We’re all familiar with what a robot looks like. Whether it be Star War’s C3PO or an actual robotic arm on a automobile assembly line they’re made of metal and gears and while they can sometimes move quickly they are never agile or flexible. The robots you see on ‘BattleBots’ have joints and manipulators that are powered by little electric motors that are costly, use a lot of power and are prone to break downs.
For years now scientists and engineers have been trying to develop ‘artificial muscles’ that would provide greater strength and dexterity while at the same time being lower cost and more efficient. Various different materials have been tried. Some, such as Shaped Memory Alloys or twisted polymer fibers were found to be energy inefficient (about 2%), slow and plagued by hysteresis, that is repeated on-off cycling does not always bring them back to their original starting point.
High-pressure actuators, either pneumatic or hydraulic, have also been widely studied but their contraction ratios are limited to about 35%, in other words they can only pull so much. Furthermore the use of high pressure can be dangerous.
Now a team of engineers at Harvard University’s Wyss Institute for Biologically Inspired Engineering is trying a new track, low pressure vacuum rather than high pressure. The team consists of Shuguang Li, Daniel Vogt, Daniela Rus and Robert Wood and they have developed a basic design of a muscle that they call a Vacuum-Actuated Muscle Inspired Pneumatic Structure (VAMPS). According to the engineers VAMPS are strong (Power density greater than 2kW/kg), lightweight, are able to contract to 10% of their initial length and can be cheaply fabricated by a variety of techniques.
The figure below illustrates the operation of the VAMPS. At the top, the Pin=Pout drawing, the triangular line represents a skeletonal structure that is wrapped inside a skin made of thermoplastic polyurethane coated nylon fabric which is fluid tight. As Pin<Pout, the middle drawing, the muscle begins to contract and as Pin gets close to a vacuum the VAPMS reaches its full contraction.
VAMPS (Credit: Wyss Institute, Harvard University)
These VAMPS can then be used as buildings blocks to construct entire robotic manipulators and limbs that are known as Fluid-driven Origami-inspired Artificial Muscles (FOAMs). These FOAMs can then be designed to fulfill a large variety of different tasks. One of the manipulators that have been designed and constructed by the Harvard group is shown in the Image at the top of this post while another is shown below, notice the one below is grabbing and lifting an automobile tire.
Origami Artificial Muscle (Credit: Wyss Institute, Harvard University)
By the way the team at Wyss is being partially funded by the Defense Advanced Research Projects Agency or DARPA which has already received mention in several posts on this blog (June17, September 23 and November 8, all of 2017).
The Harvard engineers working on the VAMPS and FOAMs are also testing their designs in a variety of different environments. In doing so they hope to be able to demonstrate that their innovations can be employed anywhere from the deepest oceans to the rigors of outer space. If you’d like to learn more about the work going on at the Wyss Institute click on the link below to be taken to the official website.
I took in a physics seminar at my old alma mater Drexel University on November 30th. I like to stop down once in a while to see what’s changed, a lot, as well as see who’s there that I still remember, seems like fewer each time.
The topic of the seminar was certainly one that interested me, Neutrinos; a kind of sub-atomic particle so difficult to detect it has been called a ghost particle. The German physicist Wolfgang Pauli first predicted the existence of neutrinos as a way of making the books balance in the radioactive process called beta (β) decay. Careful studies of the process showed that some energy was missing, and the angular momentum before and after didn’t match. Pauli suggested that if another particle was involved, one without electric charge and little or no rest mass, it could account for the differences while being very difficult to detect. The images below show the Nobel Laureate along with a diagram of the β decay process.
Wolfgang Pauli (Credit: Public Domain)Beta Decay Process (Credit: Public Domain)
So difficult were neutrinos to detect that it took more than twenty years to prove that they existed. In fact neutrinos react with normal matter so rarely that while about ten billion (billion with a b) neutrinos are flying through your body every second only two or three will interact with a particle inside you during your entire life. Even today the way we study neutrinos is to arrange for zillions to fly through a detector so sensitive it can measure the properties of the one or two that interact.
Arranging that intense beam of neutrinos, and building that detector is the job of Doctor Sowjanya Gollapinni of the University of Tennessee at Knoxville. Dr. Gollapinni is one of the chief researchers of the MicroBooNE experiment currently running at Fermilab outside of Chicago along with being one of the chief designers of the future Deep Underground Neutrino Experiment (DUNE).
The MicroBooNE, BooNE stands for Boosting Neutrino Experiment by the way, is a new type of detector using a design known as a Liquid Argon Time Projection Chamber (LArTPC). In the detector scattering events (really just two particles bouncing off of each other) between neutrinos and Argon atoms occur inside a very large, uniform electric field. The electric field pulls the ionized atoms generated by the collision toward an incredibly fine mesh of detecting wires. The resulting data plots are then interpreted to determine the kind of neutrino (see below) as well as its energy. The images below show the first high-energy neutrino collision captured by MicroBooNE along with the first recorded cosmic neutrino event.
First Recorded Neutrino Event at MicroBooNE (Credit: MicroBooNE, Fermilab)First Cosmic Neutrino event at MicroBooNE (Credit: MicroBooNE, Fermilab)
One of the reasons I like MicroBooNE so much is that it uses the Fermilab Tevatron as its source of high-energy neutrinos. The Tevatron was the world’s most powerful ‘atom smasher’ until the Large Hadron Collider (LHC) at CERN took the top spot in 2008. In the world of particle physics however being number two gets you nothing so the physicists at Fermilab have been working hard to reconfigure their equipment in order to continue to study new physics and MicroBooNE is a big part of that effort.
After talking about some of the results from MicroBooNE Dr. Gollapinni spent a little time talking about the next generation neutrino detector known as the Deep Underground Neutrino Experiment or DUNE. As shown in the figure below, DUNE will have two detectors, one just a short distance from the neutrino source at Fermilab while the second will be buried deep inside the Homestake Mine in South Dakota, a distance of 1300 kilometers away. When completed the DUNE detectors will be 400 times larger then MicroBooNE providing 400 time the data.
DUNE experimental setup (Credit: DUNE, Fermilab)
Now the reason for having a second detector a long distance away is to give the neutrinos produced at Fermilab time in order to change from one type or flavour of neutrino to another. You see one of the things we do know about neutrinos is that there are three flavours. One flavour is associated with the familiar electron, a second is associated with a particle called the muon who is like a heavy cousin of the electron while the third is associated with an even fatter cousin called the Tau particle. Even stranger is the fact that the three flavours will oscillate from one kind to another. Learning more about this oscillation process is one of the major goals of DUNE.
At the end of her discussion Dr. Gollapinni mentioned some preliminary but very exciting news. The results so far from MicroBooNE and several other neutrino experiments indicates, just indicates right now, the possible existence of a fourth flavour of neutrino, which would be a stunning result if proving to be true. Right now it’s just an indication, hopefully the DUNE experiment, scheduled to start collecting data in 2024, will give us the answer.
During the question period one of the students who were attending asked Dr. Gollapinni how many flavours of neutrino she thought there were and she answered ‘Well if we find a fourth it’ll be a Nobel Prize and that’s enough for me’.
I came across a couple of interesting stories detailing new discoveries in the field of paleontology. The stories concern my two favourite kinds of extinct animals, dinosaurs and trilobites so I have to talk about them.
I’ll start with the article about trilobites. For those who aren’t familiar with these creatures from the beginning of multi-cellular life trilobites are arthropods, similar to crustaceans, spider and insects but much simpler in physiology. (See picture below showing trilobite anatomy) Trilobites lived from the beginning of the Cambrian period (about 550 million years ago) until the mass extinction at the end of the Permian period (about 250 million years ago). During that long stretch of time over 20,000 different species are known to have existed so trilobites are a fairly common fossil; I have quite a few in my collection.
Trilobite Anatomy (Credit: Deposits Magazine)
But usually trilobite fossils consist only of the hard outer shell of the animal, the internal anatomy has decayed completely away. Only rare specimens show any of the ‘soft parts’ of animals as old as trilobites. And since trilobites are one of the earliest forms of complex life their internal workings could tell us a lot about how the nervous system, or circulatory systems or other internal parts evolved.
Now a group of researchers headed by Melanie Hopkins of the American Museum of Natural History have published a paper describing the earliest known digestive system of a trilobite. The specimens used in the study come from the Guanshan biota in the Yunnan province of China, a location that produces fossils of exceptional preservation. The fossils used in the study come from two different species, Palaeolenus lantenoisi and Redlichia mansuyi, that are common at the site.
Multiple specimens were literally dissected, imagine dissecting an animal dead for 550 million years, in order find their stomach and trace their alimentary canal. In trilobites the stomach, also know as the crop, is situated very close to the mouth beneath the glabella, see picture above. The researchers also discovered pairs of digestive organs on each side of the alimentary canal, which runs nearly the entire length of the trilobite. The image below shows some of the dissected specimens along with drawings of what was found.
Trilobite Dissected (Credit: Hopkins et al)
The digestive system of trilobites may seem simple compared to that of modern arthropods but for their time these were highly evolved. This study has given us some of the details about how the internal workings of a very important group of animals developed.
The second story I’d like to discuss comes from France where the longest known trackway of sauropod dinosaur footprints have been excavated in the Jura Mountains near the village of Plagne. The Jura Mountains by the way is where we get the name of the Jurassic Period.
The sauropod dinosaurs are the familiar long necked, long tailed plant eaters who were the largest animals to ever walk on the Earth. The 155 meter long trackway contains 110 steps and the impressions range from a little over a meter to three meters in diameter. The image below shows the trackway.
Dinosaur Trackway in France (Credit: P. Dumas)
According to the ‘Societe des Naturalistes d’Oyonnax’, a local group of amateur paleontologists who discovered the footprints, the trackway was made by a single animal approximately 35 meters in length with a mass of around 35,000 kilos. The animal walked with an average stride of 2.8 meters at a speed of about 4 kilometers per hour. The image below shows an artist’s representation of the sauropod dinosaur walking along the trackway while humans are beneath it.
Dinosaur in Trackway (Credit: A. Beneteau)
With each new find by paleontologists we are learning more about the history of life on Earth. It is a history far longer and more extensive than the history of the single species we think is so important.
In this blog I have tried to avoid even mentioning pseudo-science. Whether it be UFOs or Bigfoot or ESP there’s just no arguing with ‘True Believers’. No matter how many times they fail miserably to provide any hard evidence the ‘True Believers’ still refuse to even admit to the possibility that they could be wrong. In fact they will often get angry with you for saying ‘show me’.
Today however I’m going to make an exception and talk a little bit about Nibiru, or planet X because in just the last two months there have been THREE (!) different precise dates on which Nibiru was supposed to have destroyed us all, but we’re still here. Three complete, total failures in just two months. The image below shows an artists idea of Nibiru, which is supposed to be four times as massive as Earth, causing cataclysms here on our planet.
Nibiru Destruction (Credit: Shutterstock)
You’d think that level of failure would be sufficient to make all ‘True Believers’ completely ashamed of themselves. However I’m certain that a new ‘corrected’ date of destruction will soon be announced and accepted by the faithful. After all, the only other choice they have is to accept the fact that they’ve been a fool.
Actually the idea of Nibiru causing the apocalypse has been around for quite a while now. It was back in 1995 that Nancy Lieder claimed that she was receiving signals through an implant in her brain from aliens in the Zeta Reticuli star system. According to the Zetas a planet from the outer reaches of our solar system was going to sweep past the Earth causing all kinds of destruction by it’s gravitational and magnetic fields, this event was scheduled to take place in May of 2003. (The Zetas are Grey Aliens by the way, how many different kinds of aliens are visiting Earth I don’t know.)
The visiting planet gained the name Nibiru when Ms. Lieder read a book by a researcher on ancient alien visitations named Zecharia Sitchin. According to Mr. Sitchin, Nibiru is the name given by the Babylonians to a planet that sweeps past the Earth every 3,600 years and the inhabitants of Nibiru became the gods of Mesopotamia, chariots of the gods you remember! (By the way accredited scholars of Mesopotamia have no regard for Mr. Sitchin’s interpretation of the Babylonian records.) The image below shows Mr. Sitchin with a Babylonian tablet he claims mentions Nibiru.
Zecharia Sitchin with Babylonian Tablet (Credit: Crystalinks)
Sounds like Mr. Sitchin and Ms. Lieder are coming to the same conclusion from different paths doesn’t it? Well no, Lieder and Sitchin soon disagreed about when the planet would return, Lieder was already on record as saying 2003 while Sitchin said somewhere between 2090 and 2370!
Anyway I trust that you are all aware the Nibiru did not pass by Earth in 2003 but that didn’t stop the ‘True Believers’. They just picked a new date and Nibiru soon became the engine of destruction for the Mayan Apocalypse of December 21, 2012, which also didn’t happen.
But just because a planet doesn’t exist won’t stop people from making it a part of their attempts to gain attention, fame and money. Earlier this year a ‘Christian numerologist’ named David Meade tied together passages from the bible with Nibiru along with the American total solar eclipse back on August 21st to again predict Earthly destruction beginning on September the 23rd. When Nibiru failed to show up on time the date was immediately pushed back to mid October and then the 19th of November. Well it’s now 22November and no Nibiru! Let’s just hope the doomsday ‘theorists’ will at least wait a while before threatening us again with a non-existent planet.
I hope you’ve noticed that I haven’t mentioned any of the evidence against the existence of Nibiru. All I’ve said so far is that Nibiru never shows up when it’s predicted to destroy us. Still it’s easy to demonstrate that Nibiru is nothing more than a fantasy. First of all, if a planet four times the size of Earth came closer than the orbit of Saturn it would be quickly discovered by not only professional astronomers but by the thousands of amateur astronomers out there who are hoping to discover a comet or an asteroid. Anything as big as a planet wouldn’t be able to hide for a week!
Also, as astronomer Mike Brown has pointed out, any planet that moved back and forth between the outer and inner planets would sooner or later, within a few million years, have an encounter with Jupiter and be thrown out of the solar system. Finally, our solar system is a well-mannered, orderly place, so much so that it has often been compared to a clock; it wouldn’t be so orderly if there was anything Nibiru wandering around. The image below illustrates Nibiru’s orbit showing how Planet X goes right past the largest planets in the solar system.
Nibiru Orbit (Credit: Crystalinks)
Now I know that the people out there who are trying to sell books despite the fact that they don’t know anything will soon come up with some new fantasy. Still, hopefully by now Nibiru and its ‘supporters’ have been revealed as the delusions they always were.
There have been several very interesting things happening in space this past month so we’ve got a lot to discuss. I almost don’t know where to start.
I’ll start with the discovery of the second closest exo-planet, that is a planet orbiting another star. The star is called Ross 128 and sits in the constellation of Virgo at a distance of 11.2 Light Years (or 3.4 Parsecs) while the planet has been designated as Ross 128b.
Not only is Ross 128b close to earth it’s also just 35% more massive than our Earth so it’s expected to be a rocky planet. In addition Ross 128b orbits its star at a distance within what astronomers call the habitable zone. The habitable zone is defined as the region of space where the light coming from a star is just strong enough to give a planet a surface temperature suitable for liquid water to exist. And liquid water is obviously a prerequisite for life similar to that here on Earth.
How far the habitable zone is from a star depends on how much energy the star emits every second. A large hot star like Sirius would have its habitable zone out where Jupiter or Saturn are in our Solar System but Ross 128 is a small dim star; its habitable zone is much closer than even the orbit of Mercury. In fact Ross 128b is so close it orbits Ross 128 every 9.9 days!
One more thing about Ross 128b that has astronomers excited is that its parent star is a calm mild star, not prone to flare-ups that could make life impossible on their planets. Based on what we know about Ross 128b the planet looks like the best bet right now for discovering life outside our Solar System.
And we may be doing just that quite soon. You see over the next few years a new generation of telescopes, collectively know as Extremely Large Telescopes (ELTs) will begin to study the Universe. These huge instruments, along with the James Webb space telescope to be launched next year, should be able to separate Ross128b from the glare of its parent star and possibly detect signs of life on its surface. Detecting the spectral lines of Oxygen in the planets atmosphere in particular would be very strong evidence of life. Sometime in the next ten years we may know for certain! The image below shows an artist’s idea of what the Planet Ross 128b may look like along with artwork from NASA of the James Webb space telescope.
Imagined view of Ross 128b (Credit: M. Kornmesser)James Webb Space Telescope (Credit: NASA)
The second story is related to the first because it concerns another close, potentially inhabited exo-planet orbiting around Luyten’s star at a distance of only 12 light years. The planet GJ273b is about three times the mass of Earth and also orbits within the habitable zone of Luyten’s star.
A new organization called METI, Messaging Extra Terrestrial Intelligence, has begun sending radio signals, including music, to any potential civilization on GJ273b using a radio telescope in Norway starting in October and will be repeated in April of 2018. Traveling at the speed of light the signals will arrive at GJ273b in November of 2030. If there is a technical civilization on GJ273b then we may hear an answer in 2043. The image below shows the EISCAT parabolic dish antenna used to transmit the signals to GJ273b.
EISCAT Radio Dish (Credit: EISCAT)
Finally I like to talk a little more about one of those new telescopes that could revolutionize our knowledge of the universe. The Zwicky Transient Facility (ZTF) may not be the largest astronomical instrument but its digital camera, with a resolution of 24,000 by 24,000 pixels, will be capable of scanning the entire northern sky each night for transient events, anything that changes in brightness.
ZTF will quickly spot and localize objects ranging from supernovas to Near Earth Asteroids to supermassive black holes devouring entire stars in other galaxies. ZTF is also expected to detect the visible components of gravity wave events. Whenever ZTF spots something of interest other, more powerful but narrower focused instruments will be brought to bear to study the event in greater detail.
The ZTF telescope took its first photograph on November 14, see image below, and will be fully operational next year. If you’d like to read more about the ZTF click on the link below to be taken to the University of Maryland’s ZTF website.
First Image from ZTF (Credit: Caltech Optical Observatories)
Ever since Charles Darwin’s ‘On the Origin of Species’ had demonstrated that all of the multiform types of living creatures here on Earth had evolved over millions of years from a single primitive type of life scientists have sought to understand how that first living thing came into being. Much has been learned in the last 150 years but many of the details of the chemistry involved in the development of a complex, self-replicating molecular system, i.e. a simple living cell, are still unknown.
Now researchers at The Scripps Research Institute (TSRI) have published a paper in which they claim to have found a chemical compound that played a key role in assembling short nucleotide chains (early genetic material) with peptide chains (short version of proteins) encapsulated in a lipid vesicles (early cell walls). Finding a catalyst that could combine these three distinct types of chemicals, and which could have existed on the primitive Earth has been a goal of ‘Origins of Life’ researchers for the past several decades.
The scientists at Scripps have given their compound the name diamidophosphate or DAP for short and have published their results in the journal ‘Nature Chemistry’. The figure below shows the chemical diagram and the structure of DAP.
Chemical Formula for DAP (Credit: Ramanarayanan Kirshnamurthy)Structure of DAP (Credit: Ramanarayanan Krishnamurthy)
According to lead researcher Doctor Ramanarayanan Krishnamurthy DAP “would have allowed other chemistries that were not possible before, potentially leading to the first simple, cell based living entities.” “With DAP and water and these mild conditions, you can get these three important classes of pre-biological molecules to come together and be transformed, creating the opportunity for them to interact together, ” Krishnamurthy said. The image below shows DAP and the three classes of chemicals needed to build a simple cell.
DAP linking three classes of pre-biological complex compounds (Credit: Ramanarayanan Krishnamurthy)
Whether or not DAP was THE chemical catalyst that enabled the formation of the first living cell will be difficult to prove four billion years after the fact but Dr. Krishnamurthy and his co-authors intend to continue their study of DAP and other phosphorylating compounds. If you’d like to read the press release put out by the Scripps Institute click on the link below.
Before I go I’d like to take a moment to update one of my posts of just last week (4Nov17) about the interstellar visitor that entered our solar system and is now on its way back into the void between the stars. Well A/2017 U1 has been given the new name of 1I Oumuamua. The 1I indicates that it is the first interstellar object ever discovered while Oumuamua is a Hawaiian word meaning scout or Messenger. 1I Oumuamua was discovered by the Pan-STARRS telescope in Hawaii after all. The image below shows Oumuamua’s path through our solar system.
Path of 1I Oumuamua through our Solar System (Credit: NASA-JPL-Caltech)
More importantly a group of Astronomers are preparing a paper in which they give their estimate as to the place of origin of Oumuamua along with how long it took to reach our solar system. Working backward along the trajectory of Oumuamua Eric Gaidos and Jonathan P. Williams of the University of Hawaii along with Adam Kraus of the University of Texas are of the opinion that Oumuamua originated in the Carina and Columba Associations, clusters of young stars at a distance of 215 to 365 light years. (Carina and Columba are constellations in the southern sky).
Current research estimates that the Carina and Columba Associations were an active star-forming region about 45 million years ago. If Oumuamua had been thrown out of a newly forming solar system in the direction of our Sun at a velocity of 1-2 kilometers per second it could just now be arriving in our solar system!
Even though Oumuamua was only near enough for us to study it for about a month we have already learned a great deal from it. This is only the start, in the years to come I have no doubt that we’ll be learning a great deal more.
Last Sunday night, 5November17, the National Geographic channel broadcast the latest episode of their series ‘Star Talk’, the ‘Intersection of Science and Popular Culture’ with host Neil deGrasse Tyson. As always the show centered around a taped interview by Dr. Tyson with a guest of some importance in some field of science. Last night’s guest was Doctor Arati Prabhaker who recently stepped down from her position as the Head of the Defense Advanced Research Programs Agency or DARPA. The picture below shows Dr. Tyson with Dr. Prabhaker.
Neil deGrasse Tyson interviews Arati Prabhaker (Credit: Star Talk, National Geographic Channel)
The interview began with Dr. Tyson asking Dr. Prabhaker to describe what DARPA is and relate a bit about its history. DARPA was formed in 1958, in the wake of the USSR’s launching the first artificial satellite Sputnik I, as an agency within the Department of Defense assigned with finding ways to adapt the latest technology to our nation’s military readiness.
Over the years DARPA has had a few amazing successes such as ‘Stealth’ radar invisible aircraft and precision guided ‘Smart Bombs’ but not all of DARPA’s work has involved weapons. In fact some of the agency’s breakthroughs have been turned into many of the hi-tech devices we use everyday. One DARPA program called ‘ARPA net’ developed many of the protocols that computers use to talk to each other, a critical part of the Internet. Also, I was personally a witness to DARPA’s funding of the development of Gallium Arsenide (GaAs) as a semiconductor material for high frequency circuits; you wouldn’t have a cell phone without it.
In fact some of the technology currently being supported by DARPA has already been discussed on this blog in previous posts. The DARPA challenge race for driverless cars was the main topic of my post of 17Jun17. Meanwhile DARPA’s funding has also helped to advance the engineering of prosthetic limbs for wounded soldiers, some of the results of which were discussed in my post of 23Sept17. The images below show some of the results of DARPA’s support in these fields. The first is from the driverless vehicle challenge while the second shows the latest result of prosthetic engineering and which is currently undergoing clinical trials by the Food and Drug Administration.
Winner of DARPA Challenge from Stanford University (Credit: Stanford University)Prosthetic Arm funded by DARPA (Credit: Star Talk, National Geographic Channel)
While Dr. Tyson’s interview with Dr. Prabhaker was taped earlier several guests joined Neil in his studio at the Hayden planetarium. One was his usual sidekick the comic Chuck Nice who seemed unnaturally nervous while trying to make jokes about military weapons systems. The second guest was the journalist Sharon Weinberger who has reported about DARPA for 17 years and has written a book ‘The Imagineers of War’ about DARPA. The cover of ‘The Imagineers of War’ is show below.
The Imagineers of War by Sharon Weinberger (Credit: Amazon.com)
The episode’s final guest, Hod Lipson is a Mechanical Engineer who took part in DARPA’s road challenge with a team from Cornell University and who has written about the coming revolution in driverless cars appropriately titled ‘Driverless’. Both books are available at Amazon. The cover of ‘Driverless is shown below.
Driverless by Hod Lipson (Credit: Amazon.com)
At the end of every episode Dr. Tyson makes a few concluding comments. A few of the things he said last night bear repeating. First Neil suggested that there should be a DARPA type of agency ‘in every branch of human culture’. But the comment that I think we would all do well to consider was ‘at DARPA they take risks, risks that other sources of money do not take. Well the day you stop making mistakes is the day you can be sure you are not on the frontier.”
Over the past twenty years or so NASA has been working on a effort to find and catalog all of the small objects in our Solar System that could one day pose a threat to us here on Earth. A critical part of this effort was the design and construction of telescopes especially suited to surveying large parts of the sky in very fine detail.
One of these telescopes is Pan-STARRS at the observatory atop Mona Kea in Hawaii. With a mirror of 1.8 meters in diameter the telescope is smaller than most professional instruments, but with a 1.4 Gigapixel camera Pan-STARRS can photograph the entire sky several times a month.
That’s what you need in order to find Near Earth Objects (NEOs). Take two pictures of the same part of the sky a couple of weeks apart and compare them. Anything that moves between the two images is an NEO.
Just a few weeks ago on October 19th, Doctor Rob Weryk of the University of Hawaii’s Institute for Astronomy found something special with the Pan-STARRS telescope. At first Dr. Weryk thought he’d just found another
space rock, there are literally thousands out there. Dr. Weryk gave the 500-meter rock the designation A/2017 U1.
When he calculated the object’s position and velocity however Doctor Weryk realized that whatever it was it was moving too fast to remain in orbit around the sun. The object was a visitor from interstellar space making its first and only trip around our Sun. The photograph below shows the small dot that is A/2019 U1.
Interstellar Visitor A/2017 U1 (Credit: Alan Fitzsimmons, Isaac Newton Group)
Astronomers had long been expecting a visit from such an object. Many models of how solar systems form have a certain amount of matter being expelled as the star and planets condense. These outcasts would then wander between the stars where they could occasionally be drawn into the gravitational field of another star.
The orbits followed by these temporary visitors are not closed elliptical paths like those of planets or very comets but are an open-ended curve known as a hyperbola. Whereas the planets repeat the same orbit over and over again, an object on a hyperbolic trajectory is on a one time only orbit around a star. The figure below shows the difference between an elliptic and hyperbolic orbit.
Elliptic and Hyperbolic Orbits (Credit: R. A. Lawler)
A/2017 U1 made its closest approach to our Sun back on September 9th, more than a month before it was discovered. Coming within 23 million miles of our star A/2017 U1’s velocity increased to almost 90 kilometers per second. It passed within 15 million miles of Earth on October 14th at a velocity of 60 kps; three times the velocity that the New Horizons space probe had on its way to Pluto. In ten years or so, when it has left our Solar System behind A/2017 U1 will still have a velocity of about 25kps, faster than that of the Voyager I space probe, the first man made object to leave our Solar System. The image below shows the path of A/2017 U1 as it swung around the Sun.
Path of A/2017 U1 through our Solar System (Credit: NASA-JPL-Caltech)
So, what was A/2017 U1? What was it made of? Where did it come from?
To be honest we didn’t learn a great deal about A/2017 U1. It was very small, didn’t come that close and is already too far away for even the most powerful telescopes to see anymore. Really all we know for certain is that A/2017 U1 came from the direction of the constellation of Lyra and that it looked more like an asteroid than a comet.
But we know it came from the beyond, from outside out little neighborhood of the Galaxy. And that means there will be others, and each time one visits we will learn a little more about them. That’s the way science works after all.
Back in August I was lucky enough to have had an almost perfect view of the recent total Solar eclipse that crossed the USA, (See Post of 24August17) so went I came across an article entitled “Solar Eclipse of 1207BC helps to date the Pharaohs” I was instantly intrigued. It only took me a few minutes to find and download the original article at the journal ‘Astronomy and Geophysics’. What I read was certainly interesting but also clearly displayed some of the difficulties in trying to use modern science to study ancient, semi-legendary records of past events.
The article was written by Colin J. Humphreys of Selwyn College at Canbridge University and Graeme Waddington, an independent scholar. What Humphreys and Waddington propose is that the astronomical miracle described the Old Testament book of Joshua (Joshua 10:12-14) was not as usually translated the Sun and Moon standing still at Joshua’s command but rather a description of a Solar eclipse.
This idea is not actually new. As Humphreys and Waddington themselves point out the linguist Robert Wilson realized over a hundred years ago that the Hebrew words dôm and ‘amad could also mean that the Sun and Moon stopped shining, i.e. an eclipse. However, when astronomers did the calculations to find that ancient eclipse they discovered that there was none appearing in Canaan around the right time.
What Humphreys and Waddington realized was that the earlier calculations of ancient Solar Eclipses ignored the possibility of the event being an annular solar eclipse. Now an annular eclipse occurs when the Moon is at the farthest point in its orbit and therefore appears smaller in our sky, too small in fact to completely cover the Sun leaving a bright annular ring of sunlight. See picture below.
An Annular Eclipse (Credit: The Cosmos Within)
Doing the calculations Doctors Humphreys and Waddington found that there had been an annular eclipse across North Africa and Canaan on the 30th of October in the year 1207 BC. This eclipse they claim is the miraculous event depicted in Joshua, chapter 10. The image below shows the path of the annular eclipse.
Path of Eclipse of 1207BCE (Credit: C. Humphreys and G. Waddington)
Now to the ancient Hebrews an annular eclipse of the Sun would still be more than spooky enough to be remembered and connected to their legendary hero Joshua. At this point however the authors indulge in some hand waving, just suppose type arguments to provide a little more evidence. For example they claim that the reduction in sunlight during the afternoon, followed by the return of light after the eclipse’s maximum and then concluding with a real sunset could very easily be described as “The Sun did not hurry to set for about a whole day” (Joshua 10:13 New Revised Standard Version or NRSV).
To me this is part of the problem of trying to use modern science to describe biblical or mythological stories IN DETAIL! These stories have been so elaborated, so dramatized that any historical reality is deeply buried. You have to massage the surviving evidence to make it appropriate for the scientific explanation you’re suggesting.
In fact the very existence of the biblical hero Joshua and the Israelite “conquest” of Canaan has been seriously called into question. Professor Israel Finkelstein of the Department of Archeology at Tel Aviv University has published a series of papers and books detailing a broad spectrum of evidence that the Hebrew people developed in situ, that is the Hebrews were originally Canaanites who developed a different culture and came to consider themselves a different people, not an outside people who conquered the central highlands region of Canaan. According to Doctor Finkelstein, the stories of Exodus and Joshua are simply that, stories. There is no archeological evidence to support them. Trying to connect an astronomical event to such “history” may be completely impossible.
(If you’re interested in leaning about Doctor Finkelstein’s work I heartily recommend his “The Quest for Historical Israel” available at Amazon)
Still, up to this point I was with Doctors Humphreys and Waddington, but then they made a connection that just went to far for me. At the time of their eclipse, 30Oct1207BC, the Pharaoh in Egypt was named Merneptah, the son and successor of the famous Rameses the second. Now it happens that we know the number of years these men reigned better than the actual dates. The first year of Mernephat’s reign is considered to have been anywhere between 1213BC to 1204BC.
However, Merneptah is also know for having inscribed a stone slab with details of his victories (such a stone slab is known as a stele), including his victory over Israel! The images below show the entire stele along with the section mentioning Israel.
Merneptah’s Victory Stele (Credit: Wikipedia)Section of Stele mentioning Israel (Credit: Bible Probe)
Based on this stele Humphreys and Waddington have concluded that Merneptah’s first year as Pharaoh was either 1210BC or 1209BC. As I first read their conclusion I didn’t see the connection to Joshua’s eclipse, Mernephat’s stele mentions Israel but says nothing about anything like an eclipse. Then I thought, are they assuming that Mernephat’s victory over Israel was also Joshua’s victory over the Amorites!!!
That’s way too much of an assumption for me! There is no evidence of any kind that Mernephat and Joshua fought each other or indeed existed at the same time, if Joshua existed at all. Assuming that the two stories of battles are about the same battle is just pure speculation.
I have decided to attempt to contact Doctors Humphreys and Waddington to ask for a little clarification, who knows maybe I missed something somewhere. I’ll let you know when and if I receive an answer.
If you’d like to read the original article ” Solar Eclipse of 1207BC helps to date Pharaohs” click on the link below.
UPDATE: I received a reply from Sir Colin Humphreys, one of the authors of the article. (I didn’t know he was a Sir! The Queen’s birthday honours list of 2010 according to Wikipedia.)
Anyway, Sir Colin accepts that the battles fought by Joshua and Merneptah were not the same but he does believe that the two campaigns were near enough in time to allow him to use Joshua’s Miracle (The Eclipse of 1207BCE) to more accurately date Merneptah’s reign as Pharaoh.
I can only say once again that I am reluctant to accept the bible that literally. Or Merneptah for that matter, remember his stele states that “Israel is laid waste, his seed is not”. Well that’s a boast that rings pretty hollow. And Merneptah’s stele is contemporary with his campaign while the book of Joshua is considered to have been written 500 years later!
The science of paleontology has been a very active and exciting field of research over the past few years and this past month has seen the announcement of several new discoveries. I’ve chosen three items to discuss in today’s post.
The first discovery I’d like to discuss concerns new evidence about the appearance and skin colouration of dinosaurs. Now everybody knows that most of the dinosaur fossils that are found are just the bones of the animals. And you certainly can’t tell what colour a creature was from its bones. Impressions of the skin of dinosaurs are rare and those impressions with traces of skin colour rarer still.
Because of this fact for many years dinosaurs were usually portrayed as having rather bland colouration, normally just a shade of green. The illustration below from Sinclair Oil Company (Their symbol is an Apatasaurus) shows what we thought dinosaurs looked like in the 1950s and 60s. Notice how the animals are all green or gray and even on those with strips the strips are just a different shade of the main colour.
Dinosaur Colouration as imagined in the 1950s (Credit: Sinclair Oil, Matthew Kalmenoff)
Scientists are a patient bunch however, they kept looking for evidence of soft tissue and there are a lot of fossils out there to find. Over the last twenty years a number of fossil specimens have been found that now tell us a great deal about dinosaur appearance. It turns out that some dinosaurs at least had either vibrant colours or elaborate patterns, or both on their skins, or feathers! Yes, we also now know that many dinosaurs were covered in feathers to keep them warm.
In fact a recent paper published in the journal ‘Current Biology’ describes how small theropod dinosaur from China called Sinosauropteryx, in addition to being feathered was also decked out in alternating dark and light bands similar to the way a raccoon looks. The image below shows what the animal looked like according to co-author Fiann Smithwick of Bristol University.
Drawing of Sinosauropteryx (Credit: Robert Nicholls)
Doctor Smithwick and his colleagues came to their conclusions after an extensive study of three excellently preserved specimens of Sinosauropteryx. The specimens were not only examined under a microscope but the researchers also used cross-polarized filters to bring out the contrast in the colour patters. The image below shows one of the fossils used in the study as seen under cross-polarized light, the areas of light and dark pigmentation are evident.
Sinosauropteryx Fossil (Credit: Jacob Vinther)
This pattern of colouration is known as counter shading and is a common pattern in living animals. Doctor Smithwick suggests that the dark patches around the eyes may have served to reduce glare the same way that athletes today paint a dark stripe under their eyes.
The second news item I’d like to discuss is about the discovery of two-foot long footprints of a predatory dinosaur from Lesotho in southern Africa. While not as large as Tyrannosaurus Rex the theropod that made the footprints came from a much earlier time, the beginning of the Jurassic period about 100 million years before T rex.
According to paleontologist Fabien Knoll of the University of Manchester “Our finding corroborates the hypothesis that theropods reached a great size relatively early in the course of their evolution, but apparently not before the Triassic-Jurassic boundary.” Despite the fact that no remains of the animal have been found so far it is estimated to have been about 10 meters in length and has been given the name Kayentapus ambrokholohali. The picture below shows the footprints of Kayentapus ambrokholohali.
Footprints of Kayentapus ambrokhlolhali (Credit: Reuters)
Finally, we don’t often hear about fossil discoveries from India so the discovery of a well preserved specimen of an ichthyosaur certainly deserves a quick mention. For those who don’t know ichthyosaurs were reptile versions of dolphins that lived during the time of the dinosaurs. Returning to the sea their ancestors had left behind these air breathing lizards evolved fins in place of legs and a fish like tail. The image below shows a typical ichthyosaur.
The specimen was discovered near the Indian city of Kutch in the province of Gujarat. According to Guntupalli Prasad of the University of Delhi the 5.5 meter fossil is believed to belong to the ichthyosaur family Ophthalmosauridae and lived between 90 and 165 million years ago. The photo below shows the ichthyosaur fossil as it was being unearthed.
Fossil Ichthyosaur in India (Credit: The Hindu)
With these and other exciting fossil finds coming to light on a regular basis this is obviously a good time to be a paleontologist.
