Trying to understand the evolution of life on Earth is a bit like trying to figure out the picture on a jigsaw puzzle when you only have a dozen or so of the puzzle’s pieces. Obviously only a very few of the animals who ever lived have made fossils and of the few that have it’s usually only the hard part of the animal that fossilizes, bones and teeth for vertebrates, shells or exoskeletons for invertebrates. It’s a good question, how many species of animals with no hard parts existed in the past about whom we known absolutely nothing?
Fossils of Jellyfish are extremely rare because there’s almost nothing to fossilize. (Credit: Technology Networks)
The first multi-cellular animals, from about 600 million years ago, had no hard parts, and the very few impressions of them that paleontologists have found are so different from today’s species that it is hard to tell just what kind of animal they are. Known as the Ediacaran biota they have been described as quilt like, frond like or even balloon like in structure and whether or not they bare any relationship to the animals of today is a subject of hot debate. See images below.
Dicksonia costata is one of the stranger of the Ediacaran creatures. Is it even an animal? (Credit: Wikipedia)
Charnia is another Ediacaran creature. The fossil almost seems to indicate that the animal was quilted in structure. (Credit: Verisimilus at English Wikipedia)
Spriggina at least definitely looks like an animal that has a definite front and back and obviously moves in some fashion. (Credit: Pinterest)
Then, less than 60 million years later during the Cambrian period a very different assemblage of animals appeared as if from nowhere. These animals, best known from the famous Burgess shale fossils, are in most cases recognizable members of the modern major taxonomic groupings. The questions then arise, how did all these different groups arise at the same time, and what is their relation, if any, to the earlier Ediacaran animals.
The animals of the Cambrian, like this trilobite Olenoides, though strange are recognizably related to modern arthropods. (Credit: Trilobites.info)
Even the ‘wierd wonders’ of the Cambrian. like this artists impression of Opabinia, are still structured like modern animals. (Credit: Burgess Shale Science Foundation)
A recent discovery may provide the first definite link between an Ediacaran creature and a modern group of animals. As is happening more and more in paleontology the discovery wasn’t made by digging up a new fossil in the field but rather by looking at a fossil found years ago with a new instrument.
Tara
Selly is a research assistant professor at the Department of Geological
Sciences of the University of Missouri who was learning how to examine
specimens using the university’s new X-ray microscope. For practice she grabbed
a handy fossil, one that happened to come from Nye County in southern Nevada.
The fossil she chose was of a creature known as a cloudinomorph that dated to the end of the Ediacaran period, about 550 million years ago. Fossil cloudinomorphs are basically little tubes made of the material calcium carbonate and paleontologists have argued for years over whether the animal inside the tube was a relative of a coral medusa (technically an Anthozoan) or a tubeworm (Polychaete).
Cloudinomorphs were a well known but poorly understood Ediacaran fossil. (Credit: Tara Selly and James Schiffbauer)
When Doctor Selly looked at her cloudinomorph with the X-ray microscope she immediately saw a feature that was invisible under normal light, a tube running all the way through the fossil from one end to the other. If, as seemed likely, this tube was the intestine of the cloudinomorph that would immediate eliminate the possibility of the animals being related to a coral. You see corals and jellyfish have only one opening to their digestive system, which serves as both a mouth and an anus.
3D image of a cloudinomorph tube and the internal tube removed for inspection. The black line represents 2mm in length. (Credit: Tara Selly and James Schiffbauer)
Tara Selly shows grad student Brock Anderson how to prepare a specimen for viewing on the X-ray microscope. (Credit: Tara Selly and James Schiffbauer)
“A tube would tell us that it’s probably a worm,” according to James Schiffbauer the lead author of the study. “We can now say that their anatomical structure appears much more worm-like than coral-like.” If that is true is would establish the first firm link between an animal from the Ediacaran period and a modern group.
Possible reconstruction of the cloudinoporph animal. (Credit: New York Times)
In
any case this is also the first evidence of any kind of complex internal
structure, an internal organ of some kind inside an animal from the Ediacaran.
That alone is important because it tells us that at least some of these early
creatures were more than just balloons or quilts of undifferentiated cells.
We may only have a few pieces of the jigsaw
puzzle of life’s history but perhaps; thanks to Doctors Selly and Schiffbauer
we may have just found a very important one.
In my post of just two weeks ago, January 4th 2020, I talked about the possibility that the Red Giant star Betelgeuse might be about to explode as a Type 2 Supernova (SN2). At the end of that post I made an offhand remark about writing a post about Type 1 Supernovas (SN1) in order to clarify the difference between the two types. Well I recently came across a couple of papers concerning SN1s so I decided that now was as good a time as any to fulfill my promise.
The constellation of Orion. Betelgeuse has been acting strangely. Is it about to go Nova? (Credit: Sky and Telescope)
First of all I suppose I should start by describing how an astronomer distinguishes one type of supernova from the other when they observe one. They do this by breaking up the light from the Supernova into its spectral lines that show the elements giving off the light. In SN1s the spectral lines of hydrogen will be completely absent while in SN2s the spectra will indicate a fair amount of hydrogen. Other observational differences have been seen in a few individual Supernovas, ones near enough to observe additional details, but the presence or absence of Hydrogen is the consistent difference. Everything else is really just theory.
The Hydrogen absorption spectra. Seeing these lines in the light from a Supernova means that it is a Type 2 while the absence of these lines makes it a Type 1. (Credit: Slide Player)
So let’s examine the theories, SN2s first. As I discussed in my post about Betelgeuse, SN2s begin as stars that are ten times or more as massive as our Sun. Such stars race through their nuclear fuel very quickly, millions instead of billions of years. As the star begins to run out of its fuel it puffs up into a red giant like Betelgeuse is now. When that fuel is completely used up the star’s core collapses because of gravity but that collapse triggers an explosion of the star’s outer layers as a Supernova. Since the outermost layers of the star still possess some hydrogen, that element’s spectral lines are seen in the Supernova’s light letting astronomers know that it is an SN2.
SN1s could hardly be more different. For one thing a SN1 can only occur in a double star system. In addition one of the stars must have already gone completely through it’s energy production life span and is now a burnt out cinder known as a white dwarf. White dwarfs can be as massive as our Sun but are crushed down to the size of a planet like Earth. Because they are so dense, and under such immense gravitational force, the material of a white dwarf is not made up of normal atoms as here on Earth, with electrons orbiting around a nucleus. Instead the electrons are squeezed into their nuclei and all of the nuclei are pushed much closer together than in normal matter, because of this the spectra of a white dwarf shows no sign of the presence of hydrogen.
A white dwarf star can have the mass of our Sun but only be as large as our Earth! (Credit: Medium)
There’s
another peculiarity about white dwarfs as well. White dwarfs can only be so
massive, a value known as Chandrasekhar’s number, which is equal to about 1.4
times the mass of our Sun. Any heavier and the white dwarf will continue to
collapse down into a neutron star or black hole. That collapse triggering its
outer layers to explode as an SN1.
So where would an otherwise stable white dwarf star get the extra mass needed to make it exceed Chandrasekhar’s number and explode as a SN1? From its companion star that’s where, which is why SN1 only occur in binary star systems. Astronomers have in fact observed binary systems where a white dwarf’s intense gravity is pulling matter away from its companion, a situation that will eventually lead to a SN1.
A white dwarf star pulling material away from its companion. Eventually this dwarf will go Supernova. (Credit: www.cfa.harvard.edu)
And now astronomers Bradley E. Schaefer, Juhan Frank and Manos Chatzopoulos of the Department of Physic and Astronomy at Louisiana State University have used some very precise measurements of the faint star V Sagittae in the constellation Sagitta to actually predict that it will explode as a SN1 in or about the year 2083. In fact V Sagittae is already rapidly increasing in brightness, currently shining at 10x the brightness it did when it was first accurately measured back in 1907.
V Sigittae is currently too dim to be seen without a telescope but a new study predicts in 2083 it will be the brightest star in the sky, for a few weeks. (credit: Sky and Telescope)
This rapid increase is likely to continue over the next decades as the white dwarf devours its companion. Eventually the star, which currently cannot even be seen with the naked eye, will become as bright in our sky as the star Sirius, or perhaps even the planet Venus, but not for long. How accurate the prediction about when V Sagittae will go Nova remains to be seen but you can be certain that astronomers will be keeping a close eye upon it for many years to come.
Another
interesting thing about SN1 is that since they only occur when a white dwarf’s
mass goes above Chandrasekhar’s number then all SN1 should be pretty much the
same. That is, each SN1 should release the same amount of energy. If that is
true then a SN1 can be used as a ‘standard candle’ to accurately measure
distances throughout the Universe.
You see the distance to an object in deep space is the most difficult thing there is to measure in astronomy. We have many theories about the Universe that cannot be either confirmed or falsified simply because we can’t measure distances accurately enough to really be certain we know exactly what is going on. But if we know precisely how much energy an object puts out no matter where it is in the Universe, like a SN1, then we can measure how bright it appears in our sky and a simple formula tells us how far away it is.
Using actual Luminosity (L in watts) and brightness (B in Watts /meter-squared) to find the distance to an astronomical object. (Credit: Ohio State University)
Astronomers did just that back in the 1990s, using SN1 to accurately measure the rate at which the Universe is expanding. It was those measurements that indicated that the expansion of the Universe was actually accelerating, that ‘Dark Energy’ was pushing the Universe apart faster. This was the first and still the best evidence for the existence of Dark Energy.
The original evidence for Dark Energy. Notice how the Type 1 Supernova measurements (Red balls) indicate that the Universe is expanding faster than the ‘Standard Model’. (Credit: University of Arizona)
Now a new study threatens to upend all of that. Astronomers from the Department of Astronomy at Yonsei University in South Korea along with the Korean Astronomy and Space Science Institute have made highly detailed measurements from 60 SN1 events and have found that the absolute luminosity of an SN1 changes with the age of the Universe at which time the SN1 occurred. In other words SN1 have evolved over time. In fact if the changes in luminosity with time described in the paper are taken into account then the acceleration of the Universe simply disappears, there’s no such thing as Dark Energy!
The new evidence that SN1 have evolved over the age of the Universe. Does this mean that Dark Energy doesn’t even exist? (Credit: Phys.org)
If
this study is true it would undo much of the Astronomy of the last 30 years,
but other astronomers have to review it first, check the data, make some more
measurements to be certain. Whether or not SN1 can be used as a ‘standard
candle’ is an important matter for Astronomers but regardless of the answer to
that question they are still an awesome example of the many different objects
in our Universe.
Artificial Intelligence (AI) is here! The world’s best chess players are now machines; the best Jeopardy player is a machine. We now have AIs like Alexia and Siri in our homes acting as our personal secretaries. AI controlled robots are doing more and more of the physical and repetitive labour in our societies. More and more people today are coming to recognize that it’s only a matter of time before we have succeeded in building AIs that are as smart, or smarter, or even much smarter than we are.
IBM’s Watson AI is now doing a lot more than just winning games of Jeopardy. (Credit: www.cio.com)
How many of us now have Amazon’s Alexa AI in our homes? (Credit: Beebom)
How should we treat these creations of ours, can we control them, should we? If they become conscious entities do they have rights, legal rights that is? Or should we avoid making machines that are conscious for those reasons? And how will we ever even know if our machines do become conscious?
Questions like those are just the starting point of the book ‘Artificial You’ by Susan Schneider. As the director of the AI, Mind and Society group at the University of Connecticut and following her two-year NASA funded project exploring superintelligent AI Doctor Schneider is uniquely qualified to consider those questions from both a technical as well as a philosophical perspective.
Cover of ‘Artificial You’ by Susan Schneider (Credit: Amazon)
In fact much of Doctor Schneider’s research has been concerned with the development of tests that would allow we humans to determine whether an AI has a mind, or whether it has simply been so skillfully programmed that it can behave as if it had a mind, as some of our AL systems are already starting to do. In order to do this Doctor Schneider first asks us to consider what are the qualities of our thought processes that are different from simple computations. Questions of this sort make up the first four chapter of ‘Artificial You’.
What is our mind anyway? Can a computer even have a mind and how would we know if one has? (Credit: Seychelles Truth Reconciliation)
The
final four chapters along with the conclusion concern the even more esoteric
question of whether it may someday be possible for a human mind to merge with
an AI and thereby gain a computer’s speed, accuracy and expanded memory, and
maybe even immortality. Doctor Schneider discusses two broad methods of how
such a merger might be accomplished.
The first is bit by bit, where a human brain might get a neural lace implanted in it to enable a direct connection to a computer. Or perhaps the replacement of the brain’s hippocampus, which is essential for laying down new memories, by an artificial hippocampus. Both of these technologies are currently under development and other possible ‘chip’ enhancements to the brain are being studied. In time what began as a few ‘improvements’ to our brain could become a total replacement of it.
Wearing a neural lace in order to have direct connection to an AI is one thing, but would you ever have one implanted in your skull? (Credit: www.nrc.nl)
The world’s first prothesis for an injured part of the brain, an artificial hippocampus is being tested on monkeys. (Credit: Slideplayer.com)
The second technique involves a ‘mindscan’, a minute and detailed plotting of every connection between the neurons of the brain and a reproduction of those connections onto a silicon or other electronic substrate. By reproducing the exact pattern of a human mind in this way it is thought that the new mind so created would be an exact copy of that human mind but with all of the advantages of AI. Perhaps even including perhaps immortality?
At the moment a ‘Mindscan’ is only Science Fiction. How long will it stay that way? (Credit: Amazon)
These possibilities date back to at least the 1960s in Science Fiction such as ‘2001: A Space Odyssey’ and ‘The Ultimate Computer’ episode of ‘Star Trek’ and Doctor Schneider considers them both at some length. This kind of thinking has become known as ‘Transhumanism’ and is a growing philosophy among cybernetic engineers and researchers. Although Doctor Schneider considers herself to be a ‘Transhumanist’ nevertheless she is skeptical about their more optimistic predictions.
Did becoming a cyborg give Robocop immortality or did it take away what made him human? (Credit: Den of Geek)
That’s
the point of view that Doctor Schneider takes throughout ‘Artificial You’,
skeptical, questioning, looking for the flaws in any argument while demanding
evidence to back up any claims. Whatever your viewpoint on the issues of human
/ machine interactions you can benefit from Doctor Schneider’s clear-eyed
analysis.
‘Artificial You’ is an important book and with
future advances in AI it will only become more important.
There have been many events in the long history of Earth that have shaped the course of the evolution of life for millions of years. Whether it be the rise of multi-cellular organisms or the asteroid that ended the reign of the dinosaurs, life today would be very different if those events hadn’t happened, certainly we wouldn’t be here.
The history of life is a combination of gradual change and Earth-Shattering events. (Credit: www.seeker.com)
In today’s post I’ll be talking about recent progress that is being made in understanding two of these events. One of those events was the first time that an animal with an internal skeleton, a vertebrate left the ocean to walk on land but I’m going to start by discussing new revelations concerning the very origin of life itself.
Timeline of the history of our Planet. (Credit: Slideplayer.com)
Scientific speculation about the origin of life began even before Darwin published his ‘On the Origin of Species’ but for about a hundred years it was little more than speculation. Then in the 1950s the Miller-Urey experiment was performed showing how easily the gasses that made up our planet’s early atmosphere could be converted into complex organic molecules like amino acids. (For more information on the Miller-Urey experiment see my post of 9 March 2019.)
Setup of the Miller _ Urey experiment. (Credit: Big Picture)
For the last fifty years however real progress in determining the chemical path that led to the first living things ran into a roadblock, the chemical phosphorus. You see phosphorus is critical in many of the chemicals processes in living cells; Adenosine triphosphate is often referred to as the match that lights the chemical engine of cell metabolism while phospholipids make cell membranes stronger and more watertight. Perhaps most importantly phosphorus is an essential element in the formation of both the DNA and RNA molecules that form the genetic code of life.
The Chemical Structure of Adenosine triphosphate. The phosphorus atom on the far left contains a lot of easily usable energy. (Credit: Wikipedia)
Problem
is that phosphorus doesn’t usually combine well with organic chemicals,
combining more easily with calcium, an element that is abundant in the oceans.
This leaves very little free phosphorus around with which to create the first
living things. Biochemists were stumped, to build the first living creatures
you need phosphorus, where did those, not yet living, complex organic compounds
get it.
Jonathan D. Toner and David C. Catling of the Department of Earth and Space Sciences at the University of Washington have recently suggested a solution to this problem. In their paper published in the ‘Proceedings of the National Academy of Science’ they have suggested that carbonate rich lakes might be the locations where phosphorus was incorporated into organic chemistry. You see carbon bonds with calcium even more strongly than phosphorus does. So lakes that are rich in carbonates will use up all of the calcium leaving whatever phosphorus there is free to get incorporated into organic compounds.
Mono Lake in California. It may not look hospitable but there is plenty of primitive life here. (Credit: News Deeply)
The
kind of lakes we’re talking about here is not the sort commonly considered
hospitable to life. Lakes with little or no outlets where salts and other
chemicals can build up. Mono Lake in California and Lake Magadi in Kenya would
be a good examples. Although such environments are hostile to advanced forms of
life they are often rich in primitive bacteria and algae.
Lake Magadi in Kenya is famous for the huge number of Flamingos that feed on the small crustaceans there. (Credit: Africa Dream Safaris)
Doctors Toner and Catling have even measured high levels of free phosphorus in many such lakes, see chart below, demonstrating that the more inorganic carbon in the water, the more free phosphorus there is as well. Other scientists will have to critique and challenge Toner and Catling’s theory before it’s accepted but it certainly looks as if they may have found the solution to a longstanding problem.
Phosphorus levels versus free carbonates in lakes examined by Toner and Catling. (Credit: SciTech Daily)
Another crucial event in the history of life occurred when the first vertebrate crawled out of the water and onto the land. From the paleontological record we know that this transition occurred during the late Devonian period some 3755 million years ago. While the actual species of fish that first succeeded in wiggling out of the water is a subject of debate one possibility is Tiktaalik rosa, see image below, discovered by Neil Shubin of the University of Chicago and Edward Daeschler of the Academy of Natural Science here in Philadelphia.
Artists impression of Tiktaalik roseae. (Credit: Paleocast)
Proposed family tree of the fish who crawled out of the ocean. (Credit: Pinterest)
Looking at Tiktaalik it is immediately obvious that this animal is not a streamlined swimmer. In fact Doctors Shubin and Daeschler think that Tiktaalik crawled along the bottom of shallow, muddy lakes and ponds using its four fins more like legs than fins. Such an anatomy and lifestyle seems perfect for the first land walker but it also raises the question of how did the fins of a fish evolve into the proto-legs of Tiktaalik. Now Doctors Shubin and Daeschler, along with a few of their colleagues, have published a new paper comparing the limb-fin of Tiktaalik to those of related, and thought to be ancestral species, Sauripterus taylori and Eusthenopteron foordi.
First the researchers used CT scans of the fossil remains to construct 3-D models of not only the bones in the animals fins but also the cartilage and dermal (skin) rays. The 3-D model allowed the researchers to rotate and examine the entire skeletal structure bringing out details that are commonly lost in removing the bones from the rock encasing them.
Dermal rays of the pectoral fins of T roseae. (Credit: Thomas A. Stewart et. al.)
What
the scientists discovered was that the evolution from the earlier species to
Tiktaalik involved a reduction in the dermal rays of the fins. At the same time
the top and bottom of the fin lost their symmetry, the top growing faster than
the bottom leading to the formation of a ‘palm’ in the fin of Tiktaalik. Such a
structure would have been able to act as a support base when Tiktaalik rested
on the bottom of a pond, or on land.
The water to land transition was one of the most important events in the history of life. Thanks to the work of Doctors Daeschler and Shubin we are now filling in some of the minute details of the anatomical changes needed to make that transition. Bit by bit other paleontologists are filling in the details of other events as well giving us a clearer picture of how life evolved into all of the many the living things on Earth today.
It probably didn’t happen this way! (Credit: Thumbpress.com)
Warning: Today’s post will contain several spoilers so if you haven’t seen ‘Star Wars: The Rise of Skywalker’ yet, well you’ve been warned!
Marque poster for ‘Star Wars: The Rise of Skywalker’ distributed by Disney. (Credit: StarWars.com)
Emperor Palpatine is alive. You may have thought that he was killed by Darth Vader at the end of ‘Star Wars: Return of the Jedi’ (Episode 6) but he’s alive. Whether he somehow survived the destruction of the second ‘Death Star’ or has somehow been reborn is never explained but then the Star Wars saga has never really put that much effort in filling in the holes in its plots. Certainly ‘The Rise of Skywalker’ has more than it share of “Oh, c’mon” moments.
Emperor Palpatine is alive again. How is anybody’s guess! (Credit: Screen Rant)
Of course you could argue that any series of stories that were created over a period of more than 40 years by a large team of creators is going to have a few contradictions pop up in it. Look at Doctor Who! Or you could argue, as George Lukas has often done himself, that ‘Star Wars’ is a children’s story and the adults who expect all of the pieces to fit together precisely are taking it too seriously.
I don’t think that those arguments work for several reasons. First of all if you have 40 years in which to write the scripts for nine movies you certainly have the time to eliminate at least some of the plot holes. And as for ‘Star Wars’ being a children’s story, well the Hobbit was a children’s story and J. R. R. Tolkein managed to make it all fit together.
J. R. R. Tolkien wrote children’s fables that still appeal to adults because he cared about making his tales fit together properly. (Credit: Amazon.com)
I’d like to discuss two parts of ‘The Rise of Skywalker’ in particular. The first deals with the efforts made by the new Jedi knight Rey and her companions to discover the location of Moraband, the ‘lost planet of the Sith’. The good guys spend about half of the movie in this search. Risking their lives in order to follow vague clues. In fact we learn that Luke Skywalker also spent several years looking for Moraband during the period between episodes 6 and 7. So Moraband must be a real hard place to find.
The planet of the Sith Moraband, ancient Korriband is lost at the start of ‘Rise of Skywalker. How does a planet get lost? (Credit: Ultrasabers)
Except once they get to Moraband the good guys discover that Palpatine, or to use his Sith name Darth Sidious, has constructed a huge fleet of a thousand star destroyers, all fully manned. Now did Palpatine build those ships all by himself, using only the resources on Moraband? In any case he didn’t build the crews of those ships. For a planet that’s so hard to find there must have been a lot of traffic going back and forth between Moraband and the rest of the Galaxy. Such inconsistencies are the result of nothing but laziness and sloppiness and really detract from the movie. Also, think back for a second, wasn’t the whole plot of episode 7 the search for Luke who had exiled himself on the ‘lost planet of the Jedi’, how many times can they use the same idea?
Ahch-To was the site of the original temple of the Jedi and Luke’s hiding place in episode 7. How does a planet get lost? (Credit: YouTube)
My second example is more a criticism of Hollywood in general than just the ‘Star Wars’ saga. Often in movies you will find a character who starts the story as a bad guy but for one reason or another turns back toward the light and redeems himself in the climatic final battle. In a western for example a gunslinger might meet and fall in love with the local schoolmarm. Then in the final gunfight he betrays his bad guy boss the cattle rustler and instead protects the town Sheriff, who also loves the schoolmarm and is therefore the gunslinger’s rival. Well the good guys win of course and the gunslinger dies a noble and heroic death, but he dies, he always has to die.
Of course Darth Vader himself is one of the best-known examples of this cliché. For almost three entire movies, episodes 4, 5, and 6, he is the epitome of evil, but just as Palpatine is about to kill his son Luke he turns on Palpatine and kills him, dying himself in the process.
In Episode 6 Darth Vader dies after saving Luke and Killing Palpatine. That’s a rule in Hollywood more powerful than the Force. (Credit: Daily Express)
The same hackneyed character arc is played out in episodes 7, 8 and 9 with Ben Solo playing the bad guy as Kylo Ren. However Kylo / Ben never seems really happy as a bad guy and its obvious from the first that he loves Rey and wants her approval. Ben’s redemption is therefore actually more convincing than Vader’s was and takes place a good bit earlier in ‘The Rise of Skywalker’ allowing him and Rey to get to fight together. Then there was a moment, just a moment when I thought the scriptwriters were going to let Ben live but no, he dies. It’s a noble and heroic death but he dies. In the end I guess it wasn’t the Jedi or the Sith who won, it was Hollywood.
At the climax of Episode 9 Kylo Ren dies after saving Rey. Hollywood killed him! (Credit: YouTube)
Right
now I bet anyone who’s been reading this post thinks I must really hate ‘Star
Wars’. If that were true however I simply never would have gone to see all nine
movies! In fact I know very well that George Lukas tapped into a deep well in
the human psyche when he envisioned ‘Star Wars’ and there are many scenes
within the saga that are truly mythological in stature.
It isn’t without reason that Lukas gave a lot of credit for the inspiration of ‘Star Wars’ to the mythologist Joseph Campbell. Luke, Leia, Obi Wan and Darth Vader are all characters that have actually existed for thousands of years in hundreds of different stories. They are archetypes of human behavior which is why they can so easily become Rey as Luke, Fin as Leia, Luke as Obi Wan and Kylo Ren as Darth Vader. Just a few cosmetic changes and we’re willing to watch the same story all over again.
Is that a picture of Luke and Darth Vader? Joseph Campbell’s ‘The Hero with a Thousand Faces’ was a great influence on the ‘Star Wars’ saga. I heartily recommend it! (Credit: PJL Books)
There
are many great things about ‘Star Wars’ which only makes the laziness, the
sloppiness, the heavy dependence on CGI to create visual roller coasters, and
above all the commercialization that makes the faults in the movies all the
more tragic.
‘Star
Wars: The Rise of Skywalker’ is supposed to be the end of the Skywalker saga.
If that is true it will be both sad, and something of a relief.
One of the most familiar stars in the night sky is Betelgeuse, the star that marks the right shoulder of Orion the hunter. (Right shoulder, that means we see it on the hunter’s left!). Generally Betelgeuse is the eleventh brightest star in the sky but because there are several other very bright stars nearby Betelgeuse is very easy to find. Not only is Rigel, Orion’s left foot, slightly brighter but to Betelgeuse’s upper right is Aldebaran the eye of Taurus the Bull while to the lower left is the brightest of all true stars Sirius. I my opinion these stars together make Orion and the region around it one of the most interesting parts of the night sky, and the simplest to find.
The Constellation of Orion the Hunter. Betelgeuse is Orion’s Shoulder and is a red star. (Credit: EarthSky)
Lately however Betelgeuse has not been looking as strong and bright as usual. Astronomers have known for centuries that Betelgeuse varies in its intensity by as much as a factor of two but for the past month the star’s energy output has been the lowest it’s been for over a hundred years.
A red giant star, Betelgeuse is so large that if it replaced our Sun it would swallow all of the planets out to Jupiter. (Credit:WWW.Severe-Weather.eu)
So what’s happening to Betelgeuse? Could its recent convulsions be a prelude to something extraordinary, perhaps even the star’s soon exploding as a supernova?
Betelgeuse often goes into convulsions but its recent activity is abnormal. (Credit: Discover Magazine)
It’s worth considering; our current theories about Type 2 supernovas tell us that Betelgeuse is a prime candidate. Only very heavy stars that have used up all of their nuclear fuel end their lives as type 2 supernovas. At an estimated mass of twelve times that of our own Sun and with a bloated red sphere as large as the orbit of Jupiter indicating that both its hydrogen and helium resources are gone Betelgeuse seems to be ready to go at any time.
A Supernova explosion is so powerful that for a couple of weeks it can outshine all of the stars in its galaxy combined! (Credit: Harvard Gazette – Harvard University)
Of
course at any time for an object as long lived as a star could mean sometime in
the next million years or more. However a recent paper has suggested that
Betelgeuse’s end might come any time in the next 100,000 years so there is a
slight chance it could be happening soon.
So what would Betelgeuse going supernova mean to us here on Earth? Would there be any danger? Well at an estimated distance of 700 light years Betelgeuse is too far away for its burst of radiation, mostly gamma and X-rays, to do any damage to our atmosphere. However since the total amount of light coming from Betelgeuse could be as much as that of a full Moon, all squeezed into a single point of light in the sky, that point would be intensely bright, easily seen in daytime. It is possible that anyone staring at that point for too long could suffer some eye damage. Still, all in all there’s no reason to get too excited, but a nearby supernova would be something to see.
The Crab Nebula is the remnant of a Supernova that was seen in the year 1054. (Credit: YouTube)
Especially
for astronomers, over the last century there have been hundreds of observations
of supernova in other galaxies but those are so far away that precise
measurements of what is happening are difficult to make. Even worse, when a
star goes supernova in another galaxy astronomers almost never have any
observations of the star before it went nova.
Only once, back in 1987 when a star in the Large Magellanic Cloud, a satellite galaxy to our Milky Way, went supernova have astronomers had any observations of a star before it exploded. The last star to go supernova in our own Milky Way galaxy was way back 1604 when telescopes were nothing more than cardboard tubes with a lens at each end. If Betelgeuse or another nearby, well-known star were to explode it would allow astronomers to test many of their theories about supernovas and star evolution in general.
A Hubble space telescope image of the Supernova 1987a as seen today. The rings are a part of the expanding shell of the explosion. (Credit: SolStation.com)
Personally I’ve been hoping to see a naked eye supernova most of my life so I’ll be keeping my fingers crossed the next few months. You know, writing this post about the possibility of Betelgeuse going supernova has made me realize that I ought to write a post just about supernova. After all type 1 supernova are an entirely different kind of animal from type 2 so I ought to describe them. Maybe I’ll do so here in the next few months, so keep coming back.
I was quite young when I first heard about the mysterious phenomenon known as ‘Ball Lightning’ and I remember thinking that was the craziest idea I’d ever heard of. After all everybody knew that similar electrical charges repel each other, and when you get a build up of positive or negative charges the force pushing them apart is so great that it causes the burst of energy we call lightning. The notion of a stable build up of charges that could last for several minutes in a small volume of space just made no sense.
A rare sight to see, ball lightning is usually observed during a strong normal lightning storm (Credit: Nautilus / Science Connected)
Since that time I’ve learned a lot more about electro-magnetism, about resonate cavities, about plasmas, about the weird world of Quantum Electro-Dynamics (QED) and I still think ball lightning is hard to accept. Most scientists seem to agree with me because there are dozens of very different theories about the nature of ball lightning. Everyone of these hypotheses have some problems explaining all the observations of ball lightning and none of them have gained anything like a consensus of support.
Phenomenon similar to Ball Lightning have been created in a labouratory but are they the exact same thing? (Credit: CNET.com)
For
those who aren’t familiar with the rare and unpredictable sightings of ball
lightning the phenomenon is usually, but not always observed during a fierce
lightning storm. The ball itself can vary from a few centimeters to a few
meters in diameter, the shape is normally spherical or pear shaped, hence the
name, but a few observations of a ring like structure have been made. The ball
glows fairly brightly like a household electric lamp with any colour in the
spectrum but red and yellow predominate.
The movements of ball lightning tend to be horizontal at a steady velocity around 10 meters per second although some have been seen to remain motionless. Very strangely ball lightning has occasionally been observed in the interior of aircraft that are moving at hundreds of kilometers per hour. Despite the plane’s speed however the ball moves through the cabin at a relative speed consistent with observations made on the ground! Finally ball lightning can either dissipate quietly or explosively, it has even been the cause of several deaths.
A 19th Century Newspaper illustration of an observation of ball lightning. (Credit: National Geographic)
So I suppose it’s about time some science fiction writer got around to using ball lightning as the focus for an SF novel. Chinese science fiction author Cixin Liu has done so and his novel ‘Ball Lightning’ is a daring and imaginative story that starts as a scientific study about the nature of ball lighting and leads to the development of ball lightning weapons. Readers of this blog might recognize Cixin Liu as the author of the ‘Three Body Problem’ trilogy and ‘Ball Lightning’ is a similar wild ride.
Cover of ‘Ball Lightning’ by Cixin Lui. (Credit: Amazon.com)
Liu assumes one of the more outlandish theories about the nature of ball lightning as his starting point and takes off from there. Before long Liu is describing quantum phenomenon that are observable in the macroscopic world, even using the thought experiment of Schrödinger’s cat to question whether or not someone who is killed by ball lightning is alive or dead, or in an indeterminate quantum state.
Cixin Liu is also the Author of the ‘Three Body Problem’ trilogy. (Credit: Tor.com)
I do have a slight criticism, in the novel China goes to war but their adversary in the war is never named. However the USS Stennis, an American Guided Missile Destroyer, is explicitly named as one of the ships attacking the Chinese fleet. Now if you’re going to name your enemy’s warships you may just as well go ahead and name your enemy. In fact Liu’s descriptions of battle in general could use a little more blood and thunder. I have the feeling Liu is a pacifist who would rather not talk about fighting at all. Wouldn’t it be nice if he didn’t have to?
‘Ball Lightning’ is now the fourth novel by Cixin Liu that I have reviewed, all of them thought provoking and wildly creative. I’m certainly looking forward to reading his next novel ‘Supernova Era’ and when I do you can be certain to read about it here at Science and Science Fiction.
‘Supernova Era’ is the latest novel by Cixin Liu. (Credit: Amazon.com)
There
a lot going on in space right now. There’s both good news and bad. Let’s deal
with the bad news first.
By now I’m certain that you’ve heard about the problems that occurred during the Orbital Test Flight (OTF) of Boeing’s Starliner space capsule. Planned as an unmanned flight to the International Space Station (ISS) the OFT was to be the last scheduled test of Starliner before manned missions could begin hopefully starting early next year.
The launch of Boeing’s Starliner capsule on its OFT appeared to be perfect! (Credit: Forbes)
The
launch of Starliner took place as scheduled at 6:36AM on December 20th with the
Atlas V booster rocket making what looked like a perfect takeoff. The trouble
started about 15 minutes later as the capsule was ordered to make a 40 second
burn designed to circularize the spacecraft’s orbit. That orbital insertion
burn suffered an ‘anomaly’ however, burning for far too long and using up the
majority of Starliner’s maneuvering fuel.
Because of that anomaly Starliner was left without enough maneuvering fuel to successfully make its planned rendezvous with the ISS. Since the mission could not complete its most important objective it was quickly decided to terminate the planned eight-day mission after only two days. Starliner’s re-entry and landing took place without incident on the 22nd of December.
The Starliner’s reentry and landing went off without a hitch! (Credit: News 13)
Faced with Starliner’s problems both NASA and Boeing stressed that had any astronauts been on board they would never have been in any danger. Indeed, it is likely that a human pilot would have recognized that there was a problem with the engine burn and quickly corrected it before the capsule had used up so much fuel.
NASA chief administrator Jim Bridenstine puts on a confident face but Starliner has problems. How long will it take to fix them? (Credit: Phys.org)
Still there definitely was a problem and speculation as to the cause is already spreading across the Internet. At the moment it appears that what happened was that the computer onboard Starliner grabbed the wrong ‘Start Time Clock’ signal from the rocket’s first stage clock. (Since the liftoff of the first stage is the official start of the mission its clock is the master clock for the entire launch system and payload.) By grabbing the wrong time Starliner thought it was in a different segment of the mission and performed an orbit insertion burn rather than the required orbit circularization burn.
How long of a delay this problem is going to cause for the Starliner program is unknown at present. The solution could be just a software fix but hey, the solution to the problems of Boeing’s 737 max 8 aircraft was only supposed to be a software fix and that program is still a mess after more than a year. The big question is probably whether or not NASA will require another OFT in order to verify that the fix, whatever it is, really works. In that event the first manned launch of Starliner would almost certainly be pushed back into late next year.
Meanwhile
Boeing’s rival Space X is also preparing for the final test of its Dragon
capsule early next month, in this case the test an in-flight abort test. So the
space race between Boeing and Space X as to which will be the first to
successfully launch a manned mission could go down to the wire. Right now it’s
anybody’s guess who will win.
NASA also has a capsule of their own, the Orion capsule which is designed to carry astronauts beyond Low Earth Orbit (LOE), back to the Moon and perhaps one day even to Mars. For its Lunar missions Orion will be launched atop NASA’s massive Space Launch System (SLS). Both programs are several years behind schedule however and in fact the problems with the completion of the SLS is causing another blackeye in Boeing’s reputation.
The Orion capsule launched atop the SLS in this artist’s impression. Maybe one day we’ll see it for real. (Credit: NASA)
The current hope is that an unmanned flight test of both the SLS and Orion, officially referred to as Exploration Mission -1 or XM-1, will take place in late 2020 with a goal of taking the capsule into and back from Lunar orbit. XM-1 will be the first mission in NASA’s ambitious Artemis program for returning humans to the Moon by 2024, a program that I have previously criticized as being already behind schedule, overly ambitious and underfunded.
Now NASA has announced plans to include two human dummies in the Orion capsule for that initial test flight. The dummies will be used to measure the effectiveness of NASA’s new anti-radiation vest known as StemRad. The space agency has long been concerned about the exposure to radiation that astronauts will be subjected to on missions beyond Earth’s protective magnetic field and into deep space. StemRad is one of the solutions the space agency is currently developing.
Model wearing the StemRad anti-radiation vest. (Credit: Space.com)
Employing
polyethylene blocks to shield against solar radiation StemRad is designed to
fit over the vital organs of its wearer giving the maximum of protection while
imposing the minimum restrictions on the wearer’s movements. Also, because
studies have shown that woman are more susceptible to harm from radiation than
men are the dummies to be sent to the Moon will be female.
The
plan for the XM-1 mission is for both dummies to be outfitted with radiation
sensors but only one will wear StemRad. A direct comparison of the radiation
exposure between the two dummies will then be a measurement of the
effectiveness of the vest. At the moment StemRad is ready to go, it remains to
be seen if Orion and the SLS will be.
Finally a somewhat smaller story caught my eye, a story about a space mission that could have huge consequences some day in the future. In my posts of 14 October 2017 and 11 May 2019 I talked about NASA’s plans for a mission to attempt to perturb the orbit of the smaller of the two asteroids in the system known as Didymos. This perturbation is intended as the first practical test of a planetary defense system. Officially the mission is known as the Double Asteroid Redirection Test or DART and the plan is to literally have a space probe slam into the smaller asteroid called Didymoon.
Radar scan from Earth based radio telescope of Didymos and Didymoon. (Credit: Wikipedia)
Scheduled to be launched aboard a Space X Falcon 9 rocket in July of 2021 the DART probe is expected to reach Didymos in October of 2022. Once DART has impacted into Didymoon Earth based telescopes will then monitor the changes in the smaller asteroid’s orbit caused by the crash.
NASA plans to impact a spacecraft into Didymoon to see what effect it will have on the asteroid’s orbit around its bigger companion. (Credit: NASA)
Of course a second space mission to measure those changes from close up would provide even more accurate measurements and now it appears there will be such a mission. The European Space Agency (ESA) has officially approved a new mission called Hera that will study the Didymos system starting in either 2025 or 2026.
The ESA’s HERA mission will provide precise follow up measurements of the Didymos system. (Credit: ESA.int)
In addition to measuring the effect of the Dart collision Hera will also land a small cubesat on each asteroid. Together the DART and Hera missions will give scientists their first actual measured data of an asteroid deflection. Such information will help in the development of a defensive program to protect our plant from an asteroid collision like the one that caused the extinction of the dinosaurs.
So as you can see it was a busy month in space. Some progress, some problems, I suppose that’s why they call it rocket science.
We humans have used the waters of our world as highways for more than ten thousand years now. We have transported ourselves and our possessions across the waves in ships that have all too often proven to be fragile when compared to the fury of the ocean’s storms.
As every seaman knows a storm at sea is much more dangerous than one on land! (Credit: Steam Community)
Modern
archaeologists look upon those shipwrecks as a treasure trove. Sent to the
bottom in almost a single moment the vessels and their cargo have remained
undisturbed by man ever since. An accidental time capsule of their time and
culture, shipwrecks contain not only those goods that were considered valuable
enough to trade with other peoples but also those items the crew and passengers
used everyday.
Throughout history there have been many attempts to salvage some of the cargo from shipwrecks that were known to be carrying treasure. The Spanish fleet that was sunk by a hurricane while transporting Aztec gold is a famous example. However, without advanced underwater technology such endeavors have been mostly fruitless. Either the wreck was too deep to be reached by free divers or the cargo was so spread across the ocean floor that very little could be found and recovered in the limited time the divers could remain underwater.
The Spanish trasported the gold they stole from the native Americans back to Europe in a treasure fleet. Not all of those ships completed the voyage. (Credit: Armstrong Economics)
Real underwater archaeology only began with the development of submersible vessels and the Self Contained Underwater Breathing Apparatus or SCUBA gear. These inventions allowed scientists to both descend much deeper into the ocean depths and remain at the bottom far longer. Nevertheless underwater archaeology remains considerably more difficult and expensive than its landlubber cousin.
The Submersible Alvin, operated by Wood’s Hole Oceanographic Institute, has explored the wrecks of many ships. (Credit: Woods Hole Oceanographic)
The inventor of SCUBA gear was Jacques eves Cousteau. (Credit: Sport Diver)
Now if you think about it there are really two distinct types of shipwrecks that are studied by marine archaeology. The difference between the two is whether or not the ship was built of wood or steel. In the former case the ship itself has almost certainly decayed away leaving only the metal or ceramic items it carried that can be recovered and studied.
In a steel shipwreck however the ship itself is the biggest artifact to be found. Think of those haunting images of the Titanic, or the Bismarck. In those cases the fact that the ship is still clearly recognizable only makes the damage the vessel has suffered more poignant.
Ghostly image of the bow of the Titanic. The ship is still recognizable despite the ravages of time. (Credit: YouTube)One of the Bismarck’s gun turrets. Again the ship is still clearly recognizable. (Credit: Pinterest)
Two recently discovered shipwrecks illustrate these differences because one of the ships has been dated to the period of the early Roman Empire while the second is a German warship that was sunk by the British during WW1. Since we know the name and historical details of the German ship I’ll begin with her.
Launched on the 23rd of March in 1906 the armored cruiser SMS Scharnhorst was the flagship of Imperial Germany’s Far East squadron tasked with the defense of Germany’s Asian colonies. At the outbreak of WW1 the commander of the squadron, Vice-Admiral Maximilian Graf von Spee was ordered to both attack British shipping as well as get his squadron back to Germany so that they could add their strength to the Imperial Grand Fleet.
The SMS Scharnhorst photographed before the start of World War 1. (Credit: Pinterest)
Steaming
across the Pacific the Scharnhorst and her companions encountered a smaller
group of Royal Navy ships off the coast of Chile at Coronel. In the battle that
followed two British ships were sunk without a single German causality.
Alarmed
by this defeat the British dispatched two Battle Cruisers and five armored
cruisers to intercept von Spee’s squadron. The two fleets met in the South
Atlantic near the Falkland Islands and in a running battle the Scharnhorst
along with three other German ships were sunk on the 8th of December 1914.
Admiral von Spee, his two sons and the ship’s entire crew of 860 went down on
the Scharnhorst, altogether 2,200 German sailors died in the battle.
To commemorate the 100th anniversary of the Falkland’s battle an effort was made to locate the wreck of the Scharnhorst. However it wasn’t until this year when the deep submersible ‘The Seabed Constructor’ along with four Remote Operated Vehicles (ROVs) became available that the Scharnhorst was finally discovered. The once feared warship rests at a depth of 1,610m and the Falkland Maritime Trust team who discovered her was careful not to disturb the wreck in any way. Indeed the marine archaeologists are seeking to have the Scharnhorst site protected by law out of respect for those who fought and died aboard her.
Sonar scan of the Scharnhorst as she lies on the bottom. (Credit: The Independent)
The
Archaeologists who discovered the Roman-era trading ship about two kilometers
outside the harbour of the Aegean island of Kefalonia did not have to worry
about disturbing human remains. Whatever members of the crew of the 2,000 year
old vessel may have gone down with the ship their bodies have long since
decayed along with the wood out of which the ship was made.
While
we have no knowledge of the ship’s name or its history at an estimated size of
35m in length by 12m in width the wreck is the largest from the classical
period to be discovered in the eastern Mediterranean.
The location of the wreck was actually discovered by a sophisticated sonar scan of the area that used Artificial Intelligence (AI) to perform the image-processing that made the wreck site discernable. After being identified as a possible archaeological site the wreck was then visited by an ROV to investigate. See image below.
The sonar scan of the Roman era wreck. Not much to see here, it takes an expert to recognize the remains as a ship. (Credit: Mother Nature Network)
The most obvious evidence remaining that there was a shipwreck at the site was two concentrated groupings of amphorae, large ceramic containers used 2,000 years ago to transport goods like olive oil, wine, nuts or grains. The two groups of amphorae, which probably relates to the ship’s forward and aft cargo holds, are estimated to contain about 6,000 ceramic vessels.
The ship itself may have decayed away but the ceramic shipping vessels known as amphorae make a ghostly impression of it. (Credit: CTV News)
So
far nothing has been removed from the site but the archaeologists at the
University of Patras who announced the discovery hope to soon recover a few of
the amphorae. Once recovered the scientists will perform a DNA analysis in
order to ascertain what sort of cargo the ship was carrying when it was sunk. A
more detailed survey of the wreckage could also teach archaeologists much about
how trade was carried out during the time of the Roman Empire.
Throughout
our history trade and warfare upon the oceans and seas has been one of the
driving forces of human progress. Thanks to marine archaeology we are learning
more and more about how that progress was achieved.
Our desire for, and our ability to produce art is one of the characteristics that separates human beings from the other animals on this world. In fact many anthropologists and psychologists would assert that that the beginning of art history is actually the beginning of human history. After all art stems directly from the human imagination, which is perhaps the thing that most makes us human.
Among the most recognizable of human creations art has a way of reaching deep into our soul. (Credit: Quora.com)
The study of early art is therefore a critical part of the study of early humanity. Examples of Stone Age art are as rare as other Stone Age artifacts however so scientists greet each new discovery as if they had unearthed a gold mine, which to them it is.
Not all Stone Age art is cave paintings. Many carvings, such as this Stone Age Venus, have also been discovered. (Credit: Britannica.com)
One of the best known forms of early art is cave painting, drawings or engravings that are found on the walls and ceilings of caves. Examples of cave art were first discovered in France in the 1940s and soon hundreds of other such decorated caves were being found throughout the world. The artwork represented in these caves varies greatly but three main themes seem to dominate, drawings of the animals that early humans lived with, drawings of humans themselves and enigmatically, outlines of human hands. These were made by the artist placing their hand on the cave wall and blowing paint, probably through a tube of some sort, onto the hand leaving an outline of the hand on the cave wall.
A few of the Cave Paintings discovered in a cave at Lascaux France. (Credit: NoiseBreak)
Are these outlines of human hands our first attempts at making our mark on the world, of leaving a legacy? (Credit: Massive Science)
Determining the age of cave paintings can be enormously difficult however and so the question of which cave paintings are oldest, and therefore where cave painting originated, can generate a lot of controversy. Europe, Africa, Asia and Australia all have examples of cave art that have been dated to more than 40,000 years ago. Perhaps rather than competing to see in which area of the world humans first began to create art we should simply marvel at how long ago it was and at the skill that even those early artists showed.
Now a series of pictograms from a cave on the Indonesian island of Sulawesi just to the east of Borneo have been discovered that may represent the oldest known attempt to tell a story with art. The images painted are familiar in some ways, figures of animals that can be identified as local species along with clearly human figures. Looking at the first image below the large image is that of species of small buffalo known as an Anoa that inhabits the island. The second image shows a local species of swine called the Sulawesi Warty Pig.
Image of an Anoa from a cave on the island of Sulawesi. (Credit: BBC)
Image of a Sulawesi Warty Pig from the same cave. (Credit: BBC)
Both animals are accompanied by human-like figures arranged in a manner that suggests a hunt. That suggestion is further strengthen by the fact that some of the humans are carrying items that could be spears or rope. If that is the case then the cave art in Sulawesi may be the earliest attempt that we know of to use art in order to illustrate a story.
However there are also several other figures that have really piqued the interest of archaeologists. These small figures appear to combine human and animal characteristics. The image below illustrates this with human-like creatures that also seem to possess a tail or snout. Such human animal hybrids, technically known as therianthropes are very common in later mythology, hey we still talk about werewolves and mermaids. To have evidence of such supernatural beings from so long ago is astounding however.
One of the strange, half human, half animal figures found in the Sulawesi Cave. (Credit: Phys.org)
As
to the age of the paintings in the Sulawesi cave the archaeologists were able
to conclude that some of the images date to as long ago as 43,900 years. They
did this by radioactive measurements of the calcite deposits that have built up
on top of the images. Since the calcite is on top it must have formed after the
images were made, measuring the ratios of Uranium to Thorium in the calcite
then tells you old it is and the images beneath can only be older.
The
cave where these new paintings were discovered is just the latest of 242
similar caves with artwork found in them on just the island of Sulawesi. How
many more caves remain to be discovered only time will tell. Cave art is
teaching us a great deal about the growth of the early human imagination, the
thing that truly sets us apart from the other animals.
