Science – Page 24 – Scienceandsf -A Blog Published by Robert A. Lawler

For the last ten years an experiment aboard the International Space Station (ISS) has been counting cosmic ray events. What has it discovered about those mysterious high-energy particles.

At the beginning of the 20th century physicists were shocked to discover various substances that were emitting particles sub-atomic in size yet possessed energies that per particle were enormous, far greater than could be explained by the chemical reactions that were known at the time. The alpha and beta particles that were found coming from Uranium and other heavy elements defied everything that ‘classical physics’ understood. Remember at this time an atom meant something indivisible, nothing smaller and the concept of nuclear energy had to wait for the concept of a nucleus.

Antoine Henri Becquerel (l) visiting the Curies Pierre (m) and Marie (R). These three scientists would be awarded the 1903 Nobel Prize in Physics for their discovery of radioactivity. (Credit: Linda Hall Library)

An even bigger shock came when such particles were found to be shooting through the very air around us. At first scientists thought this radiation had to be coming from substances in the ground. To test that theory in 1912 physicist Victor Hess equipped a balloon with instruments that could detect the particles. He rode the balloon several kilometers into the air expecting that the intensity of the radiation would decrease as the balloon rose. Instead it got stronger. At an altitude of five kilometers Hess found that the intensity was twice as strong as at sea level. The particles were coming from outer space. They were cosmic rays!

Victor Hess preparing to take one of the balloon flights where he proved the radiation was coming to Earth from Outer Space. (Credit: The New York Times)

Ever since then physicists have studied these mysterious particles hoping to learn where they come from and how they were accelerated to such enormous velocities and energies. In 1932 another mystery was added when the first ever anti-particle, an anti-electron was found in cosmic rays by the physicist Carl Anderson. For their work on cosmic rays Hess and Anderson would share the 1936 Nobel Prize in physics.

Physicist Carl Anderson with the first photograph of a cosmic ray Anti-electron. (Credit: Famous Scientists)

After a lot of hard work researchers recognized one thing, the cosmic ray particles they were studying at the Earth’s surface were not the original particles. You see when a particle moving through space at nearly the speed of light enters the Earth’s atmosphere it will quickly strike the nucleus of either an oxygen or nitrogen atom, often smashing that nucleus to bits. Those bits receive energy and momentum from the original particle and so continue downward, sometimes striking other nuclei in a cascading reaction. The bits from the collisions are what physicists see down here at Earth’s surface, only rarely does the original particle reach our instruments. (Actually that’s a good thing, our atmosphere acts as a shield protecting life down here at sea level from most of the radiation.)

The high energy particles we see here at Earth’s surface are actually not the primary cosmic rays but rather the fragments of numerous collisions triggered by the original particle. (Credit: CERN)

So in order to study the primary cosmic ray particles physicists have to get their detectors above the atmosphere and ever since the beginning of the space age they’ve tried to do just that. Early instruments put aboard the Skylab Station and taken into space by the Space Shuttle discovered that there were two distinct types of cosmic rays; one type came from the particles that make up the solar wind. The other type, which are usually more energetic, come from outside our solar system, some perhaps even from outside our galaxy.

The first Alpha Magnetic Spectrometer (AMS-1) was carried into orbit aboard the space shuttle. (Credit: Symettry Magazine)

The most sophisticated instrument sent into orbit thus far is the Alpha Magnetic Spectrometer-2 (AMS-2) which for the last ten years has been attached to the outside of the International Space Station (ISS). During that time the AMS-2 has detected, measured and recorded over 44 million cosmic ray events every day. More than 160 billion cosmic ray particles have been cataloged by the instrument.

The Alpha Magnetic Spectrometer 2 (AMS-2) instrument has been attached to the outside of the International Space Station (ISS) for ten years now.

As a cosmic ray particle enters the AMS-2 its velocity is measured by either a Transition Radiation Detector (TRD) for high-energy particles or a Time of Flight Counter (TOF) for low energy particles. Inside the AMS-2 a permanent magnet causes the particle’s path to curve, the degree of curvature giving information about the particle’s mass. Finally a calorimeter measures the particle’s total energy. Using these pieces of data the physicists can both identify the cosmic particle, element and isotope, as well as its total energy.

The AMS-2 is a highly complex and sophisticated instrument that has measure the properties of over 160 billion cosmic ray particles. (Credit: ESA Earth Online)

What the AMS-2 has discovered about the cosmic rays coming from outside our solar system is first of all that they broadly fall into three categories, electrons, atomic nuclei and anti-matter particles; I’ll save the anti-matter for later. Electron intensity at high energy has been shown to be largely suppressed and we have a pretty good idea of why. You see because of their tiny mass, 1/2000th that of a proton, high-energy electrons traveling through interstellar space get pushed around by the magnetic field of the galaxy causing them to lose their energy and they cease to be part of the cosmic rays after only a few hundred light years.

Some of the results from AMS-2 for electrons and positrons (anti-electrons). (Credit: AMS Collaboration)

Protons and atomic nuclei manage to maintain their energies much further, 2000 times further or more. And keeping in mind that a proton is also the nucleus of a hydrogen atom what the measurements made by AMS-2 tell us is that cosmic ray particles are pretty much just normal stellar matter. That is about 80% of cosmic rays by mass are hydrogen nuclei (Protons) about 20% by mass are helium nuclei while all of the remaining elements make up less than 1% by mass. In fact this is just about the proportions we see when we measure the constituency of the matter in our Sun and nearby stars. The majority of cosmic rays are simply the nuclei the normal atoms that have somehow been accelerated to enormous velocities.

The cosmic ray spectrum, flux of particles versus energy as measured by AMS-2 and other experiments. Since we now have good measurements of how much energy these particles have the question is now, where do they get that energy? (Credit: SpringerLink)

Then there are the anti-matter particles and in truth the real purpose, the juicy meat of the AMS-2’s program was to detect and measure as many anti-particles as possible. You see most of the theories about how the big bang happened say that our Universe should consist equally of matter and anti-matter, but there’s virtually no anti-matter here on Earth or in our solar system. What anti-matter there is comes from high-energy collisions, like those from cosmic rays, and the anti-particles don’t last long.

All of our experiments at atom smashers, along with all our theories tell us the there should be as much anti-matter as matter in our Universe. So where is it? (Credit: Science Notes)

Our observations of the Milky Way also rule out any large amounts of anti-matter in our galaxy. In fact most astronomers think it highly unlikely that there are any anti-matter galaxies within at least 100 million light years. So where is all of the anti-matter, are there anti-matter galaxies anywhere in the observable Universe? That’s one of the big questions it was hoped that AMS-2 would help to answer.

And AMS-2 has provided quite a bit of data that has given physicists a lot to think about. The intensity of anti-electrons for one thing is about five times higher than can be accounted for by established theories. This has raised the possibility that the excess anti-electrons are produced by ‘physics beyond the standard model’ such as the decay of ‘dark matter’ particles.

AMS-2 has also found an excess number of anti-protons in the cosmic ray flux and physicists are trying to determine how well their models predict the number and energy spectrum. Remember single anti-particles are regularly produced in cosmic ray collisions. The big news however has to be the ‘preliminary’ detection of eight anti-helium nuclei. Now because of its importance these detections are being carefully scrutinized, any possible kind of contamination eliminated, nevertheless the data has physicists very excited.

The Anti-Proton to Proton ratio in the primary cosmic rays. There are about one anti-proton for every 10,000 protons but the ratio is pretty flat as a function of energy. (Credit: CERN Document Server)

After all, if the discovery of anti-helium is confirmed that would mean that somewhere in the universe there is an anti-star, a star composed entirely of anti-matter, producing anti-helium by the process of fusion, just as our Sun produces helium by fusing hydrogen. Somewhere, a billion light years or more away, there are anti-galaxies with anti-stars and anti-planets, maybe with anti-people living on them.

Is there an entire Universe composed of anti-matter, and how would we ever know? (Credit: American Physical Society)

Or are they the real people and we’re the anti-people?

Oh, you may have noticed that I’ve haven’t discussed the theories physicists have concerning how cosmic ray particles ever get so much energy. I’m saving that for a later post!

Paleontology News for June 2021: How about for a change we talk about ‘Living Fossils’.

We humans tend to think of evolution as the slow but steady upward progress of various species of life into newer, better forms. A more accurate description however would be adaptations to the anatomy and behavior of species so that they can better fit into their local environment. Evolution is after all a response to local conditions not some universal motion along a directed path toward a specific goal. In other words evolution wasn’t aiming at us in any way.

The Ascent of Man is actually not a good example of evolution at work! (Credit: Learn Biology Online)

The diversity of Darwin’s Finches, the way they adapted to a new environment, is a much better description of Natural Selection at work. (Credit: Wikipedia)

If you think about it then you might ask the question, what happens when a species becomes so well adapted to its environment that there are no longer any evolutionary pressures on it? Would such a species simply stop evolving? Well today I’d like to talk about several species, and one symbiotic relationship, that have survived mostly unchanged for hundreds of millions of years. Such creatures are often referred to as ‘Living Fossils’ and by studying them biologists have learned a lot about what evolution does, or doesn’t do.

I’ll start with the creatures with which I am personally familiar, horseshoe crabs. I wrote a post about the annual breeding of horseshoe crabs back in 22nd of May 2019 so today I’ll simply review a few of the most interesting facts about this ancient creature.

Just seeing a horseshoe crab gives one the feeling of being in the presence of a form of life far older than the dinosaurs! (Credit: National Wildlife Federation)

Based upon their fossil record horseshoe crabs first appeared back in the Ordovician period more than 450 million years ago (mya). Although they are members of the phylum arthropoda horseshoes are not true crabs but are actually more closely related to modern spiders and scorpions. Today there are four remaining species of horseshoe crabs who inhabit the near shore ocean environments where they live by crawling along the seabed consuming mostly worms and molluscs they find in the sand.

The genus Xiphosurid, from the lower Ordovician, almost 500 mya, is consider the direct ancestor of the horseshoe crabs. (Credit: ebay)

Once a year, in the spring here on the US east coast, horseshoe crabs leave their shallow ocean homes to come onto land and mate. I have witnessed this annual and very ancient ritual several times and can only hope that the mating of horseshoe crabs goes on for many millions of more years.

Horseshoe Crabs mating along the Delaware Shore. Thousands of these ancient creatures appear every year to continue a line dating back nearly 500 million years. (Credit: R. A. Lawler)

Of course the biggest threat to horseshoe crabs are human beings. Every year along the eastern seaboard about a million of these creatures are harvested to be used as bait in eel fishing. Another half a million are collected to obtain the animals blood, which is blue in colour because it is based on copper not iron. The blood of horseshoe crabs contain amebocytes, cells similar to our white blood cells and which like them fight disease pathogens. Indeed the amebocytes of horseshoe crabs are so sensitive that we use them as a means to test of the purity of drugs and medicines.

The labouratories that obtain horseshoe crab blood maintain that only about 5% of the animals harvested die in the procedure. Many scientists however doubt that assertion pointing out that there have been no studies of what happens to the crabs after they are released back into the ocean.

The biggest threat to the horseshoe crab however has to be just the ongoing development of the shoreline. As more and more houses are built right up to the beach, and as more and more beaches become tourist hot spots there is less and less room for the crabs to come onshore and breed. The question is therefore, how long before horseshoe crabs go from being ‘Living Fossils’ to just fossils?

The real danger to Horseshoe Crabs, and many other forms of aquatic life , is simply our continuing effort to take over. (Credit: Mann & Sons, inc REALTORS)

Another kind of ‘Living Fossil’ are the ancient lobe-finned fishes known as the Coelacanth. Fossil coelacanths are known from the Devonian period through the late Cretaceous with hundreds of species discovered. For over a hundred years however coelacanths were thought to have become extinct at the same time as the dinosaurs. Then in 1938 Museum curator Marjorie Courtenay-Latimer in South Africa was prowling around a fish market on the coast of the Indian Ocean when she chanced upon a dead coelacanth. Although Courtenay-Latimer could not identify the animal she immediately realized how unusual it was and contacted an ichthyologist named J. L. B. Smith at Rhodes who correctly identified it. No other coelacanths were discovered until after World War II but in the years since two species have been discovered in the depths of the Indian Ocean ranging from the coast of Africa to the Islands of Indonesia.

A live Coelacanth, again just seeing one gives the feeling of ancient life. These ancient fish are related to the first land dwelling vertebrates, in other words our ancestors! (Credit: People.com)

Coelacanths are important in the history of life because of their position as relatives of the lobe-finned fishes that left the waters and became the first land dwelling tetrapods. That means that coelacanths are actually more closely related to us than they are to tuna or salmon or flounder.

For more than 100 years coelacanths were known only from their fossils. Even today fossil coelacanths are more commonly found than live ones! (Credit: Science Fun)

And like the horseshoe crabs who also survived both the Permian extinction and the extinction of the dinosaurs the coelacanths are now under their greatest threat ever, from us. You see back in 1938 a fisherman in the Indian Ocean would only rarely catch a coelacanth because they live in rather deep waters. Today however modern advances in fishing techniques, particularly deep sea trawling, have greatly increased the number of coelacanths being captured by fishermen.

As more advanced fishing techniques are being used more coelacanths are being caught even though the fish is uneatable. How much of a danger this is to the species is unknown but it can’t be a good thing! (Credit: Pinterest)

Scientists aren’t certain just how endangered coelacanths are however because no accurate census of their numbers has ever been taken. Still, there is considerable reason for concern. And the worst part is that the fishermen don’t even want to catch coelacanths, which taste horrible and have been known to actually make some people nauseous. No, coelacanths are merely by-catch, fish that accidentally get caught in nets and die before they can be released back into the ocean. So it is that we may be threatening the survival of creatures whose lineage dates back around 400 million years simply because they get in our way.

My last story today concerns not only two kinds of living fossils but a symbiotic relationship between them that was thought to have gone extinct. Recently however Oceanographers researching invertebrates in Suruga Bay off of Japan’s big island Honshu discovered that the relationship between crinoids and anemones was alive and well after more than 273 million years.

Today living Crinoids, some species are known as ‘sea lilies’ are a rare sight. During the Paleozoic age they were perhaps the dominate for of sea life. (Credit: YouTube)

The anatomy of a crinoid has changed little over hundreds of millions of years. (Credit: Fossils-Facts-and-Finds)

Crinoids themselves are very ancient, dating back like the horseshoe crab to the Ordovician period 450 mya. Related to starfish, crinoids attach themselves to the sea floor by a long stalk and use their multiple arms to collect whatever food particles happen to float past them. This makes the crinoids look something like flowers and has given them their nickname of ‘sea lilies’. Fossils of crinoids are very common in Paleozoic rocks, I have many, but today they are somewhat rare creatures.

A couple of very nice Crinoid fossils. (Credit: Pinterest)

Sea anemones are even more ancient but because they do not fossilize well, no hard parts, we aren’t sure how old they are, 550 million years at least. Anemones are extremely simple creatures, little more than a bag of jelly like tissue with arms that again catch food. The arms of an anemone have very nasty stinging cells that allow the creature to feed on some rather large and active prey.

Sea Anemones are even more ancient than crinoids but because they don’t fossilize well much of their history is still a mystery. (Credit: BBC)

A crinoid with anemones attached to its stalk. This association is known from very ancient times but was unknown today until very recently. (Credit: Pinterest)

Well back in the carboniferous period, 300 mya anemones started attaching themselves to the stalk of the crinoids, many fossils from that time clearly display the two animals living together. It is thought that living on a crinoid’s stalk got the anemone higher up in the water column where it could feed better while the crinoid benefited by feeding on some bits of food that escaped the anemone. However beneficial the symbiotic relationship may have been it disappeared about 273 mya, or so the paleontologists thought. And the best thing about crinoids and anemones is that they’re both quite safe from extinction at present, so who knows, their symbiosis may last for another quarter of a billion years. It’s nice to know that some relationships can last.

Imagine a Science Experiment that lasts longer than a Human Lifetime. Well an Experiment that began in 1879 at Michigan State University is still going strong after more than 140 years.

The tallest tree grows from the tiniest seed, so the saying goes. Most of the familiar plants in our backyards, and on our farms reproduce by producing small, tough packets of life that we call seeds that will hopefully germinate in the soil and grow as a new plant.

The endless variety of plant life on this planet is perhaps best exemplified by the endless variety of seeds! (Credit: Amazon.com)

One of the reasons that seeds are generally so tough is that for many species their seeds are going to have to survive a hard winter before they can germinate and grow starting the next spring. In order to survive through such hard times many seeds have evolved to lie dormant for long periods of time.

Many plants only survive winter or other harsh conditions because of the hardiness of their seeds! (Credit: Prairie Moon Nursery)

How long can seeds remain dormant before they will go bad, before they lose their ability to sprout and grow? Well of course it depends on the species but I have successfully grown string beans from some leftover seeds I’d purchased three years earlier, and who knows how long those seeds had been in their package before I bought them.

It was to answer the question of how long can seeds lie dormant that botanist William J. Beal, Professor at Michigan State University buried twenty bottles, each bottle filled with seeds from 21 different species of plant, fifty seeds per species. That’s over 20,000 seeds total for the experiment.

Botanist William James Beal of Michigan State University. Beal initiated an experiment that is still going strong after 140 years. (Credit: MSU Alumni- Michigan State University)

Professor Beal’s idea was that every five years first he, and later his successors would dig up one of the bottles and plant the seeds contained within. In this way the experiment would show how long a period of time each species of seed could lie dormant and still capable of germination. After Beal’s death the time interval between bottles was lengthened, first to ten years and then twenty years. Two of the retrievals have been delayed by a year, both due to pandemics, first the scheduled 1919 bottle was delayed until 1920 because of the 1919 ‘Spanish Flu’ while the retrieval of the 2020 bottle was similarly delaying because of Covid-19.

To keep the location of the remaining jars a secret the scientists at Michigan State dig up the latest bottle at night! (Credit: The New York Times)

Nevertheless on a chilly night last month in April a team of biologists at Michigan State met in secret and followed an old map to a hidden location on the campus. After a bit of digging the group succeeded in locating their bottle and, treating it like the treasure it is took it back to their labouratory so that they could continue the work that Professor Beal had begun so long ago.

Associate Professor David Lowery holds the latest of Professor Beal’s bottles. (Credit: The New York Times)

Now the modern botanists have much more sophisticated instruments to study the seeds with than Doctor Beal did. So the experiment has evolved from a simple demonstration of what species have managed to survive and germinate into a more involved study of what changes occur to the living material in the seeds over time. Chemical sequencing of the DNA of seeds that fail to sprout may provide information about how DNA degrades over time for instance.

This DNA sequencer is just one of the modern scientific instruments that scientists can now use to study the seeds put down 140 years ago by Professor Beal. (Credit: KWIPPED)

And Professor Beal’s experiment has already found its winner, Verbascum blattaria; a small unobtrusive herb with yellow flowers and splayed leaves continues to germinate nearly half of its seeds. 11 have so far sprouted from this year’s bottle, 142 years after being buried. The seeds of no other species have managed to sprout without extra effort from the botanists but this year they plan on trying something new. Recent research has discovered that many forest plants have seeds that are not only capable of surviving through a fire but are actually triggered in their germination by the smoke of a forest fire. The botanists therefore plan to expose some of the seeds to smoke and see if that succeeds in bringing a few of them back to life.

Verbascum blattaria is a small but pretty little plant with the hardiest seed known to science thanks to Professor Beal’s experiment. (Credit: Wikipedia Commons)

It is thought that some seeds are actually encouraged to sprout by the smoke and heat of forest fires. The botanists at MSU hope to try that with some of this bottle’s seeds. (Credit: Arbor Day Foundation)

There are four more bottles left in Professor Beal’s experiment so the botanists at Michigan State can continue their work at least until the year 2100. The researchers however are currently in the midst of planning a larger follow on experiment, more plant species, more seeds per species. They even hope to include some seeds from this year’s V blattaria plants, a fitting tribute to William J. Beal. A scientist who had the foresight to begin an experiment whose completion he would never see.

Space New for May 2021: The Russian Space Agency has announced its intention to end its participation with the International Space Station (ISS) in 2025. What does that portend for the future of the ISS?

Last month, on the 15th of April the Deputy Prime Minister of the Russian Federation Yuri Borisov announced on Russian television that his nation would be terminating its commitment to the International Space Station (ISS). According to the announcement the Russian Space Agency Roscosmos would be informing their partners, that is the US, European and Japanese space agencies, that it would cease to provide crew, maintenance and support for the ISS at the end of the year 2024.

Deputy Prime Minister of Russia Yuri Borisov announced his government’s intention to end their participation in the International Space Station. (Credit: Ministry of Defense of the Russian Federation)

Now in many ways the Russian intention makes a good deal of sense. The original design of the ISS was for a twenty-year lifespan, which was completed in 2020. Currently the ISS is working on a five-year extension agreed to by all of the partners. However air leaks and other maintenance issues have multiplied over the last few years and everybody involved with the ISS recognizes that the station will require a major overhaul if it is to continue beyond 2025.

The International Space Station (ISS) is now more than 20 years old. Before long a major overhaul will be needed if the station is to continue to operate. (Credit: Wikipedia)

Besides the ISS was never the space station that Russia really wanted. You see the orbit of the ISS is such that it travels as far north as a latitude of 51 degrees, and 51 degrees south by the way. That means that while the ISS passes over all of the continental US it passes over less than 20% of the Russian Federation. That makes it all but useless to for Earth observation and monitoring of much of Russia’s territory particularly the Arctic region that Russian’s President Vladimir Putin considers vital to his country’s future.

The path of the ISS in orbit takes it over all of the US except Alaska but over very little of Russia. The Russian’s would like a space station that can observe their own country. (Credit: Quora)

For that reason over the last several years Roscosmos has been designing a new space station that will go into a polar orbit, enabling it to observe and study the entire planet. The question is can Russia afford such an undertaking? The Russian economy is not strong and over the last decade much of Roscosmos’ budget for the ISS has come from taxiing the astronauts of other nations to the ISS. With Space X now launching astronauts to the ISS at half the cost the Russian space agency has lost that revenue stream.

Initial design for a Russian space station to be placed in a polar orbit. While not as large as the ISS it would still cost a great deal. Can Russia afford it? (Credit: Russian Space Web)

In my own opinion the Russian decision was also determined as much by politics as science. Tensions between Russian the other nations involved with the ISS have continued to increase ever since it annexed the Crimea, supported rebels in Ukraine and interfered in the elections of other nations. The Russian government’s decision to abandon the ISS may just be a thumbing of their nose at nations who are better off than they are.

Having seized Crimea Russia is now supporting pro-Russian rebels in eastern Ukraine. Does this have more to do with Russia’s decision about the ISS than science? (Credit: The Irish Sun)

Nevertheless, if Russia does end its involvement with the ISS what then will be the future of the space station? The truth is that NASA would also like to considerably reduce its own commitment to the upkeep and management of the ISS. So what is going to happen to the ISS, will it be pulled out of orbit to burn up in the atmosphere like Skylab and Russia’s MIR space stations were?

America’s first space station Skylab fell out of orbit on 11July in 1979. No one was hurt when Skylab fell but the ISS is so big that it would have to be brought down carefully! (Credit: Wikipedia)

NASA hopes to avoid that possibility. The American space agency hopes to use the ISS as an asset to further the commercialization of Low Earth Orbit (LOE). This is all part of a long-range program that began when NASA started funding Space X and Boeing to develop their commercial manned space vehicles.

The commercialization of the ISS has already begun, the Bigelow inflatable space module has been attached to the ISS for over a year now allowing the aerospace company to gain insight on how to build their future station. (Credit: NASA)

Now NASA has tasked Axiom Space Corporation to organize and manage the first completely civilian mission to the ISS, which could occur as soon as January of next year, 2022. Axiom Mission One will take four persons, one a former NASA astronaut along with three businessmen, to the ISS aboard a Space X Dragon capsule. They will stay in orbit on the station for eight days performing experiments and bring the results home with them. Going forward NASA also plans for Axiom to attach a commercial habitation module to the ISS as early as 2024.

The crew of Axiom’s Mission One flight to the ISS scheduled for January 2022. (Credit: Twitter)

To get a idea of how this system is going to work consider Axiom to be the travel agency, who will purchase seats from Space X to take 4-6 astronauts to the ISS. And the astronauts don’t have to be rich, millionaire space tourists; the nation of Peru for example could purchase a ticket to take its first astronaut into space. Or corporations might also take advantage of this in order to send one of their employees into space to experiment with a new technology. Intel Corporation for example could experiment with manufacturing three-dimensional integrated circuits in a zero gee environment.

It’s gonna be awhile before going into space is this easy but maybe someday. Axiom Aerospace is working to become space’s first travel agency. (Credit: The Travel Team)

Eventually NASA hopes that Axiom or some similar space company will completely take over the operation and maintenance of the ISS and run in something like a modern resort. Customers would arrange their stays at the ISS through Axiom who would then set up their flight with Space X or some other commercial launch company. NASA’s Cape Kennedy would then become something like a municipal airport, owned by the government but renting space to commercial carriers. In time this commercialization would extend to other space stations like the one planned by Bigelow Aerospace.

Bigelow Aerospace Corp.’s concept for a commercial space station. (Credit: Business Insider)

And speaking of space stations its time to mention that back on April 28th China successfully placed into orbit the core module of their first space station called Tianhe. Most of the press coverage of this launch focused on the fact that the lunch vehicle for the module, a Long March 5B rocket, was left by the Chinese in an unstable orbit and could have re-entered the atmosphere over inhabited areas of the Earth. As it was the rocket eventually fell into the Indian Ocean doing no harm to anyone.

China has just begun the construction of their space station to be called Tianhe. I’ve alreadt seen it passing over Philadelphia. (Credit: New Scientist)

Over the next year or so Tianhe will be joined by two other modules, named Wentian and Mengtian to form a ‘T’ shaped station. The first crew to man the station is scheduled to be launched this September for a 6-month mission. When completed the Tianhe station’s planned lifespan is ten years but could be extended to 15.

And I’ve already seen the Tianhe station as it flew over Philadelphia, three times now in fact! And the first time I saw it the ISS was also flying overhead so the two were visible at the same time for about two minutes. That was quite cool.

Image from China’s Zhurong Mars rover looking back at its landing vehicle. (Credit: Al Jazeera)

And before I go I have to mention China’s other success in space, the landing on Mars of their Tianwen-1 lander, which carries a small rover named Zhurong. The lander module separated from the Tianwen-1 orbiter and successfully touched down on the Martian surface on the 15th of May. Landing in the Utopia Planitia region of Mars the rover was deployed and is now rolling around the Martian surface. The plan is for Zhurong to explore the area around its lander for 90 days, however considering how NASA’s rovers, and now helicopter, have all had their mission’s extended I shouldn’t be surprised if the Chinese rover doesn’t last a good deal longer than 90 days.

Bit by bit Astronomers are learning the secrets of the massive stellar explosions called Supernovas, even if they do occasionally come across evidence that doesn’t fit their theories.

Everyone has heard a little bit about Supernovas, you know those stars who destroy themselves in explosions that for a few weeks can outshine many billions of normal stars. Supernovas are very rare events, happening only every couple hundred years in our galaxy of one hundred billion stars. In fact supernovas are so rare that most of what we’ve learned about them comes from observing ones that happen in other galaxies. It works like this, if supernova only occur once every 100 years per big galaxy then if you keep an eye on 1,000 galaxies you should see about 10 a year!

Three images, taken on successive nights, of the Galaxy M101. On August 22 (l) there was no supernova, green arrow shows location. SN2011fe was discovered on the night of the 23rd (m) while by the night of the 24th (r) it was considerably brighter. By keeping an eye on a thousand such galaxies astronomers manage to observe a dozen or so supernova ever year. (Credit: Space.com)

The very first studies of supernovas, conducted more than 70 years ago now, used spectral analysis to show that there were two basic types. One type, not surprisingly called Type 1, had virtually no hydrogen in the spectra obtained from their light. Now hydrogen is the most common element in the Universe so for Type 1 supernovas to be completely lacking in it is really significant. Type 2 supernovas are just the opposite, their spectra shows plenty of hydrogen. One thing both types have in common is that they are very rare which indicates that only a small percentage of stars ever go supernova.

In time astrophysicists came up with two rather different models of supernovas. Type 1 begin with a white dwarf, the superdense corpse of a once normal star, for example our Sun will become a white dwarf in about 6-7 billion years when it runs out of its hydrogen fuel. A typical white dwarf has a mass about that of our Sun but its size is only that of the Earth. The surfaces of dwarfs are extremely hot but because of their small size they are much dimmer than a normal star like our Sun.

If a white dwarf star steals mass from a companion star it can grow too massive leading to a collapse that triggers a Type 1 Supernova. (Credit: Phys.org)

Now if a white dwarf happens to have a companion star, and there are many examples of binary star systems, the dwarf can start pulling material away from its companion. This stealing of matter can only go on so long however because there is a maximum limit to the mass of a white dwarf. This maximum mass is about 1.4 times the mass of our Sun and if a dwarf exceeds this limit it begins to collapse triggering the Type 1 supernova. After the explosion all that’s left of the star is a neutron star or even a black hole.

The famous Crab Nebula M1 is the remains of a Type 2 Supernova. At the center of the nebula is a neutron star that emits radio signals as a pulsar. (Credit: Wikipedia)

Type 2 supernova however start as huge, very massive stars, at least ten times the mass of the Sun. The fusion reactions in such stars use up their hydrogen fuel in only a few million years. The star will then begin to fuse helium into carbon and oxygen, which is as far as our Sun will ever get. Massive stars however have enough energy to keep going, fusing carbon and oxygen into heavier elements all the way up to iron.

The supermassive star Eta Carinae, seen here in an image from Hubble, is destined to explode in a few million years as a Type 2 supernova. (Credit: Medium)

Iron is a brick wall however, fusing iron into a heavier element doesn’t produce energy it consumes it. The fusion reactor of this huge, massive, intensely hot star suddenly comes to a screeching halt and the star begins to collapse upon itself. This collapse triggers the supernova but unlike a Type 1 supernova there is still some hydrogen left in the star’s outermost regions, which shows up in the explosion’s spectra. After the explosion all that remains of the star is a neutron star or black hole.

Nuclear binding energy per nucleon. Nuclei that are less massive than iron can be fused to produce energy while more massive than iron can be split to produce energy. Whatever you do to iron however will require energy. (Credit: Conceptual Physics)

Those are the theories, but to be certain they’re right we would have to observe a star before it goes supernova and that’s not an easy thing to do. After all there are literally trillions of stars in our galaxy and nearby ones, while only a couple of dozen of those stars will go supernova each year. The question is then, which ones? Well what astronomers have tried to do is to get observations of as many stars as possible. Then when a supernova does occur they check their archives to see if they have any prior images of it.

The star Sanduleak -69degrees 202 (r) before it exploded as SN1987A (l). This was the first time astronomers were able to identify the progenitor star to a supernova. (Credit: David Malin, Anglo-Australian Observatory)

The first time that this technique worked was the Type 2 Supernova SN 1987A, in the Large Magellanic Cloud, which is a satellite galaxy orbiting the Milky Way. Almost as soon as SN 1987A was detected astronomers quickly began looking through their past observations and succeeded in finding a few observations of the star, catalog name SK-69º202 before it exploded. Although there were a few surprises SK-69º202 turned out to be pretty much what astronomers had expected, with 15 times the mass of our Sun and a very hot surface. The data gained from SN1987A taught astrophysicists a great deal about Type 2 supernovas, but of course they wanted more, and in particular, they wanted a Type 1 supernova progenitor.

SN 2019yvr in the galaxy NGC 4666 at a distance of 46 million light years. (Credit: Remote astrophotography using Slooh.com)

Now they may have one, and it’s not what they expected. Back in December of 2019 astronomers spotted a supernova, designated SN 2019yvr in the galaxy NGC 4666 which is about 46 million light years away in the Virgo super cluster of galaxies. Even as observations were showing that SN 2019yvr was a Type 1 supernova astronomers associated with the Hubble Space Telescope were rummaging through earlier images of NGC 4666 to try to see if Hubble had ever made any observations of the star.

The Hubble space telescope has made many discoveries during its lifespan. The image of the progenitor star for SN2019yvr may be its latest. (Credit: Science Focus)

The astronomers spent more than a year of checking and crosschecking between the measurements made after the supernova began to those that had been taken earlier. Nevertheless they think they may have found the supernova’s progenitor in a series of images taken some 2.6 years before the explosion, problem is, the star they’ve identified is not the kind the theory says it should be.

Instead of a tiny, dense, extremely hot white dwarf the star that’s been identified is a fairly cool orange-yellow star more than 300 times the width of our Sun. A star like that should have plenty of hydrogen left in it but the spectra of the supernova showed none, it’s just a mystery.

The type of star Hubble found however appears to be an Orange ‘K’ type star shown here with a larger ‘G’ type star, our Sun, and a smaller red ‘M’ type star. (Credit: EarthSky)

The astronomers have already come up with several explanations for the disagreement with the theory. First of all they could simply have identified the wrong star. They can’t check to make certain right now because the debris of the supernova is currently obscuring that region of space and it will take 5-10 years before they are able to see if the orange-yellow star is still there.

The expanding debris field of SN1987A makes it difficult to observe the remaining neutron star at the center. (Credit: CEA-Irfu)

Then there’s also the possibility that the companion star, remember Type 1 supernovas require a companion star, could have given off enough material to form a cool gaseous shroud around a white dwarf that was the actual supernova progenitor. Again checking this possibility will have to wait for the debris to clear a good deal.

Of course there’s also the possibility that our theories are just wrong and have to be adjusted. Whichever possibility turns out to be true astronomers are bit by bit learning the secrets of what are some of the most spectacular events in the Universe, Supernovas.

Over the next few weeks Pennsylvania and other eastern states will be overrun by billions of Periodic Cicadas, sometimes known as the 17 year Locust.

Our planet is home to more than a million different species of insect, all of whom seem strange and alien to we humans. There are some species however whose lives are unusual even compared to those of other insects and somewhere near the top of that list must be the periodic cicada. Cicadas are those beautiful but noisy creatures who seem to vanish for several years and then suddenly appear by the millions for only a few weeks in the spring.

The number and diversity of Insects is simply overwhelming. The number of different species must number well over a million, every one unique in their own way. (Credit: Britannica)

Cicadas are a large and widespread group of insects numbering over 3000 species worldwide. With large eyes set far apart and membranous front wings cicadas mainly live by sucking the sap from the trees in which they typically live and where they lay their eggs. Cicadas are also known by the loud drumming noise made by the male that is used as a mating lure and produced by rhythmic vibrating of their body.

The 17 year cicada is notable for it large red eyes spread far apart. (Credit: NPR)

One genus of cicada native to eastern North America lives virtually its entire life underground as immature nymphs feeding off the sap in the roots of trees. These species only metamorphose into adults and emerge from the soil in order to breed. In fact these adults usually lack a mouth and digestive systems and are therefore unable to consume nourishment in any way. Some species, known as annual cicadas remain underground for 7-9 years typically with a fraction of the nymphs emerging every year in order to breed.

Difference between an annual (r) and periodic (l) cicada. Annual cicadas actually live for about 7-9 years but most of that is spent below ground and a fraction of the species mature as adults every year. (Credit: IndyStar)

Strangest of all are the periodic cicadas; members of the genus Magicicada who remain underground for either 13 or 17 years and who then emerge by the billions. In each of these types there are several broods centered in different parts of the country and this is the year for one of the biggest, Brood X of the 17 year cicada.

Map showing locations of the various broods of periodic cicadas. Brood X is in yellow! (Credit: Vox)

Biologists have been hotly debating the evolutionary reason behind such an unusual life cycle for a long time, especially the question of how the prime numbers 13, and 17 became the most common time frame. One argument is that by suddenly appearing by the billions the cicadas, who have absolutely no means of defense, simply overwhelm their predators with sheer numbers. Insect eating birds and other animals can consume their fill and there will still be billions of cicadas left to produce the next generation.

Mayflies are another kind of insect that practices predator saturation coming out as adults for only about a week or so they appear in the billions so that some manage to mate before they’re all eaten. (Credit: CNN)

This strategy is known as ‘predator saturation’ and the reason for the prime number of years in the cicada’s lifespan is that it makes it harder for a predator species to synchronize their own breeding to that of the cicadas. For example if the cicadas emerged every four years then Blue Jays or Crows might be able to evolve to lay more eggs every four years, producing more offspring during the years of cicada breeding so as to take advantage of the extra bounty available to feed their own young. Some researchers also think that the long period timing may have developed during the ice ages when living underground may have been a considerable advantage.

Did periodic cicadas evolve their strategy of living underground for years in order to avoid the worst of the ice ages? (Credit: History.com)

Either way there is now evidence that global warming may be affecting the timing of some individuals within each brood. You see biologists think that cicadas keep track of how long they’ve been underground by counting the number of times that tree sap starts rising from the roots into the tree proper. Thanks to global warming over the last few decades the eastern US has had several ‘false springs’ where it got so warm in January or February that some trees started to sprout only to have a later frost put an end to the early growth. Did some cicadas count those false springs as an extra year? Well, what is known is that a small number of Brood X cicadas emerged in 2017 in the area of Washington D.C., four years too early.

Like with so much else there is evidence that global warming is affecting the lifestyle of the periodic cicada. (Credit: Environmental Protection)

Cicadas have been around since at least the Permian period however, and with thousands of species and many billions of individuals they could very well outlast the human race.

Fossil of a cicada from the Jurassic period. They’ve been here a lot longer than we have!!(Credit: Scientific American Blogs)

So if you live in along the US east coast between Pennsylvania and Georgia and as far west as Indiana keep your ears listening this spring, it’s usual to hear cicadas before you see them remember. If you do you may encounter one of the strangest and wonderful of Earth’s living creatures, the 17 year cicada.

Archaeology news for May 2021, three stories that come from areas of the world not usually considered archaeological ‘hot spots’.

Ever notice how just a few places on Earth get all of the press coverage when it comes to evidence of ancient civilizations. Egypt of course heads the list closely followed by Greece, Mesopotamia and Central America. Then there are certain specific ancient sites that gather a lot of attention like Stonehenge or China’s terra cotta warriors. Media coverage of archaeology is minimal at best and news directors aren’t going to give precious airtime to a story from some part of the world that the average viewer doesn’t associate with archaeology.

I don’t known about you but it seems to me that anytime anything old is discovered in Egypt it gets massive press coverage while important discoveries made in out of the way areas of the Earth go almost unnoticed! (Credit: Archaeology Magazine)

Well I will! This month’s stories come from such far-flung places as Laos, the Arabian Desert and Ireland. (O’k maybe Ireland does have some well-known ancient sites like Newgrange along with a wealth of Stone Circles but this is the first time I’ve ever heard of an archaeological discovery coming from Laos!) Let’s begin with the remains that are considered to be the oldest, the mysterious mustatils of the Arabian Desert.

Aerial view of three Mustatils from the Arabian Desert showing something of the variations in construction and preservation. (Credit: Granthshala UK)

Mustatil is from the Arabic word for rectangle and they typically consist of a rectangular shaped stone enclosure as small as 20 meters to as long as 600m meters with sandstone walls averaging less than 1.5 meters in height. Over one thousand of these structures are known from the northwest corner of the Kingdom of Saudi Arabia.

Area of the Arabian peninsula where the Mustatils are found. (Credit: The Wild Hunt)

Excavations of several mustatils have revealed a chamber in the center of the enclosure that contained the bones of cattle and other animals such as sheep, goats and gazelle. Carbon-14 dating of the animal remains have given dates as far back as 5000-5300 BCE, more than 7000 years ago.

Ground level view of a Mustatil. Based upon the remains archaeologists are convinced that the walls of the enclosures were quite low, no more than 1.5 meters or so. (Credit: Eurasia Review)

The low height of the enclosure walls makes it unlikely that the mustatils were used as corrals and other signs indicate to archaeologists that the structures were used for ritualistic purposes. As such the mustatils may be the first evidence of a cattle cult in the Arabian Peninsula and in fact may represent the earliest known religious structures on Earth. Indeed the number and variety of animal remains at the mustatils are also evidence that thousands of years ago the Arabian Desert was a much more fertile grassland than they presently are.

Images of cattle are among the earliest art made by human beings. Are these images a sign of reference as well as beauty? (Credit: Pinterest)

Mustatils only became known to the scientific community in the 1970s and have still only been superficially studied. However the Saudi Royal Government has begun funding a project to carry out more thorough investigations. Part of those studies will be undertaking by the Aerial Archaeological in the Kingdom of Saudi Arabia Project (AAKSA) in the hopes of identifying and cataloguing all the mustatils.

By contrast the known archaeological sites of Ireland have already been rather thoroughly surveyed and any major new discoveries now rely on the chance unearthing of previously undiscovered remains. Just such a discovery occurred a month ago in April on the Dingle Peninsula of County Kerry as workmen who were making improvements to a farm unearthed a stone lined burial chamber known as a “cist”. The grave was discovered when the workmen were using a backhoe and overturned a large flat stone used to cap the tomb revealing what lay beneath.

View of the tomb discovered in County Kerry from above. (Credit: Live Science)

Fortunately the workers immediately notified National Monuments Service and the National Museum. An initial examination indicated that the grave was likely to date from the Bronze Age, around 2500 BCE and best of all, the entire site appears completely untouched.

Map of ancient burials discovered in Ireland. (Credit: JSTOR)

A small sample of the skeletal remains were removed and sent to a labouratory for carbon-14 dating and an unusual find of an oval shaped polished stone was discovered next to the body. There are also indications of an adjacent sub-chamber at the front of the cist. A full excavation is being planned and should commence soon. This region of Ireland is well known for its ancient burials so it is possible that further discoveries could be only a few meters away beneath the ground.

View of the inside of the Kerry Cist. The stone wall in the image center may cover the entrance to another chamber. (Credit: Live Science)

The stone Jars of the ‘Plain of Jars’ in the country of Laos may be easier to find but they are no less mysterious. In fact let’s be honest the entire country of Laos is pretty mysterious to most people. Aside from once being a part of French Indo-China and then an unwilling participant in the Vietnam War I know little this small land-locked country. So I was quite excited to hear about the archaeological research going on by the University of Melbourne and the Australian National University along with the Laos Department of Heritage in the northern part of the country.

Location of the Plain of Jars in Northern Laos.

The plain of jars is actually a series of eleven sites where massive containers carved from sandstone are spread haphazardly across the landscape. Site 1, the largest location contains over 400 of these jars many of which are 2 meters across. Rather than being used for storage these jars were used for mortuary purposes where a deceased person would be placed in a jar and exposed to the elements. Carrion birds and other wildlife would consume the flesh and after a month or so, when only the bones remained they would be removed and placed in a more permanent, usually family based internment.

Aerial view of dozens of the jars. Is the haphazard arrangement caused by different families grouping their jars away from other clans? (Credit: South China Morning Post)

Some of the individual jars are quite large and massive and must have required an enormous amount of work to transport and hollow out! (Credit: Hole in the Doughnut Cultural Travel)

This form of funeral practice was actually very common in ancient societies. The longbarrows in southern England have been found to contain the bones of hundreds of individuals stacked together. There are even cases where the skulls of the dead were placed together in one chamber of the barrow while the other bones were placed in adjacent chambers.

Typical English Long Barrow. The bones, and only the bones of hundreds of individuals could be laid to rest in such a tomb. (Credit: Photographers Resource)

Native American peoples practiced exposure of their dead. Once the flesh had been eaten by birds of prey the bones would be recovered and kept as memorials. (Credit: Native American Netroots)

The best theory for how the stone jars of Laos were employed follows much the same idea but there’s a problem. Chemical analysis of the soil beneath several of the jars indicates that they were placed in their current locations somewhere between 730 to 1350 BCE, around 3,000 years ago. However carbon-14 dating of some human remains buried near the jars give a much younger age of 800 to 1400 CE. Is it possible that the stone jars were used over such a long period of time? Or did a second, much later culture make use of the ancient jars that their distant ancestors had originally erected.

Evidence gathered at the sites of the Jars in contradictory. Chemical analysis of the soil says the jars have been there for as much as 3,000 years but remains found nearby say only about half that age. Just another mystery for a very mysterious place! (Credit: Live Science)

At least researchers have managed to identify where the stone for the jars came from. Chemical test have revealed that the stone came from a quarry just 8 km away. However, whether the stones were brought to the plain and then carved or carved first and then brought to the plain is unknown, as is the method used to move the stones, some of which weigh several tonnes.

We humans spread out across the face of the Earth thousands of years ago and so its not surprising that even the most isolated and little known parts of our world can still provide some archaeological mysteries worth studying.

What can cannibalistic moth caterpillars teach us about pacifism, turns out quite a lot!

Living creatures exhibit a wide variety of lifestyles, some of which to us can seem bewilderingly strange. Take the common pantry moth, also known as the Indian meal moth, biological name Plodia interpunctella. A frequent household pest P interpunctella lays its eggs in packages of flour, cereals and other dry goods. The caterpillar stage of the moth then lives by consuming some of the food in which it was born.

An adult Plodia interpunctella or Pantry Moth. (Credit: Pinterest)

The caterpillar stage of P interpunctella normally feeds on vegetable matter but can turn cannibalistic when it encounters another of its species. (Credit: BugGuide.net)

Normally a peaceful vegetarian when left alone, if two caterpillars of P interpunctella happen to come upon each other it can be a fight to the death with the victor literally eating its vanquished foe. And it doesn’t matter even if the two combatants are siblings the instinct to eliminate the competition, and acquire a little protein, just takes over.

P interpunctella is a well known household pest causing a considerable amount of loss of stored food. (Credit: Adobe Stock)

Such violent behavior is instinctive, adapted for a normally solitary lifestyle. It can be asked therefore, under what conditions and how long a time would be required to change those instincts? Well, a team of biologists at Rice University in Texas and the University of California at Berkeley wondered about that and set up an experiment to answer those questions. Pantry moths caterpillars it turns out make good lab animals because they’re used to living in containers, their food is cheap and their lifespans are so short you can get a lot of generations in just a few years.

Since P interpunctella is both easy to grow and a well known pest it is often used as a lab animal. (Credit: Wiley online library)

In their experimental setup the researchers wanted to control the dispersion, that is the spatial spread that a brood of caterpillars could attain. They did this by establishing five separate habitats and varying the viscosity of the food in each. The less viscous the food the greater the caterpillars could spread out, the more viscous the food the more often a caterpillar would encounter a sibling.

What the biologists discovered was that over ten generations those caterpillars that were forced to remain in close quarters with their relatives showed a marked decrease in cannibalistic behaviour. According to Volker Rudolf of Rice University and one of the study’s authors. “Families that were highly cannibalistic just didn’t do well in that system. Families that were less cannibalistic had much less mortality and produced more offspring.”

The experimental setup used to alter the behaviour of P interpunctella caterpillars. (Credit: BigThink.com)

This result provides strong evidence for a theory advanced by Rudolf and co-author Mike Boots of UC Berkeley. Their idea is that when animals, not just pantry moths, interact with each other more the degree of cannibalism declines because the odds of eating your own sibling, who shares half of your genes, increases.

Whether these results can be applied to other species remains to be seen. Also it is worth noting that in the experiment the supply of food was not constrained, everybody had plenty of food to eat. In a situation where resources are severely limited eating a sibling might be the only way for anyone to survive!

Nature red in tooth and claw. Let’s be honest the natural world is a very violent place. (Credit: The Phrase Finder)

There are many examples of species that will eat anything, even their own kind! (Credit: All that’s Interesting)

However there is a growing amount of evidence that the instinct towards violence can be altered, and over the course of not too many generations. In my post of 11 December 2019 I discussed the work of Doctor Belyayev, a Soviet biologist who conducted selective breeding experiments with foxes. By breeding together those animals that appeared tamer Doctor Belyayev succeeded in only six generations in producing a strain of fox that was as tame as a domestic dog. At the same time Dr. Belyayev mated those foxes that seemed especially violent and again in only six generations produced a strain that was pathologically vicious.

Evgeny Belyayev playing with some of the foxes he had tamed by selective breeding. (Credit: The New York Times)

And in my post of 17 June 2020 I reviewed the book ‘The Better Angels of our Nature’ by Harvard Professor of Psychology Steven Pinker. That book considered in great detail the mounting evidence that living in a civilized society is actually making human beings less violent. In a sense all three of these sources point towards the same general theory, that under the correct conditions violent behavior can be greatly reduced if not eliminated from a population within an evolutionarily short period of time.

A quote from ‘The Better Angels of our Nature’ by Steven Pinker. Hope for the future? Perhaps? (Credit: Pinterest)

Of course there is still much more that needs to be learned. But it is becoming clear that we can learn how to control our violent animal behavior, if we can only find the will to do so.

Physicists use imaginary numbers all of the time to help them describe physical reality, but do they themselves have any physical reality?

We all remember square roots from our high school math classes. You know, since 3 times 3, formally 3² squared, equals 9 that means that the square root of 9 is 3. Some numbers, like 9 have nice round square roots like 3. Other numbers, have square roots that are irrational, that is the number never comes to an end and never repeats itself. The square root of 17 is 4.12310563… for example.

The study of ‘Perfect Squares’ is a branch of number theory in mathematics. (Credit: Socratic)

Negative numbers are a special problem because you’ll remember that a negative number times another negative number gives a positive number. Therefore -3 times -3 is +9, not -9. So what is the square root of -9? Does it even have one?

(By the way, if you’ve always had difficulty imagining why a negative times a negative gives a positive consider this metaphor. Someone films a bathtub while water is draining out of it. That film is then shown running backwards! The water draining out is a negative, running the film backwards is also negative but what you would see is the water rising in the tub. A positive!)

For along time mathematicians simply ignored the possibility of the square root of a negative number. Such things just don’t exist they said. Then a sixteenth century Italian mathematician named Cardan was trying to find two numbers that when added together equal 10 but when multiplied equal 40. The solution he got was:

Cardan himself wrote that his solution was meaningless, fictitious and imaginary. But it worked. It worked so well that mathematicians quickly figured out how to contain the madness as it were.

What they did was to define an imaginary number, i²=-1, not i= √-1, the number i is actually never defined, only its square is. Nevertheless anytime mathematicians came across a √-1 they would replace it with i. So for example √-16=√16*√-1=4*√-1=4i.

If you define the imaginary number i this way mathematicians will consider you poorly educated. (Credit: Wumbo)

This is the proper way to define i. (Credit: Kahn Academy)

Formally the square root of a negative number is called imaginary, like 4i, but a combination of an imaginary number and a real number is called a complex number, 5+4i would be an example where 5 is the real portion and 4 the imaginary part. All complex numbers have a strange counterpart called the complex conjugate where every i has its sign changed, i→-i and -i→i everywhere. Whenever a complex number is multiplied by its complex conjugate the result is always entirely real, for example taking the most basic complex number A+iB where A and B are both real numbers and i²= -1 the complex conjugate would be A-iB and:

The terms in i cancel each other out while the i² term =-1. Since A and B are both real A²+B² is totally real. For a time it was thought, or perhaps hoped would be a better word, that imaginary and complex numbers were just mathematical fictions, with no application in the real world. However it was found that the familiar trigonometric functions could be expressed as complex functions.

Physicists meanwhile were starting to use the sin and cos functions to represent waves of varying kinds, light waves, sound waves, alternating current in electrical systems etc. Things got even worse during the development of quantum mechanics when the wave nature of subatomic particles became evident and the solutions ψ(x,t) of the Schrödinger wave equation:

are always complex. It was physicist Max Born who figured a way out of this dilemma when he suggested that ψ itself is not observable, its only when ψ is multiplied by its complex conjugate ψ* giving ψψ*= real that the answer to the Schrödinger equation becomes an observable. Schrödinger himself considered the presence of all those i’s in his equation to be unpleasant writing to a fellow physicist that “ψ is surely a fundamentally real function.” This is where physics has remained now for nearly a century with the solutions to our equations giving complex answers but we only pay attention to the so-called ‘real’ part.

Complex numbers are a bit easier to understand, and are very useful, if you consider them as a 2-dimensional plane. The real part is along the x-axis while the imaginary part becomes the y-axis and the complex number as a whole becomes a vector! (Credit: TeX StackExchange)

Now a group of theoreticians has proposed a thought experiment wherein the reality of imaginary numbers is required and it involves another of quantum mechanics strange properties, quantum entanglement. The basic idea of quantum entanglement is that if you measure the state of two particles those particles are now entangled and even if you separate them the measurement of them as a system must remain the same.

Physicists are currently playing all kinds of games with the particles of light called photons in order to learn more about the phenomenon of quantum entanglement. (Credit: J-Wiki at Wikipedia)

To put it more simply, if you measured a system of two coins and found it to have one head and one tail and then separated them by a great distance. Once separated if you measure one to be a head, then the other must be a tail no matter how far apart they now are. (Mind you the trick is to separate the two particles or coins without breaking the entanglement.) This effect has been both demonstrated and calculated using only the real parts of the wave function ψ.

Einstein considered quantum entanglement to be “spooky action at a distance” but that doesn’t mean it’s not real. (Credit: Quantum Mind)

The new thought experiment starts by making things more complicated. Let’s say I have two entangled particles and send one to a friend in California named Perry and the other to a friend in Florida named Nancy. Another physicist in Illinois also has a pair of entangled particles and sends one to Nancy in Florida and the other to a friend in Massachusetts named Bill. Notice how the second set of particles doesn’t come from me.

Now the question. Are the two particles received by Perry and Bill entangled, keeping in mind that Nancy got one from each of us? Well the only way to get the answer that everyone expects to be correct, remember this experiment hasn’t been performed yet, is by assuming that the imaginary part of the wave function of the entire system has a physical reality.

Euler’s equation, which contains only the five principal constants of mathematics, is often called the most beautiful equation. (Credit: Live Science)

At the moment the paper, which includes physicists Marc-Olivier Renou of the Institute of Photonic Sciences in Spain and Nicolas Gisin at the University of Geneva, is undergoing peer review so these results are preliminary. Also, if the groups thought experiment does survive scrutiny you can bet someone is going to try to perform the experiment for real.

We all feel this way sometimes when we have to work with imaginary numbers! (Credit: Medium)

Imaginary numbers have befuddled both mathematicians and scientists for going on 500 years now and will undoubtedly continue to do so for even longer. The whole thing seems so simple, yet so weird, and trust me if you don’t pay attention you can screw them up so easily. I guess maybe it’s just a little more evidence of how important our imagination is in understanding reality.

Book Review: ‘Prelude to Extinction’ by Andreas Karpf.

Attention all ‘Star Trek’ fans, here’s a book I think you’ll enjoy. Really, ‘Prelude to Extinction’ the first novel by experimental physicist Andreas Karpf reads very much like a good episode of that sci-fi classic. Captain Jack Harrison of the Earth vessel Magellan is absolutely cut from the same cloth as James T. Kirk and his first officer George Palmer and science officer Don Martinez will often remind you of Mister Spock and ‘Bones’ McCoy.

Cover of ‘Prelude to Extinction’ by Andreas Karpf. (Credit: Amazon)

And like an episode of ‘Star Trek’ the story line in ‘Prelude to Extinction’ is as much action-adventure as it is sci-fi. Even so Author Karpf manages to give the star ship Magellan a good hard feel, all the technology is based on extrapolation from present knowledge so you can actually imagine Magellan as a real ship. This is very much like the feel sci-fi fans got when they first traveled aboard the U.S.S. Enterprise back in 1967, deliberately so I’m certain.

Like the starship Enterprise in ‘Star Trek’ the starship Magellan has the feel of a ship that could actually exist. (Credit: Popular Mechanics)

Now don’t get me wrong, ‘Prelude to Extinction’ is not fan fiction. The novel is set in a completely different imaginary reality with completely different characters. It just all feels familiar, Mister Karpf’s style is right out of the style of the original ‘Star Trek’ series and it shows.

*When he’s not writing novels Author Andreas Karpf is a Research Project Manager at NYU Center for Urban Science & Progress. (Credit: Twitter)*

The story takes place in the year 2124, just a hundred years from now as the first Earth starship Magellan is entering the Epsilon Eridani star system at a distance of a little over 10 light years from our Solar System. Now astronomers know that E Eridani is a bit smaller and cooler than the Sun, and that it has several planets orbiting it. The fourth of those planets, E Eridani D orbits within the star’s ‘habitable zone’ where liquid water can exist and therefore is a potential home for life.

Epsilon Eridani is one of the closest stars to our Sun and the closest with a large solar system, one planet of which could have liquid water on its surface. (Credit: stars.astro.illinois.edu)

In the novel recent observations by telescopes on the Moon have found conflicting evidence for the existence of intelligent life on D. This is the mission of the Magellan, to discover if there is a civilization on E Eridani D.

The Epsilon Eridani star system compared to our own. E Eridani is the closest star that appears to have a planet within the so-called ‘habitable zone’. (Credit: Sci-News.com)

What the crew of the Magellan find is the ruins of a single city, destroyed apparently by violence along with a strange alien artifact in orbit around the planet. It isn’t long thereafter that the Earthlings are caught in the middle of an interstellar war between two much more advanced alien species, a war that could quickly engulf the Earth and all of humanity.

I do have a few problems with ‘Prelude to Extinction’, for one thing there is a dry stretch about one quarter into the book between where the crew are beginning to realize what’s going on and their first meeting with aliens. Then there are the aliens themselves, one species is just too goody-goody while the other are too bloodthirsty, both just a bit too cartoonish. Finally in the battle sequences Captain Harrison comes off as a bit too heroic, so much so he makes Captain Kirk seem like a pansy.

There were times in ‘Star Trek’ when Captain Kirk was just tooooo heroic. Captain Harrison in ‘Prelude to Extinction’ is often that way as well! (Credit: Neatorama)

‘Prelude to Extinction’ isn’t a profound work of SF that examines humanity’s place in the Universe like ‘Childhood’s End’ or ‘The Foundation Trilogy’. Neither does it try to illustrate how we humans are going to have to learn to live on the new worlds we explore like ‘The Martian.’ No, ‘Prelude to Extinction’ doesn’t pretend to be anything more than an action adventure Sci-Fi novel and in that respect it succeeds. If you’re in the mood for an enjoyable ‘Star Trek style’ story you should check out ‘Prelude to Extinction’ by Andreas Karpf.