Science – Page 47 – Scienceandsf -A Blog Published by Robert A. Lawler

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.

Have Sterile Neutrinos been detected? Some experiments say yes, others say no.

Regular readers of this blog will have noticed that I have a deep interest in particle physics, also called high-energy physics, and in particular the so-called ‘ghost particle’ of the atom, the neutrino. Well after all my degrees are in physics and studying how the most elementary particles that exist interact is certainly the most basic way to understand how the Universe itself works. Also, my grad school advisor’s own research concerned neutrinos.

Neutrinos are a hot topic right now and a soon to be published paper is going to turn the temperature way up. The MiniBooNE experiment, which I discussed in some detail in my post of 2Dec2017, is detecting more neutrinos that calculations predict that it should and one possible explanation for the excess would be the existence of a fourth type of neutrino, a sterile neutrino. MiniBooNE is a cooperative experiment at Fermilab outside of Chicago, which produces the neutrinos the MiniBooNE detector. The image below shows the layout of MiniBooNE.

Layout of the MiniBooNE Experiment (Credit: Fermilab)

O’k a little background first describing the fermion or matter side of the standard model of elementary particles. Since the 1960s physicists have known that all of the matter we see around us, all of the atoms are built from four different particles. There is a pair of quarks called up and down who themselves make up the familiar protons and neutrons in the atom’s nucleus. There’s also a pair of leptons, the electron and the neutrino but while the electron orbits around the nucleus the neutrino is a ‘ghost particle’, rarely interacting with other particles.

If you think that sounds weird it gets worse. In the extremely high-energy collisions we generate in our modern atom smashers we have found that each of those four particles has two heavier, more massive cousins. The cousins of the up quark for example are called the charm and top quarks. The charm and top are identical to the up in every way except being more massive. They have the same electric charge, the same spin, the same weak charge, and same colour charge.

Similarly the down quark has two cousins named strange and bottom while the electron’s cousins are the muon and tau. Why these heavier cousins should even exist we have no idea but they certainly do.

There are three neutrinos as well but they simply called the electron-neutrino, the muon-neutrino and the tau-neutrino because they have the have the bazaar ability to oscillate from one type into another. One of the first attempts to study this oscillation property was called the Liquid Scintillator Neutrino Detector (LSND) at the Los Alamos back in the 1990’s. When the LSND found a surprising excess in the number of neutrinos some theoretical physicists suggested the existence of a fourth kind of neutrino, a sterile neutrino that would interact even less than normal ‘active’ neutrinos but which would oscillate like the others, in other words after a period of time it would become one of the other types. (I know how crazy that all sounds and I will tell you the math is almost easier to understand than the description!)

Other experiments quickly tries to find additional evidence of sterile neutrinos but failed. Both the Underground Oscillation Project with Emulsion-Tracking Apparatus Experiment in Switzerland and the Ice Cube Neutrino Observatory failed to discovery any hint of sterile neutrinos in their data. Physicists began to believe that there must have been some problem with the LSND data or its analysis. The Images below show the Ice Cube Neutrino Observatory in Antarctica.

Ice Cube Neutrino Observatory Credit: South Pole Doc)

Ice Cube Experiment Layout (Credit: Inspire.hep)

But now MiniBooNE has found the same signature of sterile neutrinos as the LSND had making physicists scratch their heads and wonder, what’s going on here? Perhaps one clue is that both LSND and MiniBooNE employ photomultiplier tubes to detect the energy released by a neutrino interacting with another particle while Ice Cube and the Underground Oscillation Project use other techniques. But whether the photomultiplier tubes are enabling the detection of sterile neutrinos, or are causing a false signal that is being interpreted as sterile neutrinos is as yet completely unknown. The image below shows the photomultiplier Tube array in the LSND. When in use the chamber is filled with water for the neutrinos to interact with.

Photomultiplier Tubes are a common technique for detecting Neutrino interactions (Credit: Amusing Universe)

Neutrinos have been leading physicists on both an exciting and yet very twisted journey ever since Wolfgang Pauli first predicted their existence back in the 1930s. I’m certain that there are a few more twists still to come.

Paleontology News for June 2018.

Two new fossils have been discovered recently of new species that are both very important in our understanding of the evolutionary history of life on our planet. Following the rule of age before beauty I’ll begin by discussing the earliest known ancestor of the group of reptiles known as the lizards.

Most people know lizards as simply any reptile that obviously isn’t either a crocodile or a turtle or a snake but lizards are actually the largest family of reptiles having over 6,000 species. Lizards range in size from tiny geckoes only a couple of centimeters long to the Komodo dragon that can exceed 3m in length.

The ‘new’ species has been named Megachirella wachtleri and the specimen was actually found twenty years ago in the Dolomites region of Northern Italy. As is the case with many recent fossil discoveries it was only when M. wachtleri was re-examined with new, more powerful instruments, a CT scan in the instance, that the features of M. wachtleri that made it important could be seen. The image below shows the fossil of Megachirella wachtleri.

Fossil of Megachirella wachtleri (Credit: Live Science)

The study of M. wachtleri was co-authored by Tiago Simoes of the University of Alberta in Canada who had spent more than 400 days visiting over 50 university and museum fossil collections in 17 different countries. Doctor Simoes is one of a number of researchers making important discoveries among the forgotten and misidentified specimens locked away in museum drawers.

Megachirella wachtleri lived some 240 million years ago making it the oldest fossil lizard by about 75 million years. Just as importantly, since M. wachtleri shows so many classic lizard features it probably pushes the common ancestor of lizards and other reptiles back to more than 252 million years.

Why is that important? Well you see 252 million years ago was the Permian / Triassic extinction when more than 95% of all of the different species of living creatures vanished. If the lizards split off from the other reptiles before then that means that at least one species of lizard survived the Permian extinction. The image below shows an artist’s impression of what M. wachtleri looked like.

Artists view of Megachirella wachleri (Credit: Live Science, Davide Bonadonna)

Our second discovery this month comes from a fossil site in the state of Utah and consists of a well preserved skull of an early relative of the mammals from an extinct group known as the haramiyidan. Named Cifelliodon wahkarmoosuch the fossil is thought to be between 139 and 124 million years old. The image below shows the fossil skull.

Skull of Cifelliodon wahkarmoosuch(Credit: Utah Geological Survey)

As I mentioned above the haramiyidan were a group of creatures that broke away from the reptiles at about the same time as the mammals and which share certain characteristics with our ancestors such as hairy fur but which retained other reptilian characteristics like giving birth via eggs. The exact nature of haramiyidans is still largely unknown since the group of animals did not last long and most of what we know comes from fossil teeth. Larger bones and especially skulls are often so smashed that little can be learned from them.

Paleontologists appear to have gotten lucky this time because the skull of C. wahkarmoosuch was well preserved enough to reveal an enormous amount of detail under X-rays and CT scans. Again, we see how newer more sophisticated instruments are leading to ever more discoveries! The excellent preservation of the fossil was despite the fact that the skull of C. wahkarmoosuch was found beneath the foot of a new species of iguanodon type dinosaur named Hippodraco.

C. wahkarmoosuch was a very small animal, less than 15 centimeters in length and weighing little more than a kilo. Based upon an examination of its eye sockets and large olfactory cavities the animal probably had poor eyesight but a very good sense of smell. The image below shows an artist’s impression of what C. wahkarmoosuch may have looked like.

Artist’s Impression of Cifelliodon wahkarmoosuch trying to scare off a dinosaur(Credit: Utah Geological Survey)

With every new discovery we are filling in the details of the tree of life and finding it to be far more complex and detailed than we had ever imagined.

Giant Carnivorous Worms are Invading France. No, that’s not the Plot of the Latest Disaster Movie.

Before you get too frightened the ‘Giant’ worms invading France are less than half a meter in length and while they are meat-eaters they mostly eat other, more familiar worms. However that doesn’t mean that they aren’t a big problem.

What we’re talking about are Hammerhead Flatworms, see images below. Creatures that are native to Asia but that have been unintentionally been brought to Europe and have now become established in southern France. This news raises two important issues, how human activity has enabled invasive species to harm environments around the world and, what do we actually mean when we talk about worms?

Diversibipalium multilineatum (Credit: Live Science)

Bipalium kewense eating an Earthworm (Credit: Live Science)

I’ll consider the second issue first. We humans tend to call any small creature that is long and narrow with no noticeable appendages, legs or head or etc., a worm. Now the typical earthworm that we can dig up in our backyard and use as bait when we go fishing is a species, in fact an entire class of species within the phylum Annelid, the segmented worms, see image below.

Common Earthworm, Lumbricus terrestris, Segmented Worm (Credit: Mira.com)

While Annelid worms may look simple on the outside they are really rather complex creatures with a full range of internal organs including both a circulatory and respiratory system. Indeed the internal structure of the segmented worms is so similar to that of the Arthropods, insects and crustaceans etc., that the two phyla are considered to be evolutionary cousins.

On the other hand the animals invading France are Flatworms, members of the phylum Platyhelminthes which are far simpler creatures having no internal body cavity at all. Without either a circulatory or respiratory system flatworms have to be flat because every cell in their body has to be near its skin surface in order to get its oxygen from the outside world.

So from now on we should all bear in mind that ‘worm’ can really mean a lot of very different animals, segmented worms, flatworms and oh, there is an entire phylum of roundworms as well.

So now let’s consider the problem of species of animals that ‘ride along’ with human beings as we travel around the world. These creatures often establish themselves in new environments were they have no natural predators to keep them in check so they breed out of control and end up destroying many native species. Examples of this phenomenon are so numerous I’ll only mention a few.

Before humans came, the island of Guam had no snakes so many of the species of birds there evolved to nest on the ground. Once Humans brought some snakes as pets a few got loose and within just a couple of decades all those birds were extinct, which actually hurt the snakes themselves as they had destroyed their own food source.

Right now the Asian carp is an invasive species spreading throughout the Mississippi river region and that are now threatening to get into the Great Lakes. The carp simply crowd out more valuable, well to us more valuable, native fish species destroying both recreational and industrial fishing wherever they spread. Also the carp have the habit of jumping out of the water whenever they are startled which has actually caused injuries to a few people. The image below shows how violent this habit can be.

The surprising thing about the Hammerhead Flatworms in France is that gardeners in southern France have been telling the ‘smart’ professional biologists about the flatworms for a couple of decades but the professionals weren’t really listening. Yes, the scientists admitted, some of these animals could hitch a ride on shipments of vegetables and fruit from south Asia but they couldn’t survive in France’s colder climate. This is one actual case where the professional scientists should have paid more attention to the ordinary, average person.

And the Hammerhead Flatworms are more than a slight embarrassment, they do real damage. You see the native segmented worms are responsible for a lot of the aeration and mixing of the soil we use for agriculture. Studies have shown that fields without earthworms are as much as 10% less productive.

Since the Hammerhead Flatworms can quickly decimate the earthworm population in an area we could be dealing with a very big problem. Any program to eradicate the flatworms would be very expensive and would probably still have little effect. Scientists are at least now determined to keep a closer watch on these creatures to see how quickly and how far they spread along with getting a better idea of the damage they do.

We like to think that we rule this world and take advantage of other creature for our purposes but the Hammerhead Flatworms are just one more example of how other species can sometimes take advantage of us for their purposes.

Astronomers declare Asteroid near Jupiter to be an Interstellar Immigrant.

It was only last October that astronomers discovered the first known interstellar visitor to our Solar System. (See my post of 4Nov17) The asteroid, which was discovered by the Panoramic Survey Telescope and Rapid Response System or Pan-STARRS telescope in Hawaii, was moving much too fast for the Sun’s gravity to keep it in a permanent orbit so it must have come from interstellar space and only spent a short period of time going around our Sun.

Astronomers named the asteroid Oumuamua, Hawaiian for scout, and we learned quite a lot about it in the few months Oumuamua was close enough to study. Astronomers found the composition of Oumuamua was like that of an iron-nickel meteorite than a dirty snowball like a comet. They also discovered that Oumuamua possessed a very unusual cigar shape being at least ten times longer than it was wide. The image below is an artist’s impression of Oumuamua.

The Interstellar Visitor Oumuamua (Credit: Space.com)

Now the astronomers at Pan-STARRS have discovered another asteroid that, while it is a permanent member of our Solar System, its orbit is so strange that it may not be an original member. Orbital simulations suggest that it could be an interstellar immigrant.

The new find hasn’t been given a name yet so I’ll be using its astronomical designation, which is 2015 BZ509. Now 2015 BZ509 orbits the Sun with a semi-major axis (Average distance) only slightly less than that of Jupiter. The most unusual thing about its orbit however is that 2015 BZ509 orbits in the opposite direction of nearly every other object in the Solar System. It has what is called retrograde motion. The image below shows a telescopic view of 2015 BZ509, it’s in the yellow circle.

Two pictures of the Asteroid 2015 BZ509, in yellow circle (Credit: Los Angeles Times)

To understand what retrograde means let’s imagine ourselves looking down on the Solar System from the Sun’s north pole (which happens to correspond to Earth’s north pole). Looking at the image below of the inner Solar System ( the whole thing is too big to really illustrate my point), the orbits of the planets, the spin of the Sun and the spins of all of the planets, even the motions of the major moons all go counterclockwise. The reason for this is simple; the original gas and dust cloud that formed our Solar System must have had a counterclockwise spin and so the Sun, the planets and all of the moons shared that counterclockwise motion.

The Inner Solar System (Credit: University of Rochester)

Objects that orbit in a clockwise motion are very rare, but not completely unknown. There is an entire class of objects known as Centaurs who orbit the Sun between the orbits of the gas giant planets (Jupiter, Saturn, Uranus and Neptune). This small number of asteroids are of great interest to astronomers simply because of their unusual orbits and astronomers have done an enormous amount of computer modeling trying to understand how those asteroids got those orbits. What they found was that the powerful gravity of the gas giants could capture an object out of the Ort cloud and an object so captured could on occasion wind up going the wrong way. Astronomers also found that such orbits are unstable, lasting less than 100 million years. The image below shows a few of the crazy orbits of the Centaur asteroids.

Centaur asteroid Orbits (Credit: Nick Fiorenza, Lunar Planner.com)

2015 BZ509 isn’t a Centaur however, it’s not between two gas giants its in an orbit very similar to Jupiter’s only backward. And when researchers F. Namouni of the Universite Cote d’Azur in Nice France and M. H. M. Morais of the Universidade Estadual Paulista in Sao Paulo Brazil carried out one million simulations of the orbit of 2015 BZ509 they found that its orbit was stable going back to the very beginning of our Solar System four and a half billion years ago.

So if 2015 BZ509 has been sitting around Jupiter pretty much since the formation of Jupiter and the other planets how did it get its backwards orbit. Doctors Namouni and Morais theorize that, back when the Solar System was very young and we were a part of a star cluster like the Pleiades or the Orion nebula 2015 BZ509 could have been grabbed from another star system that was also in the process of formation.

Personally I think that claiming that 2015 BZ509 is interstellar in origin just because it has a very unusual, but nevertheless stable orbit is a bit of a stretch. I want to see some more evidence, and I expect I’ll get my wish as astronomers continue to study this fascinating object.

P.S. Orbital dynamics isn’t my forte but I do know how to calculate the difference between the specific energy of an object (that’s the energy per kilogram of mass) between being free of the Sun’s gravity and being captured at Jupiter’s orbit. I calculate that 2015 BZ509 would have to have somehow lost 85 million Joules of energy for every kilogram of its mass if it is an interstellar immigrant. That’s lot so you can see why I’m more than a little doubtful!

The Coriolis “Force”, it’s what makes Hurricanes, Tornadoes and the water in your Toilet spin.

Did you ever take a ride on a Merry-Go-Round with a friend and while the ride was spinning you tried to toss something, let’s say a piece of candy to them? Well I bet the candy took off in a sharp turn and you missed by a mile! You’re left with a surprised look on your face as the candy flies off as if it had a mind of its own!

Think about it, because of the motion of the Merry-Go-Round both you and your friend are moving in a circle! That means that by the time the candy gets to where your friend was when you threw it, they’re not there anymore! And because of the circular motion of the Carousel your candy appears to you to take a sharp turn in the opposite direction of the spin of the Merry-Go-Round! Click on the link below to be taken to a youtube video of a very nice demonstration of what I’m describing from a freshman physics course at MIT.

This effect is commonly known as the Coriolis “Force” although any physicist will point out that there’s really no force acting on the candy. Technically what’s happening is that you are in a rotating frame of reference, the Carousel, but once you let go of the candy it no longer is. This makes the candy’s straight line motion look to you as if it’s curved. That’s right the candy is moving in a straight line, you’re on the Merry-Go-Round, you’re the one going in a circle!

Now we all live our lives on a great big Merry-Go-Round, better known as the spinning globe of the Earth, so the coriolis effect has a major influence on many of the phenomena we see every day. (That’s right you flat Earth loonies, the Earth is a spinning globe and the phenomena I’m about to talk about are demonstrations of that fact!!!). Since the Earth’s equator is 40,000 km in circumference and the planet rotates once every 24 hours that means that a person standing on the equator is actually moving at 1666.6 kilometers per hour (40,000km / 24 hours=1666.6 kph). On the other hand someone standing at the north or south pole isn’t moving at all (relative to the center of the Earth at least) but simply turning around once every 24 hours. In between you can calculate your speed if you know your latitude using the formula:

v=1666.6 x sin(Latitude)

For example I live in Philadelphia at a latitude of 40º N so I’m moving at a speed of 1071 kph. The image below illustrates this.

Your speed due to the Earth’s spin depends on your latitude.

This difference in velocities has a major effect on our weather and to see how let’s look at how a LOW pressure system behaves. Now I hope you remember that a low pressure system is also a storm system because it pulls in and condenses moisture laden air leading to rain and strong winds.

Looking at the image below we see that a super strong Low Pressure system is sitting right over me in Philadelphia. This low is so strong it’s pulling in air all the way from the equator and the north pole. Now as I said above Philadelphia is moving at 1071 kph and so is the air above it. The air at the equator is moving much faster however, 1666 kph so when it get pulled toward the low it misses, going in front of the low, to the east. The air at the pole however is moving much slower so it misses the low to the rear, the west. The result is a counter-clockwise flow of air around the low pressure system giving hurricanes and tornados their familiar spiral shape, see image of a hurricane below. That is why you often hear your local meteorologist, in the northern hemisphere, talk about storms having a counterclockwise motion while a fair weather system has a clockwise spin.

Hurricane Irma Spinning Counter-Clockwise (Credit: National Geographic)

The mirror image of this happens in the southern hemisphere. The air from the equator still misses to the front of the low and the air from the pole misses to the rear but because the equator and pole have flipped positions, see image below, the low now has a clockwise flow. The very movements of the weather systems on Earth are due to our planet being a spinning globe.

Before I go I’ll mention one more example of the coriolis effect that you probably see several times a day, whenever you flush your toilet in fact. Think about it, isn’t all that water flowing out causing a low pressure system, and doesn’t the water spin counter-clockwise north of the equator and clockwise south of it. That’s the coriolis effect right inside your own home.

And you don’t have to be very far north or south of the equator to see the spinning. Click on the link below to be taken to a youtube video shot at the equator in Uganda. The presenter demonstrates the coriolis effect just a few feet north of, right on and a few feet south of the equator.

https://www.youtube.com/watch?v=_xqtXBnuXiA

So remember, the next time some you arguing with a flat Earth idiot just flush the toilet and tell them the spinning globe of the Earth is causing the spin in the water. Then you can flush their nonsense down the toilet as well.

The SuperCDMS Experiment and the Search for Dark Matter.

It was back in my undergraduate days (early 1980s) that the topic of Dark Matter first began to be seriously considered by astro-physicists and cosmologists. The idea that there was some kind of matter in the Universe that was for some reason invisible to our telescopes was considered as a solution to two of the biggest problems in our study of the Universe.

The first problem concerned the stability of all of the rotating spiral galaxies we were studying. The idea that the stars in the outer reaches of a galaxy, like our own sun, would orbit around the center of the galaxy made perfect sense. After all, it was just Newton’s laws of gravity at work we thought. However, when we estimated the mass a galaxy, basically counting the numbers of stars, and measured the speed at which the stars were orbiting we found that there wasn’t enough mass, the galaxies should fly apart! There had to be some mass that we weren’t seeing, some invisible matter whose gravitational attraction was holding galaxies together. See image below.

At the same time other astronomers were studying the Cosmic Microwave Background (CMB), the leftover radiation from the original big bang, and used that data to calculate how the Universe should look today. Problem was that the calculations didn’t match the reality, not based on the amount of mass we could see. In order to make the calculations work the Universe had to have about four times as much invisible matter as the matter we could see.

O’k so the Universe had a lot of matter that didn’t emit light the way normal matter did in the stars, some sort of Dark Matter. The search was on to discover just what this Dark Matter was. The astro-physicists, with some help from the high-energy physicists, came up with a lot of ideas: Cold Dark Matter, Hot Dark Matter, MACHOS (Mass Concentrations) and WIMPs (Weakly Interacting Massive Particles).

That was almost forty years ago now, and we’re still waiting for direct experimental evidence of any kind of dark matter. Oh, we’ve made some progress, everybody pretty much agrees on WIMPs as Dark matter but that doesn’t mean everybody’s right. We need good hard evidence.

Hopefully soon we’ll get some from the Super Cryogenic Dark Matter Search now under construction by the Stanford Linear Accelerator Center (SLAC) at Stanford University and which will be set up over 2000 meters underground at SNOLAB at the Vale Inco Mine in Sudbury, Canada.

Setting up sophisticated, delicate physics experiments deep down in an old mine because all of the rock above the instruments helps insulate them from the interference of cosmic ray particles. And the SuperCDMS needs to eliminate all of the interference it can, it’s trying to measure the tiny amount of energy produced when a WIMP bounces against a normal atom. The image below shows the Sudbury neutrino telescope already in operation at Sudbury.

Neutrino Telescope in Sudbury Mine (Credit: Pinterest)

Physicists calculate that such collisions are very rare, you may have to wait many trillions of trillions of years for a particular atom to experience such a collision. Rather than waiting so long physicists will use trillion of trillions of atoms and then ‘listen’, that’s right listen for the sound of any collisions. Technically the intent is to detect the minute phonon signals of the collisions with germanium crystal detectors. The image below shows one of SuperCDMS’s detectors.

But in order to ‘hear’ the sound of a WIMP hitting an atom the physicists have to eliminate as much as possible the racket caused by all of the atoms hitting each other caused by thermal vibrations and the only way to do that is to reduce the detector’s temperature down to a small fraction of a degree above absolute zero, hence Super Cryogenic Dark Matter Search.

The experimental setup is shown in the image below. The cyrostat and detector section is modular in design allowing more detectors to be installed in the future. Around the detectors is a lining of lead (Pb) shielding with water shielding around that. The entire apparatus is then mounted on seismic isolators because even the slightest outside movement could be picked up as an erroneous signal. It’s often true that in today’s physics experiments, eliminating the unwanted signals can be a bigger job than detecting the minuscule signal you’re looking for!

SuperCDMS Experimental Layout (Credit: SuperCDMS)

SuperCDMS is scheduled to be up and running by the year 2020 but it will take four or five years of data collection before any results can be announced but I’ll let you in on my opinion. Now I’ll be very happy to be proven wrong but I’ve always been skeptical of WIMPs, we’ve been looking for them for forty years and have no evidence so far. Personally I was a MACHO supporter, basically the idea here was that for every star we can see there would be dozens of smaller brown dwarfs, objects just too small to start nuclear fusion and so don’t glow, and on top of that there would be literally thousands of planetary sized objects in interstellar space. I still think we need to consider MACHOS as a possible solution to the Dark Matter problem.

Fossil Reveals First Steps in the Evolution of the Beaks of Birds.

In today’s world the taxonomic group we call birds have two unique anatomic characteristics that no other animals possess, feathers and beaks. Trying to understand how these distinct features evolved has been a goal of paleontologists since Darwin’s days.

Considerable progress has been made in the study of feathers with the discovery not only of early birds with feathers like Archaeopteryx but also of new evidence that some species of dinosaurs sported primitive feathers for insulation. The images below show archaeopteryx and a feathered T-rex (yes some paleontologists think the mighty T-rex might have been partially covered by feathers).

Archaeopteryx: Feathers and Teeth! (Credit: Independent)

T-rex with Feathers? (Credit: American Museum of Natural History)

Evidence for the evolution of the bird’s beak however is much sparser; and the development of the beak is mostly unknown. Beaks by the way are composed of bony upper and lower mandibles (jaws) that are covered by a thin later of keratin (the protein in your hair and fingernails) and which lack teeth composed of dentine. Although similar in some ways to the mouths of other vertebrates the avian beak is a structure unique to birds.

The big problem in studying the development of the beak is that usually the delicate bones making up the skull of an early bird are so squashed that little can be learned from them. One thing we were certain of however was that feathers came first; there are many fossil specimens, again like Archaeopteryx, of early birds covered with feathers but sporting a mouthful of teeth.

Now a new study, combining both recent fossil finds and a reexamination of older specimens with the latest instruments, is changing that. It started in 2014 when Kristopher Super, then an undergraduate student at Fort Hays State University in Kansas, found an almost complete fossil of the well know early bird Ichthyornis dispar encased in limestone. A transitional species between the dinosaurs and birds I. dispar was a seagull sized creature that lived between 66 and 100 million years ago.

When the find was shown to Yale Professor of Paleontology Bhart-Anjan Bhullar he suggested that instead of trying to remove the specimen from the limestone it should be scanned by computerized tomography (CT scanning). What they found led them to perform CT scans on three other fossils for conformation. There, right at the very end of a long bony jaw filled with very sharp teeth sat a tip covered in keratin, a beak. Professor Bhullar suggests that even a tiny tip of a beak may have given I. dispar a greater ability to manipulate its food and preen its feathers. Exactly the behavioral activities that modern birds use their beaks for. The image below shows a composite of the CT scans of I. dispar.

Ichthyornis CT Scan (Keratin Beak is at tip) (Credit: Science Magazine)

The scientists also found that the skull of I. dispar shared a mixture of dinosaur and bird like features, a large brain case like that of a bird along with the powerful jaw muscles of a velociraptor like dinosaur. The evidence provided by I. dispar pushes back by millions of years the development of the bird’s beak while at the same time indicating that birds may have existed for millions of years with both a partial beak and a mouthful of teeth. The image below shows an artists rendering of the head of Ichthyornis dispar.

Ichthyornis Head (Artist’s Rendering) (Credit: Science Magazine)

The first fossils of Ichthyornis were discovered in the 1870s by the US paleontologist Othniel C. Marsh, famous for his ‘Dinosaur Wars’ with Edward D. Cope. Even after almost 150 years we’re still leaning more about these amazing dino-birds.