Tiangong-1 is falling, Tiangong-1 is falling, but don’t worry, it won’t hit you on the head.

Over the last several weeks it’s been next to impossible to avoid all of the news stories telling you about how China’s first space station the Tiangong-1 is out of control and will come crashing back to Earth any day now. The headlines grab you by announcing the crash is bold letters while the small print inside reveals that there’s a one in ten billion, or less, chance that anything will actually hit you.

The Tiangong-1 station, Tiangong means ‘Heavenly Palace’ in Chinese, was launched by China in 2011 as both a target for practicing rendezvous maneuvers in space as well as some extra living space for the crews of their Shenzhou manned spacecraft. The design of the Tiangong-1 station is based upon the design of the Shenzhou but with a slightly larger habitable section giving it a slightly greater mass (8500kg versus 7840kg for the Shenzhou). The image below compares the Tiangong and Shenzhou.

Tiangong-1 space station and the Shenzhou-8 spacecraft. (Credit: The Daily Mirror)

Like the United States’ Skylab and Russia’s Salyut early space stations the Tiangong-1 was launched into space unmanned and in one piece and then visited several times by manned spacecraft. The Shenzhou-9 mission rendezvoused with the Tiangong-1 in June of 2012 with a crew of three and stayed for ten days while the Shenzhou-10 mission, also with a crew of three, visited the Tiangong in June of 2013.

In both of these missions China’s growing space program demonstrated the ability to carryout the routine operations necessary for more complicated space missions in the future whether that be building a modular space station or even missions to deep space. The image below shows the launch of the Shenzhou-9 mission on its Long March 2F rocket.

Launch of Shenzhou-9 on a Long March 2F rocket (Credit: CCTV)

After the two successful missions to Tiangong-1 China launched the Tiangong-2 station as a replacement for Tiangong-1 and the first station was then placed into a sleep mode. The plan was to maintain Tiangong-1 in orbit as a test platform for the longevity of both components and systems in a space environment before the station was brought back to Earth in a controlled reentry into an ocean.

Apparently that test didn’t go so well because on 21Mar2016 China’s Space Engineering Office announced that they had lost their radio telemetry link with the station. Amateur satellite watchers soon confirmed that the Tiangong station was tumbling out of control. Notice how China never actually admitted that the station was out of control.

It wasn’t long before scientists were calculating that the Tiangong-1 would be making an uncontrolled reentry back to Earth sometime in either March or April of 2018. That estimate has since been fine-tuned down to between 29Mar and 9April of this year.

So here we are, all of the news stories loudly telling us that Tiangong-1 is falling out of control, is there any real danger? Well first of all let me tell you that most of the station will burn up during reentry, only a few hundred kilograms of material are expected to survive to reach the ground. Also remember that the Earth’s surface is 70% ocean so Tiangong will probably sink without a trace.

Then, even if Tiangong does hit dry land there are literally millions of square kilometers of emptiness out there so the odds of anyone being hurt are less than ten billion to one. In fact when the much larger and heavier US Skylab station also fell to Earth in an uncontrolled reentry back in 1979 pieces of it fell near the city of Perth Australia but no one was injured in any way. A few people did get some really neat pieces of space debris however as souvenirs.

Finally, the orbit of Tiangong is tilted at an angle of 42.8º to the equator. That means that Tiangong never goes further north than 42.8º of Latitude nor further south than 42.8º. If you live outside of that band you have absolutely nothing to fear.  See the image below to know if you should be worried. I live in Philadelphia at a latitude of 40º  but I ain’t gonna fret!

Tiangong-1 will fall somewhere between 40N and 40S (between the Lines) (Credit: Mail Online)

Ball Lightning: The Mysterious Phenomenon that has produced more Theories than detailed Observations.

Descriptions of the strange, almost unearthly phenomenon known today as Ball Lightning date back as far as Aristotle. However the recorded incidents of ball lightning have been so infrequent, and the behavior of the phenomenon so varied, even contradictory that up until the mid-twentieth century many if not most scientists regarded ball lightning to be an imaginary rather than a real physical event. The image below shows an illustration of a nineteenth century occurrence of ball lightning.

19th Century Illustration of Ball Lightning (Credit: Public Domain)

It is true that ball lightning can range in size from less than a centimeter to as much as a meter in diameter. The colour of ball lightning can also vary tremendously although red, orange and yellow predominate. The movement of ball lightning is generally horizontal but they have been known to move up or down or even remain motionless. They can even appear right out of walls or other solid objects.

Perhaps the greatest variance in the different observations of ball lightning however is in the way they dissipate. Sometimes they can just disappear like a light bulb that’s turned off while sometimes they disappear by passing into walls or other solid objects. And then sometimes they can explode doing considerable damage and even death. The image below shows of modern photograph of ball lightning.

Photograph of Ball Lightning (Credit: Miyuki Ishikawa)


About the only things that all the different reported incidents agree upon is that ball lightning usually occurs during a thunderstorm and normally right after ordinary cloud to ground lightning bolt has struck nearby. Over the last century however reports of ball lightning have also been connected with heavy electrical equipment like generators and there are even reports of ball lightning occurring in submarines during World War II went the sub was switching from its diesel engines to battery power.

Theories about the nature of ball lightning abound and over the last 50 years scientists have even succeeded in produced ball lightning-like objects in the labouratory. Despite these successes there are arguments as to whether those labouratory creations are the ‘real’ ball lightning. The image below shows one of the labouratory attempts to create ball lightning.

Ball Lightning in the Lab (Credit: Narod.ru)

The best data concerning natural ball lightning comes from a group of scientists from Northwest Normal University in Lanzhou China who in July of 2012 were studying ordinary cloud to ground lightning on the Tibetan plateau. While they were making their observations they spotting ball lightning and were able to record 1.6 seconds of video of the event. Because the cameras that the scientists were using in their cloud to ground lightning observations were equipped with slitless spectrographs the researchers also succeeded in obtaining the first ever optical spectra of ball lightning.

The spectra obtained by the scientists showed strong emission lines for the elements of silicon, calcium, iron, nitrogen and oxygen. The spectra also showed that the ball lightning had a temperature of less than 14,000K. See spectra below.

Spectra of Ball Lightning (Credit: Wikipedia)


This remarkable data has bolstered one of the leading theories about the origin of ball lightning, the ‘Vapourized Silicon Hypothesis’. In this model ordinary lightning strikes the ground vapourizing and ionizing the silicon-dioxide in the soil. As the vapour cools the silicon becomes an aerosol that is bound together by the charges on the ions. The glow of the ball lightning is produced as the silicon recombines with the oxygen.

There are rival hypotheses however, some rooted in solid science, some a little bit kooky. The Microwave Cavity Hypothesis considers ball lightning to be generated by microwave radiation that ionizes the air with the discharge of that ionization causing the glow. The problem with this idea is that while ordinary cloud to ground lightning does produce a lot of radio energy most of it is in the AM and short wave bands rather than microwaves.

Then there’s the Electrically Charged Solid Core hypothesis where a solid object acquires a positive electric charge and becomes surrounded by a layer of electrons. A microwave field keeps the positive and negative charges apart and the high voltage generated between the charges is what we see as the ball lightning. In addition to requiring microwaves again this hypothesis also requires a solid object inside the ball lightning, something not seen in any observations, as well as being something that would have difficulty in passing through solid walls!

Among the more outlandish suggestions there is the mini-black hole model where an atom sized, primordial black hole is passing through our atmosphere and we see it as ball lightning. However there is no reason for a mini-black hole to be as closely associated with ordinary lightning or large electric generators as ball lightning certainly is. Also a mini-black hole would not simply blink out of existence as ball lightning is known to often do.

The mystery of ball lightning will probably continue for some time into the future. However, with so many people nowadays carrying cell phone cameras with them we are likely to get more and better observations of the phenomenon. At the same time scientists will continue working in their labouratories to discover more ways of creating ball lightning-like objects. Considering only 50 years ago some scientists even doubted the existence of ball lightning we’ve made a lot of progress. Clink on the link below to be taken to a youtube video of ball lightning taken outside New Orleans in 2015.



Volcanic ‘Hotspot’ that formed the Hawaiian Islands moved about 50 Million Years Ago.

Geologists have learned a great deal in the last fifty years about the mechanics of how volcanoes are created and operate. According to the modern theory of ‘Plate Tectonics’ the surface of the Earth consists of a number of hard plates that ride over our planet’s softer, more fluid mantel. These plates move around the surface of the earth very slowly with time. As the plates move they can either pull apart from or collide into each other and those are the areas of the Earth where seismic activity like earthquakes or volcanoes normally occurs.

Normally, but not always, the volcanoes that have formed the Hawaiian Islands are a major exception to this model. Geologists have recognized the existence of a stationary ‘Hotspot’ in the Pacific Ocean that is presently feeding the active volcano of Kilauea on Hawaii’s big Island.

The Kilauea volcano is only about half a million years old however and before then the hotspot generated the now extinct volcanoes of Mauna Kea, Diamond Head and all of the other volcanoes of the Hawaiian chain. The images below show Kilauea and Diamond Head.

Kilauea Volcano (Credit: Milliyet.com)
Diamond Head extinct Volcano (Credit: lexpress.fir)

In fact, as the Pacific Tectonic Plate has moved northwestward over the last 70 million years the hotspot has generated a long series of now extinct volcanoes known as the Hawaiian-Emperor chain. Most of these volcanic peaks have now dropped back below the surface of the ocean but the entire chain stretches in a straight line from Kilauea almost to the Aleutian Islands. The illustration below shows what the Hawaiian-Emperor chain would look like if the water of the Pacific Ocean were removed.

Hawaiian Emperor Volcano Chain (Credit: Earth Science)

Recently more accurate underwater mapping of the Hawaiian-Emperor chain has led researchers at the GFZ Research Center for Geosciences in Germany to conclude that the Hawaiian-Emperor chain may not be as straight as was thought. According to the scientists at GFZ about 47 million years ago the chain took a temporary bend to the left, as seen from Hawaii, an indication that the hotspot had moved several dozen miles to the south over the course of around a million years. The image below shows the bend identified by the geologists.

Bend in the Hawaiian-Emperor Hotspot (Credit: T. Torsvik, GFZ)

“If you try to explain this bend with just a sudden change in the movement of the Pacific Plate.” Says Bernhard Steinberger a researcher at GFZ. “You would expect a significantly different direction of motion at that time relative to adjacent tectonic plates. But we have not found any evidence for that.”

The scientists also checked the position of the Hawaiian hot spot against two other hot spots, the Rurutu volcanic chain in the western Pacific and the Louisville chain in the southern Pacific. The results indicate that it was the Hawaiian hotpot that moved some 50 million years ago.

The geologists at GFZ will continue to study the movement of the Hawaiian hotspot. “With more field data and information about the processes deep in the mantel, we hope to explain in more detail how the bend in the Hawaiian-Emperor chain has evolved.” Steinberger said.

The more we learn about volcanoes the better we will be able to understand how the Earth itself works. I look forward to hearing more from the GFZ Research Center for Geosciences about their work on the Hawaiian hotspot.


Movie Review: Annihilation. H. P. Lovecraft’s ‘The Colour out of Space’ updated with a lot of Unnecessary Emotional Baggage.

Annihilation (Credit: Paramount Pictures)

At the beginning of Paramount Pictures new Movie ‘Annihilation’ we witness a meteor streaking through the atmosphere to wind up crashing into a small lighthouse. A little while later we learn that the lighthouse has become the center of an unearthly ‘shimmer’ that is slowly growing and that anyone who enters the shimmer never returns.

After several failed expeditions a team of five women enter the shimmer to discover that the plants and animals are all mutating. It was at this point, not quite halfway into the film that I said to myself: ‘this is the Colour out of Space by H. P. Lovecraft’. Actually ‘Annihilation’ would have been better if it had just stuck to being an update of Lovecraft’s story.

For those who haven’t read Lovecraft, in the ‘Colour out of Space’ a meteor lands on a New England farm and a strange unearthly colour (Lovecraft was thinking of something like Ultraviolet or Infrared light but somehow alive) begins to spread. The colour proceeds to suck the life out of every living thing on the farm.

O’k so in ‘Annihilation’ the meteor lands in a lighthouse instead of a farm, it generates a shimmer rather than a colour and causes mutations instead of sucking the lifeforce but those are just details. It’s really the same story plot.

Some of the Mutations in Annihilation (Credit: Paramount Pictures)

The only part of ‘Annihilation’ that is different is an idea that gets mentioned along the way that anyone who volunteers for a suicide mission must have something terribly wrong with their life. The main character Lena, played by Natalie Portman certainly does. Her husband joined an earlier mission into the shimmer because he found out she was having an affair and now she feels guilty about him so she volunteers for the next mission. Much too much of the movie is taken up with this pointless subplot.

Oh, I know. Nowadays when you tell a story you simply have to have well-developed characters that your readers or viewers can care about. You can take it from me however, there’s no one in this movie to care about. Also you can add the fact that the ‘surprise ending’ simply wasn’t.

Now Annihilation wasn’t all bad, the special effects were good and the basic idea of something really alien coming to our world on a meteor is intriguing. In fact it is revealed later in the movie that the shimmer isn’t causing mutations so much as mixing the DNA of different creatures.

Then when Lena finally reaches the lighthouse we see things like glass trees along the beach. Since glass is made out of sand I started to wonder if the shimmer is now mixing life and non-life! That would have been cool but nothing is done with the concept!

Glass Trees that nothing is done with! (Credit: Paramount Pictures)

Really, eliminating the trite infidelity subplot and putting a lot more thought into the Science Fiction elements would have made Annihilation a much better film. As it is we never learn anything about why this ‘Shimmer’ came to Earth or where it came from or what it is trying to do.

Annihilation is based on a novel of the same name by Jeff VanderMeer (who also wrote the screenplay with director Alex Garland) and is the first part of a trilogy. Maybe in the other novels we get some of the answers but frankly I don’t know if I’m interested. I think I’ll reread ‘The Colour out of Space’ instead.

The Colour out of Space by H. P. Lovecraft (Credit: Classics Illustrated)


Amateur Astronomer trying out his new camera accidentally photographs the first instant of a Supernova explosion.

Supernovas are among the most energetic events in the entire universe. A star, at least five times the mass of our Sun ends it’s life in a tremendous explosion that for a few weeks can be as bright as an entire galaxy of 100 billion stars. Supernovas are so bright in fact that they are usually observed and studied in other galaxies sometimes billions of light years away. Supernovas are also one of the most keenly studied class of objects in the Universe with astronomers and astro-physicists searching tirelessly for any new scrap of information, any new observation.

Now supernovas might be very bright, but usually they’re also very far away and since they occur randomly anywhere in the sky, they can often be hard to spot. The way that astronomers find a supernova is to compare a picture of a far off galaxy with a picture of the same galaxy taken a month or more ago. If a new star appears in the latest picture, you’ve got a supernova.

The problem with that technique is that astronomers have only ever seen a supernova several days or more after the explosion has taken place. They’ve never actually seen the first moments of the supernova explosion itself.

Until now, in September of 2016 an amateur astronomer named Victor Buso of Argentina was testing out a new camera with his 16-inch telescope when a supernova happened right in his field of view. Buso was taking one exposure every thirty seconds of a galaxy designated NGC 613 for a period of twenty-five  minutes and managed to capture the rapid increase in brightness, what astrophysicists call the ‘Shock Breakout’ of the supernova. The image below shows an image of NCG 613 with the supernova bracketed by the red lines.

Supernova SN2017 gkg (bracketed by red lines) Credit: Carnegie Institute of Science, Las Campanas Observatory)

Four of the images captured by Mister Buso are shown below with the supernova, which has been designated SN 2016 gkg, inside the red circle.

Four of the Images Captured by Victor Buso of SN 2017 gkg (Credit: Victor Buso)

In the first image, labeled 1:44 AM, the supernova is not visible but in each of the succeeding three images it grows brighter. According to astronomer Alex Filippenko of the University of California at Berkeley, “Professional astronomers have long been searching for such an event.” Adding. “Buso’s data are exceptional. This is an outstanding example of a partnership between amateur and professional astronomers.” The image below shows Mister Buso proudly standing by his telescope, and he has a great deal to be proud about.

Victor Buso and his 16″ Telescope (Credit: Nature)

Once Mister Buso realized what he’d discovered he quickly contacted the Instituto de Astrofisica de La Plata in Argentina and within hours astronomers around the world were hard at work learning everything they could about Buso’s supernova.

Examining the spectra of the SN 2016 gkg enabled an international team of astronomers to determine that the supernova is a type IIb. The spectra of this type of supernova is rich in hydrogen and is the violent death of a star calculated to be five times the mass of our sun.

There are several well-known stars in our night sky that could be headed toward the same end as SN 2016 gkg. Betelgeuse and Antares are large, very massive stars that are approaching the end of their nuclear fuel and it is believed that they will both become supernovas ‘sometime in the next million years’.

Right now however scientists do not know how to predict exactly when a star will go nova but a lot of progress has been made in the last twenty years. (See my post of 11January 2017) Hopefully Victor Buso’s discovery of SN 2016 gkg will provide more data for astro-physicists to check their current theories against, and to help them generate newer, more accurate models of supernovas.

Scientists at CERN take Anti-Matter for a Sunday Drive, and just what is Anti-Matter anyway.

We’ve all heard about anti-matter. We’ve been told that anti-matter is made up of anti-particles which are some weird mirror images of familiar particles like the electron or proton. We’ve also know that whenever a particle and its anti-particle come in contact they annihilate each other leaving only a burst of energy.

I know that anti-matter seems like the stuff of science fiction, after all doesn’t the starship Enterprise in Star Trek have matter / anti-matter engines. Anti-matter isn’t real, it’s just some strange theory that Einstein or some other physicist thought up, right?

It’s true that the English physicist Paul Dirac predicted the existence of anti-matter in 1926 as he was trying to mathematically combine Einstein’s special theory of relativity with quantum mechanics. What Dirac’s calculations told him was that for every kind of particle there should be another particle, having the same mass but the opposite charge. Even Dirac wasn’t certain what to make of his own prediction.

It was only six years later in 1932 however that the first picture of an anti-particle was taken by the American physicist Carl Anderson who was doing research on the cosmic ray particles striking our planet from outer space. That first evidence of the reality of anti-matter is shown below in a picture made in what is known as a cloud chamber.

First Photograph of an Anti-Particle taken by Carl Anderson (Credit: Public Domain)

Since the time of Dirac and Anderson physicists have continued to study anti-matter in cosmic rays. Not only that but they have also used their high-energy atom smashers; we call them particle accelerators nowadays, to actually manufacture anti-matter.

How do they manufacture anti-matter you ask? Well if a particle and anti-particle annihilate each other leaving only energy, then energy can be separated into a particle and its particular anti-particle. Out of the debris that comes from collisions in particle accelerators we have found the anti-particle of nearly every known particle. The photon of light is an exception because it is actually its own anti-particle! Below is an image taken of the products of some of these collisions along with a breakdown of what is happening.

Bubble Chamber Photograph from CERN (left) along with analysis of interactions (Credit: CERN)

Handling the anti-matter is obviously a delicate task but slowly scientists are learning how to confine charged anti-particles in a vacuum bottle with a magnetic field that keeps the particles from even touching the bottle’s walls. Using such a magnetic bottle the physicists at CERN now plan for the first time to transport anti-protons from the labouratory where they were produced to another labouratory at the CERN facility.

You see the physicists working on the PUMA experiment (that’s the anti-Proton Unstable Matter Annihilation experiment) are studying the structure of Protons and Neutrons in large, unstable nuclei. The researchers working on PUMA intend to use the anti-protons as probes that can tell them a great deal about the arrangement of the protons and neutrons in the nuclei that they study.

You remember from high school that the nucleus of every atom is made up of protons and neutrons. You may also recall that the lighter, more stable nuclei like Carbon-12 have six protons and six neutrons, an equal number of each. However large unstable nuclei like Uranium have more neutrons, 146 than protons 92 and physicists want to learn the details of how the different particles arrange themselves.

Now an anti-proton will annihilate a proton but it will also react with a neutron in a different way so observing the reactions will paint a picture of the structure of the target nucleus. The planned setup for the PUMA experiments is shown in the image below.

Outline of PUMA experiment at CERN (Credit: Nature)

There are still a lot of things we don’t know about anti-matter and scientists will continue to study these mirror particles for years to come. However it is a measure of how much we’ve learned that we are now using anti-matter to study other phenomenon.


Guns and Gun Violence: Just the Facts, Part Two.

This is the second part of a two-part post concerning guns and gun violence here in the United States. In the first part I compared gun violence in the US to that in nineteen other nations starting with a comparison of gun ownership to the rate of gun violence.

I also considered the question of whether simply removing guns would only result in murders being committed by other means. In other words, ‘guns aren’t the problem, people are the problem’. Finally I looked at how gun suicide is actually a much greater problem than gun homicide.

In today’s post I intent to continue to look at the issue of gun violence from state to state within the US. As in the first part I will try to only present the facts and allow you to make up your own mind. Consider the evidence below and hopefully we can find some solutions to this horrific problem.

One thing I discovered in researching data for this post is that very often it is impossible to find the exact same type of data for different countries or different areas within a country. For example in my last post I described the number of guns in a country as the number of guns owned per person, which was the statistic I used.

However for different states within the United States that statistic is not available. What statistical measure is available is the percentage of households in each state with a gun, which is the statistic I will employ today. The fact that different governments and agencies within governments often keep different statistical measurements is one of the reasons why making sense of issues like gun violence is so very difficult.

In the table below I list twenty states and the percentage of households in those states that possess guns. The states were chosen at random except I intentionally included my home state of Pennsylvania.

Table 1

Column 1 of the table gives the percent of households with guns while column 2 gives the number of gun related deaths per 300,000 people in those states. The relationship between those statistics can be seen more clearly when they are plotted together as in Figure 1.

Figure 1

The figure makes clear the dependence of gun violence on gun availability. I’ll bet you didn’t know that Arkansas was so much more dangerous a place that New York or New Jersey. Those states with stricter controls on guns simply have less gun violence, that is just a fact.

However, as in my last post we must consider the argument that if people can’t get guns they will still commit murders with other weapons. To analyze that argument I will plot the total number of homicides in each state (in table 1 the far column on the right) versus the number of homicides committed by guns (third column from the left) in Figure 2.

Figure 2

This figure shows clearly that the total number of homicides in a state tracks pretty well with the number of gun homicides. The percentage of total to gun homicides (shown in the second column from the right) varies between about 75% and 55%, except for Hawaii which has hardly any gun homicides.

So for the argument that if people can’t get guns they’ll still commit violence with other weapons consider this. Arkansas has almost no gun restrictions and people there choose a gun to commit murder 71% of the time. Meanwhile New Jersey has some of the most restrictive gun laws in the US and there people use a gun to commit murder 71% of the time. The people in New Jersey are not using other weapons to kill each other they are actually killing each other less often!

In my last post I also discovered that a greater availability of guns in a country greatly increased the number of gun related suicides in that country. I will now show that this is also true for the states within the US. Figure 3 shows a breakdown of the total number of gun deaths into homicides and suicides along with accidental gun deaths.

Again it can be seen that the number of gun suicides is higher than gun homicides in all but two out of twenty states. In fact, what is going on in Montana which has relatively few gun homicides but by far the greatest number of gun suicides! The Suicide rate there is more than ten times the homicide rate!

I don’t know about you but I think I learned quite a bit in researching the statistical evidence for these last two posts. I particular I admit I was shocked by the amount of gun related suicides.

However all of the evidence I’ve shown here only confirmed something I had already known before I started. More Guns Just Means More Violence! This is true whether you are considering gun violence across different nations (as in Figures 1 and 2 in my last post) or across different states (as in Figure 1 of this post).

Also, while it is true that people will commit violence even without guns the reason we so often choose guns to commit our violence is because they make it so easy to commit violence. Guns make us more efficient killers and therefore just increase the bloodshed.

It’s just a fact that the countries with fewer guns, Denmark, England or Japan for example, have less violence, not just less gun violence. The same is true of states; Hawaii and Massachusetts are just safer places to live because they have fewer guns!

I’ll end my analysis here. The evidence speaks for itself.

Guns and Gun Violence: Just the Facts, Part One.

Gun violence, and the use of gun control in an effort to reduce that violence, is arguably the most contentious issue plaguing the United States today. The arguments both for and against, along with their proponents have become so entrenched, and so heated that the actual facts get lost in a flood of rhetoric and vindictiveness. All too often the talking heads in the media skip over the available objective evidence in their hurry to tell you what ‘Is the only possible solution’.

Now before I begin, I’m going to try to just give the facts, no proposals about what we have to do. I only ask you to consider the evidence cited below and make up you’re own mind. I’ve always hated it when anyone told me what to think or do so I will try my best to avoid doing that.

This will be a two-part post. Today I will be comparing the situation here in the United States to that in other nations while in my next post I will examine the nature of gun violence between different states within the US.

Also, the evidence given below is statistical in nature. We are dealing with the populations of countries and states numbering in the millions. We will be considering crimes numbering in the tens of thousands. Only statistical methods can adequately describe the behavior of such large groups, which are technically know as ensembles. Anecdotal evidence of the sort ‘there was this guy in outer Slobovia who stabbed a bunch of people so see, guns don’t kill people, people kill people’ is immaterial and indeed, can be little short of a falsehood. (Obviously the example I just made up is a falsehood)

First of all let’s just consider these two questions, how many guns are there in the US and how does that number that compare with that in other nations. In table 1 below the first column gives the number of privately owned guns for every 100 persons for both the US and 19 other nations.

Table 1


(At this point I must admit that, aside from trying to get at least two countries from every continent, I just picked the first 19 countries I thought of with 2 big exceptions. Russia and China have not been included because I was unable to obtain the information I needed about them. I suppose their governments don’t want us to make any comparisons about them. The data above is the latest I could find dating from 2014 for the US and 2011 and after for the other countries)

(Also the data which is given in the table above and used in the figures below comes from GunPolicy.org at the University of Sidney Australia which you can visit at the link below)


In the table it is clear that the US possesses fully three times as many guns per person as any other nation. Comparing this value with the number of gun deaths per 10,000 people every year, which is listed in column two, we can see the relationship between the number of guns in a country and the rate of deaths caused by guns. This relationship can be more clearly seen if the two columns are plotting together as shown in Figure 1 below.

Figure 1

Two things are immediately clear from the figure. The first is that three nations, The US, Mexico and especially Brazil have far higher rates of gun deaths than any of the other 17 countries. The second is that, with the exception of Mexico and Brazil, gun ownership per person tracks very well with gun deaths per 10,000 each year.

Statistically Mexico and Brazil are called outliers, that is there is some factor causing a high rate of gun deaths in those nations that is not a factor in the other 18 countries. Indeed anyone who follows world events knows that Mexico and Brazil are both are fighting bloody civil conflicts against well-organized criminal gangs, a condition that is not present in our other countries.

Since we are trying to determine the effect of guns on gun deaths, not the effect of organized crime, we are justified in removing the outliers from our data set provided we make it clear that we are doing and detail our rational for doing so, as I have done above. With Mexico and Brazil removed Figure 1 now becomes Figure 2.

Figure 2



The relationship between gun ownership and gun death can now be clearly seen, you can almost write it as an equation. For every gun owned per person in a country, one person out of 10,000 will be killed by a gun every year.

At this point it can be argued that guns are not the only way to kill someone, indeed people were killing each other on a regular basis long before guns were invented. If you reduce the number of guns the argument goes, won’t people just go back to killing each other with swords or knives or even rocks if they have to?

In order evaluate this argument I will now plot the total homicides, murders by all kinds of weapons, versus gun homicides only. For the argument to be valid, nations with low gun ownership should have a large difference between the two numbers due to homicides by other means. This comparison is shown in Figure 2.

With respect to the data in Table 1 I am now comparing the third column from the left with the last column all the way on the right.

Figure 3


This figure does in fact appear to bare out the argument that taking away guns won’t stop violence. Consider India for example. India has the second highest total homicide rate but very, very few gun homicides. Checking table 1 for gun ownership in India we also see that the country possesses very few privately owned guns so India’s problem with violence cannot be linked to guns. To a lesser degree the same can be said for Norway and Vietnam which also have a fairly large number of homicides but few of them are gun related.

Nevertheless that is only three out of twenty nations and even India’s second highest total homicide rate is still significantly lower that that of the United States. While it is true that if people really want to kill each other they will find a way to do it, it is also clearly true that readily available guns just make it so much easier to commit murder! It is true that people kill people, but guns multiply the body count by a large factor!

As a last issue for analysis today I’d like to take a closer look inside the figures for the number of gun related deaths for each nation. You see those deaths are not all homicides, gun suicide and accidental gun deaths are also a significant factor. Very significant as you can see in Figure 4.

Figure 4


I have to admit that this result shocked me. The number of gun suicides in the United States is nearly double the number of gun homicides. In plain English we are killing ourselves twice as often with our guns as we are killing someone else. The chart shows that this ratio is approximately true in general around the world.

Surely we can all agree to do something about this aspect of gun violence. Surely we can find ways to prevent people who admit that they are suffering from depression or other mental problems from obtaining the guns with which they kill themselves. Even just allowing doctors and psychologists to try to convince those of their patients who are depressed to voluntarily give up their right to bare arms could make a significant difference.

But I guess I’m now crossing over into telling you what I think should be done and I promised not to do that. Rather than go any further I’ll stop here for today. In my next post I will look at how gun violence differs from state to state within US.


New developments in Prosthetic and Robotic Engineering, E-skin and Smart-arms.

Scientists and engineers are making rapid progress in the development of artificial manipulative limbs that are both as dexterous and sensitive as human arms and hands. A significant step in that direction has been taken by researchers at the University of Colorado in Boulder who have created a new form of electronic or e-skin.

The new material is composed of a type of polymer known as a polyimine to which silver nanoparticles have been added to give it strength, stability and electrical conductivity. The e-skin can be formed into thin, translucent sheets that can be wrapped around artificial limbs. The material can also have sensors embedded within it given the e-skin the ability to sense pressure, temperature and even humidity, making the artificial limb more like a real human one. The image below shows a sample of e-skin on a real human arm for comparison.

E-skin (Credit: Jianliang Xiao, University of Colorado Boulder)

The ability to sense pressure in particular has long been a goal of researchers. Think of how difficult it would be to pick up an egg or a glass of water if you couldn’t tell whether or not you were squeezing it too hard.

This new technology will give both human prosthetics and robots the ability to feel as if they had human skin. According to Chemistry Professor Wei Zhang of CU Boulder and co-author of the study; “If you think about what real skin can do, real skin can prevent people getting burned…can prevent people getting hurt.”

Program leader Jianliang Xiao, Professor of Mechanical Engineering describes the benefits of e-skin in robotics. “Sensing is important because when human beings interact with robots we want to make sure that robots don’t hurt people.”

E-skin has several other amazing properties as well. For one the material can repair itself simply by mixing the compounds from which it is formed in ethanol and applying the mixture to the damaged area. Finally, e-skin can even be recycled by immersing it in a solution that breaks it down into its component chemicals that can then be reused to produce new e-skin. Even the silver nanoparticles can be recovered as they sink to the bottom; nothing is wasted or thrown away.

Other scientists are also working on other versions of e-skin so one thing is certain, prosthetics like Luke Skywalker’s arm and androids like Data are only a matter of time.

At the same time scientists are also busy working on improving the interface between the human nervous system and artificial limbs with the goal of increasing the dexterity of prosthetic devices. Considerable progress is being made at the OrthoCarolina Reconstructive Center for Lost Limbs by hand surgeons Glenn Gaston M. D. and Bryan Loeffler M. D.

What Doctors Gaston and Loeffler have developed is a surgical technique to transfer nerves that once controlled the lost hand of amputees to other parts of the arm, reinserting those nerve endings into another muscle. The signals that would have been sent from the brain to the hand through these nerves can then be picked up by transducers implanted in the same muscle as the nerves and used to control a prosthetic hand. In other words the patient controls their new, artificial hand just as they had their natural hand. See images below.

Artificial Hand (Credit: OrthoCarolina, CNN)
Artificial Hand (Credit: OrthoCarolina, CNN)

Doctors Gaston and Loeffler call their procedure ‘Targeted muscle reinnervation surgery’ and so far they have had amazing success giving their patients artificial arms and hands with the ability of control the wrist, thumb and fingers as a group. In one recent operation however a man who had lost his middle, fourth and little fingers was given a prosthetic that for the first time the ability to control each artificial finger separately, a major advance. See image below.

Three Finger Prosthetic with Individual Finger Control (Credit: OrthoCarolina, Fox News)

Combining the progress of the University of Colorado at Boulder with that at OrthoCarolina brings the long-term goal of prosthetic limbs that truly are every bit as ‘human’ as our natural ones several steps closer to reality.


Two New Genetic Studies Illustrate just how really Weird Living Creatures can be.

We all learned back in school that it was Gregor Mendel who discovered the laws of genetics in the mid 19th century. Since that time the study of how living creatures pass on their characteristics to their offspring has uncovered more than a few strange and wondrous facts of nature.

There have been two recent studies published that caught my eye because they both showed again just how strange and miraculous living things can be. The first study deals with a newly discovered species that reproduces naturally by cloning while the second species seems to have found a way to live without actually aging.

The first species is known as a marbled crawfish, a species that is becoming a very common animal in the streams and ponds of Europe. The crawfish is also widely kept in the aquariums of people who maintain fish as a hobby, a few of you out there may have one or more in your tank. See the image below.

The Marbled Crawfish (Credit: Ranja Andriantsoa)

In fact it was these hobbyists who first brought the crawfish, also known as a marmorkreb which is German for marbled crawfish, to the attention of geneticists when it appeared that their pets were reproducing without ever having mated, and the offspring were all female. The crawfish it seems were laying already fertilized eggs, in other words they were cloning themselves.

For the past five years now biologist Frank Lyko of the German cancer research center has been unraveling the genome of the marmorkreb and has found some amazing results. Probably the strangest thing that the scientists found was that the crawfish possessed triplets of chromosomes instead on pairs as in most creatures, technically this makes the marbled crawfish a triploid. Think about that, we humans have 23 pairs of chromosomes and in each of those pairs we got one chromosome from our mother and one from our father.

Normal crawfish have pairs of chromosomes like other animals but the marmorkreb crawfish is a triploid and the eggs laid by the marmorkreb are also triploids and are therefore already fertilized. Dr. Lyko isn’t certain how the crawfish manage to live with all of that extra DNA but they certainly do live. In many areas of Europe the crawfish are becoming a nuisance, pushing out their more normal relatives.

Dr. Lyko also believes that the marmorkreb crawfish is not just a newly discovered species but an actual new species, one that is perhaps as little as 25 years old. Dr. Lyko speculates that a single mutation, perhaps in someone’s home aquarium, gave birth to this new species.

Now before you start thinking that the marmorkreb crawfish is the weirdest thing you’ve ever heard of I should point out that scientists do know of other species that reproduce by cloning as well as species that are triploid in their chromosomes. In some ways cloning is a big disadvantage however since all the members of a species are identical any disease that can kill one of them can also kill all of them. For this reason biologists think that cloning species do not survive for very long. Another example of how diversity is a measure of the health of a species.


Our second unusual species is known as the naked mole rat and it is perhaps best known as one of the ugliest animals alive, see image below.

Naked Mole Rat (Credit: Physics.Org)

Scientists have known for a long time that naked mole rats are quite different from other rodents. Living almost their entire lives underground they have evolved to obviously be almost hairless as well as nearly blind. Naked mole rats were also known to be virtually cold-blooded like a reptile.

Now scientists at Calico Life Sciences LLC have found considerable evidence that naked mole rats do not physically age. Specifically they assert that naked mole rats do not obey Gompertz’s law of mortality.

Now Gompertz’s law of mortality is just a specific statement of something everybody recognizes. The older you are the more likely you are to die by natural causes in the near future. In other words an 80 year old person is more likely to die in the next year than a 60 year old, a 60 year old is more likely to die than a 40 year old and so on.

Every other known species of mammal obeys Gompertz’s law, even other rodents. The common brown rat for example has a much greater chance of dying by natural causes at age five, that’s old for a rat, than it did at age four.

Naked mole rats live on the other hand are known to live past 35 years of age, that’s very old for a rodent, and the researchers at Calico Life Sciences have been keeping a careful track of 3,000 data points of the mortality of mole rats versus their age and their conclusions are that a 30 year old mole rat is no more likely to die by natural causes than a 20 year old or even a 10 year old.

Naked mole rats also show many other signs indicating that they do not physically age. They rarely get cancer, their hearts and bones do not weaken with age and they never go into menopause.

Obviously scientists would like to know what is in the naked mole rats DNA that gives them these peculiar characteristics. As for the rest of us, maybe from now on instead of insulting mole rats for their appearance we might want to envy them, at least a little.