile environments. The ability to get energy from light that other ‘more advanced’ living things can’t use gives these single celled creatures the advantage they need to survive.

Life forms that can life in such extreme conditions are of great interest to space scientists who want to understand what life on other worlds, with very different environments, might be like. In fact Mars, further from the Sun with lower levels of light, might be the perfect environment for bacteria using the chlorophyll-f style of photosynthesis.

Some scientists have gone even further and are already suggesting that such bacteria be taken from Earth to Mars in order to start producing oxygen that one day people might breath. Importing and spreading such low light using, oxygen producing bacteria across the planet would be one of the first steps in Terraforming Mars for human habitation.

I’m certain that there’s still a great deal more to be learned about chlorophyll and the process of photosynthesis just as I’m certain scientists will keep studying it. And maybe someday soon we will find life on Mars or Europa or elsewhere and we will get the chance to learn how true aliens produce their food.

Archaeology News for June 2018, better precision for Carbon 14 dating in the Middle East and a Spectacular find whose date could be effected.

Starting in the 1950s the science of Archaeology was revolutionized by the use of radioactive carbon-14 as a means of giving precise, hard dates to objects discovered during archaeological digs. Like any measuring tool however, carbon-14 (¹⁴C) dating has been, and continues to be improved in order to make its measurements more accurate, more precise and more reliable. Now a new study from researchers at Cornell and Oxford Universities seeks to further improve the accuracy of ¹⁴C dating for the Middle Eastern region by comparing it to the dates obtained by examinations of tree rings.

To understand the significance of the study let me take a few minutes to describe what ¹⁴C is and how we use it to date things. If you remember from you high school chemistry all atoms are made up of particles called protons, neutrons and electrons. The protons and neutrons reside in the very center of the atom, which is called the nucleus while the electrons fly around the nucleus. In a neutral atom the number of protons and electrons is equal and it is that number that determines what kind of atom, what chemical element it is. For example an atom of carbon has six protons and six electrons.

The number of neutrons can vary, but if the nucleus has too few, or too many neutrons it will be radioactively unstable. For carbon the stable number of neutrons is either six, making carbon-12 (¹²C) which makes up almost 99% of the cosmic abundance, or seven making carbon-13 (¹³C) at a little over 1%.

With eight neutrons carbon-14, (¹⁴C) is radioactive with a half-life of 5568 years. This means that if you had a thousand atoms of ¹⁴C in 5568 years you would only have 500 atoms of ¹⁴C left. Then in another 5568 years (11136 years total) you would only have 250 atoms of ¹⁴C. This having goes on every 5568 years until the ¹⁴C is gone. The image below shows the decay of a ¹⁴C atom.

The Decay of Carbon -14 (Credit: Science Blogs)

But if ¹⁴C shrinks by half in just a few thousand years, how is there is any left? After all the Earth is billions of years old isn’t it? Shouldn’t the ¹⁴C be all gone by now?

It would have, if not for the solar wind striking the top of our atmosphere which produces a small amount of ¹⁴C all of the time. This trace of ¹⁴C drifts down into the lower atmosphere where it is absorbed into plants during photosynthesis. The image below shows the reaction that produces ¹⁴C.

The Production of Carbon-14 (Credit: Science Blogs)

Animals, like us, then eat the plants so some radioactive ¹⁴C gets absorbed into our bodies. (That’s right, you are radioactive. Well a little bit!) The ratio of ¹⁴C to ¹²C can be measured. When the animal or plant dies the ¹⁴C begins to decay, half of it disappearing every 5568 years. If you measure the ratio ¹⁴C/¹²C in organic material you can calculate how long it’s been dead! This was what scientists first thought 70 years ago.

Turns out it wasn’t quite that easy. You may also remember from high school that the Sun has an eleven year Sunspot cycle and that cycle, along with other factors alter the amount of ¹⁴C produced each year leading to some small inaccuracies. Because of this scientists have done a lot of work over the years in order to develop calibration factors that improve both the accuracy and precision of ¹²C dating.

The new study is one such attempt at a better calibration. The study consisted of taking samples from tree rings of a historically known date. For example if a building in Jerusalem is documented to have been built in 1830, wood used in its construction would have been cut down in 1829 and if you count in 100 rings from the last ring you then have material from the year 1729. Measuring the age of that material using ¹⁴C and by comparing that date to 1729 you get a calibration of ¹⁴C dating in Jerusalem.

That’s a part of the issue, the study from Cornell have found discrepancies between ¹⁴C dates in the Middle East and similar studies in other parts of the northern hemisphere. The researchers have found an average of a 19-year variation over the period 1610 to 1940CE. They speculate that the reason could be tied to the fact that the growing season for agriculture in the Middle East is actually during the winter rather than the summer as in Europe and Asia. The question is however, if the dates from 400 years ago are off by 19 years what about the date of something from say 3,000 years ago?

That would be nice to know because as it happens a very important find has recently been dug up at the archaeological site Abel Beth Maacah in northern Israel. The find is a 5cm tall figure of the head of a man, see image below. The head is made of a glass like material called faience and is almost certainly that of a high noble if not a king.

Figurine of head of a biblical King? (Credit: Fox News)

The find has been ¹⁴C dated to the 9th century BCE when a village called Abil al-Qamh was the crossroads of three biblical kingdoms, Tyre, the Aramean kingdom based in Damascus and Israel itself. In fact Abil al-Qamh is mentioned several times in the bible and based on the ¹⁴C date it has been suggested that the figurine may in fact be that of the well-known biblical king Ahab or that of his son Jehu. However it is just as likely that the head could be that of the Aramean king Ben Hadad or king Ithobaal of Tyre. Each of these men are mentioned in the bible so a definite identification as any one of them would be a discovery of historical as well as archaeological importance.

The Cambrian explosion, did all of the major forms of life on Earth appear in a flash? New study measures the pace of evolution during the Cambrian.

“I cannot doubt that all the Silurian trilobites have descended from one crustacean, which must have lived long before the Silurian age…Consequently, if my theory be true, it is indisputable that before the lowest Silurian strata was deposited, long periods elapsed, as long as, or probably longer than, the whole interval from the Silurian to the present day…The case must at present remain inexplicable; and may be truely urged as a valid argument against the views here entertained.”

Charles Darwin, On the Origin of Species, 1859

You have to admire the sort of person who points out the flaws in their theories before their critics get a chance to. First of all it shows that they’re honest enough to admit they don’t know everything, that even the best ideas aren’t perfect. Yet at the same time by pointing out the problems in their work up front they take some of the wind out of their opponent’s sails.

What we now call the Cambrian explosion was just such a problem for Darwin and his theory of Evolution by Natural Selection. Examining the fossil record, it appears as if all of the major forms of animal life, everything from arthropods to mollusks, segmented worms to starfish all came into being somewhere between 550 and 500 million years ago. The image below shows what kind of life inhabited the Cambrian.

That was the way it appeared to Darwin back in 1859, but in the 150 years since then we have made some progress. We now have an enormous amount of evidence for single-celled life forms dating back more than two billion years before the Cambrian. We also now have fossils of a group of multi-cellular creatures that lived 60-80 million years before the Cambrian, known as the Ediacarana fossils. Nevertheless, the Cambrian explosion is still one of the biggest problems in evolutionary theory. The image below shows how the diversity of life grew during the Cambrian.

Chart of the Cambrian Explosion (Credit: Royal Ontario Museum)

A new paper has been published by a team of paleontologists at Oxford University and the University of Lausanne which asserts that, while the rate of evolution was very high during the Cambrian the major changes were spread out over the entire 50 million year period, a really slow explosion in other words. According to lead author Professor Allison Daley of Oxford’s Museum of Natural History ‘…the Cambrian explosion, rather than being a sudden event, unfolded gradually over the ~40 million years of the lower to middle Cambrian.”

What Professor Daley and her colleagues did was to carry out the most comprehensive survey of the early fossil group Euarthropoda, a group that includes all of the arthropods (insects, spiders, crustaceans and trilobites etc.) along with similar now extinct creatures. What they found was that during the Cambrian radiation of the Euarthropoda into distinct sub-groups and species took place at a high but nevertheless steady rate over the period of ~40 million years.

At the same time a number of different physiological characteristics, such as an exo-skeleton, jointed limbs, compound eyes and the earliest biting jaws came into existence, but again gradually, one part at a time. In precise detail Professor Daley et al show how the Euarthropoda grew and diversified throughout the Cambrian, rapidly but not explosively. The paper estimates that the speed of evolution during the Cambrian was about five times that in the many years since.

Still the paper leaves unanswered the question of why the rate of evolution should have been five times higher during the fifty million years of the Cambrian. Several possible explanations for the high rate of evolution during the Cambrian have been advanced over the last several decades; arguable the two best are interrelated.

The first explanation proposes that the evolution of the first predator species caused other species to have evolved rapidly in order to develop some means of protection from the predators. Naturalists have in fact studied the effect of inserting a predator into a previously peaceful ecological niche and have found that the rate of evolutionary charge increases dramatically.

The second explanation deals with one of those means of protection, the development of hard parts. It was in fact during the Cambrian period that the first animals with hard parts, shells and exo-skeletons, evolved. Combining these two ideas some evolutionary biologists have described the Cambrian explosion as an arms race with new species finding new ways to eat other species while the other species desperately try to find new ways to not get eaten.

Whatever the cause, the Cambrian period was the time when both the kinds of living creatures and the modes of living that we recognize today came into existence. Explosion or not it was a very important period indeed.

Volcanic Eruptions in Hawaii and Guatemala, Why are they so Different?

One of the biggest news stories over the last month has been the continuous eruption of the Kilauea volcano on the big island in Hawaii. Now Kilauea has actually been quietly erupting for the past fifty years but recently the amount and intensity of the lava flow has increased by more than an order of magnitude.

More than twenty new fissures of the volcano have opened destroying hundreds of homes. At the same time, although no one has been reported to have died thousands of people have been forced to flee to safety. The images below show some of the power of the Kilauea volcano.

Eruption of Kilauea (Credit: UK Express)

Destruction of Kilauea (Credit: Newsweek)

Now just four days ago in the Central American nation of Guatemala the Volcan de Fuego, that’s Spanish for the Volcano of Fire, erupted sending a torrent of hot ash and mud through surrounding villages. This landslide of material is technically known as a pyroclastic flow and is the same phenomenon that buried the ancient Roman town of Pompeii.

Within minutes of the eruption in Guatemala hundreds were either dead or missing and thousands left homeless. The images below show some of the destruction cause by the Volcan de Fuego.

Pyroclastic flow from Volcan de Fuego (Credit: El Universal)

So what’s the difference here? The power of both volcanoes is inexorable; all that we humans can do is just run away until the volcano calms down as they always do. Still the lava flow from Kilauea has been steady, measured. So much so that you can almost walk to safety.

The ash flow from de Fuego however was like a tsunami, so fast that many people were engulfed before they knew what was happening, so fast that cars sometimes could not keep ahead of it.

The volcanic material from the two volcanoes even looks completely different. The lava from Kilauea is the classic molten red liquid that cools to a pitch-black hard rock. The material from Volcan de Fuego on the other hand is a gray powder that coats and chokes everything. The images below show the differences in the material coming from the two volcanoes.

Lava from Kilauea moves slowly (Credit: USA Today)

Ash Produced by Volcan de Fuego (Credit: Lavanguardian)

How can they be so different, they are both volcanoes aren’t they? Yes, they are both volcanoes but there are profound differences between them, and those differences can teach us a great deal about our planet. Kilauea is the simpler to describe and understand so I’ll start with it.

Kilauea, and all of the volcanoes that formed the Hawaiian island chain sit on a hole in the Earth’s crust that allows material from deep down to rise to the surface. Technically known as a ‘Hot Spot’ this hole reaches into the mantel, or even deeper, where the material is both hotter and more thoroughly mixed. Because of this smooth consistency volcanoes like Kilauea do not get clogged, they tend to spew out some lava all of the time.

Another thing to remember about Hot Spots is that they don’t move with the Earth’s tectonic plates. That’s how the Hawaiian island chain was formed as the Pacific plate slide across the Hot Spot forming new volcanoes, i.e. new islands as the plate shifted. So Kilauea is not caused by plate tectonics.

On the other hand Volcan de Fuego is a product of plate tectonics, it is directly generated by the movement of the North American plate over the Pacific plate. As the material of the Pacific plate is subducted beneath the North American it pushes upward spawning mountains and volcanoes. It is this mechanism that has produced the so-called ‘Ring of Fire’ around the Pacific Ocean. The image below illustrates how such a subduction zone works.

Diagram of Subduction Zone (Credit: Oregon State University)

However the material that rises up through volcanoes like Volcan de Fuego doesn’t come up as consistently as it does from a Hot Spot. This means that these volcanoes can go dormant for years or even decades. During this dormancy the volcano dome and lava chamber can harden and when pressure again starts to build the dome becomes a cap and the pressure just builds until it explodes destroying everything for kilometers in a matter of minutes. This is what happened at Vesuvius in 86CE, at Mount St. Helens in 1980 and happened at the Volcan de Fuego this week.

Kilauea and Volcan de Fuego may appear very similar above ground but by studying their differences we have learned a deeper truth about the forces that created them.