Scienceandsf -A Blog Published by Robert A. Lawler – Page 43 – Discussions of Topics Related to Science and Science Fiction

Space News for August 2019.

We generally think of a story in the news as a report of some sort of dramatic occurrence, a story about an event full of action and yes, even danger. Space news therefore would consist primarily of accounts about rocket launches and space probes landing on distant worlds.

Of course we know that isn’t quite true. In space exploration the calm, deliberate decisions that are made in engineering conferences are every bit as vital to accomplishing the mission as the more spectacular moments. In this post I will be discussing three such stories illustrating the kind of planning and decision making that will make future space missions possible.

Many ideas are developed, and problems solved, in Engineering Meetings (Credit: PSM.com)

One such important decision announced by NASA on August 19 was to give a go ahead to begin construction of their ambitious Europa Clipper space probe, named for it’s target, Jupiter’s moon Europa. The intended mission of the Europa Clipper is to study that icy world in an effort to determine if the moon is actually a possible home for life. Some 40 close flybys of Europa are planned during which the probe will measure of thickness of the moon’s ice surface along with confirming the existence of a liquid ocean beneath the ice.

The Europa Clipper Space probe will make 40 flybys of the icy moon of Jupiter (Credit: ABC57.com)

The decision by NASA means that the design phase of the mission is now over and construction will now begin at NASA’s Jet Propulsion Laboratory (JPL) with a planned launch date of 2023 or 2025. One decision about the Europa Clipper still remains to be made however. What launch vehicle will be used to send the probe on it’s way to Jupiter?

Currently congress has ordered NASA to use the Space Launch System (SLS) as the launch system but that massive rocket is still not ready for it’s first test launch, and there is the real possibility that the SLS might not be ready by 2025. Also, launching the Europa Clipper with the SLS will cost over a billion dollars.

After many delays and budget overruns NASA’s massive Space Launch System (SLS) still has not flown (Credit: NASA)

NASA on the other hand would prefer to launch the Europa clipper using a commercial launcher such as Space X’s Falcon Heavy. Launching the space probe with a commercial rocket would not only save hundreds of millions of dollars but also firm up the launch schedule since the Falcon Heavy has already successfully flown three times. Unfortunately the decision here may be made by politics because the SLS is being built at NASA’s Marshall Space Flight Center in Alabama and some very important republican senators are strongly supporting it.

The Space X Falcon Heavy rocket has already flown successfully three times (Credit: The Verge)

Speaking of the Marshall Space Flight Center, NASA has made another decision naming them as the lead management center in the development of the Lunar Lander for the space agency’s big Artemis program. Artemis is the name that NASA has now given to its plans for returning astronauts to the Moon’s surface by 2024. Since Marshall is already developing the SLS as the Artemis launch vehicle their choice as lead for the Lander now puts two big pieces of the Artemis pie on Alabama’s plate.

The Marshall Space Flight Center is where NASA has developed rockets like the Saturn V and Space Shuttle (Credit: Wikipedia)

Again the decision here was made on the basis of political, not engineering grounds and that’s never a good thing. In fact the decision could very well be changed. You see the Johnson Manned Space Flight Center is in Houston Texas and there are a couple of powerful Texas senators, also republican by the way, who think the Johnson center would be a much better selection as management lead for the lander’s development.

The Johnson Space Flight Center in Texas is Where NASA’s Manned Space Missions are developed (Credit: Wikipedia)

None of this arguing back and forth will make the lander perform any better, or be built any faster or cheaper. Indeed that sort of political infighting is more likely to stall funding appropriations that could lead to schedule delays and cost overruns.

On a more hopeful note NASA has also decided to team up with Space X in order to develop the technology necessary for the refueling of spacecraft in space! Again the idea is to reuse spacecraft rather than just throw them away after one use and build another. In space refueling has long been considered essential towards developing a space infrastructure that will enable longer and more difficult space missions.

Refueling in space would extent the operational life of satellites, thereby reducing their cost (Credit: Engadget)

Take for example the communications satellites that are now in geostationary orbit 35,000 km above the earth’s equator. These multi-million dollar radio relays must keep their antennas pointed very precisely at Earth in order to perform their job at all. To do this the satellites have small, station keeping rocket engines that keep the satellite exactly where they’re supposed to be. After about 5-7 years however those engines run out of fuel and the craft soon begins to drift until the antennas are no longer directed at Earth. Once that happens the satellite becomes nothing more than a very expensive piece of junk up in space. If you could refuel those satellites while in orbit however you could extend their useful life by years and save billions of dollars.

For manned spaceflight in space refueling would allow the development true spaceships that could travel back and forth to the Moon or Mars multiple times. Such spaceships would be refueled at the end of each mission in exactly the way you refuel your car after a long trip.

Developing the technology for refueling in space won’t be easy however. Most of the chemicals used as rocket fuel, liquid oxygen, liquid hydrogen or liquid methane have to be kept cryogenically cold, requiring both refrigeration equipment and power. And everything has to be kept airtight or that fuel that you spent so much money getting into orbit will simply boil off into space. That’s why NASA teaming up with Space X makes sense. While Space X is the leader in reusable spacecraft NASA’s Glenn Research Center in Ohio and Marshall Space Flight Center are the recognized experts in handling and storing various kinds of rocket fuel. Hopefully this teaming up of skills will solve the problems of refueling in space and one day soon in addition to orbiting space stations we will see orbiting gas stations as well.

Will there soon be a ‘Gas Station’ in orbit above the Earth? (Credit: Ars Technica)

The Transistor and Integrated Circuit, the story of the Miniaturization Revolution in Electronics

Earlier this year I celebrated the fiftieth anniversary of the Moon landing of Apollo 11 by publishing a series of eight articles about the ‘Space Race’ of the 1960s. I enjoyed that task so much that I decided to write a few more posts about some of the other cool technologies of that time, I hope you enjoy them.

In most homes today you’ll find that the number of electronic devices outnumbers the number of human beings by a factor of three, four or even more. Add up all of the TVs, computers, smartphones, hey even our ovens and refrigerators have microprocessors in them nowadays!!! Electronics are so cheap, so versatile and so small that we’re putting them in just about everything.

Just some of the electronics that can be found in a modern home. (Credit: Santa Barbara Loan and Jewelry)

Back in the 60s however electronics were big and expensive. Most homes had one TV, one record player and one, maybe two radios. The reason was simple; electronics were built around the vacuum tube, which were themselves large and expensive. See image below.

An Electronic Vacuum Tube (Credit: Parts Express)

Now if you think that a vacuum tube looks something like an incandescent light bulb you’re quite right, vacuum tubes were developed from light bulbs and like them require a considerable amount of power, voltage and current, in order to just turn on. This makes vacuum tubes wasteful of energy, hot and rather large.

Things started to change during the 60s when the first transistor electronics came on the market, the small, hand held AM transistor radio being the most popular. Now pretty much everyone knows that transistors are made primarily of silicon and, like a vacuum tube a transistor is an ultra fast electrical switch. Unlike a tube however a transistor doesn’t have to be hot in order to work.

An antique six transistor radio. (Credit: ETSY)

This means a transistor needs only a small fraction of the power of a vacuum tube in order to function and therefore they can be made much smaller and packed in together more tightly. Whereas a vacuum tube radio was as large as a piece of furniture a transistor radio could be held in one hand, and with the transistor radio the word miniaturization came into common usage.

Vacuum Tube radios could hardly be considered mobile! (Credit: Flickr)

Still, my first little transistor radio was build of ‘discrete’ transistors. That is to say each transistor was a separate object, an individual piece of silicon packaged in it’s own plastic coating. When I bought my second transistor radio I of course disassembled the first one and inside I found six transistors, along with numerous other components. The transistors were each about the size of a pea; I learned later that the transistors were packaged in a standard format known as TO-92.

A single 2N3904 Bipolar NPN General Purpose Transistor packed in a TO-92 case. (Credit: Addicore)

Even as the first transistorized consumer products were becoming available there were engineers who began to wonder if it would be possible to fit two transistors, or even more, on a single piece of silicon, and how many could you fit? The first experiments with Integrated Circuits (ICs), as these components came to be known, were carried out at Texas Instruments Corp. in 1958. See image below.

The World’s first integrated circuit contain two transistors on a single piece of germanium, not silicon (Credit: Texas Instruments)

The advantages of ICs were many, reduced cost, size and power requirement along with increased operating speed. The drawback to ICs was their high initial start up costs. The facilities needed for manufacturing ICs, known as a ‘foundry’, are very expensive even though, once you had a foundry millions of ICs could then be made very cheaply. In the business this is known as a high Non-Recurring Expense (NRE) with a small Recurring Expense (RE).

A look inside a foundry for the manufacture of Integrated Circuits. (Credit: SemiWiki)

So, who was going to pay for the first IC foundries? The U.S. government that’s who! In the 1960s both NASA and the military had a tremendous need for ever more sophisticated radios, radars, guidance systems and even computers. And all of these new electronics had to be smaller in order to fit into rockets, airplanes and ships. The IC was the only possible technology that could satisfy that need.

Then, once the first foundries were built the miniaturization revolution really got under way. One of the pioneers of the IC industry Gordon Moore declared in 1965 that the number of transistors on a single silicon ‘chip’ would double ever two years. This prediction is commonly called Moore’s Law and has worked now for over 50 years with the current technology being capable of placing millions of transistors on a chip of silicon no larger than a fingernail.

Gordon Moore was an early pioneer in the development of Integrated Circuits. (Credit: Computer History Museum)

A Look inside a typical Integrated Circuit, this one is a Pentium 4 Microprocessor used in many personal computers. (Credit: Calvin College)

With this technological progress has come personal computers, smartphones, digital cameras, digital television and myriad other devices that we all have in our homes or carry on our person. The transistor and Integrated Circuit have become the true symbols of our modern age and their revolution began in the 1960s.

There’s some good news about the Environment for a Change. Plastic microparticles may not be a health danger after all!

Everyday it seems as if we hear another news story about how all the pollutants and trash that we’re dumping into the environment are coming back to do us harm. If it isn’t climate change it’s harmful chemicals in the air or water. One possible threat that’s been in the news recently is plastic microparticles.

Just a small part of the Great Pacific Garbage Patch. Most of this muck is plastic! (Credit: The Brag)

What are plastic microparticles? Well you see, all those millions of tons of plastic we keep throwing away may be chemically inert but ultra-violet light from the Sun combined with mechanical action from ocean waves or weather can break it down into particles less than 5mm in diameter.

Waste Plastic doesn’t decay in the environment but it does break down into small pieces the smallest of which are microparticles (Credit: Lifegate)

Environmental researchers are finding plastic microparticles nearly everywhere. In the oceans they have been discovered in both the artic regions as well as the bottom of the Mariannas trench, the deepest part of the ocean. Scientists in both France and Colorado have even found plastic fibers in rainwater while in Norway they’ve been found in snow. I suppose we’ll have to stop using the phrase ‘Pure as the driven Snow’. With plastic microparticles everywhere we are certainly going to be ingesting some as we eat and drink so the question is. Can they get from our stomach into our bodies and if so what harm will they do there?

Plastic bags have even been found at the bottom of the deepest part of the Oceans (Credit: Science Alert)

Researchers have begun to study this possibility with the intent of determining the health threat posed by plastic microparticles. A leading scientist at the Center for Organismal Studies at the University of Heidelberg, Doctor Thomas Braunbeck has been investigating whether or not plastic microparticles can pass easily through the lining of the intestines of vertebrate animals. In other words if we ingest these particles will they get into us?

Professor Doctor Thomas Braunbeck of Heidelberg University (Credit: Researchgate)

The test animal Dr. Braunbeck choose for his work are the well known fresh water aquarium fish the zebra danio (Danio rerio) because he could study many animals at once quite easily. Also, the zebrafish’s growth rate is so high if plastic microparticles can be absorbed a lot would be absorbed in a short time making detection more certain.

To carry out his experiment Dr. Braunbeck used microparticles that were coated with a phosphorescent chemical that made them easier to track and the particle size he choose was around 10μm. First the particles were fed to a kind of small crustacean that is also well known to tropical fish hobbyists as brine shrimp. Once he was certain that the shrimp had indeed absorbed the microparticles he then fed the shrimp to his zebrafish.

Now here’s the good news. When Dr. Braunbeck checked the fish for signs that plastic microparticles had been absorbed he found none. The particles had been unable to pass through the lining of the zebrafish’s intestine. Instead the microparticles had simply passed all the way through the fish’s digestive system and out the back end.

Since this is one of the first experiments to determine if plastic microparticles can be absorbed through the intestine of a vertebrate the negative result is good news. Before you start celebrating however remember I mentioned above that the particles used in the study were 10μm in diameter. Dr. Braunbeck cautions that smaller particles might still be able to get through. Nevertheless it is nice to hear a little hopeful news about pollution for a change.

Of course just because plastic microparticles may not be a very big health risk certainly doesn’t mean that we shouldn’t be concerned about the millions of tones of plastic waste that’s just turning our planet into a trash dump. Fortunately there are more and more people who are trying to find solutions to the problem. Earlier this year, see my post of 9 January 2019, I wrote about the young man from Holland named Boyan Slat who had invented a 700m long ‘U’ shaped boom to sweep up the Great Pacific Garbage Patch. The first test of Slat’s invention ran into some problems but the upgrades are in progress and a second test is coming soon!

The 700m floating boom used to remove plastic from the ocean still has some bugs to work out. (Credit: Twitter)

While Boyan Slat’s boom is intended to remove large pieces plastic from the Ocean a teenager from Ireland has developed a technique for eliminating up to 88% of plastic microparticles from water. The teenager’s name is Fionn Ferreira and his project won him the Grand Prize in Google’s annual science fair. The native of the town of Ballydehob is planning on using his $50,000 to pay for his further education in college. Fionn’s technique for collecting the plastic microparticles in water involves attracting and removing the particles with a magnet.

Fionn Ferrerira, the winner of this years Google science prize for his technique to remove plastic microparticles from water. (Credit: ABC News)

Wait a minute, you say. Plastic isn’t magnetic. You can’t attract plastic with a magnet. That’s true, however in water plastic microparticles are attracted to ferrofluids, mixtures of oils and iron based magnetite. The oil in the ferrofluid clumps with the microplasic and the magnetite can then be lifted out with a magnet carrying the oil and plastic with it.

If this sounds almost too good to be true you could be right. The biggest technical problem as I see it will be to scale up the whole process, there’s a lot of plastic microparticles out there to be collected. In particular separating the ferrofluid from the plastic so that it can be used again and again could prove difficult. Of course the real problem will be the cost, nobody is going to be making a profit off of this you know.

And that’s the real problem with cleaning up the environment in general, the cost. There are many things we could do to clean up the mess we’re making of this planet of ours. The question is, who’s going to pay for it?

In a revolutionary experiment scientists are using the Gene editing tool CRISPR to treat patients suffering with the genetic disorder Sickle Cell Anemia.

In all of modern science there is perhaps no more rapidly advancing field than that of genetic research. Much of that progress has come about because of the development of the molecular gene editing tool CRISPR (which stands for Clustered Regularly Interspaced Short Palindromic Repeats) that allows biochemists to literally cut and/or paste sections of DNA into the chromosomes of living cells. I have talked about CRISPR several times in previous articles, see posts of 2 March 2019, 12 January 2019, 1 December 2018, 1 September 2018 and 5 August 2017, and the full potential of CRISPR is still only being guessed at.

How CRISPR Works (Credit: Cambridge University Press)

Now the latest experiment is making a bold and daring attempt to treat fully grown persons who are sufferers of the inherited genetic disorder Sickle Cell Anemia, a condition that affects about 100,000 people living here in the United States and millions of others worldwide. This is the first ever attempt to use CRISPR to modify the cells of adult patients in the hopes that the altered cells will allow those patients to live a more normal life.

The Genetic disease Sickle Cell Anemia is a chronic ailment for millions of people (Credit: Familydoctor.org

Before I continue let me talk a little bit about the genetic disease Sickle Cell Anemia. This is a disorder that affects the bone marrow and leads to the production of red blood cells with a defective protein that causes the cells to be deformed, sickle shaped. These deformed blood cells are thereby unable to carry a normal amount of oxygen leading to a permanent and in some cases crippling weakness in the affected person. Most sufferers of Sickle Cell Anemia are ethnic African or African-American and since the disease is inherited it can devastate a family for generations.

Sickle Cell Anemia is an inherited genetic disorder (Credit: Synthego)

The procedure being tested is to take cells from the patient’s bone marrow and modify the cells DNA using CISPR in order to make them produce a protein that is normally only formed by the human body while in the womb and during early childhood. It is hoped that the production of this protein will correct the deformations of blood cells caused by the defective protein, thereby alleviating the anemia caused by sickle cell.

Possible Techniques for using CRISPR to cure Sickle Cell (Credit: American Chemical Society)

The experimental treatment for Sickle Cell Anemia is being conducted at eight hospitals and clinics in North America and Europe and is being overseen by CRISPR Therapeutics of Cambridge Massachusetts in association with Vertex Pharmaceuticals of Boston. The current plan is to have up to 45 patients take part in the initial trials of the experiment.

Patient undergoing CRISPR treatment for Sickle Cell Anemia (Credit: NPR)

It will be months before the researchers know for certain whether or not the modified cells are even producing the desired protein let alone if the protein is actually helping to improve the health of the study’s patients. Then, even if there is strong evidence that the procedure has worked, there is the question of how long will the benefits last? Will this technique produce a permanent cure or will the effect be only temporary?

These are questions that only time can answer, but we are at the threshold of a new medical technology. This may be the first attempt to treat patients with a genetic disease by using CRISPR but it certainly will not be the last.

Newly developed Prosthetic arm is so advanced it not only is controlled by the brain but it gives the user an almost natural sense of feeling.

The development of prosthetic limbs has advanced so quickly in the last few years that it really seems as if our technology is catching up to the science fiction ‘bionic’ limbs in movies and TV from 40 or 50 years ago. In fact a new prosthetic arm being developed at the University of Utah is so sophisticated that the researchers have named it the ‘Luke Arm’ for the ‘Star Wars’ character Luke Skywalker who famously lost his arm to Darth Vader and had it replaced with an artificial one.

Steve Austin, ‘The Six Million Dollar Man’ was a cyborg with an artificial arm and two artificial legs (Credit: Amazon)

In ‘The Empire Strikes Back’ Luke Skywalker looses his arm in a fight with Darth Vader and gets a replacement! (Credit: 20th century Fox)

While the prosthetic undergoing testing is designed for people who have had their left arm amputated below the elbow but the developers are confident that the design can be easily adapted to both the right hand and amputations above the elbow. Mechanically the arm is constructed of metal motors overlayed by a clear silicon skin which has had one hundred electronic sensors imbedded in it.

The Luke arm being benchtested at the University of Utah (Credit: Unews, University of Utah)

So sophisticated is the prosthetic that not only can it move and grab in response to signals from the wearer’s brain but it can send sensory signals back to the brain that are interpreted as the feelings of touch, heat and even pain. This is accomplished by a system of microelectrodes and wires that are implanted in the wearer’s forearm and connected between the nerve endings of the lost limb and the arm’s one hundred sensors.

The Luke Arm’s Sensoty electrode carries 100 sensory inputs between the arm and the Brain (Credit: Unews, University of Utah)

The system of microelectrodes has been named the Utah Slanted Electrode Array and was invented by Professor Emeritus Richard A. Normann. The array is connected to an external computer that serves as a translator between the biological and electronic signals.

Patients using the ‘Luke Arm’ have succeeded in performing even delicate activities such as removing a single grape from a bunch or picking up an egg. This is because the sensors in the arm allow the user to actually feel the softness or hardness of the objects they touch. One test subject, Keven Walgomott of West Valley City Utah, even asserted that he could feel the softness of his wife’s hand as he held it with the ‘Luke Arm’.

Volunteer amputee Keven Walgomott using the Luke Arm (Credit: Interesting Engineering)

According to Jacob George, the study main author and a doctoral candidate at the University of Utah. “We changed the way we are sending that information to the brain so that it matches the human body…We’re making more biologically realistic signals.”

The researchers are currently working on a portable version of the Luke arm that will allow in home trials to begin. Testing of the Luke arm could take another few years before FDA approval is granted and the prosthetic becomes commercially available. Nevertheless, the day is coming when artificial limbs will be providing amputees with a quality of life that is nearly equal to the natural ones they have lost.

If you’d like to see the Luke arm in action click on the link below to be taken to a youtube video from the University of Utah. https://www.youtube.com/watch?v=_Xl6rFvuR08

In the story above I mentioned that Luke arm has one hundred sensors implanted with it. Now that may sound like a lot but of course a real arm has thousands of nerve endings giving our brain a much more complete impression of everything that’s happening to that limb. Could an electronic skin, like that on Luke arm, ever be developed that possesses as many sensors as natural skin?

They’re already working on it! Scientists at the Department of Materials Science and Engineering at the National University of Singapore have developed a sampling architecture of sensor arrays that they have named the ‘Asynchronously Coded Electronic Skin’ (ACES). The engineers assert that ACES could work with arrays of up to 10,000 sensors and have even fabricated and tested a 250 sensor array to demonstrate their technique.

Some of the sensors used to test ACES (Credit: Edgy.app)

Now there are several problems that you’re to need to overcome if you intend to greatly increase the number of sensors in your system. The first is simply data overload, that is more data than a computer, or even our brain can handle. The second is sampling speed. With thousands of sensors waiting to have their data taken, even at a high sampling rate a large faction of a second or more can pass between each time a particular sensor is sampled. That means that an emergency signal, burning heat or a stabbing wound could go unnoticed until real damage is done.

The technique used by the engineers in Singapore is actually modeled on the way the nerves in our body communicate with the brain, an ‘event based’ sampling protocol. Think about it, when you first sit down in a chair you feel a large area of pressure as your skin makes contact, but after a second or so you hardly feel the chair at all. This is because our brain only reacts to changes to the messages from our nerves. The brain only pays attention when our nerves tell it that something, an event, is happening.

The electronic architecture of ACES (Credit: Cosmos Magazine)

The ACES system does much the same thing, only passing on the data of sensors that are measuring changes to their environment. In this way it prevents data overload while at the same time enabling important information to quickly become available to the controlling intelligence. The researchers in Singapore hope that their ACES system will prove to be applicable not only for sensors in prosthetic limbs but also for increasing the ability of Artificial Intelligence systems to sense and manipulate their environment. In that way ACES may be another step forward in shaping the human-machine interface of the future.

Who were the Philistines of the bible, modern DNA measurements may hold the answer.

The ancient writers of the bible liked to portray all of their neighbors in a very negative way but undoubtedly the people they called the Philistines received more than their share of bed press. According to the bible the Philistines lived along the Mediterranean coast just to the east of the central highlands where the Hebrew people resided. Here they built five city-states, Gaza, Ashkelon, Ashdod, Ekron and Gath.

Map of Ancient Canaan showing the region ruled by the Philistines (Credit: Crystalinks)

So who were the Philistines, the original Hebrew word Philištim simply means ‘people of Plešt’ whoever or whatever Plešt may have been. In the Bible however the Philistines are always treated as somehow different from the Canaanites or Moabites or Egyptians who were the Semitic neighbors of the Hebrews. Philistine names, like Goliath or Delilah, and the customs recorded in the bible also point to a non-Semitic origin.

In the bible the Philistines are depicted as being continually at war with the Hebrews (Credit: Facts and Details)

The first clues to the origin of the Philistines were discovered during the early archaeological expeditions to Egypt in the 1840s. It was the Egyptologists Edward Hincks and William Osborn jr. who published the history of the Pharaoh Ramesses III and his battles with a ‘sea peoples’ that were also known by the name of Peleset (Philistines???). According to Egyptian inscriptions Ramesses III defeated these Peleset in a naval battle in the River Nile as well as a land battle along the eastern Mediterranean not far from the city of Gaza!! The inscriptions go on to state that Ramesses III later settled his captives in a series of ‘strongholds’.

Inscription of Ramesses III defeating the ‘Sea People” (Credit: TheTorah.Com)

Captive Philistines as illustrated by the Egyptians (Credit: Encyclopedia Britannica)

There are those who doubt that theory however stating that the similarity of names is hardly conclusive evidence. At the same time there is little archaeological support for a large-scale settlement of people in the region around Gaza in the 11th century BCE. Some scholars point to the use of the term ‘allophyloi’ (of another tribe) in the Greek translation of the bible, the septuagint to indicate that the Philistines were simply ‘non-Hebrews’, any enemies of the Hebrews. However the bible’s own descriptions clearly seem to refer to a definite ethnic group living in a definite place.

None of which gets us any loser to answering the question, who were the Philistines? If they weren’t Semites like the Hebrews or Egyptians or Canaanites, who were they linguistically and culturally? Where did they come from?

Based upon the clues in the bible and the Egyptian inscriptions the leading hypothesis is that the ‘sea peoples’ came mostly from the area around the Aegean Sea including Crete, Cyprus, the western coast of modern Turkey as well as Greece itself! The idea that a large force of bronze age Greeks might have invaded the southeastern Mediterranean coast fits also in with the well attested destruction of the Mycenaean cites at that time.

How can we ever know? That was three thousand ago and the records from that time are incomplete and not conclusive. Yes there is some archeological evidence such as the discovery at Ashkelon of Late Helladic IIIc Mycenaean pottery but the pottery could have come via trade. The evidence may lean toward an Aegean origin but how can we be sure?

Examples of Philistine Pottery that resembles that of Pottery from the Aegean (Credit: Bible Odyssey)

Perhaps the modern science of DNA testing can give us the answer. After all, we’ve all seen the ads telling us how DNA can reveal our ancestry. And remember how DNA was used to prove that the body found in a parking lot was actually England’s King Richard III. Couldn’t the same techniques be employed on skeletons from the right area and time period by archeologists?

In fact scientists have now done just that. In 2016 archeologists working at Ashkelon announced that they had discovered the first known Philistine cemetery, the culmination of 30 years of digging. The team, led by co-director Daniel Master of Wheaton College unearthed the remains of at least 108 individuals from which DNA was successfully removed from ten. The results of the DNA analysis clearly showed that the people buried in the cemetery were not related to any of the local ethnic groups but instead showed a strong European, probably a southern European relationship.

Archaeologists at work at the Philistine cemetery at Ashkelon (credit: National Geographic)

So it appears as if the hypotheses about an Aegean origin for the people know in the bible as Philistines was true. Goliath and Delilah may have been the descendants of Odysseus or Agamemnon or some of the other well-known characters of the Greek heroic age.

Think about that for a moment, could the ‘sea peoples’ have brought with them the stories that would become the later Greek myths. We could speculate that the Philistines told their stories about Hercules and the Hebrews responded by imagining stories of their strongman Samson. After all the first of Hercules twelve labours is strangling the Nemean lion whose hide was so tough no weapon could pierce it, while in the bible Samson’s first feat of strength is strangling a lion with his bare hands!!

Hercules slaying the Nemean Lion (Credit: Theoi Greek Mythology)

Could the story of Yahweh testing Abraham by demanding the sacrifice of Isaac, and then stopping the ritual once he was sure of Abraham’s faith, be the Hebrew answer to the Greek tale of the Goddess Artemis’s demand that Agamemnon sacrifice his daughter Iphigenia to her!

Iphigenia and Isaac being prepared for Sacrifice (Credit: PD)

We may never know the answer to these questions, cultural cross connections leave few traces in the archeological record. One thing we can be certain of however is that since this is the Middle East the DNA results would quickly become politicized!

In fact Israeli Prime Minister Benjamin Netanyahu has already used the results to declare that since the Philistines came from Europe then the modern Palestinians have no claim to any of the lands of the Middle East. He is of course assuming that the Latin word Palaestina is the same as the Greek word Philistinoi which maybe true but is a subject of considerable contention among scholars.

I suppose the only thing we can really be sure of is that David didn’t defeat Goliath; they’re still fighting it out!!!

No matter what you’ve heard this war ain’t over yet!!!! (Credit: Leadership Platform)

Controversy erupts over claims that newly invented glasses can correct colourblindness.

Before I start to discuss colourblindness perhaps I should start by taking a moment to talk briefly about how it is that we are able to see colour in the first place. Now most people are familiar with the fact that at the back of our eyes, the retina, there are two groups of light sensitive cells that are called rods and cones based upon their shape. The rods are sensitive to the intensity of the light whatever the colour, if we had only rods we’d see everything in black and white, complete colourblindness.

The Anatomy of the Human Eye (Credit: Wikipedia)

The cones on the other hand come in three types; some are sensitive to the longer wavelengths of visible light, the colour red. Others are sensitive to the shorter visible wavelengths, the colour blue. The final group is sensitive to the middle wavelengths, the colour green. Together these three types of cones give us the ability to distinguish thousands of shades of colour.

Colourblindness is defined as a decreased ability to discern the full range of the colour spectrum of visible light. In other words some of the cone cells are not functioning properly.

The most common form of colourblindness consists of some degree of difficulty in distinguishing between the colours red and green and is known clinically as dichromatic. Dichromatic colourblindness is both genetic in nature and sex related since the gene for the red / green cone cells occurs on the X chromosome of the X-y sex pair.

How people with Dichromatic colourblindness see the world (Credit: School Work Helper)

The defective gene for colourblindness is recessive in nature so since women have two X sex chromosomes both of the chromosomes must have the defective gene in order for her to be colourblind. A woman with only a single defective X chromosome can be a ‘carrier’ of colourblindness however.

The X-Y Chromosomes determine whether you’s a girl or a boy but can also carry sex related mutations like colourblindness and hair loss (Credit: Socratic)

A male on the other hand has only one X sex chromosome, which he gets from his mother. Therefore if a woman is colourblind all of her male offspring will be colourblind. If a woman is only a carrier of colourblindness then half of her sons will inherit the defective gene and develop colourblindness. Because of this many more men are colourblind, about 8%, as opposed to women, 0.5%.

Colourblindness varies in degree with most colourblind people having only a small loss of colour vision. The chart below shows the different recognized ‘types’ of colourblindness along with the percentage of the population effected.

Types of Colourblindnesss and percent of population effected (Credit: Wikipedia)

Determining whether of not a person has colourblindness is usually accomplished by testing them with one or more Ishihara colour test plates, an example of which is given below. In this example a person with normal colour vision can clearly see the number 27 in the center of the design while a person with a slight colour deficiency will see the number 21. A person with total red / green colourblindness will not see any number at all!

An Ishihara test for Red-Green Colourblindness (Credit: Wikipedia)

There is no cure for colourblindness. Recently however there have been attempts to ‘correct’ colourblindness with specially designed glasses in a manner similar to the way that near or farsightedness can be corrected. The glasses are commercially available under the trademarked name EnChroma® and were developed by developed by a pair of scientists, Andrew Schmeder, a mathematician who studies the psychology of perception, and Don McPherson a glass researcher who has invented specialized laser safety glasses for surgeons.

How the Enchroma glasses are supposed to work (Credit: All About Vision)

According to the inventors the EnChroma® glasses work by eliminating just those wavelengths of red and green light that confuse the eye’s cone cell receptor which allows the brain to perceive a greater colour contrast. EnChroma® Inc. estimates that 80% of colourblind people can see improved colour vision with the help of the glasses and judging by the reaction in Youtube videos of colourblind people who try them for the first time they succeed miraculously.

Not everybody is so convinced however. Researchers at the University of Grenada’s department of Optics in Spain have conducted a test of the EnChroma® glasses with 48 colourblind individuals, over 200 people volunteered for the test. The results of this study, which were published in the journal Optics Express, seem to show that the EnChroma® glasses only marginally perform better than ordinary hunting glasses at increasing colour perception. The conclusion reached was that the wearers of EnChroma® do not perceive new colours so much as see the same colours in a new way.

Sounds a bit like we’re arguing semantics to me. While it’s true that the claims made by EnChroma® Inc are exaggerated, they’re trying to sell the glasses after all, the company has never claimed to be able to ‘cure’ colourblindness. Reality is probably somewhere in the middle with the EnChroma® glasses allowing people with a mild form of red / green colourblindness to separate the two colours more readily.

And at least that’s a start. The development of EnChroma® glasses is the first even slightly successful treatment for colourblindness. Hopefully in the years to come improved versions of the glasses will be developed that perform better, and for more types of colourblindness.

In the long run there has been some research conducted by Maureen Neitz at the University of Washington that has employed gene therapy to cure colourblindness in monkeys. It may in fact be only a few years before there are some treatments available that can significantly improve the ability of people born with colourblindness to see the world with all of the rich tapestry of colours the rest of us take for granted everyday.

Space News for August 2019.

There have been a lot of things happening in the exploration of space lately, some of it’s been hopeful, some not so much. Both manned and robotic space missions are concerned and with so many stories to cover let’s get to it.

Perhaps the best news concerns the successful test of the Orion manned capsule’s launch abort escape system that NASA conducted on the 2nd of July. The entire test went perfectly with a small booster rocket taking the unmanned Orion capsule to approximately 10,000 m, see image below of takeoff. This altitude was chosen for the test because on an actual flight using NASA’s Space Launch System (SLS) as the launch vehicle 10,000 m will represent the time of ‘max-Q’ or maximum pressure due to air resistance.

The Orion Space Capsule sits atop it’s test booster ready for its abort Test (Credit: Spaceflight Now)

At 10,000 m Orion’s abort system fired its own rockets to pull the capsule away from the booster, demonstrating its ability to swiftly remove the astronauts to a safe distance from any potential danger. This latest test clearly shows that the Orion capsule and its support systems are ready for their first mission. Now all we need is for the SLS to be completed in order to get the Orion into space and beyond Earth orbit.

The moment of ignition of the Orion capsule’s Abort rockets (Credit: CBS News)

As usual Space X is also making news. Thanks to their reusable Falcon 9 rocket the Hawthorne California based commercial launch corporation is swiftly coming to dominate the business of putting satellites and cargo into Low Earth Orbit (LOE). This month however it’s their Falcon Heavy rocket that’s pushing the envelope. On the 25th of June Space X successfully launched its Falcon Heavy rocket for the third time placing an incredible 24 separate satellites into Low Earth Orbit (LOE).

Liftoff of the third launch of Space X’s Falcon Heavy rocket (Credit: Business Insider)

This latest mission again demonstrated the ability of Space X to recover and reuse its first stage boosters with the two side boosters of the Falcon heavy returning safely to Cape Canaveral. In addition, for the first time ever the nosecone fairing, used to protect the cargo during the launch, was successfully caught in a net aboard a recovery ship, ready to be reused as well.

Unfortunately the Falcon Heavy’s central booster missed its recovery ship, exploding in the water nearby. However this launch required the central booster to attempt the longest, 1,200 km downrange, landing yet by Space X so a safe landing was considered to be a 50 / 50 shot at best.

There is also some bad news for Space X however. The tentative date for the first manned launch of their Dragon capsule has been pushed back into November and is likely to be even further delayed. After a successful unmanned test of their Crewed Dragon Capsule back in April there had been hopes that a manned mission could occur as early as this month or August. Unfortunately a later static test of the capsule’s abort system produced an ‘anomaly’, in other words an explosion, which led to this latest delay. This is yet another setback for NASA’s commercial crew program and leaves the space agency dependent for a little while longer on the Russian Soyuz space vehicle for getting American astronauts to and from the International Space Station.

The ‘Anomaly’ that occured during testing of the Space X Dragon Capsule (Credit: Express.co.uk)

As I mentioned above Space X is grabbing an ever larger share of the space launch industry, which if you think about it means that somebody has to be losing their share of the market. One of the organizations that are falling behind is the European Space Agency (ESA) whose Arian 5 rocket was just five years ago arguably the most popular vehicle for putting a commercial satellite into orbit. The reduction in cost that the reusability of the Falcon 9 rocket provides however, has made the Arian 5 effectively obsolete so now the ESA is rapidly trying to play catch up to the American firm.

Therefore the ESA is looking into developing a reusable rocket of its own in order to compete with Space X and regain some of their lost market. The space agency has recently announced that five million euros have been provided to the German space agency, DLR to perform an initial design study of such a rocket which has been given the tentative name of Callisto.

Going by the stated goals of the project the result of the study is certain to be a virtual copy of the Falcon 9. In fact the Europeans are quite open about it. “We are convinced that it is absolutely necessary to investigate Retro Propulsion Assisted Landing Technologies,” that’s the formal name of the landing technique used by the Falcon 9, “to make re-usability state-of-the-art in Europe.”

Planned European rocket ‘Callisto’ looks little different from the Falcon 9 (Credit: Space News)

For my last story this month I’ll discuss something a bit more long range, and a lot further from planet Earth. On the 22nd of June NASA announced a new mission that will be a part of their New Frontiers program. The chosen mission is to send a robotic aerial drone that will fly in the dense atmosphere of Saturn’s moon Titan.

To say that this mission, which has been named ‘Dragonfly’, will be ambitious is putting it mildly; there are a large number of engineering difficulties to be overcome. The surface gravity of Titan is only one quarter that of Earth however, and the moon’s atmosphere is fully 50% denser than Earth’s so the idea of a flying probe seems quite feasible.

Mission profile of NASA’s planned Dragonfly mission the Titan (Credit: Wikipedia)

As I see it there are two big problems to overcome, power and communications. Power is a problem because Titan is so far from the Sun that any kind of solar power is useless. All of our probes beyond Jupiter so far have been powered by Radioisotope Thermoelectric Generators (RTGs) and NASA plans on during the same for Dragonfly. Nevertheless flying takes a lot of energy so there will undoubtedly be a considerable amount of time spent on the ground recharging Dragonfly’s batteries between flights.

Communications will be a tougher problem to deal with because of a very simple fact: at its closest Titan is more than a light-hour’s distance from Earth. This means that if the drone encounters violent, buffeting winds or some other unexpected problem while its flying the controllers back on Earth won’t even know that it’s happening for at least an hour. And then any instructions sent to the probe will take an equal amount of time to get back to it. By that time the emergency would probably be over, or the probe may have crashed and been destroyed!

Probably the only way around this problem will be for the probe to have the most sophisticated computer Artificial Intelligence (AI) ever installed on a space probe. Such a computer will be essential in order to enable the space probe to handle whatever Titan throws at it, without human instruction or control.

Expected to launch in 2026 and reach Titan in 2034 Dragonfly is the sort of deep space mission that would have been considered impossible just a few years ago. The space agency’s recent successes with its Mars rovers and space probes to Jupiter along with asteroids and comets have given NASA the skills, and the confidence to even tackle flying on Titan!

Paleontology News for August 2019: Special Trilobite edition

A couple of new discoveries have recently been published about the ancient and extinct sea creatures known as trilobites so I thought that this would be a good opportunity to discuss these fascinating creatures in some detail. I’ll begin with a few general facts about trilobites.

The Trilobite Phacops rana, the state fossil of Pennsylvania (Credit: Flickr)

First of all trilobites are members of the phylum arthropoda, the jointed limbed animals that include crustaceans, insects and spiders. In fact trilobites are generally recognized as the earliest members of that group of animals with fossils going back as far as 540 Million years ago. Trilobites not only evolved a long time ago they also went extinct a long time ago. The last trilobites died in the Permian extinction event about 250 million years ago, see my posts of 16 February 2019 and 2 June 2018. That’s several million years before the first dinosaur ever evolved!

Because trilobites lasted so long, and their exoskeleton fossilized so easily paleontologists have been able to identify more than 50,000 different species. During their almost 300 million year existence trilobites evolved to occupy nearly all of the ecological niches occupied by modern marine arthropods including that of scavenger, predator, filter feeder and even a swimming species that fed off of the plankton near the surface.

Looking at the figure below, you can see that Anatomically trilobites are defined by their broadly oval shape and the three main sections of their body going side to side, right pleural lobe, axial lobe, which is often raised, and left pleural lobe. Many people incorrectly think that the three lobes of the name trilobite refer to the three sections going front to back with the cephalon (head), thorax and pygidium (tail). (I did when I was young!)

The main anatomic parts of a Trilobite (Credit: Wikipedia)

Early trilobites, such as Olenellus from the Cambrian period seen below, had a cephalon that was much larger than their pygidium. As trilobites evolved however their tails grew to almost the same size and shape as their head as seen below in Phacops from the Devonian period. This adaptation allowed later trilobites to roll up into a protective ball in much the same way as a modern armadillo does. Fossils of such rolled trilobites are often found in Devonian, Mississippian and Pennsylvanian rocks.

The Cambrian Trilobite Olenellus fremonti (Credit: American Museum of Natural History)

An enrolled specimen of Phacops rana (Credit: Fine Art America)

With a history of 300 million years and at least 50,000 species trilobites varied considerably in their particulars, especially size and ornamentation, see images below. The largest known trilobites are from the genus Isotelus of the Ordovician period some 450 million years ago specimens of which are as long as a meter. There are a number of candidates for the smallest member of the group but many small trilobites were no larger than a pea.

A beautiful specimen of Isotelus maximum (Credit: Geoclassics)

A species of Trilobite ornamented with spines, presumably for protection (Credit: Tack Raccoons)

Another spiny trilobite (Credit: Catawiki)

For the most part however trilobites remained rather conservative in their basic body plan. This may have contributed to their eventual extinction as competitors such as crustaceans and fish evolved structures like jaws and manipulating pincers that allowed them to outperform the trilobites.

As fossils a complete trilobite is fairly rare, one or two can represent a good day’s hunting. On the other hand recognizable pieces of trilobites are very common. The reason for this is that like all arthropods trilobites had to molt in order to grow. So a single live trilobite could in the course of its life produce many empty shells that would quickly break up to produce a lot of trilobite pieces.

Fragments of many fossils including a Trilobite tail right in the middle (Credit: The fissil forum)

A couple of recent studies have further increased our knowledge of these ancient creatures. The first concerns the discovery of a new species of trilobite from Australia that has been named Redlichia rex. The name is a reference to the well known dinosaur Tyrannosaurus rex because of R rex’s large size, 30cm, and leg spines that could be used to crush the trilobites food. The fossils of R rex come from the Emu bay shale of Australia’s Kangaroo island and are exceptionally well preserved revealing details of even the animal’s delicate antenna, see image below.

Artists impression of Redlichia rex along with a fossil specimen (Credit: Species new to Science)

Because of R rex’s large size and crushing legs it is believed that the trilobite was a predator, and perhaps even a cannibal. Specimens of R rex have been found with healed injuries so the question is, what could have preyed on these large, for the Cambrian period, animals. While there are several possibilities it has also been suggested that R rex may have preyed on its own kind!

The second discovery also comes from a fossil site that is well known for exceptionally well-preserved specimens, the Guanshan location in eastern Yunnan province China. In this study it’s not a new species of trilobite that’s been announced, it’s the discovery of the earliest known evidence for a stomach and digestive system!

Using some of the best specimens of the trilobite Palaeolenus lanteroisi, see image below, researchers from the American Museum of Natural History in New York and the Early Life Institute at Northwest University in Xi’an China actually succeeded in ‘dissecting’ the fossils. That is, they have managed to carefully remove a portion of the upper layers of the fossil in order to examine the petrified remains of the animal’s internal organs.

Examples of dissections performed on fossils of long dead Trilobites (Credit: Hopkins, Chen, Hu and Zhang)

What they found was a well-developed digestive system with a large stomach or ‘crop’ in its cephalon. That’s right trilobites appear to have had their stomach’s in their heads not far from their mouths! A long alimentary canal then went through the length of the rest of the trilobite’s body to an anus at the animal’s posterior. Trilobites have a special place in the history of life, as one of the first complex, multi-cellular forms of animal they dominated the ancient Cambrian and Ordovician seas. Thereafter they gradually declined, finally becoming extinct during the Permian catastrophe. Nowadays for any fossil hunter a good trilobite specimen will always be a small prize to be treasured.

The Space Race part 8: Apollo 11 and the fulfillment of mankind’s age-old dream of traveling to the Moon.

This is the eight and final post in a series celebrating the fiftieth anniversary man’s first landing on the Moon. In this post I will discuss the mission of Apollo 11 and the contribution of all of those who contributed to the achievement of mankind’s oldest, greatest dream.

We will never know who was the first human to dream about going to the Moon but surely that is one of humanity’s oldest desires! (Credit: NASA)

Whoever was the first human being to imagine going to the Moon is lost in the mists of prehistory but we know that the Roman poet Lucretius wrote a story about traveling to the Moon in a dream during the first century BCE. Other similar dream like stories where occasionally written during the next sixteen hundred years before the French author Cyrano de Bergerac penned the first non-supernatural trip to the Moon around 1662. In Cyrano’s ‘Comical History of the States and Empires of the Moon’ the trip from Earth was made using balloons and, get this, rockets!

Cover of a modern edition of Cyrano de Bergerac’s ‘A Voyage to the Moon” (Credit: Barnes and Noble)

Starting in the late 19th century the pace of Moon travel stories picked up with Jules Verne and H. G. Wells penning the best-known novels. 20th century stories about going to the Moon are too numerous to mention but you take my point, people have been wondering about the Moon, dreaming about what it would be like to travel there ever since we’ve been human. Indeed, in my own opinion, the sense of wonder and mystery that we feel when we look up at the night sky is the key difference between our animal ancestors and ourselves.

Starting in the early 20th century there were other sorts of dreamers thinking about the Moon, dreamers with training in mathematics or engineering. Men like Constantine Tsiolkovsky, Robert Goddard and Herman Oberth who began to consider how a trip into outer space could actually be accomplished. Men who began working on the designs and technology of the rockets that would be needed to take a man to the Moon.

Left to Right Tsiolkovsky, Goddard and Oberth (Credit Public Domain)

In my previous posts about the Space Race I’ve mentioned the names of Werner von Braun and Sergei Korolev as the two men who built the rockets that took us into space and it’s worth noting that van Braun knew Oberth very well and Korolev read all of Tsiolkovsky’s writings as a student in the Soviet Union.

So it was that during the middle of the 20th century the technology needed to reach the Moon was within reach. Getting to the Moon was going to take more than just good engineers however; it was going to take money, lots of it, and the political will to provide that money.

Enter the space race, a contest of will between the two opposing superpowers of the United States and the Soviet Union. A test of two ideologies each determined to prove to the rest of the world that their way of life was superior. As I have written in my earlier posts, the race began when the Russians succeeded in surprising the world by launching Sputnik before the Americans even attempted to put a satellite into space.

When President Kennedy announced NASA’s goal of reaching the Moon he didn’t explicitly give the space race a finish line, the Russians never admitted to being in the race after all. Nevertheless the race was on and by the beginning of 1969 the Americans were on the verge of meeting Kennedy’s challenge while the Soviet Union’s space program was beset with a string of failures.

John F. Kennedy gives the United States the goal of sending a man to the Moon! (Credit: NASA)

Which brings me to Apollo 11 and its crew of Neil Armstrong, Edwin ‘Buzz’ Aldrin and Michael Collins. Armstrong and Aldrin would be the two astronauts who would make the final descent and landing in the Lunar Module (LM) while Collins remained aboard the Apollo Command and Service Modules (CSM) in Lunar orbit.

The Crew of Apollo 11. Left to right Armstrong, Collins ans Aldrin (Credit: NASA)

The mission of Apollo 11 began on the 16th of July at 13:32 UTC as the Saturn V rocket rose from launch pad 39A at Cape Kennedy. After spending an orbit checking out their spacecraft Apollo 11 reignited the engine on their S-IVB stage at 16:22:13 UTC in order to break free of Earth’s gravity and send the three crewmen on their way to the Moon.

Apollo 11 entered lunar orbit three days later on the 19th at 17:21:50 UTC and Armstrong and Aldren began preparing the LM for the last, historic leg of their journey. The LM began its descent at 17:44 UTC on the 20th.

The Apollo 11 Lunar Module prepares to descend to the Moon’s Surface (Credit: NASA)

Much has been said about the last few seconds of that descent. It wasn’t until several days later that the general public learned that the LM’s autopilot was sending the craft straight into a large crater filled with dangerous boulders. With the total lack of nerves for which he was known even among his fellow astronauts, Armstrong took manual control and flew the LM several kilometers farther, finally finding a suitable landing area with only about 25 seconds of fuel remaining in the craft.

Human beings landed on the Moon for the first time on 20 July 1969 at 20:17:40 UTC. At 02:51 on the 21st, Armstrong squeezed out of the LM’s landing hatch and began climbing down the nine rung ladder. Stopping long enough to pull a D-ring that opened an equipment storage panel Armstrong activated a black and white TV camera that sent the momentous images back to Earth for all humanity to watch.

Neil Armstrong takes the first step on the Moon (Credit: NASA)

As he stepped off the LM’s landing pad and made the very first footprint on the Moon Armstrong said the words that have now become history. “That’s one small step for a man, one giant leap for Mankind.” Much has been said over the last 50 years about the missing “a” in the first phrase. Did Armstrong forget himself for an instant and not say it, did a radio glitch cause it to get lost. It doesn’t matter the sentiment is exactly right.

Armstrong was soon joined by Aldrin on the Lunar surface and for a little over two hours the astronauts gathered about 45 kg of Lunar rocks and soil for analysis back on Earth. They also deployed a number of science experiments that included a seismograph and a Laser reflector. The astronauts returned to the cabin of the LM and closed the hatch at 05:01 UTC.

After a sleep period of seven hours, mission control in Houston woke the astronauts and they prepared for their liftoff for the Moon’s surface. Liftoff took place at 17:54 UTC. In all the astronauts spent 21.5 hours on the Lunar surface.

Returning to orbit around the Moon the LM rendezvoused with the CMS at 21:24 UTC. The Moon walkers spent the next two hours transferring all of their samples along with the film that they had taken before jettisoning the LM module. The LM would later be remotely directed to crash back onto the Moon’s surface so that the seismograph the astronauts had left behind could detect the vibrations. Analyzing those vibrations would tell geologists a great deal about the structure of the Moon’s interior.

Buzz Aldrin stands next to the Seismograph left on the Moon by the Apollo 11 astronauts. (Credit: NASA)

With the entire Apollo 11 crew now reunited in the CSM the preparations began for the engine burn that would return the astronauts to Earth. After leaving Lunar orbit the three-day journey back to Earth passed uneventfully. The Apollo 11 Command module, with the three astronauts and their cargo of the first ever samples of a extraterrestrial body splashed down in the Pacific Ocean 2,660 kilometers to the east of Wake Island at 16:51 UTC on the 24th of July. The total mission duration was 8 days, 3 hours and 19 minutes but in another sense the journey of Apollo 11 had really begun when the first human gazed at the Moon and wondered.

So mankind’s greatest journey came to an end, ten more American astronauts would later walk on the Lunar surface in the next two and a half years but of course it is Apollo 11 that is the best remembered. Eugene Cernan would be the last man to walk on the Moon in December 1972. At the time no one would have imagined that after the triumph of Apollo that 47 years would pass without another human being going any further than Low Earth Orbit (LOE).

So what happened to the spirit of Apollo? What happened to man’s insatiable curiosity? Why haven’t we gone on, beyond Apollo, beyond the Moon?

In some sense we have. Since Apollo we’ve sent robotic probes to every planet along with moons, comets and asteroids. Robotic probes are both far cheaper and less risky since there’s no need to keep fragile human beings alive so to a large extent robots have taken over the role of explorer from human beings.

The Unmanned Cassini spacecraft spent years studying the planet Saturn and its Moons (Credit: NASA)

The Voyager space probes have even left the Solar System (Credit: NASA)

There’s also been a lot of political turmoil, the Soviet Union of course actually collapsed in the 1990’s. Meanwhile here in the United States it has seemed as if every new President that gets elected has a new goal for NASA to pursue, with the result that NASA gets nowhere.

Whatever the cause of this 40 year pause in manned space exploration it does seem to be coming to a close. NASA is nearing completion of the Orion manned Capsule and the Space Launch System for exploring beyond LOE. Meanwhile China is slowly but slowly but surely progressing with their space program and, perhaps most importantly commercial companies like Space X and Boeing are about to send people into space.

The Space race is once again picking up its pace, and this time a return to the Moon or a voyage to Mars will not be a one shot deal just to demonstrate we can do it. Next time it will be the beginning of a permanent human presence, the beginning of the human colonization of outer space.

The Apollo 11 Landing site as photographed by the Lunar Reconnaissance Orbiter in 2011 (Credit: NASA)

And I promise that I’ll keep you informed of all of the developments here on ‘Science and Science fiction’.