Category: Science

Magnetic Resonance Imaging (MRI), what is it like to have one, how do the work and what do they do?

MRIs (Magnetic Resonance Images) are becoming an increasingly common tool used by doctors to aid them in diagnosing the medical condition of their patients. I’ve just had my third MRI taken this morning so I thought this would be a good opportunity to talk about how MRIs work and why they are such useful tools for doctors.

Patient being prepared for an MRI. (Credit: Northwest Radiology)

For those who have never received an MRI I’ll start with a short description of the experience. First and foremost, no metal of any kind can be placed within or even near an MRI machine. MRI machines produce intense magnetic fields, so intense that magnetic materials like iron can be hurled across the room while even non-magnetic metals like copper or aluminum can be inductively heated to dangerous temperatures. Patients being examined must remove all wristwatches, rings etc. while people with metal implants in their bodies, say a steel rod to strengthen a broken bone, simply cannot have an MRI because it would be extremely dangerous for them.

The magnetic field at the center of an MRI machine can be 30,000 times as powerful as Earth’s magnetic field. (Credit: Magnetic Resonance Imaging)

There are two basic designs of MRI machines, open and closed. Closed are the original and still more common type, if only because they cost less. A closed MRI machine consists of a doughnut shaped solenoid, barely large enough to fit a slab that a person can lay on through the doughnut hole. The portion of the patient’s body being examined is kept motionless in the center of the doughnut solenoid, which produces the intense magnetic fields required for the resonance imaging.

Because the opening of the doughnut in a closed MRI machine is so small many people get a strong feeling of claustrophobia while being examined. So open MRI machines were developed with larger, more open volumes of intense magnetic field. Of course, since generating a intense magnetic is costly; generating a larger volume of intense magnetic field is even more expensive. Therefore open MRIs are less common than the smaller, less costly closed version.

Typical Open MRI machine. The extra space can make patients feel better but costs a fair penny! (Credit: Medical Imaging)

MRIs are also very noisy. If you’ve ever walked past an electric power sub-station you will have heard the 60 hertz hum of the transformers, a sound I know all too well. That sound is caused by the alternating current flowing around the magnetic core of the transformers literally causing them to vibrate. Well the magnetic fields generated during an MRI exam are even stronger, turn on and off frequently and consist of many different frequencies. All that causes the MRI machine to bleep and chirp and buzz at very loud volumes, and remember the patient is stuck right in the middle of the noise. Most states, perhaps all of them by now, require MRI patients to wear ear protection in order to prevent any damage to their hearing from the noise.

So much for the experience of having an MRI. How do MRIs work and what makes them different from say, having an X-ray taken?

Nuclear Magnetic Resonance (NMR) is a purely quantum mechanical phenomena dealing with those atoms whose nuclei possess an odd number of either protons or neutrons. Such nuclei have a sum magnetic moment of one Bohr magnetron to them and when placed into a strong external magnetic field they will align that magnetic moment with the external field. (Actually each proton and neutron have their own magnetic moment but in a stable nucleus the protons and neutrons arrange themselves so the entire nucleus has a total magnetic moment of no more than one.)

Now if a second, oscillating magnetic field is applied perpendicular to the stable field at just the right, resonant frequency the nucleus will begin to precess like a top that is losing its spin. That resonate frequency is determined by the properties of the nuclei and the strength of the stable magnetic field. That precession then causes the nucleus to radiate electro-magnetic waves in the 60-1000 million Hertz range (MHz), almost the same frequencies as broadcast television. Frequencies that radio engineers know very well how to detect and measure.

Nuclear Magnetic Resonance is caused by the precession of the nucleus of an atom. (Credit: www.jeol.co.jp)

By observing those EM waves physicists have been able to learn a great deal about the internal structure of many different nuclei with devices known as Nuclear Magnetic Resonance Spectrographs. As far as medical diagnostics is concerned however only the simple nucleus of a hydrogen atom, just a single proton, is used. You see with all of the water in our bodies, and every molecule of water having two hydrogen atoms medical MRI machines can scan our entire bodies using only hydrogen. This concentration on a single type of nucleus helps make a very expensive machine a little bit less costly.

A Nuclear Magnetic resonance Spectrograph is an instrument that physicists use to study the nuclei of various atoms. (Credit: www.the-scientist.com)

This is how an MRI machine can see inside our bodies, measuring the variations in the moisture level of our different organs by the intensity of EM radiation given off by the hydrogen nuclei in that organ. That is what makes MRIs more sensitive to things like tumors, lesions, tears and other abnormalities than X-rays. That is why more and more doctors are prescribing MRI examinations in order to help diagnose their patients medical problems, despite their high cost.

When I tore the rotator cuff in my right shoulder the Doctor diagnosed the condition using MRI. (Credit: Centeno-Schultz Clinic)
An MRI of a human brain. Images like this are teaching us so much about how the human body works. (Credit: kxci.org)

 Over the last century we humans have been developing ever more powerful and sensitive drugs, treatments and instruments for dealing with our diseases and other aliments. MRI is one of the more remarkable of those developments, allowing doctors to see inside the human body with a clarity never before possible.

Building things from living tissue. Two scientific projects highlight the advances being made in using life as a construction material.

It’s built into the language that we use, we build with non-living materials and we grow living things. Those time-honoured definitions are starting to get a little blurry however as scientists and engineers develop ever more complicated and sophisticated machines that behave almost like living things. Meanwhile there are biologists and biochemists who are working to develop techniques by which we can build things with living tissue. In this post I’m going to talk about two projects that are making considerable progress in the latter category.

As Children we quickly learn the difference between living and non-living things. Thanks to scientists today that difference is steadily shrinking. (Credit: Pinterest)

The first group, working at the University of Colorado Boulder’s Department of Civil, Environmental and Architectural Engineering, has literally discovered a method to construct a living brick, as in a brick for building your house. The bricks are manufactured by incorporating the bacteria Synechococcus cyanobacteria into a solution of sand, gelatin and a bit of water. As the bacteria metabolize the gelatin, absorbing CO2 from that air in the process, it becomes the mineral calcium carbonate, a cement that holds the sand together as in concrete.

Living bricks growing at the lab at the University of Colorado. (Credit: C4ISRNET)

These ‘living bricks’ have several advantages over the bricks that humans have made for thousands of years. As I’ve already mentioned the bacteria absorb CO2 from the air in order to convert the gelatin into cement, and in today’s world getting rid of some CO2 is definitely a good thing.

The life cycle of living bricks! (Credit: SlashGear)

However the main advantages of the living brick are twofold. First of all instead of manufacturing the bricks one at a time since they use a bacteria to bind them together you can actually grow them. So long as you have a starter brick you can produce as many bricks as you need just by adding sand and gelatin, almost like having a starter yeast in bread making. The second advantage is that when damaged, say a crack forms in the brick for some reason; the living bricks can actually repair themselves to a degree, just like a cut on your arm healing.

There are still several problems remain to be overcome, for one the gelatin is made from animal collagen and is fairly expensive in large quantities. Nevertheless it is hoped that the living brick could soon be useful in construction projects in remote locations, like perhaps Mars!

The second development project is even more ambitious, attempting to create a ‘living robot’ from stem cells, those cells in the body that have yet to be turned into muscle cells or stomach cells or brain cells. The team of scientists from the University of Vermont, Tufts University in Maine and Harvard University used the stem cells in frogs to fabricate a small living creature made up of several hundred cells living cells. The actual species of frog whose stem cells were used was the African clawed frog, Xenopus laevis and the tiny machines made from their stem cells are called xenobots. The xenobot’s outside was made of skin cells to give it shape while inside were heart muscle cells to enable it to move.

The African clawed frog, Xenopus Iaevis. Stem cells from this critter were used to manufacture the first living machine. (Credit: Wikipedia)
Introducing the Xenobot, a robot ‘manufactured from living cells. (Credit: MIT Technology Review)

But something that simply moves isn’t a robot, robots are specifically designed to execute instructions, to perform a task and the researchers have actually succeeded in ‘evolving’ their creatures to carry out simple commands. They did this by employing a computer algorithm that ‘reproduced’ inside the algorithm those xenobots that came closer to behaving in a desired manner while eliminating from the program those that did not.

A computer algorithm was used to determine where to put skin cells (green) and where to put muscle cells (red) in order to make the xenobots perform desired functions. (University of Vermont)

After several generations the researchers had developed an entirely new form of living creature that would carry out simple tasks. The researchers hope that in time xenobots could be used to help remove toxic or even radioactive material from spills, collecting microplastic particles and perhaps even removing plaque from inside our arteries or delivering drugs to areas inside the bodies.

One day perhaps xenobots will be employed in our bloodstreams to deliver drugs or even remove blockages! (Credit: European Pharmaceutical Review)

There’s a lot of work still to be done but xenobots are something entirely new, neither machine nor living creature they are a new kind of tool for us to use. Who knows what kind of jobs they’ll enable us to do one day?

Scientists make crucial discover that extends the lifespan of a worm by a factor of five! Could that discovery lead to techniques that would extend the Human lifespan?

Ever wanted to live forever? O’k maybe that’s a bit too much but how does living five times as long sound? Interested? Who wouldn’t be?

Throughout history we humans have searched for ways to extend our lifespans. We’ve tried various potions, prayers and exercise regiments without any success. The medieval alchemists actually believed that the same process that could turn lead to gold, called the Philosopher’s stone by them, would make humans immortal. I’ve never been able to figure that one out.

Recipe for a Philosopher’s Stone. I can’t figure it out but maybe you can. Do you believe there are still people peddling this nonsense? (Credit: Evolveconsciousness.org)

All of which begs the question, why do we age anyway? As children the cells of our body reproduce at a rate that actually causes us to grow, in fact some animals never stop growing no matter how old they get. Then during our twenties our cells reproduce at a rate that replaces lost cells, so that we neither grow nor decay. As we enter middle age however the reproduction of our cells drops off, our bodies don’t replace them as fast as needed, we age. So the question then becomes, what is happening inside our cells that causes the process of aging?

Some animals. like lobsters, actually don’t age at all! They just keep on growing until something kills them! (Credit: Pinterest)

It’s only been within the last few decades however that we have learned any of the details of aging at the cellular level. Surprisingly enough much of the research into the causes of aging has been conducted using a primitive nematode worm called Caenorhabditis elegans. Geneticists have several reasons for using C elegans as their test subject. First of all we share many of the genes that regulate metabolism within our cells with C elegans. Also the lifespan of C elegans is so short, only about a month, that it allows geneticists to quickly determine the results of their experiments.

C elegans, image (top) and drawing illustrating internal anatomy. (Credit: Research Gate)

Using C elegans what biologists have discovered is that much of the process that we call aging comes from a failure of the cell’s mitochondria to properly regulate their energy production. The mitochondria within the cells of our bodies are the powerhouse of cell metabolism, breaking down sugars and fats to release their energy. In fact mitochondria are so complex that they are almost cells with cells, even having their own DNA.

Cell structure with enlarged mitochondria. (Credit: Science Learning hub)

Now researchers Jarod A. Rollins at the Mount Desert Island Biological Laboratory in Bar Harbour Maine and Jianfeng Lan at Nanjing University in China have achieved some startling results in extending the lifespan of C elegans through two mutations affecting the stress response within the mitochondria. The first mutation boosts the efficiency of the Insulin Signaling (IIS) pathway and by itself has been shown to increase the life span of C elegans by 100%. The second mutation affects the TOR pathway and increases the lifespan of C elegans by 30%.

Jarod Rollings in his lab at MDIBL. (Credit: MDIslander)

Now you’re probably guessing that a double mutation that alters both pathways would increase the lifespan by 130% or so, which would still be a major result. You’d be wrong however, biological systems don’t work in such a nice linear fashion. In fact when the researchers performed the experiment they found that the lifespans of their test subjects were increased by 500%, the equivalent of a human being living to 400-500 years! Such a reaction to a combination of changes is technically known as a synergistic interaction, where a combination of therapies produces a far greater result then any single therapy.

The best news is that, since both of these pathways are also inside our mitochondria it could be possible to develop drugs that that can produce the same results inside our cells. Such drugs and other therapies are now under development and animal trials could begin soon. While it is not expected that these drugs, even in combination, will extend human lifespan by 500%, humans are a much more complex organism than a nematode worm after all, it is hoped that these therapies could help us live a healthier, more vigorous life much longer.

Imagine 80 or 90 year olds running marathons! (Credit: Pinterest)

Think of that for just a moment, not just more people living into their 80s, 90s and beyond but people in their 80s or 90s running marathons, people in their 100s who are still physically and mentally healthy. All this could be possible by proper regulation of the mitochondria in our cells.

Space News for January 2020: Space X clinches the final test of its Crew Dragon capsule before manned launches can begin.

The big news this month is of course the successful completion of the In Flight Abort (IFA) test by Space X’s Crew Dragon capsule. The test, which was conducted with an unmanned capsule, was designed to simulate a major failure of the Falcon 9 booster rocket in order to demonstrate that the Dragon capsule is capable of separating itself from its boosters in flight and returning its crew safely back to the ground. The simulated failure was scheduled to occur about one and a half minutes into the fight, the moment at which both the spacecraft and its launch system are exposed to the maximum aerodynamic pressure, making it the most hazardous time of the launch. If you’d like to watch the actual flight, it takes about six minutes, click on the link below to be taken to a YouTube video. https://www.youtube.com/watch?v=gkd5PNyRLng

Liftoff of the Space X Crew Dragon capsule on its In Flight Abort Test . (Credit: WTOP.com)

To complete the test the Dragon capsule had to separate from its boosters and deploy parachutes in order to safely splashdown in the Atlantic. Separation was accomplished by firing solid rocket engines aboard the Dragon capsule, pulling it away from the launch vehicle seconds before the first two stages were intentionally destroyed.

Firing of the Dragon capsule’s solid fuel abort engines, at top. (Credit: True Median)

The IFA test is a critical part of the checkout of the final safety system of any manned spacecraft. The importance of the in-flight abort system was demonstrated back in October of 2018 when a Soyuz rocket carrying the American astronaut Nick Hague along with Russian Cosmonaut Alexey Ovchinin failed just after launch and the Soyuz capsule’s in-flight abort system saved the lives of the two space travelers.

Failure of a Soyuz rocket back in October 2018. The crew was saved by the capsule’s abort system. (Credit: NPR)

The Space X IFA test had been originally scheduled to take place at 8AM Eastern Standard Time on the 18th of January but was delayed until the 19th because of high winds at the launch area along with choppy seas in the recovery zone. Even on the 19th the launch had to be delayed until 10:30 AM to allow clouds to disperse.

Despite the less than optimal weather the test flight itself went perfectly with the Falcon 9 rocket lifting off smoothly from launch pad 39A at Cape Kennedy. This was the fourth launch for the first stage of the Falcon 9, an example of Space X’s commitment to reducing the cost of space travel by reusing every part of the launch system that it possibly can.

For the next minute and a half minute everything appeared just like a normal launch until exactly on schedule the Dragon Capsule was yanked away from its boosters by the solid fuel rockets. Seconds later the Falcon 9 booster was detonated on command while the capsule began dropping back to Earth.

Destruction of the Space X Falcon 9 booster rocket during the IFA test. The capsule got safely away. (Credit: Space News)

As the capsule entered the denser part of the atmosphere drogue parachutes were deployed in order to stabilize the capsule’s orientation. About a minute later the four main ‘chutes deployed slowing the capsule’s descent until it landed softly in the ocean.

Seen from inside the Dragon capsule the four main parachutes are a beautiful sight. (Credit: CNBC.com)

Immediately small recovery boats headed toward the capsule, a practice run for how they would rescue the crew of any aborted manned mission. A large recovery vessel later rendezvoused with and lifted the capsule out of the ocean. Less than twelve hours after it had lifted off the Dragon capsule would be returned to Cape Kennedy, mission accomplished.

The Dragon capsule returning to the Cape less than twelve hours after completing its IFA test. (Credit: Spaceflight Now)

Now the finer details of the test still have to be reviewed by NASA and Space X engineers, but nevertheless the Dragon capsule’s IFA test was clearly a success. If the test had been a real launch failure of a manned mission the astronauts on board would have survived the failure without any serious injury.

With the IFA test accomplished Space X can now prepare for their first actual manned launch, which company CEO Elon Musk has stated will take place sometime within a April to June time frame. So the next time a Falcon 9 rocket with a Dragon capsule lifts off from the Cape it will be the first time in nine years, since the end of NASA’s shuttle program, that American astronauts will fly into space aboard an American rocket from American soil.

The first astronauts to ride a Dragon capsule into space will be Bob Behknen (r) and Doug Hurley (l). (Credit: Electrek)

A Quick Update on an Earlier Post:

Just a week ago, on the 18th of January I posted an article about the observation that the red giant star Betelgeuse has been rapidly dimming in brightness and could be in the early stages of exploding as a Type 2 Supernova (SN2). Since that time the massive star has continued to dim, its brightness is now less than at any time since astronomers first began taking accurate measurements of its luminosity back in the 1920s. See graph below.

Betelgeuse is a variable star but recently its brightness has dimmed more than ever seen before. (Credit: AAVSO)

Our theories about SN2 tell us that Betelgeuse will go nova sometime in the next 100,000 years or so, but is that time now? Astronomers think that’s unlikely but you can bet that they will be keeping a close eye on Betelgeuse in the near future.

Paleontologists discover possible oldest fossil intestines. These fossils could help show a path from the earliest multi-cellular life to the more familiar lifeforms of today.

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.

Type 1 Supernovas, how do they differ from Type 2 Supernovas and how that makes them important to our understanding of the size and evolution of the Universe?

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.

The Type 2 Supernova SN1987a, before (r) and during (l) images. (Credit: “© Anglo-Australian Observatory” and (optionally) “Photograph by David Malin”)

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.

Book Review: ‘Artificial You’ by Susan Schneider

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.

The red super giant star Betelgeuse in the constellation Orion has lost half its brilliance. Could that mean it is about to explode as a Supernova?

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.

Space News for December 2019.

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.

Marine Archaeology: Two newly discovered shipwrecks illustrate both the difficulties and the promise of studying the human past at the bottom of the ocean.

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.