August 2020 – Scienceandsf -A Blog Published by Robert A. Lawler

Gelatin and pectin, what are they, how do they work and how are they different?

Many of the foods that we buy in the supermarket are made more appetizing and longer lasting by the addition of a thickening agent to give them more body and volume. Thickeners work by increasing the viscosity of a liquid, normally without altering their taste or colour and one of the most common forms of thickening agents is known as a Gel. In chemistry a gel is defined as a liquid contained within a cross-linked solid network of molecules by surface tension that prevents the liquid from being able to flow. In some respects a gel acts almost like a sponge, a lattice of fibers that holds in a liquid.

Making Jams and Jellies at home is a popular hobby, one that requires the use of pectin! (Credit: Amazon.com)

Gelatins, on the other hand, are thickened by gelatin. (Credit: Dr. Oetker shop)

Commercially the two most common types of gels are pectin and gelatin, from which the word gel is derived. Both pectin and gelatin form their cross linked network from long chains of molecules, technically called a polymer. The primary difference between the two chemicals being that in pectin the chains are made up of sugar molecules while in gelatin they are composed of proteins. Those differences stem from the sources of the two classes of chemicals with pectin being derived from plant tissue while gelatin is produced from animal tissue.

Whether you’re talking about a sugar or a protein, this is a protein, you’re describing an extremely complex molecule formed as a chain of smaller molecules. (Credit: Biochemantics)

In plants pectin consists of a large number of compounds derived from sugars, technically polysaccharides, which serve as structural components in the cell wall. Pectin serves to not only strengthen the cell walls of the non-woody parts of plants but also allows for cell growth while at the same time holding plant cells together. The softening of fruit as it ripens is caused by the breakdown of pectin through the action of enzymes, as is the rotting of the leaves of deciduous trees.

Fruit becomes overripe when the pectin in the cell walls begins to break down. (Credit: Women’s Health)

Historically pectin has been used in food production for many centuries, just how many is not precisely known. However it was in 1825 that chemist Henri Braconnot first succeeded in isolating Pectin. Although pectin can be obtained from numerous fruits and vegetables modern commercial production of pectin is primarily derived from the peels of citrus fruits.

Today pectin is commercially produced from the peels of citrus fruit, (Credit: NDTV Food)

Pectin is perhaps best known in food preparation for the production of jellies and jams, indeed without pectin your favourite jelly would be nothing but a sweet juice. In addition to jellies pectin is also used to provide a bit of substance in low fat baked goods and health drinks. Being both colourless and tasteless Pectin does not interfere with the natural appearance or flavour of the food it is adding body to.

Raw pectin ready to be used. When dissolved in a sweet juice pectin has neither a taste nor colour. (Credit: Wikipedia)

Pectin is also frequently used in non-food products, being added to cosmetics and drugs such as in time-release drug capsules. In fact the increase in viscosity and volume provided by pectin have led to it being prescribed as a medication for constipation and diarrhea.

As mentioned earlier, unlike pectin gelatins are produced from animal parts, specifically protein collagens obtained from the hooves, bones and skins of pigs and cows. Despite being chemically so different from pectin gelatin behaves in much the same fashion and is often used in much the same way.

Raw gelatin can come in crystal form as shown here or as cubes of even sheets to be dissolved in water. (Credit: Alibaba.com)

Everyone is familiar with Jell-O, the brand name for fruit flavoured gelatin desserts. Other food products that obtain their firmness from gelatin include marshmallows, gummy candies, ice cream, cream cheese and even margarine. Like pectin, gelatin has no taste or colour and can be added to almost any food in order to give it some firmness without altering the flavour or appearance.

There’s always room for Jell-O. Sorry I just had to say that once. (Credit: Amazon.com)

Gelatin also has a large number of non-food uses including a variety of glues and other adhesives. In photographic film gelatin is by far the most commonly used material for holding the silver halide crystals onto the photographic paper. Other uses include the capsules of some powdered drugs as well as the binder for matches and sandpaper. Ballistics gelatin is commonly used in measuring the performance of firearms and their projectiles.

The chemicals that react to light are held onto photographic film by gelatin! (Credit: Wiki-Camera)

Ballistics Gel, made from gelatin, is used in the testing of firearms because its density and thickness is very close to that of animal flesh. (Credit: Wikipedia)

The earliest known uses of gelatin come from 15th century England where the hooves of cows were boiled to obtain gelatin. Modern gelatin production comes the hides of both pork and cows (75%) or their bones (25%) although some cooks still produce their own gelatin at home from animal bones and cuts of meat containing a good deal of cartilage.

Because it is made from animals the consumption of gelatin by some people may be taboo for religious or ethical reasons. Jews and Moslems are forbidden from eating gelatin made from pork while Hindus are forbidden from eating gelatin made from cows. A vegan of course would refuse to consume gelatin of any kind. Pectin on the other hand, being produced from plants doesn’t raise any such moral conflicts.

Almost everyone has some kind of food they will not eat but many religions require people to refrain from certain foods. (Credit: Slide Player)

Subjective opinions aside, pectin and gelatin are two very different classes of chemicals that nevertheless are used in very similar ways in the production of food. Providing another reminder that cooking is really just chemistry.

Meteorologists update their estimate for the 2020 Hurricane season. Hold onto your hat, stormy weather’s a headin’ our way.

It was only three months ago, 27May2020, that I published a post discussing how the 2020 hurricane season was shaping up to be a very active one. The official estimates at that time from both Colorado State University’s Tropical Meteorology Project and the National Oceanographic and Atmospherics Administration (NOAA) were predicting around 15-20 named storms with 8-10 becoming hurricanes and 3-5 turning into major hurricanes.

Beautiful but deadly. Hurricane Florence in 2018 as seen from Earth orbit. (Credit: Spectrum News)

Those predictions have already been proven to be conservative. We are still not through August and there have already been 12 tropical storms, five of which have developed into hurricanes. As I write these words Tropical Storm Marco, downgraded from a Cat1 hurricane, has battering the state of Louisiana while hurricane Laura, just upgraded to Cat3, is headed for almost the exact same area of the gulf coast. And the next month and a half is usually the busiest part of the Atlantic hurricane season.

Even as Marco (upper left) dumps rain on the Gulf States Laura is headed towards the very same region for a one-two punch that’s unprecedented. (Credit: CNN.com)

It’s not surprising therefore that the same institutes that made those predictions three months ago have reevaluated their estimates and are now publishing the most dire forecast in the history of hurricane studies. The meteorological team at Colorado State University now estimates that the 2020 hurricane season will consist of 24 named tropical storms of which 12 are likely to become hurricanes with 5 developing into major hurricanes.

If that forecast turns out to be accurate it would make the 2020 season the second most active in recorded history, surpassed only by the 2005 season which saw 28 named storms, including hurricanes Katrina and Wilma. And since hurricane forecasters only select 21 names for storms each year, the letters Q, U, X, Y and Z are not used to name storms, if there are 24 named storms meteorologists will be forced to use Greek letters to identify the last three instead of names, again something that has only ever happened once back in 2005.

So why is this year already so active, and what conditions are the meteorologists seeing that made them redo their forecasts. Well one factor that often inhibits the formation of hurricanes is a strong El Niño in the eastern Pacific Ocean. The strong winds developed by El Niño can produce wind shear that disperse low pressure systems in the Atlantic before they can even develop into tropical storms. This year however there is absolutely no trace of El Niño, a condition that will allow storms to grow unchecked.

A strong El Nino in the Pacific sends winds into the Atlantic that can break up hurricane’s before they become dangerous. There is no El Nino this year. (Credit: NOAA)

At the same time low-pressure systems moving westward off of North Africa are stronger than usual because of exceptional rainfall amounts in the Sahel region of Africa between the Sahara Desert and the Congo rainforest. This region generates almost 90% of the low-pressure systems that develop into tropical Atlantic storms and this year the excess rainfall is making them particularly intense.

Pressure waves moving west off of the Sahel region of North Africa often grow into Atlantic hurricanes. Sahel waves are especially strong this year. (Credit: The Weather Channel)

Those pressure waves often become the seeds that turn into deadly hurricanes like Laura! (Credit: The Weather Channel)

But of course the biggest factor in generating tropical storms is simply the temperature of the waters of the Atlantic Ocean and Gulf of Mexico both of which are at or even beyond historic levels. Warm tropical waters evaporate more quickly, putting not only more water but more energy into those low-pressure systems coming from Africa, leading to more, and more powerful storms.

Surface water temperature in the Gulf of Mexico is becoming higher every year thanks to Global Warming! This increase in energy is reflected in more and more powerful Gulf hurricanes. (Credit: ResearchGate)

And what is it that’s making the waters of the Atlantic and Gulf warmer than ever observed before? Well if you haven’t already guessed Global Warming where have you been the last 20 years? Seriously the conditions caused by our continued, reckless emissions of carbon dioxide have grown beyond the point of causing ‘Slightly Higher Averages’ so that now nearly every year is noticeably hotter they were just 20 years ago.

This increase is occurring both globally and locally. For example, here in Philadelphia this past winter we had a very warm winter with no snow accumulation at all and right now we are enduring our 34nd day of +32ºC (+90º F) temperatures, our average is 22 days. The entire west coast of the US is currently suffering through a heat wave on a scale never seen before, hundreds of all time high records are expected to be broken while the wild fire season is already turning out to be especially destructive. In fact the National Weather Service has for the first time ever issued a warning for ‘Fire-Nadoes’, tornadoes generated by the extreme winds in a massive. Meanwhile the temperature in Death Valley was recently measured at 54.4ºC (130º F), the highest reliably recorded temperature ever in the entire world.

This summer in Philadelphia has been excessively hot, with stronger than normal storms added in. (Credit: 6ABC)

Meanwhile the western US is suffering under an historic heat wave. (Credit: CBS News)

Globally last year, 2019 was the second hottest ever recorded, coming in only slightly below 2016. In fact according to NOAA 9 out of the ten hottest years ever recorded have come in the last 15 years. A team of climatologists working in Greenland have recently announced that, in their opinion the glaciers there are beyond the point of no return.

Greenland is melting while we watch, and all of that water is rising sea levels! (Credit: YouTube)

So I guess the question is how much more destruction is the environment going to have to cause before we’ll finally start to pay attention. Personally I’m beginning to fear that even a disaster on the scale of the sinking of Miami might not be enough, after all Katrina and New Orleans in 2005 weren’t. Currently millions of Americans are doing everything they can to ignore the worst epidemic to hit this country in 100 years. I’m almost certain they can find excuses to keep on ignoring climate change even as it’s blowing down their homes!

Ancient Navan Fort in Northern Ireland may just be the top layer of a vast complex of Bronze and Iron Age structures.

According to ancient Irish history and myth the high kings of Ulster, who ruled from about 1000BCE to 500CE, resided at a place known as Emain Macha. Today that site is called Navan Fort and is located just outside of the town of Armagh in Northern Ireland.

Navan Fort, ancient Emain Macha in what id today Northern Ireland. (Credit: Smithsonian Magazine)

Just how much of those ancient records are history, and how much are myth is often difficult to tell, that’s why the discoveries made by archaeology are so important in helping us to separate fact from fiction. Now a new study of Navan Fort is giving preliminary indications that there are more structures hidden in the soil than previous studies had found, that we’ve literally only just scratched the surface of the archaeological remains at Emain Macha.

Ancient manuscript telling the Irish myth of Cul Dreimhe (The Wild Geese). How much of these stories are based on actual events is unknown. (Credit: The Wild Geese)

The study was conducted by Queen’s University in Belfast but because the site is a well known historical and tourist attraction none of the usual digging associated with archaeology was conducted. Instead the researchers, led by study authors James O’Driscoll, Patrick Gleeson and Gordon Noble surveyed the site using high tech, non-invasive tools such as those I described in my post of 27 June 2020.

The scientists began their work with an aerial mapping of the site conducted by a technique known as LiDAR. The LiDAR instrument uses laser beams similar to those in a bar code scanner to sweep the ground from an airplane in order to construct a point-by-point 3D contour model of the entire site. LiDAR scans are so precise and accurate that small bumps and gullys that are imperceptible on the ground become clearly visible in a LiDAR generated plot. See image below.

Airborne LiDAR scans the ground with a laser beam generating an extremely accurate 3D model of the surface. (Credit: Abhipedia)

Having obtained a LiDAR survey of the entire site the researchers followed up their high altitude study with ground level Magnetic Gradiometry and soil Electric Resistance measurements. See images below.

When assembled into one map of the entire site the multiple readings reveal a large number of hidden, subsurface structures within the main outer ring of the fort. See image below.

Of particular interest to the archaeologists was a number of what appears to be two circular structures overlapping each other and forming a figure eight shape. While round houses are typical throughout the ancient Celtic world the purpose of these overlapping figure eights is currently unknown. That’s the problem with the high tech, non-invasive techniques, while they may shown the location and general shape of what’s hidden under the ground they can’t reveal exactly what those structures are nor precisely when they were built and occupied. To answer those questions it is necessary to do some actual digging.

During the Iron Age a typical Irish farmstead would consist of a roundhouse surrounded by a wooden fence. The new survey of Navan Fort has uncovered evidence of many such structures. (Credit: Virtual Visit Tours)

This is not the first time that Navan fort has been surveyed by archaeologists, excavations carried out during 1960s and 1990s discovered the largest known building dating from prehistoric Ireland, a 40m diameter roundhouse. Like Stonehenge in England however Navan fort is important both historically and culturally so any actual digging that takes place there must be carried out sparingly and carefully.

Like Stonehenge, Navan Fort is an archaeological site that is so famous and culturally important that extra special permission is required to disturb it in any way. (Credit: The New York Times)

It was in the hopes of acquiring the funding for actual excavations that the archaeologists at Queen’s University conducted their high tech examination. By first using non-destructive instruments to locate hidden structures the scientists can concentrate on the most interesting areas, hoping to not only get the most bang for their buck but the most discoveries for each shovel full of dirt.

The stories associated with Navan Fort are rooted deep in Irish culture. Most famously the location plays a prominent part in the Ulster Cycle of stories as the home of the hero Cù Chulainn, Conchobar mac Nessa the king of Ulster and Deirdre the most beautiful woman in Ireland.

Known as the Hound of Ulster, Cu is Irish for Dog, Cu Chulain is the hero of a large cycle of myths central to Irish culture. (Credit: Twitter)

Whether of not archaeology can ever provide evidence that those legendary characters ever lived is questionable, but it is the only way we have of learning something about how it was that the people of those times lived.

Space News for August 2020.

Without doubt the big news for this month is the successful conclusion of the Space X crew demo 2 manned mission. The mission of astronauts Bob Behnken and Doug Hurley began back on the 30th of May 2020 as their Space X Dragon capsule blasted off from Kennedy Space Center in Florida. The very next day the spacecraft followed up its successful launch by docking at the International Space Station (ISS). For the last two months Behnken and Hurley have served as regular members of the ISS crew with Behnken even participating in two EVAs.

Splashdown of Space X’s demo1 capsule. The safe return of astronauts Behnken and Hurley completes the first manned space mission by a commercial company. (Credit: Space News)

The Demo1 capsule safely aboard the recovery ship. Space X intends to reuse their capsules as a part of their program to reduce the cost of space travel. (Credit: Space.com)

The mission of Space X crew demo 2 however was to demonstrate the ability of the Dragon capsule to take astronauts into, and back from space. So in order to complete their mission on the first of August Behnken and Hurley climbed back aboard their capsule and undocked from the ISS. The next day the Dragon fired its retro-rockets to slow its orbital speed so that it could reenter the atmosphere.

The whole operation went without a hitch; the capsule endured its fiery descent caused by friction with the atmosphere before first a pair of drogue parachutes and then four big main chutes brought the capsule velocity to less than 15kph. The most notable part of the whole reentry procedure was that this was the first American manned splashdown in 45 years. (The space shuttle you may recall, landed like an airplane on a runway).

So what’s next for the Space X Crew Dragon spacecraft? Well remember this mission was actually the last of the demonstration missions required by NASA to qualify the Dragon for taking their astronauts back and forth to the ISS. The next mission will officially begin NASA’s Commercial Crew Program with a mission to the ISS. That launch, the commercial crew 1 mission is currently scheduled for 23 October 2020. NASA astronauts Michael Hopkins, Victor Glover and Shannon Walker will be joined by Japanese astronaut Soichi Noguchi for a full six-month tour aboard the ISS.

Official poster for the upcoming Space X commercial Crew 1 mission to the ISS. (Credit: Reddit)

And NASA and Space X have also just announced the crewmembers for the commercial crew 2 mission scheduled for the spring of 2021. NASA astronauts Shane Kimbrough and Megan McArthur will serve as mission commander and pilot respectively. Japanese astronaut Akihiko Hoshide and European astronaut Thomas Pesquet will join Kimbrough and McArthur as mission specialists.

And the Space X corporation has even more news to celebrate, on August the 4th the SN5 prototype of Space X’s planned Starship rocket successfully completed its first short powered flight. Now Space X has had its share of problems in previous attempts at this first test flight. While one of the earlier prototype simply collapsed under its own weight several others actually exploded in spectacular fashion. But engineering is trial and error and eventually Space X got it right. Now this first test was only a short 150m hop but if you follow the link below to the youtube video below you’ll see that the rocket was under complete control the entire flight.https://www.youtube.com/watch?v=s1HA9LlFNM0

It sure doesn’t look much like a rocket but it sure flew with more control than any rocket ever! (Credit: New Atlas)

Still, this is only the beginning, the final starship rocket envisioned by Space X founder Elon Musk is projected to be 120m in height, four times that of its SN5 prototype. So there’s still a lot of work still to do before Space X can even begin its long term plans for using the starship rocket for the colonizing of the Moon and Mars.

Artist’s impression of Space X’s eventual starship rocket for travel to the Moon and Mars. (Credit: Techcrunch)

Believe it or not there is some space news that doesn’t deal with Space X. On July 30th NASA launched its latest rover on a mission to Mars. Perseverance will reach the red planet in February, landing in the Martian crater Jezero. Perseverance is the first rover vehicle designed to be able to look for signs of ancient life on Mars. The rover also carries with it a small helicopter as a demonstration model which if successful would become the first man made aircraft to fly anywhere outside of the Earth.

Launch of the Perseverance rover on its way to Mars. (Credit: BBC.com)

Finally there’s good news in the preparations of the Lucy space probe for its mission to the Trojan asteroids scheduled for launch in October of 2021. Despite problems caused by the Covid-19 virus on 27 July the mission planners passed their System Integration Review. This will now allow assembly of the space probe to begin at Lockheed Martin’s Space Systems facility in Littleton, Colorado, where all of the mission systems are to be integrated onto the spacecraft’s main bus. Once assembly is completed testing of the entire probe can then begin.

NASA has to have a patch to commemorate every mission, here’s Lucy’s. (Credit: Twitter)

The schedule is tight, the mission planners are hoping to use a flyby of Mars as a gravity boost to speed Lucy on its 12 year mission so if they miss their October 2021 deadline they’ll have to wait another two years to launch. During its mission Lucy will visit as many as seven different asteroids making it in many ways the most complex mission ever attempted.

Axions, the elementary particle that ought to exist, but do they?

The sub-atomic physics that I was taught in high school was pretty simple. Atoms were made up of Neutrons, Protons and Electrons. The Neutrons and Protons stayed in the atom’s nucleus, and are given the name nucleons for that reason while the Electrons orbited around the nucleus. We also learned that the Protons had a positive charge, the Electrons a negative charge while the Neutrons were electrically neutral.

The Bohr model of an atom of Nitrogen. This is about as sophisticated as high school science classes will get. (Credit: SlidePlayer)

That was about all you’d learn in class, if you wanted to learn any more you’d have to do outside reading on your own, of which I did plenty. It was from books like George Gamow’s “Thirty Years that shook Physics” that I learned about other particles like the neutrino, muon, pion, Lepton and Delta particles. (Although the science may be rather outdated, I still highly recommend Gamow’s book as a history of Quantum Mechanics!!!) Oh, and I also learned that every one of those particles had an anti-particle, identical in every way to its partner except having the opposite electrical charge.

Thirty Years that Shook Physics by George Gamow. Highly Recommended!!! (Credit: Flickr)

But even as I was attending high school physicists were digging deeper. In fact it was in 1964 that physicist Murray Gell-Mann proposed the quark theory of nucleons. Gell-Mann’s idea was that the Proton and Neutron were composed of three smaller particles called quarks, two up quarks and a down quark made a proton while a neutron was two downs and an up. At the same time the lambda and delta particles were also composed of three quarks but for these unusual particles one of the quarks was a strange quark, a name given to the particle to indicate how little physicists understood it at the time. In Gell-Mann’s theory the pion was also composed of quarks but they were made of a quark anti-quark pair. Meanwhile the electron, muon and neutrino were not made of quarks, they remained elementary, fundamental particles that cannot be decomposed into smaller pieces.

The Gell-Mann model of nucleon structure. Three quarks make a proton or neutron while a quark anti-quark pair make a pion! (Credit: Lumen Learning)

It took physicists more than 20 years to work out the ramifications of Gell-Mann’s theory but by the early 1990s they had a framework called ‘The Standard Model’ that was able to broadly describe the interactions between the particles that they saw in their high energy ‘atom smasher’ experiments. The final piece in the standard model was the discovery in 2012 of the Higgs boson, the particle that gives all other particles their mass.

Robert Higgs standing in front of a photograph of some of the equipment needed to finally discover his Higgs boson. (Credit: Science / How Stuff Works)

The standard model doesn’t answer all our questions however. For example while the Higgs boson does give other particles their mass we don’t understand why those particles have the mass they do. The up and down quarks have roughly the same mass, about 5 times that of an electron but other quarks have much larger masses. At the same time we know that the neutrino also has a mass but one that is so small that we haven’t been able to measure it accurately yet, it’s less than one millionth that of the electron. What sets all of the masses for these different particles, we just don’t know?

The masses, in millions of electron volts (MeV) of some elementary particles. What makes all of these masses what they are is completely unknown! (Credit: Semantic Scholar)

One of the problems not addressed by the standard model is that according to theory the neutron should possess a strong electric dipole, it should act like a strong positive and strong negative charges brought close together, a property that would be easily discovered. In order to solve this dilemma, known as the strong CP problem (for Charge Conjugation / Parity) in 1977 the physicists Roberto Peccei, Helen Quinn, Frank Wilczek and Steven Weinberg proposed a new particle called the axion. This new particle would have a very low mass, like the neutrino on the order of one millionth that of an electron, and hardly interact with other types of particles.

One interesting experiment that might discover the axion. (Credit: Universe-Review.ca)

Even while particle physicists were trying to make sense of the concept of the axion astrophysicists and cosmologists heard about the particle and realized that the axion, if it existed, could be a major component of Dark Matter. With its low mass the axion would have been created in enormous numbers during the original Big Bang, and since they hardly interact with other particles they would still exist. Could the axion be the dark matter that the astrophysicists were searching for?

Now predicting new particles is a risky business. If you’re right you’ll become famous like Wolfgang Pauli with the neutrino or Robert Higgs and his boson. On the other hand there are dozens of ‘predicted particles’ that have never been found. And it often takes decades for experimentalists to develop the technology needed to prove that a particle exists. Pauli predicted the neutrino in 1930 and it wasn’t proven to exist until 1956. Same for the Higgs boson, Robert Higgs wrote his original paper in 1964 but the particle was only officially discovered in 2012.

That discovery is what researchers at the Gran Sasso National Labouratory in Italy hope to accomplish with their XENON1T experiment. The experiment consists of a 3.2 metric ton tank of Xenon gas in what is known as a Time Projection Chamber. Photomultiplier tubes inside the tank detect the tiny flashes of light produced by the interactions and the entire apparatus was constructed deep within a mine beneath the Gran Sasso Mountain in order to shield the experiment from false signals due to cosmic rays.

Main Detector of the Xenon1T experiment being readied for installation. (Credit: LNGS-Infn)

After two years of operation the XENON1T team has now announced the first ever measured evidence for the existence of axions. At a news conference on June the 17th the XENON1T physicists presented their data showing an excess number of flashes in the low energy region. This was exactly the sort of signal that would be expected for interactions with axions produced in the interior of the Sun. According to the announcement the amount of data collected was sufficient for a 3.5 sigma confidence level in the discovery.

Latout of the Gran Sasso Labouratory, now the world’s largest underground physics labouratory. (Credit: Nature)

That 3.5-sigma level is the problem; statistically 3.5-sigma means that there is only a one in 10,000 chance that the excess flashes are simply a matter of luck. Like rolling a pair of dice and getting boxcars three times in a row, something that only happens very rarely, but it does happen. The physics community has agreed that in order to really announce a ‘Discovery’ an experiment must achieve a confidence level of 5-sigma, which means that there is only one chance in 3.5 million that the data is just a statistical fluke.

Scientists express their ‘confidence level’ by using the normal of bell curve distribution. The larger the sigma value the more of the bell is contained, the more confident you are! (Credit: Dummies.com)

So what do experimental physicists do when their experiment looks like it’s found something but the data is too small to be certain? Build a bigger, more sensitive experiment of course. The scientists at XENON1T are already doing just that, upgrading their equipment to an 8 metric ton container of Xenon for a new 5-year run that should be able to cross the magic 5-sigma threshold.

So has the axion been found? Well some other physicists are already criticizing the whole setup; the same signal could be produced by the detector being contaminated by the isotope of hydrogen called tritium. It takes time to be certain so we’re all just going to have to wait. Making a discovery is what every scientist dreams of but as they all know, it’s more important to be right than to be first!

China’s Space Goals and will they lead to a new Space race with the United States?

On the 23rd of July 2020 at 0441 GMT China successfully launched the Tianwen-1 Mars probe from its Wenchang Satellite Launch Center on the island on Hainan. Scheduled to arrive at the red planet in February 2021, Tianwen-1 is China’s first solo Mars mission and a very ambitious one at that. Combining an orbiter, lander and rover, if Tianwen-1 is a complete success it will leapfrog China, formally the People’s Republic of China or PRC, into a leading position in planetary exploration.

Liftoff of China’s Tianwen-1 space probe on its way to Mars. (Credit: The New York Times)

Artists impression of the Tianwen-1 lander preparing to deploy its rover onto the Martian surface. (Credit: BOL News)

The launch of Tianwen-1 comes just a year and a half after China’s successful landing of their Chang’e-4 probe onto the surface of our Moon. Chang’e-4 was the PRC’s second lunar lander and the first by any nation onto the Moon’s far side. Chang’e-4 also deployed a small rover onto the Lunar surface that is still operating, setting a record for continuous operation by a robotic rover on the Moon.

The Chang’e 4 lander (l) and rover (r) on the lunar surface. (Credit: NSSDCA – NASA)

And it was only back in 2003 that China became just the third nation to successfully carry out a manned space mission. Shenzhou -5 was the first of six missions to date in a continuing series, each of which is designed to step by step increase China’s skill and capability in space. The last three of China’s manned missions in fact succeeded in docking with an unmanned Tiangong space labouratory module, similar to the Russian Salyut from the 1970s, giving China useful experience in operating and maintaining a space station.

China’s manned space capsule Shenzhou bears more than a slight resemblance to Russia’s Soyuz. (Credit: Zee News)

The Shenzhou capsule (upper left) docked with the Tiangong space labouratory. (Credit: The Australian)

The PRC government in Beijing has shown considerable and steady support for its space program. In China their successes in space are a much publicized source of national pride as well as being considered a key element of the nation’s future as a leader in technological development. With China’s growing wealth and power it seems certain that the country’s space program will continue to grow as well.

So, what are the PRC’s future plans for space? And is this the beginning of a new space race with the United States?

To answer these questions it is important to recognize the difference between long-range goals and those programs to which a strong commitment has been made, in other words those programs that are getting the funding. Officials with all national space programs often talk about the mission plans they would love to be working on, but few of these plans ever make it past the drawing board.

With respect to manned spaceflight Chinese officials have often spoken about their intentions for a manned Lunar mission sometime around 2030 with a permanent Lunar base to come sometime after that. At present however neither the large launch rocket needed for a Moon mission nor a manned lander to put Chinese Taikonauts on the Moon’s surface are in development.

Currently China’s manned efforts appear to be focused on the construction of a space station similar to the USSR’s old Mir station. China’s next five manned space missions are all dedicated to this endeavor with construction scheduled to start in 2021 and lasting through 2023. It seems likely therefore that China’s manned space program will be rather occupied for the next half dozen years or more.

Artists impression of China’s planned Tianhe space station. Construction is scheduled to begin next year (2021) and should take several years. (Credit: YouTube)

As far as unmanned, robotic space probes are concerned China intends to build on the success of its Chang’e series with the Chang’e-5 lander that will collect and send samples of the Moon back to Earth. The success of that mission would make China only the third nation to succeed in returning Moon rocks. There are also plans to carry out a similar sample return mission to Mars. The time frame for the Mars return mission is sometime around 2030.

The mission profile for the planned Chang’e 5 space probe is very complex and if successful will make China only the third country to bring pieces of the Moon back to Earth. (Credit: The Planetary Society)

Longer term robotic missions that have been mentioned by Chinese officials include a probe to Jupiter and its Moons as well as a possible probe to Uranus. If either of those missions ever come to pass it would make China only the second nation, after the US, to send a probe to the outer Solar System.

NASA’s Pioneer 10 probe to Jupiter, launched in 1972 was the first probe to travel beyond the orbit of Mars. To this day no other country have managed that feat! (Credit: NASA)

So are China and the US headed for another space race? Well if you look at the situation reasonably there’s no technical or scientific reason to once again turn space exploration into a contest. There is more than room enough in our Solar System for both countries to conduct a great deal of exploration without stepping on each other’s toes.

America won the first Space Race, but do we really need to have a second! (Credit: Pinterest)

We humans are a competitive bunch however. Whenever two people, or groups of people try to achieve the same thing we have to make it a challenge to see who does it first or better. While a new space race, to put a man on Mars for example, might serve to increase interest in space exploration temporarily, once the race was won it could also lead to the same falling off of attention as happened after the Apollo Moon landings.

China has progressed with their space program in a slow, steady, step by step fashion, unlike the US. You don’t think maybe they could be on to something do you?

Bioluminescence

Last night, after I had switched off the light in my bedroom and before I could get into bed I saw a small, brief glow of light only about a meter in front of my face. A firefly, Photuris lucicrescens, had somehow gotten into my bedroom.

Now I’ve a lot of experience in handling fireflies going back about sixty years now so I quickly, and carefully caught the little guy and released him back outside where at least a dozen of his friends were waiting for him. But it got me to wondering, why was I so nice to a firefly when any other bug or spider that gets in my house I’ll just swat or squish.

It’s bioluminescence, that small glow that gives fireflies their name that makes them pretty to us. Catching fireflies on a warm summer’s night is a game no child can resist but even as a child I would always let the creature go after playing with it for a few minutes. The fact that a living creature, a small insect can generate light within its body mystifies and delights us.

Deep Sea angler fish use a bioluminescent lure to attract their prey! (Credit: Google Sites)

Bioluminescence occurs in a wide range of living things both aquatic and terrestrial. Everything from bacteria and fungi to molluscs, arthropods and even species of vertebrates have shown bioluminescence. Although many creatures, like the firefly produce their light using their own metabolism there are other animals, such as the deep-sea anglerfish, who obtain their light by growing bioluminescent bacteria within their bodies. Bioluminescence is so spread out, here and there across so many different kinds of living things, at least 11 different animal phyla and several of fungi and plants that biologists are convinced that the ability of a living thing to produce light has evolved independently more than 40 times in the history of life.

Many species of jellyfish are bioluminescent. (Credit: Hakai Magazine)

Bioluminescent glowworms in caves attract their insect prey to their sticky lines by their glow! (Credit: New Scientist)

Because there is such a wide diversity of living things that produce bioluminescence the early study of the phenomenon concentrated on individual species rather than examining it as a single subject. While both Aristotle and Pliny the Elder discussed the glow produced by damp, dead wood it wasn’t until centuries later that Robert Boyle showed that the gas oxygen played a major role in producing the light. And even then it took more than another hundred years, until 1854, that Johann Florian Heller finally discovered that it was actually a fungus growing in and consuming the wood that was producing the light.

Many species of mushrooms and other fungi are bioluminescent. (Credit: Time for Kids)

At about the same time Charles Darwin suggested that the bioluminescence often seen in the tropical ocean capping crests of waves and illuminating the wakes of ships was due to ‘minute crustacea’, one of the few times he was wrong in his hypothesis. The greenish light that is produced in disturbed ocean waters is in fact caused by several species of dinoflagellates in the plankton.

Bioluminescent waves at night are caused by billions of single celled plankton. Whatever causes then they are still mysteriously beautiful. (Credit: Treehugger)

It is really only since the mid 20th century that the chemical processes that generate bioluminescence have been adequately described. Simply put the chemical reaction involves an organic pigment referred to as the luciferin, which is induced to emit light by an enzyme called the luciferase. Problem is that there are so many different chemicals that living things use as their luciferin and luciferase that the only thing that can be said about the reactions in general is the use of oxygen as the source of energy. The fact that so many different chemical reactions can produce bioluminescence is undoubtedly one of the reasons that the ability has evolved independently so many times.

One of the many biochemical reaction that will produce light. (Credit: photobiology.info)

And with so many different kinds of living things using bioluminescence it’s hardly surprising that they use it in a wide variety of different ways. It is well known that the fireflies in my backyard use their glowing tails as a means of attracting a mate; it’s only the male who does the blinking by the way. Deep-sea anglerfish on the other hand use their bioluminescence as a lure to draw smaller fish in close so that they can then eat’em.

Those are two of the more straightforward uses of bioluminescence; some others are not so obvious. For example the glowing of fungi in damp, dead wood that Aristotle noticed. It is thought by some naturalists that the glow might cause insects or animals to come and investigate, the fungi then is able to spread some of its spores onto the animal’s skin, feathers or fur. Those spores may then be able to pass on to other dead, damp pieces of wood allowing the fungi to propagate.

Many species of cephalopods, squid and octopi use bioluminescence as a defensive measure. Whenever they feel threatened they will squirt out a cloud of bioluminescent material that startles and blinds the attacker allowing the cephalopod to escape, sort of the exact opposite of the black ink used by other cephalopods for the same reason.

This bioluminescent squid, Abralia veranyi, uses the lights on its belly as a form of camouflage, animals beneath it assume the light is coming from the sky above the surface. (Credit: PBS)

Since we humans have always been intrigued by bioluminescence it’s not surprising that genetic researchers have been playing around with the genes responsible. As far back as 1986 the firefly gene that produced its version of luciferin was successfully implanted into tobacco plants. Currently there is a considerable amount of research underway to see if bioluminescent bacteria can actually be used to manufacture a form of living light bulb. Such a light bulb would not require electricity to generate light but as you might guess the greatest difficulty at present is the low light intensity, the low amount of energy in other words.

Bioluminescent lightbulb! The bacteria in this bulb don’t produce a great deal of light but they do so without electricity! (Credit: ScienceBlogs)

Whether or not any of these experiments manage to develop something that is practical, something of commercial value is questionable at the moment. Still bioluminescence has always fascinated us, so much so that scientists will keep on studying it, if only for a bit of fun.

The Atacama Desert in Chile, an astronomer’s dream location.

The Atacama Desert of northern Chile is situated on a broad plateau between the Andes Mountains and the Chilean coastal range. Being at an average elevation of 3,000m and surrounded by two high mountain ranges little moisture reaches the Atacama so that it has been measured as being the driest place on Earth with the possible exception of some areas in Antarctica.

Not only is the Atacama Desert bone dry but many areas are salt flats making it even more hostile to life. (Credit: Live Science)

With an average annual rainfall of about 15mm you shouldn’t be surprised that there is little life in the Atacama, vegetable or animal. While those parts of the Atacama that receive some moisture are home to several species of cacti and saltgrass along with insects, scorpions and even a few lizards there are areas where the desert is so arid that no life can survive for very long.

Although several species of lizards inhabit the Atacama their population is extremely low. (Credit: Atacama Photo)

However there is one form of life that recently has begun to rapidly multiply in the Atacama Desert, scientists, particularly the sub-species astronomers. In fact the very extreme nature of the climate in the Atacama is what has many scientists excited, even anxious to work there.

NASA scientists are interested in the Atacama because it is the region of Earth that most closely resembles the conditions on Mars, cold, dry and at 3,000m altitude even the air is thin. In fact a team from NASA duplicated the tests for life that had been performed on Mars by the two Viking landers and got the same results as the Vikings, no life. NASA has also used the Atacama on several occasions to test various instruments for several of their Mars landers.

If you want to test your Mars rover in realistic conditions the Atacama is the best place on Earth to do so. (Credit: MIT Technology Review)

But it’s the astronomers who really love the Atacama. The thin, dry almost cloud free air of the high desert along with the lack of city lights of any kind make it one of the best places on the surface of the Earth for viewing the Universe. Three large observatories have been built and are being operated by the European Southern Observatory (ESO). The United States by the way has built and maintained its largest observatories either on top of the Mauna Kea volcano in Hawaii or the mountains of the desert southwest.

Although the Atacama Desert has been used for astronomical observations for more than a century the first permanent observatory there was the ESO’s La Silla observatory that began operations in 1964. Currently La Silla operates 10 medium to small telescopes including the 3.6m New Technology Telescope that back in 1984 was one of the earliest telescopes to employ adaptive optics.

The La Silla Observatory features a half dozen instruments for observing the Universe. (Credit: Britanica)

The largest optical telescope in the Atacama, indeed the second telescope in the world is the Very Large Telescope (VLT) at the Paranal Observatory. The VLT actually consists of four 8.2m telescopes whose light is ‘added together’ by means of computer controlled optics. This ‘adding together’ of the light from the four large telescopes effectively makes them into a single huge instrument. (Let me tell you a little secret. I understand the math used to perform this magical feat but I freely admit that the precision needed to do this accurately at optical frequencies makes my head swim!)

The Very Large Telescope at the Paranal Observatory is actually four identical ‘scopes whose light is combined to make them the 2nd largest telescope in the World. (Credit: Wikipedia)

In addition to the four main telescopes the VLT also possesses four smaller 1.8m telescopes that are located at a distance from the larger ‘scopes. The light captured by the smaller instruments can also be added to that of the big telescopes allowing the VLT to conduct interferometric measurements of astronomical objects.

The third observatory in the Atacama Desert is the Llano de Chajnantor, a radio observatory specializing in studying the Universe in millimeter and submillimeter wavelengths. In fact because water vapour in the air effectively blocks such high frequency radio and infrared light the arid Atacama Desert is really the only place on Earth’s surface where such an observatory could be built. The main instrument at Llano de Chajnantor is the Atacama Large Millimeter Array, a collection of 54 12m-radio dishes whose signals are again added together to make them act as a single instrument. (Performing this operation at radio frequencies is much easier; in fact I have worked on such adaptive arrays many times in my career.) Also at Llano de Chajnantor is a single 12m-submillimeter dish one of the few instruments in the world working at such high frequencies.

Part of the array of radio dishes at the Llano de Chajnartor observatory. The Atacama is one of the few locations where such high frequency radio observations can be made. (Credit: Taipei Times)

So that’s a brief description of the observatories and instruments expanding our knowledge of the Universe currently operating in the high Chilean desert. Today there are actually so many astronomers working in the Atacama that they even have their own hotel there.

The hotel exclusively for astronomers is located near the Paranal observatory. (Credit: Modlar)

And there’s more to come. The ESO’s Extremely Large Telescope (ELT) is now under construction at the new Cerro Armazones Observatory. When completed the ELT will have a primary objective 39.3 m in diameter making it the largest optical telescope in the world by a considerable margin. The telescope is expected to be completed and begin observations, a moment that astronomers like to refer to as ‘first light’, in 2025.

Artists impression of what the Extremely Large Telescope will look like upon completion. (Credit: Wikipedia)

Right now we can only guess what kind of discoveries that instrument will make. All of this astronomical activity clearly shows that the future of the Atacama Desert as a haven for scientists is only beginning.