Medical researchers are studying the effectiveness of Face Masks in reducing the spread of Covid-19.

The infectious disease Cov-19 continues to spread around the world taking an ever increasing toll of lives and suffering. Here in the United States the daily numbers of new cases is at its highest level ever while the daily death numbers are not far behind.

The Spread of Covid-19 across the US as of 14July2020. Not a pretty Picture. (Credit: CNN, Johns Hopkins University)

Without an effective vaccine to combat this disease the only tools we have to control the spread, to reduce the number of people getting sick are our own personal habits. We must change the way we live if we all hope to survive this deadly pandemic.

Now Cov-19 is a respiratory virus, it kills by getting into the lungs and destroying the fragile tissue with which we breathe. It spreads through the air, as an infected person coughs or even talks droplets of water are injected into the air, droplets containing the virus. Anyone breathing in one of those droplets is then likely to become infected, passing the virus on to others in turn.

The Coronovirus Covid-19. Although most deadly as a respiratory disease recent studies have provided evidence that Covid-19 can attack every organ in our body! (Credit: The Baton Rouge Clinic)

The Covid-19 virus is in fact so contagious that under normal living conditions one infected person on average will infect about six other people. Those six will then infect 36 who will then infect 216 in their turn and so on. You can see just how rapidly this virus will spread unless we somehow reduce its ability to infect new victims. And to do that we need to change the way we live.

The growth of an infectious disease in a population is governed by the infection rate ‘r’, shown here for a value of r=3. (Credit: James Holland Jones, Stanford University)

The best way to avoid becoming infected is to stay home, simply avoiding other people. Of Course that’s not really possible, even someone who is retired as I am still has to go out occasionally in order to buy food while for most people work is still a daily necessity. Therefore all of us must learn to practice habits that will reduce if not eliminate the chance of transmission of Covis-19. And recent studies have now clearly demonstrated that properly wearing a good face mask is the most effective tool we have to stop that spread when we are outside our homes.

Wearing a face mask when in public will greatly reduce the spread of Covid-19, and you can use it to show off your individuality! (Credit: New York Times)

Proper wearing of a facemask simply requires that the mask should cover both the wearer’s mouth and nose and that the material of the mask should fit snuggly against the face. What constitutes a good effective mask is more difficult to determine owning to the great variety of styles and materials that are being used to manufacture masks for fighting Covis-19.

Without any facial covering a cough can travel more than 3 meters infecting everyone it touches. (Credit: Florida Atlantic University)

To try to pinpoint some of the factors that make a facemask more effect researchers at Florida Atlantic University have been conducting a series of tests to evaluate the ability of different mask styles to prevent the spread of those virus containing droplets. As a test ‘subject’ the scientists modified the head of a manikin with a manual pump and smoke generator. By activating the pump a ‘cough’ was simulated producing droplets that traveled more than two and a half meters from the manikin’s head. This setup was then used to measure to what degree various masks succeeded in reducing the travel distance of the droplets.

Testing simple forms of masks such as a bandanna wrapped around the face or a handkerchief held up to the face it was found that the distance the droplets traveled was reduced to one meter for the bandanna and a half meter for the handkerchief. Closer fitting masks were found to perform much better with a cone shaped mask reducing the distance to 20cm while the best of all performance came from a stitched-quilted mask that reduced the spread to only 8cm. Basically it all comes down to a nice tight fit around the nose and mouth, the tighter the better.

Even a simple Bandanna worn around the face reduces the spread by more than half. (Credit: Florida Atlantic University)
A close fitting mask, such as this cone mask, greatly reduces the distance the cough droplets travel greatly reducing the risk of infection. (Credit: Florida Atlantic University)

The material that the mask is composed of can also make a big difference as scientists at the National Institute of Standards discovered. Testing the ability of a variety of materials to filter out the droplets, while still allowing air to get through so that the wearer can breathe, the researchers discovered a considerable difference in performance. Artificial fibers in particular performed very badly while the best performance came from multi-layered, tightly woven cotton cloth.

Masks made of close woven cotton fibers has been shown to be best at filtering out the virus laden droplets. (Credit: Phys.org)

Based upon these studies it’s clear to see that the best performing mask for the general public would be a close-fitting mask made from several layers of tightly woven, in others words high thread count cotton. In fact epidemiologists estimate that the spread of Covid-19 could be reduced by as much as 80% if everyone wore such a mask whenever they went out in public. That means that instead of one infected person infecting six others they would on average only infect a little more than one person, simply by wearing a mask.

Workers wearing face masks while making face masks! Long periods of time spent in close quarters demands the wearing of masks! (Credit: CNBC.com)

Which makes you wonder why, in the face of all of these facts has the wearing of masks become a political issue? How is it possible that some people are suing their government leaders and health officials on the grounds that requiring people to wear a mask is a violation of their constitutional rights? Are there really people foolish enough to fight for the right to get sick and possibly die?

No it’s not! A face mask is the best way of protecting your life and the life of your family. In this pandemic it is the only way we have of getting our economy working again. (Credit: Today Show)

The virus hasn’t read the Constitution; it isn’t capable of understanding the concept of civil rights. All that the virus is capable of doing is spreading from one person to another, making many of us sick while killing a few percent unless we take the necessary steps to stop it.

This isn’t a hoax; it isn’t an attempt to impose an authoritarian regime on freedom loving Americans. This is a disease, an old fashioned infectious disease like the Black Death, or cholera, or yellow fever, diseases that we fought with public health measures before we had any modern drugs or vaccines. As the virus spreads, as the case numbers in the US set new records everyday we truly are all in this together and only by working together sensibly can we get through this pandemic without a devastating amount of damage to our country.

During the Middle Ages people understood the destructive power of infectious diseases. Have we lost their hard won wisdom! (Credit: EarthSky)

Collective Intelligence: Some species of animals have learned how to put their heads together in order to solve problems that no individual member can solve by themselves.

‘Let’s put our heads together and see if we can’t come up with a solution,’ is a very human method of coming together, tossing out ideas and taking advantage of multiple points of view in an effort to solve very difficult problems. This idea of ‘Collective Intelligence’ is something uniquely human, one of the greatest advantages that we have over the mere animals with which we share our world.

Our ability to communicate ideas effectively makes us as a group smarter than any individual! (Credit: Istock)

Or maybe not! Turns out that there are many known cases of animals who work collectively in order to survive the dangers and difficulties life throws at them. Consider the prairie dog, a species of squirrel that inhabit the treeless plains of central North America and who live in ‘towns’ that can number several hundred individuals.

Just a small part of a typical prairie dog town. (Credit: Pinterest)

Whenever the town’s inhabitants go out to forage for food several of the older adults position themselves around the group standing watch, keeping an eye out for predators instead of finding food for themselves. Whenever a threat is detected the guards will sound the alarum, a series of calls so sophisticated not only do the other prairie dogs know whether the menace is coming from the ground, a coyote, or the air, an eagle, but the calls tell them from what direction! In fact the whole prairie dog system is so well arranged that those adults who are feeding know when it is their turn to stand watch so that their fellows who have been on guard duty can grab a bite. Numerous other examples in nature can be cited and now naturalists have uncovered another, similar type of collective intelligence in animals that are individually much less intelligent than a prairie dog.

Prairie Dog ob guard duty, center, signaling the approach of danger! (Credit: Treehugger)

It’s well known that ant colonies send out forager ants to search for sources of food. These foragers lay down a sent trail as they search both to enable them to find their way home but also to enable the other ants in the colony to find the food source they’ve discovered. Once the forger has alerted the colony to the presence of the food an entire army of worker ants will follow the sent trail and begin the process of bringing the food back to the nest.

If you ever spot a single ant far from its colony it’s probably a forger ant searching for a food supply. (Credit: EurekAlert)

What if however, something should happen to destroy the sent trail, a branch of a tree could fall across it or you might actually step on it. In that case, how do the ants find their way back home? Now naturalists at the Weizmann Institute of Science in Israel have set up an experiment in the lab to study just how, and how well ants solve such dilemmas. As Aviram Gelblum the lead author of the study put it. “We addressed this question by studying the cooperative transport of ants as they attempted to transport large loads through semi-natural environments.”

Using Longhorn crazy ants as their test subjects the researchers set up a labyrinth using cubes of the same size randomly spread across a surface separating the ant’s nest from a food source. The cubes were used to block the ant’s direct path home and force them into searching for an alternate route. The movements of the ants were tracked by image processing and compared to a computer program that mimicked a random walk in the direction of the nest.

By making the food source an object to large to move easily through the maze the researchers forced the ants to find a new path home, other than the one they took to find the food. (Credit: Aviram Gelblum et al)
Test setup used in Weizmann Institute experiment to test ant navigation. The random setting of the blocks made it impossible for the ants to return with the food to their nest by a straight line. (Credit: Aviram Gelblum et al)

What the biologists found was that the ants consistently outperformed the random method, and they did so by cooperating. You see in addition to the large number of worker ants who are carrying the loads there are a smaller number of leader ants who fan out from the column as far as a maximum distance of 10cm.

When faced with a blocked path the leader ants act as scouts searching for possible alternative paths and then coordinate with each other to steer the worker ants into the new chosen path. This process is repeated until the obstacle has been bypassed and the way back to the nest is clear. Having the leaders acting as scouts at a distance from the main group allowed the ants as a whole to significantly reduce the time spent searching for another way back home when their original path becomes blocked.

By putting our heads together in order to solve problems we humans have succeeded in building our civilizations. It’s hardly surprising therefore that other animals have also discovered the advantages of collective intelligence.

Invasive Species Alert: The Spotted Lanternfly is spreading throughout the Mid-Atlantic United States and a look back at the Japanese Beetle.

One of the most profound impacts that our human civilization has had upon the natural world is in the creation of ‘Invasive Species’. In brief, an invasive species is a species of animal or plant that we humans have transported from one part of the world to another, sometimes deliberately but more often by accident. Having no natural enemies in its new environment the invasive species spreads rapidly causing destruction to, if not actually displacing native species.

Rabbits in Australia are a well known example of animals that were deliberately brought from Europe to be raised for food by the early British colonists. A few animals managed to escape and found the local environment to their liking. Breeding like rabbits they quickly became an enormous problem that Australians are still unable to completely control.

Brought to Australia by early European settlers the rabbit population is now completely out of control no matter how many the Australians kill. (Credit: Full Spectrum Biology)

Having this example, and many others to learn from, today the intentional transportation of species from one part of the world to another is only allowed after careful consideration of the possible environmental consequences. Still, even as we humans have learned not to intentionally cause invasive species the growth of international, intercontinental travel and trade has led to a tremendous increase in the number of accidental invasive species.

The world has become a much smaller place the last 100 years, not only for we humans but for those species who hitchhike along for the ride! (Credit: eTurboNews)

The Spotted Lanternfly, Lycorma delicatula, is native to Southern China, Vietnam, Thailand and India where it feeds primarily on Chinese Sumac along with grape vines and stone fruit trees such as peaches. In its natural environment the spotted lanternfly’s population is kept in check by its natural predators and diseases. In its own home the L delicatula was an agricultural pest, but not a terrible one.

The Adult Spotted Lanternfly. Looks rather harmless, actually quite pretty but by the millions they can cause tremendous destruction and without any predators they are spreading rapidly throughout the NE USA. (Rutgers NJAES – Rutgers University)

Like most species of insect that live for only one year the spotted lanternfly hatches as a nymph from an egg in late April to early May. As a nymph the spotted lanternfly goes through several stages known as instars. The first instar is black with white spots and bites into the stem of its host plant in order to suck at the plant’s sap for nourishment. Later instar stages add red spots to the white. The adults with their distinctive wings can appear as early as July and will mate and lay their eggs in September.

The first Instar nymph stage of the spotted lanternfly. They can’t fly but they can certainly jump! (Credit: R. A. Lawler)
The second Instar stage. At this stage the nymph is also nearly twice as large. (Credit: R. A. Lawler)

It was in September of 2014 that the spotted lanternfly first appeared suddenly in Berks county Pennsylvania. How it got to that mostly rural part of Pennsylvania is unknown but the eggs of L delicatula are small, laid in egg masses of 30-50, and will stick to almost any smooth, hard vertical surface, even the metal of a motor vehicle.

Egg masses for the spotted lanternfly. If you see any of these destroy them! (Credit: UC ANR)

However it got here, with no predators to control it, the spotted lanternfly has now spread to New Jersey, Delaware, eastern Maryland and Virginia. Already L delicatula has caused an appreciable amount of damage to the wine and fruit industries in the Mid-Atlantic States and will without doubt become even more of a pest in the years to come.

I first spotted some L delicatula nymphs in my garden just a few days ago feeding on a wild grape vine growing along my back fence. So far they haven’t infested any of my vegetables, the insect typically doesn’t attack plants like tomato, potatoes or peppers but you can be certain I’ll be keeping a close watch on my raspberry bushes.

This invasion of the spotted lanternfly reminds me a great deal of the infestation of Japanese Beetles, Popillia japonica, that caused so much damage when I was young back in the 1960s. Like L delicatula the Japanese Beetle somehow got to America, the first discovery was way back in 1916 in New Jersey. Since that time P japonica has spread across the country so that now only nine western states are considered free of it.

The Japanese Beetle. Again it’s actually an attractive little bug, in small numbers. Sixty years ago the damage it did was tremendous. (Credit: Wikipedia)

Like the Spotted Lanternfly the P japonica is only a minor pest in its natural environment, natural predators and parasites keep its population under control. Here in North America however the insect bred uncontrollably causing an enormous amount of destruction to a wide variety of plant species.

As a boy my mother kept a fair sized rose garden that she was very proud of. In fact just about every lady on our block had a half dozen or more rose bushes that they tended. So to the ladies of my street the Japanese Beetle was an utter disaster. It became my job every day to pick off all of the beetles that I could find from every rose bush. On some days I filled up a small jelly jar with the pests there were so many of them. In exchange for my efforts each of my neighbors gave me a nickel, hey, when you’re six or seven 25¢ every day was a lot of money.

This is the way I remember Japanese Beetles, a half dozen or more eating a rose flower. (Credit: The Denver Post)

The good news is that by around 1970 the Japanese beetle population began to plummet, some of the local birds and other animals realized that Japanese beetles were tasty and with so many around they represented a lot of food. With some local predators to control their population the threat of Japanese Beetles quickly diminished.

Today Japanese Beetles are actually rare in eastern Pennsylvania; it’s been three years since I last saw one. In the long run this is true of every invasive species, eventually they just become part of their new environment, it’s just a question of how much damage will they do before then. The same thing will happen to the Spotted Lanternfly, someday some species will begin to prey on them and they will become less of a threat, hopefully sooner rather than later.

Hopefully before long some birds like this Warbler will learn to start eating the spotted lanternfly! (Credit: Bird Watcher’s Digest)

It’s too bad we can’t just tell a few species of bird, hey, eat these things, they’re good!

Book Review: First Encounter (Ascension Wars Book 1) by Jasper T. Scott.

At the beginning of ‘First Encounter’ by Jasper T Scott we meet the starship Forerunner as it is approaching its destination, the Trappist star system. It’s the year 2150 AD and humanity has begun the exploration and settlement of other star systems. Forerunner is in fact a colony ship with over a thousand would be pioneers ready to begin the work of building a new world on Trappist-E, one of the planets within the habitable zone of the star Trappist.

Cover of ‘First Encounter’ by Jasper T. Scott. (Credit: Amazon.com)

Forerunner is a sleeper ship; its passengers and most of its crew have been in hibernation for most of the ninety-year long journey from Earth. Now that their goal is in sight the entire crew has been awakened, including the ship’s captain Clayton Cross and are preparing for their first landing.

Jasper T. Scott author of ‘First Encounter’. (Credit: Book Bub)

Once the ship enters orbit around Trappist-E Captain Cross organizes a landing party that quickly descends to the planet’s surface. Aware of the possibility of encountering alien life, perhaps even intelligent life the landing party also includes an ambassador Richard Morgan who will take charge of any interactions with intelligent aliens.

In fact almost as soon as the landing party has left their shuttle they encounter a species of primitive aliens who immediately attack them. The landing party, not wishing to turn this first encounter into a battle retreat back to the shuttle but are forced to kill several of the aliens along the way.

But what the Forerunner crew are not aware of is that they are also under attack by a second species of aliens, a species with a superior technology. The landing party is barely able to return to their ship before the Forerunner must flee the entire Trappist star system to avoid a battle against an alien fleet.

At a distance of 40 light years and having seven known planets, three is the habitable zone, the Trappist star system is a logical choice for the location of humanity’s first encounter with alien intelligence. (Credit: Space.com)

That’s just the first quarter of the book, the middle half of ‘First Encounter’ consists of variations on the movies ‘Alien’ and ‘Predator’ with a bit of the original ‘Star Wars’ or perhaps ‘Battlestar Galactica’ thrown in at the end. And remember this is only Book 1 of Ascension Wars. It’s all just a bit too much of a roller coaster ride, too much action without a great deal of reason behind the action.

Don’t get me wrong, ‘First Encounter’ will keep your attention and it’s certainly a quick read, I finished it in less than two days. However one of the reasons it’s such an easy read is that there’s not a lot to think about, you’re too busy going from one slam, bam episode to another. In fact ‘First Encounter’ is rather a lot like several episodes of an old SF serial like Buck Rodgers.

The old Buck Rodgers serials had slam, bam action galore, and they were certainly entertaining. (Credit: Bleeding Cool)

And like Buck Rogers you soon find yourself trying to guess what’s going to happen next, and too often getting it right. And like Buck Rodgers there are a few plot problems getting in the way. For example, the superior aliens have faster than light travel, their ships can travel one light year in two hours, but they don’t come to Earth. Instead they wait for Forerunner to take ninety years to reach the Trappist system before starting their war with humanity!

“Occupied Earth’ is the second book in the series begun with ‘First Encounter’. I think the title pretty much says it all. (Credit: Amazon.com)

So if you’re looking for a ‘Space Opera’ with a lot of shoot’em up action then you’ll probably like ‘First Encounter’ by Jasper T. Scott. However I like my SF a little more thoughtful, a little more awe inspiring than heart pounding.

After having made the first flybys of Pluto and the Kuiper Belt object Arrokoth the New Horizons space probe is now being used by astronomers to help them measure the distances to nearby stars.

The most difficult, and therefore most important measurement that astronomers try to make of the many objects in our sky is distance. Think about it, how would you, without the help of an astronomer or other scientist, measure the distance to the Moon, the very closest neighbor to our Earth?

The Earth Moon Distance is enormous, and the Moon is our closest neighbor in space. (Credit: ZME science)

Well the way astronomers first measured the distance to the Moon, and the nearby planets Venus and Mars, is called parallax and it’s a technique that you’re very familiar with whether you know it or not. You see parallax is the way that you judge distances using your two eyes.

Did you ever stick one of your fingers up in front of you face and close one eye. Then, by switching back and forth between your two eyes, one at a time, your finger seems to move against the background of more distant objects. That’s parallax, and by simple use of trigonometry you can use that apparent movement to measure the distance to your finger.

The difference in viewpoint between our two eyes enables us to judge the distance to close objects. This is also known as depth perception. (Credit: The Parallax Perspective)

Of course as objects get further away the apparent movement becomes smaller, more difficult to measure accurately. Conversely if the baseline, that is the distance between the two observation points, is made wider the apparent movement is increased making it easier to accurately measure the apparent movement. Therefore astronomers want the widest possible baseline in order to measure the greatest possible distances.

To judge the distance to distant targets the military developed rage finding spotter scopes that widen the baseline of our eyes. (Credit: Wikipedia)

It was the early Greeks who first recognized now parallax could be used to the measure distances to astronomical objects and indeed it was a Greek mathematician named Hipparchus who used the width of the Earth itself as his baseline in order to estimate that the Moon’s distance was about 60 times the Earth’s radius. That works out to be about 380,000 kilometers, so he was pretty accurate.

How Hipparchus first determined the distance to the Moon using parallax. (Credit: www.spof.gsfc.nasa.gov)

Still, even using the entire width of the Earth as a baseline the angle formed by the Moon is only about two degrees while that for Venus or Mars at their closest is only about one second of arc. One second of arc is a very small angle but using their telescopes astronomers can measure it and by doing so they could accurately find the distances across our Solar System.

Once astronomers had all of the distances within our Solar System they realized that they now had a newer, much bigger baseline from which to measure the distances to the stars themselves, Earth’s orbit around the Sun. You see if you measure the position of what you think is a nearby star against stars that you think are much further away in June, and then make the same measurement six months later in December the Earth will be on the other side of the Sun from where you made the first measurement. In that way your baseline will be the diameter of Earth’s orbit, about 150,000,000 kilometers. Using this new baseline in 1838 the astronomer Friedrich Bessel made the first measurement of the distance to a star, the star 61 Cygni at a distance of about 105 Trillion kilometers or 11.2 light years.

Astronomers use measurements of a nearby star’s position six months apart in order to measure its distance. (Credit: www.astronomy.ohio-state.edu)

Using Earth’s orbit as their baseline, and with the newest telescopes, including the Hubble Space Telescope, astronomers are now able to accurately measure the distances to stars as far away as 10,000 light years. Even with those powerful telescopes however astronomers would still like to be able to extend that baseline farther. To somehow get a telescope well beyond Earth’s orbit.

NASA has begun experimenting with just that using the camera on board the New Horizons space probe, currently 40 times further from the Sun than the Earth is. Therefore using New Horizons as one observation point and a telescope here on Earth as the other would give a baseline of more than 6 billion kilometers, more than 40 times that possible using only telescopes here on Earth.

The New Horizons space probe has visited the most distant object yet, Arrokoth. Because NASA hopes it may still visit an even further object its cameras are still working, unlike the cameras on the two Voyager space probes. (Credit: The Guardian)

On April 22-23 of this year the scientists controlling New Horizons commanded the spacecraft to photograph the areas of the sky containing two of the nearest stars, Proxima Centauri and Wolf 359. Those images were then compared to images of the same regions taken by an Earth bound telescope and the effect of parallax was immediately clear.

Comparing images of Proxima Centauri taken by New Horizons (l) and an Earth bound telescope the parallax of the star is obvious. (Credit: Room The Space Journal -EU.com)

Now the camera onboard New Horizons is neither powerful enough nor accurate enough to be used to make more accurate measurements than the more powerful Earth bound telescopes. This was just an experiment on NASA’s part. It is worth considering however, that if the Hubble space telescope could somehow be placed where New Horizons currently is a combination of it and an Earthbound telescope using parallax would allow astronomers to completely and accurately measure the distance to objects as far away as 400,000 light years.

If Hubble were where New Horizons currently is astronomers could map our entire galaxy using parallax. (Credit: ABC News)

Perhaps in the near future NASA may consider just such a mission. Consider a smaller version of Hubble; say with a one-meter diameter mirror instead of Hubble’s 2.5-meter diameter but a telescope with the same focal length and stability as Hubble. Using flybys of Jupiter and Neptune such a telescope could be placed into an orbit around the Sun beyond Neptune’s where it would be in position to allow astronomers to finally obtain a complete and accurate 3D map of our entire galaxy.

I’ll bet you there’s someone at NASA working up a design right now!

Two interesting examples of how the latest in technology is enabling archaeologists to learn more about some of humanity’s oldest settlements.

In the early days of archaeology the only way that an archaeologist could be certain whether or not a potential site was worth excavating was to actually start digging. Even finding a few coins or broken pieces of pottery on the surface only gave a general idea of where more artifacts might lay buried. Many days, weeks and even months could be wasted in fruitless digging just ten or twenty meters away from major discoveries.

When archaeologist Heinrich Schliemann went searching for the ruins of Troy all he had to go on were local stories about where the city lay buried. He got lucky but destroyed much of what he was looking for in his blind attempts at excavation. (Credit: Magnolia Box)

Enter modern technology, in particular the development of Ground Penetrating Radar (GPR). Like the better known version of radar used to locate and track objects in the sky GPR transmits a pulse of electromagnet (EM) energy and then receives the echoes that bounce back from any objects that are struck by the pulse. Of course the difference is that in GPR the pulses are aimed into the ground and are capable of not only detecting objects hidden in the soil but also changes in the material of the soil, say from loose sand to denser clay, or from soil to a buried stone wall.

Principle of Ground Penetrating Radar. (Credit: KCI Technologies)

GPR is not without its problems, for example wet clay readily absorbs the EM energy limiting the depth in which anything might be found. Also, since a GPR set must be dragged across the ground, rocky, uneven terrain makes using GPR difficult. In addition, GPR cannot always distinguish between natural or man-made objects that are buried in the ground, in order to be certain you often have to dig it up.

In spite of these drawbacks GPR is being employed more and more often in the earliest stages of an archaeological expedition. In fact a recent archaeological survey has gone further than ever before in exploiting the capabilities of GPR. A team of archaeologists from the University of Cambridge in the UK and Ghent University in Belgium has succeeded in mapping the entirety of an ancient Roman town using GPR.

Located just a short distance north of Rome the ancient town of Falerii Novi was a typical walled Roman town some 75 acres in size. During its heyday in the second and third centuries BCE Falerii Novi had a population of between two or three thousand people. Such a large site would require many years to excavate using traditional techniques so instead the decision was made to use GPR in order to locate the most interesting areas within the town.

Ground Penetrating Radar image of Falerii Novi superimposed on an aerial photograph of its actual location. (Credit: Archaeology Magazine)

Several factors combined in making the Falerii Novi a good choice for the first such extensive use of GPR. The terrain at the location where the small town was known to have existed was smooth and flat over a wide area while the composition of the soil was nice and sandy.

The full map of Falerii Novi required the collection of over seventy million readings with the GPR and a total of 28.68 billion data points. Thanks to that full map however the archaeologists have been able to locate many of the town’s important structures such as the local temple as well as the marketplace and a possible Roman bath.

GPR image of what is presumed to be the ancient Temple at Falerii Novi. (Credit: Archaeology Wiki)

By allowing archaeologists to quickly locate those areas of a site that are most promising for excavation Ground Penetrating Radar has become one of the most useful instruments in the archaeologist’s toolbox. But if GPR helps archaeologists locate where in space the artifacts they are searching for may be found they require other hi-tech tools in order to locate what period in time those same artifacts come from. Two of the most important and accurate techniques that archaeologists use to determine the dates of the ancient sites they study are carbon-14 and tree ring dating, formally known as dendrochronology. Now, for the first time these two techniques have been combined to precisely date the building of one of the most mysterious ancient sites known.

How the tree rings from different, in some cases ancient trees can be used to date archaeological sites. (Credit: Archaeology Magazine)

The deserted clay walled city of Por-Bajin is situated on an island in a lake in the Siberian region of Russia not far north of the border with Mongolia. Despite being in the middle of one of the most arid and least populated places on Earth the grassy steppes of central Asia are dotted with the ruins of cities like Por-Bajin that sprang up seemingly out of nowhere, flourished for a century or two and then fell into obscurity. Many, but not all of these ‘ghost towns’ were associated with the famous ‘Silk Road’ the trail of caravans that connected the Middle East with China for more than a thousand years.

The Silk Road was a series of caravan routes connecting Europe with China. Because of the wealth that flowed along that road many now forgotten cities and kingdoms flourished for a few centuries before vanishing into history. (Credit: Chinasage)

Based upon earlier expeditions by Russian archaeologists Por-Bajin was thought to have been built during the 8th century by the ethnic Uyghurs. If these estimates were true the question was then whether the founder of Por-Bajin was the great Uyghur Khan Moyanchur or his successor Bögü. In either case not long after its founding there is evidence that Por-Bajin became a monastery of the eastern ‘Manichaean’ version of Christianity. Then, after only about a century of occupation Por-Bajin suffered a devastating earthquake that caused a collapse of the southern and eastern walls and triggered a fire that destroyed most of the city’s buildings. The site was abandoned shortly after that although some investigators have speculated that Por-Bajin was actually deserted before the earthquake and point to the almost total lack of artifacts or provisions found there as evidence that the site was in fact empty when the earthquake struck.

The ruined city of Por-Bajin. Built in the 700s and abandoned less than a century later it had remained virtually untouched for more the 1200 years. (Credit: SciTechDaily)

Previous dating of the site by the Carbon-14 technique had given a date in the latter half of the 8th century; see my post of June 20th, 2018 for a description of Carbon-14 dating. But now a new study from the Center for Isotope Research at the University of Groningen in the Netherlands along with Lomonosov Moscow University in Russia have combined Carbon-14 dating with tree ring data from other areas of the world to give a much more precise dating for the founding of Por-Bajin.

A more distant view of Por-Bajin giving a better idea of how isolated the site is. (Credit: Amusing Planet)

Normally the use of tree rings to date archaeological sites requires that the wood from a particular site be compared to tree rings from wood at an already reliably dated site within the same climate so that the widths of the tree rings can be matched up, see my post of April 18th, 2020 for a description of using dendrochronology to date archaeological sites. Unfortunately the wood from Por-Bajin could not be easily compared to any known useful set of already dated tree rings however.

However the Archaeologists succeeded in finding one tree ring that possessed a spike of carbon-14, a spike that had been recognized in 2013 as existing in tree rings from wood around the world and was reliably dated to the year 775. Based upon the discovery of the spike in wood from Por-Bajin the archaeologists can now definitely say that the founding of the city took place in the year 777 CE, a date that eliminates Khan Moyanchur as it’s possible builder.

Thanks to the combining of Carbon-14 dating and Dendrochronology. Historians now know exactly when and by whom Por-Bajin was built. This will give them a much better chance of figuring out why it was built. (Credit: PNAS)

So by combining their dating methods the scientists had been able to definitively answer a question that had been a mystery for over a thousand years. Por-Bajin may be the first time that archaeologists have combined the two dating techniques of Carbon-14 and Tree Rings but you can be certain that it won’t be the last. Together with Ground Penetrating Radar and the other hi-tech instruments now being employed at ancient dig sites these new tools will enable archaeologists to better understand the history of all of our cultures.

We’ve sent a space probes to photograph the surface of every planet and the Voyagers are now exploring interstellar space, but we still know so little about what our own planet is like just beneath our feet.

When I was growing up I occasionally heard a remark that scientists knew more about the surface of the Moon or Mars than they did about the inside of our own planet. Back then all we really knew about the deep interior of our Earth was that the pressure just keep getting greater as you went down simply because of the weight of all of the rock above you. At the same time the temperature got hotter and hotter because of all of the heat generated by the radioactive elements down there.

Back around 1960 this was literally about all we knew about the interior of the Earth. (Credit: ProProfs)

By studying the seismic waves generated through earthquakes scientists knew that deep within the Earth, about 5500 kilometers down, there was a liquid core because certain kinds of waves, called shear waves, will not go through a liquid. We also knew that above the core there was a quasi-plastic region called the mantel composed of rock under enormous pressure. Finally on top, where we lived there was the crust only about ten kilometers thick, made of the kind of rock that we’re all familiar with.

Geologists study the waves generated by Earthquakes to learn about the Earth’s interior. The S waves (Shear Waves) will not go through the core because it is liquid however the P waves (Pressure Waves) will. (Credit: Views of the Solar System)

Then, during the late 1960s and 70s the science of geology underwent a revolution as the controversial theory of ‘Continental Drift’ was proven to be correct and became the basis for the modern model of ‘Plate Tectonics’. The idea that Earth’s outer, solid crust is actually broken into a number of large plates that floated on top of the planet’s quasi-plastic mantel carrying the continents with them explained so much.

First proposed by Alfred Wegener in 1912, the theory of Continental Drift was largely discounted because geologists couldn’t imagine how a continent could move. (Credit: Earth How)

According to plate tectonics, earthquake fault lines, volcanoes and even the process of mountain building were found to take place in regions where two plates were either banging into each other or spreading further apart. Nevertheless, despite its success plate tectonics still only broadly describes the processes in the top one hundred kilometers or so of the Earth.

Plate Tectonics incorporates Continental Drift by recognizing that the Earth’s crust is broken into pieces that flat upon the quasi-plastic Mantel. (Credit: National Park Service)

We had little detail about conditions and processes deep within our planet, after all the deepest well ever drilled was only 12.2 kilometers deep. How could we know anything about what’s below that? Are the Earth’s liquid core and mantel uniform, is there anything like structure down there. We just didn’t know.

Until now that is. Using the latest in machine learning software a team of geophysicists from the University of Maryland have analyzed 30 years of data collected by hundreds of seismographs to generate a detailed 3D map of the region where the Earth’s core and mantel meet. Concentrating their efforts on the Pacific Ocean basin the researchers were interested in trying to understand the regions directly below the Hawaiian and Marquesas islands, volcanic ‘hot spots’ that are not connected in any way to the motion of tectonic plates. Since the Pacific Ocean is surrounded by the volcano and earthquake prone ‘ring of fire’ the geophysicists were able to collect over 7,000 seismic events of magnitude 6.5 or greater, an enormous amount of data to work with.

Caused by the interaction of the Pacific Plate with other plates the Pacific ‘Ring of Fire’ is the most geologically active region on Earth. (Credit: Phys.org)

What they found were regions of greater density and heat than even the surrounding material, previously unknown structure directly beneath the Hawaiian and Marquesas hot spots as well as other areas of the core-mantel boundary. Because these regions are hotter and denser than nearby areas the seismic waves travel more slowly through them so the geophysicists have named them Ultra-Low Velocity Zones or (ULVZs).

Using the latest in computer learning and by studying the waves generated by thousands of Earthquakes Geologists at the University of Maryland have discovered structure deep beneath the Earth’s surface. (Credit: Sci-News.com)

At the interfaces between the ULVZs and the more normal material around them echoes of seismic waves can be produced. In the past these echoes have been difficult to distinguish from random noise but the machine learning algorithm was able to recognize them, adding a lot of detail to the nature of the ULVZs.

According to Doyeon Kim, lead author of the study. “By looking at thousands of core-mantel boundary echoes at once, instead of focusing on a few at a time, as is usually done, we have gotten a totally new perspective. This is showing us that the core-mantel boundary region has lots of structures that can produce these echoes and that was something we didn’t realize before because we only had a narrow view.”

Geologists are only beginning to understand the role that Ultra Low Velocity Zones (ULVZ) have on the movement of plates and the Earth’s volcanic ‘Hot Spots’. (Credit: www3.nd.edu)

Further refinements for the technique developed by the geologists at the University of Maryland will undoubtedly discover more structures in other sections of the core-mantel boundary while at the same time providing clearer images of those ULVZs already located. Even if the deep interior of the Earth is unreachable to us physically, scientists are still finding ways study it and learn its secrets.

Does the entire Universe spin like a top? Astronomers find evidence that it just might.

We see examples of spin, angular rotations everyday in our lives, the spinning of a child’s top, the rotation of our car’s tires or the blades of a fan. How about the spin of the water as we flush the toilet or drain our bathwater?

Much more than just a child’s amusement, spin is a fundamental part of the Universe. (Credit: NicePGN)

Spin in astronomy is even more common. Not only does the Earth spin on its axis it also orbits around the Sun, another form of angular momentum. In fact all of the planets both spin on their axis and orbit around the Sun. Going further up the cosmic ladder the Sun orbits around the center of our galaxy, as do all of the other stars of the Milky Way, so that means that the entire galaxy has a rotation to it, a spin. In fact astronomers have studied clusters of thousands of galaxies and yes, the galaxies in the cluster orbit around the center of mass of the cluster as a whole.

Our Earth not only rotates on its axis it also orbits around the Sun, both with anticlockwise spin. In fact every astronomical object we know of has some spin to it. (Credit: Pinterest)

Now remember that there are two kinds of rotation, clockwise and anticlockwise, also known as counterclockwise. Scientists prefer to think of the two spin states as right handed and left handed and here’s how to tell which is which. If you put your left hand in front of your face with the thumb pointed towards you the direction your fingers curl is clockwise, see image below, therefore clockwise is left handed.

The curling of the fingers of your left hand are in an anticlockwise direction. Therefore physicists call anticlockwise lefthanded spin. (Credit: R. A. Lawler)

Conversely the way your fingers curl on your right hand is anticlockwise; see image below, so anticlockwise is right handed. By the way if you point the thumb of your right hand parallel with the North Pole then the Earth rotates the way your fingers curl, the Earth’s spin is right handed. If fact the Earth’s orbit is also right handed, as is the spin of almost everything in our Solar System, our entire galaxy in fact.

The curling of the fingers of your right hand are in a clockwise direction. Therefore physicists call clockwise righthanded spin. (Credit: R. A. Lawler)

Back in high school you may remember hearing that angular moment, that is spin, has to be conserved. That means if you try to start something spinning clockwise you’re also going to start something spinning anticlockwise! Usually we don’t notice this because when we spin a top clockwise the tiny amount of anticlockwise spin created is absorbed into the Earth and appears to vanish. The astronauts in space are well aware of this law of nature however. Anytime an astronaut on the Space Station tries to screw in a nut if they’re not careful they’ll start spinning in the other direction because of conservation of angular momentum.

When NASA astronauts try to screw in a nut they have to be careful to make certain that they themselves are securely tied down or they will start rotating in the opposite direction. (Credit: Gateway Foundation)

Since anytime you try to generate one kind of spin you have to generate just as much of the other kind physics have always accepted the idea that the Universe in total had no spin. After all it was hard to imagine how the Universe could have begun with spin, and why it would have started with one kind rather than the other. That would mean then, that all of the many spins we see out there in the cosmos would cancel each other out, leaving the Universe as a whole without spin.

The Hubble Space Telescope’s deep field image. Every dot you see is a galaxy, all spinning in a random direction so that the Universe as a whole has a net spin of zero. Or does it? (Credit: NASA, Hubble Space Telescope)

Of course assumptions like that have to be tested and the way to determine whether the Universe has any total spin or not would be to add up all of the spins of the various parts of the Universe, that is all of the galaxies, and see if they do actually cancel each other out. Now that’s a lot of work, there are tens of billions of galaxies that we know of, only a few hundred thousand of which have been studied to any degree.

Still, those few hundred thousand can serve as a sampling poll. That’s right the same mathematical techniques that the Gallop Poll uses to estimate which candidate the American people prefer for President can be used to estimate whether or not the Universe has spin. That is just what Lior Shamir, a computational astronomer at Kansas State University has done.

Doctor Shamir developed a computer algorithm that was able to determine the direction of rotation of a galaxy from its image, far left. (Credit: Lior Shamir, Kansas State University)

Using the data collected in the Sloan Digital Sky Survey (SDSS) Doctor Shamir identified more than 170,000 spiral galaxies whose direction of spin he could resolve. Adding in a further 32,000 similar galaxies from the Pan-STARRS survey for a total of more than 200,000 Dr. Shamir found that that the number of clockwise galaxies outnumbered the number of anticlockwise galaxies by a fraction more than 1%.

If you’re thinking that 1% isn’t that much, well for a sample size of 200,000 the odds of such an imbalance being randomly generated is almost one in 300,000 against. More than that, the further away a galaxy is, and hence the older it is, the more likely Dr. Shamir found it to be rotating clockwise indicating that the early Universe may have had a more uniform clockwise spin.

Dr. Shamir also found that the degree of the imbalance depended on which area in the sky you were observing with the greater number of extra clockwise galaxies concentrated along Earth’s poles. A finding that has allowed Dr. Shamir to actually identify a possible axis of rotation for the entire Universe.

Possible directions of the spin axis of the entire Universe in Earth’s sky. They ate not too far from our poles which sit along the center line at 90 and 270 degrees. (Credit: Lior Shamir, Kansas State University)

Now to be honest, Dr. Shamir’s paper has yet to be published in a peer reviewed journal and even then it will be subjected to criticism and checking. The idea that the Universe as a whole spins clockwise would pretty much mean that the initial Big Bang must have had a tiny amount of spin to it.

How the Big Bang could have had spin, and how that would have effected the early Universe is just unknown at present.

Book Review: ‘The Better Angels of Our Nature’ By Steven Pinker.

Turn on the news for ten minutes in the morning and you’d be forgiven for thinking that we live in a world saturated with violence. The events that take place everyday can seem like an endless list of war, crime, and brutality. Even our movies and the entertainment shows we watch on TV are full of violence and aggression.

The entire genre of slasher movies simply consists of one violent murder after another! (Credit: India.com)

As I begin this post my television is showing the funeral of George Floyd, the black man who while handcuffed was slowly choked to death by the knee of a Minneapolis police officer. A so-called peace officer who had sworn an oath to protect the people of his city. It’s understandable then that many people recoil from the violence of our period in history and dream about returning to a more peaceful time in the past.

The Garden of Eden was a time before the here was any violence, Yea, Right! If you believe that you’ll believe anything! (Credit: Trumpet Call)

Ah, just when was that? To be honest the only events we know of from the Bronze and Iron Ages were wars, battles and massacres. The Roman Empire was founded and maintained by the sword of the legionary while the Dark ages began with barbarian invasions and just got worse from there. I assume I don’t need to go on, and war is just the wholesale side of violence, we mustn’t forget the person to person violence like robbery, rape and murder.

Achilles slaying Hector in the Iliad. The earliest stories we have are all about war and murder. (Credit: Quora)

So it takes a brave man to declare that things are actually getting better, that human beings and human societies are actually becoming less violent. Nevertheless that’s the thesis of Steven Pinker’s book ‘The Better Angels of our Nature’ and Professor Pinker has the evidence to back it up. As the Johnstone Professor of Psychology at Harvard University Professor Pinker has gathered together a huge mass of data from subjects like anthropology, history, philosophy, crime statistics, psychological studies and the mathematics of game theory in his examination of how violence has declined through human history.

Cover for ‘The Better Angels of our Nature’ by Steven Pinker. (Credit: Amazon)
Professor Steven Pinker of Harvard University, author of ‘The Better Angels of our Nature’. (Credit: Britannica)

A warning, when I said that Professor Pinker has amassed a lot of data I wasn’t kidding. The 696 pages of ‘The Better Angels of our Nature’ are completely crammed with both historical accounts and statistical data. More than that, over the course of the book Professor Pinker employs a greater number of distinct analytical concepts than most of the Physics textbooks I’ve read in my life. In fact, a degree of familiarity with some of the mathematical techniques for analyzing data is a big help when reading ‘The Better Angels of our Nature’.

One of the mathematical techniques used regularly in ‘The Better Angels of our Nature’ is the correlation function in order to to discern trends in large amounts of data. (Credit: Medium)

Right from the start of ‘The Better Angels of our Nature’ Professor Pinker realizes that he has to convince you that violence has in fact gone down through the centuries. One of Pinker’s techniques for doing so is to examine the historical record for examples for violent behaviors that were once commonplace but have largely disappeared.

Whereas executions were once popular entertainment, even such grisly ones as crucifixion and drawing and quartering, many countries today have banned the death penalty altogether. Whereas torture was once routinely used to extract confessions from suspects, today no country openly practices it; even authoritarian states like North Korea officially deny using torture. Whereas looting and burning and rape were once considered a part of a soldier’s wages today they are classified as war crimes and some world leaders are actually being prosecuted for them. Whereas slavery was once the very foundation of many civilizations today it is at least illegal everywhere on Earth. In many ways, Professor Pinker points out, violent behavior that was once simply taken for granted as a part of life have today become sources of horror.

When the Romans defeated the slave army of Spartacus they crucified all of the survivors! (Credit: Pinterest)
Just a few of the many ways that we humans have invented to cause pain to our fellow creatures! (Credit: Life’s Pleasures)

At the same time Professor Pinker reviews the historical evidence for all of the wars throughout history, concluding that centuries in the past nations were in a constant state of conflict while it is only slowly over time that peace has become the norm and war the rarity. Pinker then goes on investigate the idea that even while it appears that wars may have become rarer, because of new technology they have become much more destructive. That argument is demolished by demonstrating that wars like the Thirty Years War or the Mongol invasions of Genghis Khan actually killed an even larger proportion of the populations involved then did the two World Wars despite the more advanced weaponry of the 20th Century. 

It’s easy to get them mixed up! (Credit: Reddit)

Convincing you that violence has actually decreased over the centuries is only the beginning of Professor Pinker’s task. In subsequent sections of the book the various influences on human violence, both those causing it as well as those that seek to control it are not only discussed but put to the test by examining records of war casualties, crime statistics and other evidence. Even the results of modern psychological testing and advances in neurology are brought to bare as evidence to better understand why it is we commit violence, and why century by century we are committing less of it.

While it may seem that peace movements have made little progress it’s worth remembering that before the late 20th century they hardly even existed!
The Rights Movements are another aspect of how humanity has grown more peaceful. The very concept of treating someone different from you fairly and justly is a very recent invention. (Credit: The Birmingham Times)

As I said ‘The Better Angels of our Nature’ is a dense book, a book about a very sobering topic. Nevertheless Professor Pinker has a habit of dropping in references to popular culture that occasionally lighten the mood. Sprinkled through the book are quotations from authorities as diverse as Martin Luther King Jr. and Conan the Barbarian.

Sometimes it’s really just a question of good manners. Even Conan knows that! (Credit: Pinterest)

‘The Better Angles of our Nature’ is not an easy book to read, but it is A VERY IMPORTANT BOOK. If you have the time, and are willing to undertake the effort you will be well rewarded. 

Paleontology News for June 2020.

There have been a number of small but important discoveries recently illuminating portions of the history of life here on Earth. As usual I think I’ll start with the earliest and move forward in time.

One of the most common modes of life in the natural world is parasitism, where an individual of one species spends a large part of its life literally living off of a member of another species. While parasitism is technically a form of symbiosis it differs from mutually beneficial symbiosis in that the parasite gains at the expense of its host.

In addition to feeding off of our blood, external parasites such as this tick cab carry illnesses like Lyme disease. (Credit: Science Insider)
Internal parasites, such as this tapeworm, may also cause illness. (Credit: WebMD)

A very large number of different species, spread across every major taxonomic group of both animals and plants are parasites for at least a part of their lives. There are so many parasites out there that you would expect that there would be a lot of evidence of parasites in the fossil record.

A lice from the Cretaceous period preserved in amber. Could it contain any dino DNA? (Credit: Daily Mail)

It’s not that easy, a lot of parasites don’t fossilize well, think of a tapeworm. Or consider a dinosaur that is infected with fleas. If that dino dies the fleas will quickly leave to try to find another host, they won’t be fossilized with the dinosaur.

Even if you do find two different species fossilized together you have the problem of determining whether your fossil is a true example of parasitism. For example in my collection I have a small clamshell from the cretaceous period that has the tube of a feather duster worm attached to it. For all I know the worm could have built its home on the shell after the clam had died. So trying to figure out when one creature is benefiting by harming the other isn’t easy.

Fragment of clam shell from the Cretaceous period in my collection with the tube of a feather duster worm attached. This is not an example of parasitism because the tube is on the inside of the shell which means the clam was already dead when the worm attached itself. (Credit R. A. Lawler)

Nevertheless a team of paleontologists from Northwest University in Xi’an China, the Swedish Museum of Natural History and Macquarie University in Sidney Australia has announced what they assert is the earliest known example of parasitism. Their evidence comes from the Cambrian period, approximately 515 million years ago and resembles in many ways my fossil mentioned above.

The fossils consisted of a large number of shells of a species of brachiopod, a creature whose shell resembles that of a clam although the animal inside is totally different. While brachiopods today are quite rare, in the early period of life’s history, more than 250 million years ago, they were more common than clams.

Some of the Brachiopod shells used in the study of ancient parasitism. (Credit: Macquarie University)

Examining the brachiopod shells the paleontologists found that approximately half were encrusted with the tubes of worms, just like my fossil, while the other half were not. Measuring the shells of the brachiopods and using that as an indication of the animal’s health the researchers discovered that the encrusted brachiopods were consistently smaller, by about 26%. This is clear evidence that the worms were harming the brachiopods. In other words the worms were parasites.

Artists impression of a Brachiopod shell infested with parasitic worms. (Credit: Ars Technica)

Not only that, but because like a clam, the shells of brachiopods grow outward from their edges the scientists were able to determine how early in the life of a brachiopod it had become encrusted. Again, those brachiopods that were encrusted earlier in their lives showed the most pronounced size reduction, further evidence of parasitism.

So it appears that parasitism as a mode of life has existed for nearly as long as multi-cellular creatures have. Another common mode of life that has also recently been found to have ancient roots is suspension feeding; animals that swim with their mouths wide open, filtering plankton and other small creatures out of the water. In today’s oceans baleen whales and basking sharks are the best known suspension feeders and are among the largest creatures on Earth.

Now a new study by paleontologists at the Universities of Bristol and Zurich of an ancient fish from the Devonian period, about 380 million years ago, has provided strong evidence that at least one of the ocean’s largest inhabitants back then lived in much the same way. The animal in question belongs to the group of armored fish known as placoderms and is formally called Titanichthys. A giant for its time Titanichthys measured more than five meters in length but crucially its jaw was more than a meter in length. Modern suspension feeders also have greatly elongated lower jaws allowing them to scoop up the greatest amount of water as they swim.

School of Titanichthys feeding as they swim. At five meters in length Titanichthys was one of the largest living things during the Devonian age. (Credit: Sci-News.com)

The new research also found that while the lower jaw of Titanichthys was long it wasn’t very strong, neither the bones themselves nor the muscles attached to the jawbones would have been sufficient to deliver a strong bite, further evidence of the fishes lifestyle as a suspension feeder.

The fossilized skull of Titanichthys. That huge open mouth certainly could have collected a lot of food. (Credit: Black Hills Institute)

Moving forward in time we come to my final story for this month, which concerns the asteroid that is presumed to have caused the extinction of the dinosaurs. It was only about twenty years ago that geologists succeeded in finding actual site of that impact, the Chicxulub crater in the Yucatan peninsula of Mexico.

The Chicxulub crater in the Yucatan peninsula of Mexico. The asteroid that struck here is generally considered to have caused the extinction of the dinosaurs. (Credit: Wikipedia)

Ever since that discovery geologists have surveyed Chicxulub, hoping to learn as much as they can about how the 10 kilometer wide space rock caused so much damage. Destruction so great that it led to the extinction of about 75% of all of the species on Earth. In a paper published in Nature Communications scientists from the University of Texas at Austin, the Imperial College London and the University of Freiberg in Germany have used computer simulations to investigate what the likely initial conditions of that asteroid strike were in order to order for it to have produced the effects seen in the Yucatan today.

Based upon the diameter of the Chicxulub crater, its depth and the observed distribution of ejected material from sites around the world the team of geologists have concluded that the asteroid struck the Earth at an angle of 60º, an angle that they argue produced the greatest amount of destruction. According to the simulations a steeper angle, say 70-90º would have produced a deeper crater but one where the ejecta was more confined to the area around the crater, in other words the other side of the Earth might have been subjected to considerably less devastation. On the other hand, if the asteroid had struck at a shallower angle, say 30º or less, the crater would have also been shallower and the distribution of ejecta would have been much more concentrated in the direction of the asteroid’s motion, which again might have spared some parts of the Earth from baring the full brunt of the asteroid’s destructive power.

Computer simulation of the asteroid strike with the asteroid coming in at an angel of 60 degrees. (Credit: Collins, Patel, Davidson et. al.)

If the simulations produced by the team of geologists do in fact correspond to what actually happened 66 million years ago then the dinosaurs were doubly unlucky. Not only did the asteroid strike suddenly from out of the depths of space but it also struck in just the right way to both produce the maximum destruction and to spread that destruction evenly around the entire world.

Of course as mammals we should remember that what was bad luck for the dinosaurs was good luck for us!