2017 Nobel prizes in Medicine, Physics and Chemistry.

Over past week the Nobel committee has been announcing their selections for this year’s prizes. This year it seems as if trios are popular because each of the prizes for science was awarded to a trio of researchers.

The award for medicine / physiology was the first to be announced on Monday. The winners were Jeffery C. Hall and Michael Rosbash, who worked together at Brandeis University in Massachusetts along with Michael W. Young at Rockefeller University in New York. See Picture below.

2017-Nobel Winners for Medicine. L-R Jeffery Hall, Michael Rosbash, Michael Young. (Credit: Nobel Foundation)

The Three scientists were honoured for their research into the biological rhythms built into living creatures, a phenomenon known as the Circadian clock, the 24 hour day-night cycle caused by the rotation of the Earth.

The two teams conducted their research using fruit flies, a species that has been center stage in biological studies for over a century now. What they discovered was that the mechanism of the clock consisted of a network of genes and proteins that time the release of hormones turning on then turn off sleep, raise and low body’s temperature and blood pressure while regulating other body processes. Occasional disruptions in this genetic rhythm results in the familiar ‘Jet-Lag’ while prolonged disruptions can result in a number of serious health problems.

Before I move on I would to mention that much of the original work on circadian clocks was carried out by two scientists named Seymour Benzer and Ronald Konopka. It was these two men who discovered the ‘Period’ gene that initiates the entire process. Benzer and Konopka are ineligible to share in the prize however as they are both deceased. Alfred Nobel’s will specifically states that only living scientists can receive the award and this is not the first time that a scientist worthy of the honour has died before the committee saw fit to select them.

On Tuesday it was the Physics prize that was announced and I was very pleased to learn that it had been shared by Rainer Weiss of the Massachusetts Institute of Technology (MIT) along with Kip Thorne and Barry Barish of the California Institute of Technology (Caltech not CIT). See picture below.

Nobel Physics winners. Rainer Weiss, Kip Thorne and Barry Barish (Credit: Getty Images)

The work for which these scientists won the prize was the detection and measurement of Gravitational waves, a phenomenon predicted by Albert Einstein in his Theory of General Relativity almost exactly a century before they were finally detected.

Professors Weiss, Thorne and Barish are the principle designers and leaders of the Laser Gravity Wave Observatory (LIGO) project. I have written posts about the LIGO project earlier (14Jun2017) but simply put the LIGO project consists of two, four kilometer long L shaped laser detectors, one in Hanford Washington the other in Livingston Louisiana.

By comparing the laser beams traveling up and down the two arms of the L the detector is capable of measuring tiny distortions in the fabric of space-time itself. Using the two detectors allows the direction of signals source to be estimated and now that a third detector in Italy (VIRGO) has come on line the accuracy of the direction measurement will increase.

Detecting gravity waves is a completely new way of looking at the Universe and every time science has succeeded in doing that we’ve discovered thousands of new wonders. We can only hope that the study of gravity waves will prove to be as fruitful.

On Wednesday it was the Chemistry prize that was announced. The recipients were Jacques Dubochet of Lausanne University in Switzerland; Joachim Frank of Columbia University in New York along with Richard Henderson of Cambridge University’s Labouratory of Molecular Biology. It’s worth noting that Professor Henderson is the 15th Nobel laureate from the Lab (Not 15 Nobel laureates at Cambridge, 15 at just that lab at Cambridge!!!). See picture below.

Nobel Chemistry. Jacques Dubochet, Joachim Frank, Richard Henderson (Credit: EPA-EFE/REX/Shutterstock)

The work these three men carried out was the development of a series of techniques that have enabled scientists to better image complex organic molecules and structures with electron microscopes. Electron microscopes are similar to the microscopes you used back in High School but because the wavelength of an electron is so much smaller than that of visible light an electron microscope can magnify an image thousands of times more. I’ve had several occasions in my career to use electron microscopes to study electronics and they are wonderful instruments that can provide so much useful data.

Electron microscopes have problems when used to study living tissue however. First of all the electron beam must be in a vacuum, a condition that is not only lethal but can also cause the water in the cells to evaporate explosively, and remember we are composed of 70% water. Also the beam of electrons itself can be powerful enough to physically alter the specimen being studied.

Professor Henderson developed a technique for replacing the water in organic structures with a sugar cocktail that could withstand the vacuum. Professor Dubochet took a different tack, creating a process that quick froze the specimens so that the water in them did not crystallize. This process is called Cryo-electron-microscopy. Finally Professor Frank used computer algorithms to increase the precision of the data allowing scientists to learn even more from their instruments. An example of just how detailed the images provided by an electronic microscope have become the picture below shows a protein molecule.

Improvement in Electron Microscope Resolution. (Credit: Nobel Foundation)

The discoveries made by this year’s Nobel laureates have brought great advances to human knowledge. In a world filled with an almost daily barrage of bad news maybe we should think of a way to honour our scientists more than three days a year!

Season Premier of Star Talk with Neil deGrasse Tyson, where Science and Pop Culture Collide.

Sunday night, 1Oct17, the National Geographic Channel broadcast the fourth season premier of Neil deGrasse Tyson’s Star Talk from the Hayden Planetarium in New York’s Museum of Natural History. The show included Neil’s interview with Lance Armstrong the bicyclist who won the Tour de France seven consecutive times only to have his titles taken away from him because of his use of performance enhancing drugs. The choice of Armstrong as the interview choice for the first show of the season was an unusual one but the show was both interesting and informative. The image below shows Neil with Lance Armstrong.

Neil deGrasse Tyson with Lance Armstrong (Credit: Star Talk, National Geographic Channel)

Now the interview with Armstrong was taped but Neil had two guests with him live at the Hayden Planetarium. One of the guests was Scott Adsit, a comedian who has appeared on the show several times now. Neil always has a comic as one of his guests to interject a few laughs into the more serious discussion. To provide the background on the science of bicycling the other guest was Max Ginskin, the author of the book Cycling Science.

The first half of the show dealt with the history and science of cycling discussing topics such as the history of the Tour de France along with the importance of aerodynamics in cycling. There was also a segment on the way the performance of a cyclist is measured using the ratio of the power his muscles can produce to his body mass in kilos. The image below shows one of the show’s regulars undergoing the sort of testing professional athletes use to measure their performance.

Athletic Training (Credit: Star Talk, National Geographic Channel)

The second half of the show dealt with the more controversial subject of Lance Armstrong’s admitted use of performance enhancing drugs or PDEs. For this segment Professor Arthur Caplan, a bioethicist from New York University joined Neil and his live discussion.

As I said, Armstrong has now admitted to using PDEs but maintains not only that everybody was using them but also that the drugs had become so powerful and pervasive that it was impossible to compete without them. Without absolving Armstrong, Professor Caplan agreed the governing body in cycling shared the responsibility for failing to address the problem with adequate testing and appropriate penalties.

To challenge Professor Caplan, Neil brought up the argument that, if everybody is using PDEs then the playing field is still level, the competition still fair so why not let the athletes use PDEs if they want. Professor Caplan replied with three points that I’d like to repeat.

  1. If everyone uses PDEs the competition is only longer between athletes but between drug companies negating the whole point of athletics.
  2. For those who love their sports part of the fun is comparing past performances to modern ones. Just this past season in Major League Baseball’s Juan Carlo Stanton hit 59 home runs leaving him just one short of a level of success that only two players in history have ever fairly attained! Like cycling the MLB has to confront its having turned a blind eye to drug use in the past.
  3. (And this is the most important point). These drugs are not safe. Even the use of cortisone for pain relief should be done cautiously. Steroids and other even more powerful drugs have numerous long term health risks. And even if you think adults should be allowed to take such risks if they choose to, what about the 16, 17 hey even 14 year old who dreams of a career in sports? For a teenager to use PDEs will certainly lead to severe health problems when they are in their 40s or 50s.

That’s the value of science, that it gives you the facts so you can make an ethical, reasonable judgment. And that’s the value of Star Talk with Neil deGrasse Tyson. If you’d like to learn more about the show ‘Star Talk’, find out where you can watch it, click on the link below to be taken to the Star Talk website.

http://channel.nationalgeographic.com/startalk/

 

Space News for September 2017

A lot happened this past month in outer space. Of course the biggest story in September was the end of the Cassini mission to Saturn as the spacecraft plunged into the planet’s atmosphere. I’ve already talked about that however (See post of 13Sept17), so in today’s post I’ll be talking about several other items of interest.

The first story I’m going to discuss also concerns one of NASA’s interplanetary space probes. The Osiris-Ex mission is an ambitious attempt to land on the asteroid Bennu, collect a sample and return that sample to Earth. The picture below shows an illustration of the Osiris-Ex probe hovering above Bennu taking a sample.

Osiris-Ex Probe (Credit: NASA)

The Osiris-Ex spacecraft was launched last year and placed on a trajectory that initially took it closer to the Sun. That orbit was designed to bring the probe back around for a gravity-assisting flyby of Earth. On 22Sept17 the spacecraft flew 17,500 km over Antarctica not only boosting its velocity by 3.7 kilometers per second but altering the plane of its orbit around the Sun to match that of Bennu.

The Earth flyby was accomplished without a hitch and as it moved past our planet the spacecraft took several pictures of Earth, one of which is shown below. Osiris-Ex is now expected to reach Bennu in October of 2018. Once in orbit around Bennu the probe will spend two years mapped and examining the asteroid with a variety of instruments before reaching out with a robotic arm to try to grab a sample of as much as two kilos of material from Bennu. The spacecraft will then leave Bennu for a return to Earth carrying that material. The expected arrival date for the sample is September of 2023.

Earth as seen by Osiris-Ex (Credit: NASA)

Long range planning is key to the success of any space endeavor. With that in mind Lockheed-Martin Corporation (known in the aerospace industry as Lock-Mart) has published some details and illustrations of their ideas for a Mars Base Camp program. Lock-Mart’s plan calls for a space station to be built in orbit around Mars which can then be visited by astronauts from Earth. Four of the astronauts can then take two week long excursions down to the Martian surface using a single stage Mars Assent / Descent Vehicle (MADV). The illustration below shows what the Mars station could look like in orbit around the red planet.

Proposed Mars Base Camp (Credit: Lockheed Martin)

The MADV lander is intended to land on the Martian surface using the supersonic retropropulsion technique that Space-X Corporation has developed to land their Falcon-9 rockets for reuse. The illustration below shows the MADV sitting upright on the surface of Mars.

Proposed Mars Assent / Decent Vehicle (Credit: Lockheed Martin)

Perhaps the thing I like best about Lock-Mart’s scheme is how it looks and feels so similar to the hardware Andy Weir described in his novel “The Martian”

Another important news item this month concerns President Trump’s finally making his choice for a new director of NASA. This month Trump chose Oklahoma Congressmen James Bridenstine for the job. Now Trump’s choice is controversial for several reasons first and foremost of which is the fact that, unlike every NASA director since the agency’s founding, Bridenstine has no background in either science or engineering. The picture below is of Congressman Bridenstine.

James Bridenstine, official portrait from US House of Representatives

The congressman is also well known for several opinions that have put him at odds with the majority of the scientific community. The most notable of these is global warming with Bridenstine being a consistent climate change denier.

On the other hand Bridenstine is a strong supporter of human exploration of space. He also is on record as preferring a return to the Moon before going on to Mars, a position I have advocated in several posts (22Feb17 and 19July17). Bridenstine is also a strong supporter of the commercialization of space by companies such as Space X and Orbital Science.

Only time will tell whether Congressman Bridenstine turns out to be a good choice for NASA. More than anything else NASA needs a coherent long term goal, and then to stick to that goal. I’m actually more concerned about the incoherence of Bridenstine’s future boss than I am about Bridenstine.

My final item is also more political than anything else. After the successful cooperation between the US and Russia in the building and operation of the International Space Station the two nations have agreed this past week to cooperate on the construction of a space station in lunar orbit, the Deep Space Gateway project. The picture below shows what the Deep Space Gateway project could look like.

Proposed Deep Space Gateway (Credit: NASA)

If that concept sounds familiar well of course its really the same plan as the one from Lock-Mart we discussed above for Mars. I suppose the idea is to take human exploration one step at a time, using the knowledge and technology gained in the last step to ensure the success of the next step. That could all be for the best but we will still need definite goals and a firm commitment from those who hold the purse strings if we’re going to finally return to truly exploring outer space.

Cyborgs now have their own Olympics, the Cybathlon

This story actually dates from almost a year ago but I only just heard about it myself and since it relates directly with one of my previous posts (11Mar17) I hope you’ll still find it interesting.

In October of 2016 the first ever athletic competition for cyborgs, yes you heard me right cyborgs, was held in Zurich, Switzerland. The competition was conceived by Robert Riener of the Swiss Federal Institute of Technology as a way to promote the development of computerized assistive technologies for the physically disabled. The organizers of the event also did so in an effort to get engineers working with assistive technologies to interact more with their potential users in order to improve their designs.

The event consisted of six events ranging from paralyzed individuals using exo-skeleton suits to walk through obstacle courses to amputees grasping and using everyday objects with powered prosthetic limbs. There was also a ‘virtual marathon’ where tetraplegics, people with little or no use of any limb, used their brains only to control computerized avatars.

The exo-skeleton obstacle course was designed to replicate normal life with walking up ramps and stairs along with maneuvering around corners. In other words the competition was not so much an athletic event as a side by side test of locomotive technologies to determine which was best suited to improving the lives of the disabled. The pictures below show  of the obstacle courses used in the cybathlon.

Cybathlon Obstacle Course (Credit: Alessandro Della Bella)
Cybathlon Obstacle Course (Credit: Nicola Pitaro)

The same is true of the events for powered prosthetics, which were intended to test ranges of motion as well as the ability to manipulate everyday objects. The pictures below show some of the innovative technologies in action.

Prosthetic Arm- Nicola Pitaro)
Prosthetic Arm (Credit: Alessandro Della Bella)

If those contests seem like something out of a Sci-Fi novel the virtual marathon using brain computer interface only is unquestionably futuristic. Electrodes in skullcaps were used to detect and measure brain waves that were fed into a software algorithm which ‘decoded’ the brain waves into commands for the avatars to either run, jump or slide as required for the virtual race. Interestingly, the race also had sections were the avatar was ordered to do nothing. This required the contestants to control there brain waves in order to give no commands, a situation that would occur frequently in real life.

Developing the software that decoded the brain waves required a long iterative process that matched a brain wave to an intended action. At the same time the contestants also had to train themselves to frame their thoughts properly, allowing the program a better chance of decoding it accurately. The pictures below show the skullcap used by one team of contestants along with an illustration of how the ‘virtual marathon’ was conducted.

Skullcap (Credit: Erik Tham)
Virtual Marathon (Illustration: James Provost)

 

Technology competitions of this kind have proven to be great spurs for the development of technology. In a previous post (17Jun17) I wrote about how DARPA’s road race challenge for robotic vehicles played a significant role in the development of the driverless cars now taking their first tentative ‘drives’ on our highways. The same can be said for the Xprize competition for space technology.

There are already plans for the next cybathlon scheduled to take place in 2020. With the advances in assistive technologies that are taking place in labouratories around the world Cybathlon 2020 may really be science fiction come true. If you’d like to read more about cybathlon click on the link below to be taken to the events official website.

http://www.cybathlon.ethz.ch/

 

 

Is Global Warming Responsible for the Increased Number and Strength of Hurricanes?

The hurricane season for 2017 is just past its half way point and already this year has proven to be abnormally deadly and destructive. Hurricane Harvey inundated southeast Texas with over a meter of rain while Hurricane Irma wrecked several Caribbean Islands before causing a trail of destruction the length of the Florida peninsula. By some measurements Irma was the strongest Atlantic storm ever seen, remaining a category five storm longer than any on record with the second highest wind speed ever measured. For a short time both Irma and Jose were cat 5, the first time ever two such powerful storms have existed at once. Plus, I just heard on the news that Jose has now been officially a hurricane longer than any storm on record.

Even now there are three powerful storms in the Atlantic. Jose has been downgraded to a cat 1 but is still a possible threat to the US east coast. Maria has strengthened to a cat 5 and is expected to strike Puerto Rico today and then perhaps hit the Carolina coast. Finally there is tropical storm Lee, so far out in the Atlantic we don’t yet know what it’s going to do. And hurricane season still has two months to go! The picture below is Irma taken from space and while beautiful you can still feel something of its power in the image. By the way, the small brown object to the left of the storm is Puerto Rico giving an idea of just how big this storm was.

Hurricane Irma from the Space Station (Credit: NASA)

The number and destructive power of these storms force us to ask the question, could global warming be responsible? Has all the carbon dioxide and methane we’ve been pouring into the atmosphere increased storm activity in the Atlantic?

First of all there is simply no doubt that carbon dioxide and methane are greenhouse gasses. Any college freshman chemistry lab is capable of making the necessary measurements. I know that because I did it way back in the 1970s!

Secondly, we know with great accuracy the amount of those gasses that are produced by our burning fossil fuels in our vehicles and power plants. Yes, I know the Earth’s atmosphere is huge but over 30 trillion kilograms of pollution every year is also an enormous amount, many cities throughout the world have smog problems and air pollution is a major health concern.

Thirdly, we can measure the rise in temperature over the last 50 years of the atmosphere, 0.6 degrees Celsius, and the oceans, 0.32 degrees. While these may seem like at small changes when you consider the world’s oceans it is simply an enormous amount of energy. The graph below from the National Oceanographic and Atmospheric Administration (NOAA) shows the increase in the amount of energy in the Oceans due to global warming. The total amount is about 15×1022 joules but to give you an idea just how much energy that is it’s more than the energy in 35 million one megaton nuclear bombs. That’s right, the increase in energy is more than 35 million nuclear bombs!!!

Increase in Oceanic Heat Content (Credit: NOAA)

So even if only a small fraction of that energy increase gets into the storms that form over the oceans it would certainly be enough to significantly amplify the number and power of those storms. So, what are the numbers? Has there been an increase in the number of tropical storms and hurricanes in the Atlantic?

The table below shows the average number of both tropical storms and hurricanes as a function of decade for the 1970s, 80s, 90s, 2000s along with 2010 to 2016. The obvious increase is between the 1990s and 2000s, a more than 40% increase but the increase from the 80s to the 90s is not insignificant. Now, climatologists like to look at long term trends, to them even a decade is a short period of time. Nevertheless over the last 16-17 years there has been an undeniable increase in both the number and strength of Atlantic storms.

Yearly Average of Tropical Storms in decades (Credit: R. A. Lawler)

Now I’ve only been talking about tropical storms in the Atlantic. The Pacific Ocean has also seen an uptick in activity along with an increase in tornadoes across North America and just an increase in rainfall in general throughout the world. All this is a strong indication that global warming is causing more powerful, more violent weather everywhere.

The time is past for debates, the effects of climate change are already upon us. There’s much worse to come unless we seriously reduce the amount of polluting gasses we generate. Sea level rise combined with increased hurricane activity could soon lead to much greater destruction than we’ve seen so far. Quick and decisive action is required before it’s too late.

Here we go Again. A Recent Paper by a Group of Cosmologists raises doubts about the very Existence of Dark Energy.

We’ve all heard the old saying ‘Two steps forward, one step back’. Well, when it comes to Cosmology, the study of the Universe as a whole, it seems like we take a step forward, another sideways, close your eyes and spin, take two steps etc, etc, you get the idea. The Universe is so large, the measurements so difficult to make, the theories so complex that progress in cosmology has always been slow with many wrong turns. So hang on folks, today’s post is going to be a little trip with Alice into wonderland.

Today the best model we have for the basic nature of the Universe is that is consists of billions of Galaxies like our Milky Way. That the Universe is expanding, all those Galaxies are moving away from each other, and that the expansion is not being slowed by the gravity of the Galaxies. In fact the expansion is accelerating. This basic model is outlined in the image below.

Big Bang Model (Credit: NASA)

It was Carl Hubble, back in the 1920s and 30s who discovered that the Universe was made of Galaxies and that it was expanding. The acceleration of the Universal expansion was discovered in the 1990s by two groups of astronomers led by Saul Perlmutter and Adam Riess.

The cause of this acceleration was completely unknown and quickly given the name ‘Dark Energy’, although cosmologists prefer the name ‘Vacuum Pressure’. Today we know almost nothing about ‘Dark Energy’ and it ranks as one of the greatest mysteries in all of science.

Now a recent paper published by Lawrence H. Dam, Asta Heinesen and David L. Wiltshire of the University of Canterbury in New Zealand may be about to throw the whole science of cosmology into a state of confusion. According to Professor Dam and his colleagues there is no such thing as Dark Energy, it simply doesn’t exist. Cosmologists only think there’s Dark Energy because they’re trying to fit their measurements to an incorrect mathematical model of the Universe.

To understand what Professors Dam, Heinesen and Wiltshire are saying we need to talk a little bit about the mathematical ideas we use to describe the Universe and of course we start with Albert Einstein. When Einstein published his General Theory of Relativity, also known as his Theory of Gravity, it was quickly realized that since it was gravity that held the Universe together then Einstein’s Gravity theory was the best way in which to study the Universe. The full Einstein equation for gravity is shown below, it’s the lambda (L) symbol that relates to Dark Energy.

Einstein’s Field Equation

A trio of physicists named Alexander Friedman, Howard Robertson, and Arthur Walker used Einstein’s theory to develop an exact set of equations for a Universe where matter was spread smoothly (homogenous) and the same in every direction (isotropic). A mathematician named Georges Lemaitre later expanded the FRW model to include the expansion of the Universe thereby creating the ‘Big Bang Theory’, although technically it is referred to as the FLRW model.

Now remember the two assumptions of the FLRW model, that the matter in the Universe is smoothly distributed with no preferred direction, i.e. it is homogenous and isotropic. At first glance however the Universe sure doesn’t look smooth, it’s got the Galaxies, clusters of stars with a whole lot of empty space between them. However, the idea was that when you considered the whole Universe with tens of billions of Galaxies they would all spread out evenly.

Except that they don’t. Another important astronomy project of the last twenty years has been the Sloan Digital Sky Survey (SDSS), an ambitious attempt to map the positions of nearly a million Galaxies and what the Sloan team has discovered is that the Universe actually looks more like Swiss cheese or soap bubbles with regions that are quite dense surrounding immense empty voids. The image below shows a sample of the results of the SDSS and clearly illustrates the ‘lumpiness’ of the Universe.

Results of Sloan Digital Sky Survey (Credit: SDSS)

So the basic assumptions of the FLRW model aren’t quiet right and Professors Dam, Heinesen and Wiltshire say that a new mathematical model, which they call the Timescape model, must be used instead. It’s in this mathematical model that the measurements made by Perlmutter and Riess fit without the need for anything like Dark Energy.

Now there’s a long way to go before the Timescape model is generally accepted, if it ever is. Chances are that this theory will not stand the test of close examination and Dark Energy will continue to be a mystery that needs to be solved. You never know though, every time we look further into the Universe it just seems to get stranger and stranger.

I realize that this post was rather long and heavy and dealt with some strange and difficult topics. However I hope that it wasn’t too abstract. The intersection between math and measurement is central to the advance of science and after all, we are taking about the basic structure of the Universe as a whole!

End of the Cassini Mission to Saturn

Two days from now, on Friday the 15th of September 2017 the Cassini Spacecraft will make it’s final orbit around Saturn. After exploring Saturn and its moons for the past 13 years Cassini is now nearly out of fuel and NASA has decided to plunge the probe into the atmosphere of the ringed planet. The reason for ending the probe’s mission in this fiery fashion is to make certain that Cassini does not crash onto one of Saturn’s moons and possibly contaminate it with micro-organisms from Earth.

The Cassini-Huygens mission began almost 20 years ago on the 15th of October 1997 when the spacecraft was launched from Kennedy Space Center aboard a Titan IV-Centaur rocket. The probe’s long seven year journey to Saturn required gravity boosting flybys from Venus (twice), Earth and Jupiter in order to gain enough energy to reach the outer Solar System. The image below shows the Cassini-Huygens spacecraft prior to its launch.

Cassini-Huygens Spacecraft (Credit: NASA)

Entering orbit around Saturn on the first of July 2004 Cassini released the Huygens landing module on the 25th of December 2004 and Huygens successfully landed on the Moon Titan on January the 14th, 2005. The lander, which was built by the European Space Agency, operated for 90 minutes sending back images and instrument measurements from the surface of the second largest moon in the Solar System. The first image below is a picture of the Huygens lander and the second is an image from the surface of Titan.

Huygens Lander (Credit: David Monniaux)
The Surface of Titan (Credit: ESA-NASA-JPL)

During it’s short operating life the Huygens lander found that the atmosphere of Titan was denser than Earth’s by about 45% with a composition of 95% nitrogen and 5% methane at a temperature of 98.3 degrees Kelvin (-179.3 Celsius). The rocks in the surface image above are actually water ice at a temperature so cold they are as hard as rocks!

The discoveries on Titan by Huygens were augmented by those of the Cassini orbiter which found both large lakes of liquid methane along with signs of channels other indications of erosion caused by flowing liquid methane. Between them Cassini and Huygens portray Titan as a world very similar to our own except it is so cold that methane has replaced water.

Since then the Cassini orbiter has continued its mission, making several major discoveries. One of the most important has been the eruptions of water ‘volcanoes’ spewing out of the moon Enceladus. The energy causing these eruptions is thought to be generated by the tidal forces of Saturn and its other moons and is similar to the process that heats Jupiter’s moons Io and Europa. After discovering the ‘volcanos’ the Cassini spacecraft was even sent into them in an attempt to analyze their composition. The plumes are indeed water but with a small amount of complex hydro-carbons mixed in. Are these complex molecules a sign of the beginning of life on Enceladus? Only time, and a lander to the moon will tell. The picture below is an artists idea of the hydro-thermal activity on Enceladus.

Hydro-Thermal Activity on Enceladus (Credit: NASA-JPL-Caltech)

As far as I’m concerned however the best part of any mission to Saturn is simply the images of the planet and its system of rings. So without further ado I’ll just add a few below.

Saturn by Cassini (Credit: NASA-JPL)
Saturn’s North Pole (Credit: NASA-JPL)
Saturn’s Rings (Credit: NASA-JPL)

NASA has actually set up live internet coverage of Cassini’s final moments, although we can’t be quite certain exactly when that will happen. The show will start at 7AM Eastern Daylight Time on Friday the 15th and if you’d like to tune in, I will be, click on the link below to be taken to NASA’s Cassini End of Mission Activities website.

https://www.nasa.gov/press-release/nasa-announces-cassini-end-of-mission-media-activities

5.7 Million Year Old Footprints Discovered on Crete. Did a Bipedal Ape inhabit Europe Millions of Years Earlier than Previously Thought?

Not long ago (My Post of June 10th 2017) I complained that important finds of human and hominid fossils are too often reported in the press as ‘Shocking new Discoveries that will rewrite Human Pre-History’. Well I may have to eat my words this time because the recent unearthing at Trachilos on the island of Crete of 5.7 million year old fossil footprints could indeed rewrite human pre-history.

The footprints of human beings and the human like, upright walking apes called hominids are different from any other kind of creature. First of all like all of the primates we have no claws and our inner toes are substantially larger than the others, hence the ‘big toe’. Unlike our cousins the apes however our big toe does not stick out at a right angle the way our thumb does. These characteristics combine to make hominid footprints truly distinctive.

For the past 40 years the earliest known fossil hominid footprints were those discovered by Mary Leakey at lake Laetoli in Kenya, which were dated to 3.66 million years ago. These footprints are thought to have been made by a member of the species Australopithecus afarensis, the same species as the famous fossil Lucy. The images below show the fossils of Lucy and a reconstruction of what she may have looked like.

(Skeleton of Lucy: Credit Getty Images)
Reconstruction of A. afarensis (Credit: Cleveland Museum of Natural History)

The footprints at Laetoli, along with fossil remains like Lucy, are some of the key evidence for the ‘East African Cradle’ model of human evolution. The basic idea is that about 4.5 million years ago our ancestors moved from the jungle onto the East African grasslands. Adapting to their new environment by 3.5 million years ago our ancestors had become fully bi-pedal like Lucy and the makers of the Laetoli footprints. All subsequent hominid species, including us, are descended from those early walkers.

The footprints discovered on Crete could require a significant extension of if not an almost complete rewrite of that theory. Not only are they two million years older than the prints at Laetoli but they are on a different continent!

The Trachilos footprints were discovered and have been studied by a group of paleo-anthropologists led by Matthew Robert Bennett of the University of Bournemouth in the UK and Per Ahlberg of the University of Uppsala in Sweden. The footprints, several of which are shown in the images below, have been dated very precisely by the presence of fossil shells of marine microorganisms called foraminifera. The shells of these tiny single celled creatures evolved very quickly making foraminifera very useful fossils for dating the sediments in which they’re found.

Crete Footprints (Credit: Matthew R. Bennett)

Doctors Bennett and Ahlberg point out that at the time the footprints were made the sea level in the Mediterranean was much lower. Back then Crete was not an island but rather a part of the Greek mainland. In fact the size and depth of the Mediterranean Sea has varied greatly over the past 10 million years and it is quite possible that groups of early or even pre-hominid apes may have wandered around the eastern Mediterranean basin with one of them making the footprints on Crete.

Of course it is also possible that we have simply misidentified the footprints. Precise identification of any fossil is a hard thing to do and trace fossils, such as footprints or burrows, can be the hardest of all.

One thing is certain; if Greece or Sicily or east cost of the Mediterranean was inhabited by groups of early hominids then there are more fossils out there to be found. More evidence that could lead to a more complete picture of human evolution. Perhaps an ‘East Africa and Eastern Mediterranean Cradle’ model. If you’d like to read more about the footprints discovered at Trachilos Crete click on the link below.

https://theconversation.com/ancient-footprints-in-crete-challenge-theory-of-human-evolution-but-what-actually-made-them-83412

 

 

Voyager. The Longest Journey

Today is the 40th anniversary of the launch of the Voyager 1 spacecraft. On September the fifth in 1997 a Titan 3-C rocket took off from Kennedy Space Center carrying a 773 kilo spacecraft that has completely changed the way we see our solar system and even now is exploring the space between the stars themselves. How many things do you know of that are still working after 40 years. The picture below shows Voyager and the various parts of the spacecraft.

Voyage Spacecraft (Credit: NASA)

The original concept for the Voyager missions was to be a ‘Grand Tour’ of the outer solar system with flybys of four planets Jupiter, Saturn, Uranus and Neptune. Indeed, the Voyager 2 spacecraft did succeed in visiting them all giving us our first close up view of Uranus and Neptune.

The discoveries made by these two robot explorers are too numerous to mention. I can only mention a few: Jupiter’s Rings, volcanoes on Io, the ice covering on Europa, shepherd moons in Saturn’s rings, the dense hydrocarbon atmosphere of Titan, the broken moon Miranda of Uranus and the great black spot on Neptune. Before Voyager all of these places were at best hazy smudges in a telescope, it was Voyage that turned them into worlds for us. The mosaic picture below shows some of the images taken by the Voyager spacecraft.

Mosaic of Voyager Images (Credit: Don Davis, NASA)

Because their mission was planned to take them on a journey so far from the Sun the Voyagers could not be powered by solar cells as most spacecraft are. Instead, each of the two probes carries three Radioisotope-Thermoelectric-Generators (RTGs). RTGs are basically a rod of radioactive material surrounded by thermocouples that convert the heat into electricity. the three generators combined produced a combined 470 watts of power at launch and even today after 40 years they are still generating about half that amount. That is still enough power to enable the Voyager probes to remain in contact with Earth although most of the probe’s instruments, such as the cameras, have been turned off to conserve power. Only the magnetometer and the low and high energy particle detectors continue to operate, continue to give us information about the space through which Voyager still journeys.

Today Voyager 1 has entered interstellar space, the first object made by mankind to do so. When the Voyagers were launched 40 years ago no one had any idea what the edge of the solar system would be like let alone where it might be. It was Voyager 1 who showed how the solar wind, pushing out from the Sun, comes to a pause known as the heliopause. Beyond that the low energy particles from the Sun disappear while the magnetic field shifts to that of the Milky Way.

Voyager 1 entered interstellar space in August of 2012 and Voyager 2 will soon join it. NASA estimates that the power sources on the spacecraft will allow them to remain in contact with Earth until sometime around 2030.

When that contact is lost the long mission of these explorers will finally be over, but only for human beings! You see the scientists and engineers who built Voyager knew that their creation could travel between the stars for thousands if not millions of years and there was the remote but still exciting possibility that one of the Voyagers might someday be found by non-human intelligences.

So the men who built Voyager included a greeting to any aliens that might find it. A golden record was stored away in the Voyager spacecraft. This record contained some of the sounds of Earth, music and greetings, along with images of life on Earth. The cover protecting the record has instructions for playing the record and even a stylus to be used in the playback. It is possible that the messages sent on Voyager may one day be the only record of our ever existing!

In 40,000 years Voyager 1 will pass about 1.6 light years from the star Gliese 445 while at the same time Voyager 2 will pass about 1.7 light years away from the star Ross 248 (both are red dwarf type stars). Even then the Voyagers will continue on and where their journey will end no one can say.

As of this morning Voyager 1 was 20,884,724,316 kilometers from the Sun and getting 16.995 kilometers further every second. Voyager 2 was 17,178,385,861 from the Sun and moving at a velocity of 15.374 kps.

If you’d like to know more about the Voyager spacecraft NASA has two websites. The first deals with the entire voyager mission while the second is for ‘Voyager the Interstellar Mission’. Click on the links below to be taken to those sites.

https://www.nasa.gov/mission_pages/voyager/index.html

https://voyager.jpl.nasa.gov/

Nuclear Fusion: Has MIT Found the right Recipe?

For over half a century now Hydrogen Fusion has been the Holy Grail of energy production for the human race. Fusion is the energy source that powers the stars themselves and the potential for Fusion power plants to provide cheap, inexhaustible, pollution free energy was never in doubt. The question has always been whether the extreme conditions necessary for Fusion to occur could be controlled and maintained, whether a reliable Fusion reactor was possible or, like the Holy Grail, just a dream.

Let me take a moment to provide a little background. The chemical elements we’re all familiar with from high school run from the simple ones like Hydrogen, just a proton and electron, to extremely complex ones such as Uranium with 92 protons, 92 electrons along with 146 neutrons.

Now it turns out that you can release energy by either splitting big atoms like Uranium, this is called Fission, or Fusing small ones like taking 4 Hydrogen atoms to form one Helium atom. The pictures below show the two different types of reactions.

Fission of a Uranium Nuclei (Public Domain)
Fusion of Hydrogen into Helium (Public Domain)

We all know that Atomic Fission reactors have been producing energy for over 50 years but they’re dangerous, even after you’ve shut them down they remain hot and if the reaction gets out of control a tremendous amount of harmful radiation can be released, as in Chernobyl or Fukashima. Another problem with Fission reactors is that the leftover fuel rods are also highly radioactive and storing them safely is a very difficult problem.

Fusion reactors on the other hand would have a number of clear advantages. First of all Hydrogen Fusion simply produces more energy per kilo of fuel. More importantly however is the fact that Fusion would produce zero dangerous waste. Also, the conditions needed to produce Fusion are difficult to initiate and maintain, so difficult in fact that if anything were to go wrong the reaction would just instantly stop with no chance of a meltdown or release of radiation.

So if Fusion is such a better form of energy production why aren’t we building them by the hundreds in order to satisfy the need for pollution free energy? Well, as I said the conditions needed for Fusion are difficult to initiate and maintain, so difficult in fact that the world’s best scientists have been unable to maintain a Fusion reaction for more than a fraction of a second.

A recent advance may help to change that however. Scientists at MIT’s Plasma Science and Fusion Center have been experimenting with a new recipe for the fuel in their Alcator C-Mod Tokamak reactor. Now a Tokamak is a doughnut shaped vacuum chamber that uses intense magnetic fields to confine plasma, a gas of atoms that have been stripped of one or more electrons. Producing and heating plasma to extremely high temperatures and pressures is how you initiate a Fusion reaction. The picture below shows the MIT Tokamak.

Inside MIT’s Tokamak (Credit: Bob Mumgaard-Plasma Science and Fusion Center)

For the last several decades the fuel recipe that researchers have used has consisted of about 5% ordinary Hydrogen and 95% Deuterium, Hydrogen with a neutron attached to the proton. Microwaves then heat the ordinary Hydrogen and Fusion occurs as the superheated Hydrogen slams into the Deuterium. As I said earlier no one has succeeded in keeping this reaction going for more than a second.

Now the team at MIT has added a trace, less than 1%, of Helium-3 to the mixture. (Helium-3 is an atom of Helium lacking a neutron) When the Helium-3 is heated by microwaves they were able to increase the Helium-3 to energy levels ten times greater than previously seen!

The results obtained by the MIT team were so exciting that they quickly shared their results with colleagues at the Joint European Torus (JET in Culham UK), which is the world’s largest experimental Fusion reactor. The JET team soon confirmed MIT’s results and so now both teams are fine-tuning the recipe in order to get the highest energy levels possible.

Whether or not this breakthrough will soon lead to practical Nuclear Fusion only time will tell. It is possible however that before too long humanity may possess an almost limitless supply of pollution free energy.

If you’d like to read more about the research at MIT click on the link below to be taken to the Plasma Science and Fusion Center webpage.

https://www.psfc.mit.edu/news/2017/fusion-heating-gets-a-boost