Have Sterile Neutrinos been detected? Some experiments say yes, others say no.

Regular readers of this blog will have noticed that I have a deep interest in particle physics, also called high-energy physics, and in particular the so-called ‘ghost particle’ of the atom, the neutrino. Well after all my degrees are in physics and studying how the most elementary particles that exist interact is certainly the most basic way to understand how the Universe itself works. Also, my grad school advisor’s own research concerned neutrinos.

Neutrinos are a hot topic right now and a soon to be published paper is going to turn the temperature way up. The MiniBooNE experiment, which I discussed in some detail in my post of 2Dec2017, is detecting more neutrinos that calculations predict that it should and one possible explanation for the excess would be the existence of a fourth type of neutrino, a sterile neutrino. MiniBooNE is a cooperative experiment at Fermilab outside of Chicago, which produces the neutrinos the MiniBooNE detector. The image below shows the layout of MiniBooNE.

Layout of the MiniBooNE Experiment (Credit: Fermilab)

O’k a little background first describing the fermion or matter side of the standard model of elementary particles. Since the 1960s physicists have known that all of the matter we see around us, all of the atoms are built from four different particles. There is a pair of quarks called up and down who themselves make up the familiar protons and neutrons in the atom’s nucleus. There’s also a pair of leptons, the electron and the neutrino but while the electron orbits around the nucleus the neutrino is a ‘ghost particle’, rarely interacting with other particles.

If you think that sounds weird it gets worse. In the extremely high-energy collisions we generate in our modern atom smashers we have found that each of those four particles has two heavier, more massive cousins. The cousins of the up quark for example are called the charm and top quarks. The charm and top are identical to the up in every way except being more massive. They have the same electric charge, the same spin, the same weak charge, and same colour charge.

Similarly the down quark has two cousins named strange and bottom while the electron’s cousins are the muon and tau. Why these heavier cousins should even exist we have no idea but they certainly do.

There are three neutrinos as well but they simply called the electron-neutrino, the muon-neutrino and the tau-neutrino because they have the have the bazaar ability to oscillate from one type into another. One of the first attempts to study this oscillation property was called the Liquid Scintillator Neutrino Detector (LSND) at the Los Alamos back in the 1990’s. When the LSND found a surprising excess in the number of neutrinos some theoretical physicists suggested the existence of a fourth kind of neutrino, a sterile neutrino that would interact even less than normal ‘active’ neutrinos but which would oscillate like the others, in other words after a period of time it would become one of the other types. (I know how crazy that all sounds and I will tell you the math is almost easier to understand than the description!)

Other experiments quickly tries to find additional evidence of sterile neutrinos but failed. Both the Underground Oscillation Project with Emulsion-Tracking Apparatus Experiment in Switzerland and the Ice Cube Neutrino Observatory failed to discovery any hint of sterile neutrinos in their data. Physicists began to believe that there must have been some problem with the LSND data or its analysis. The Images below show the Ice Cube Neutrino Observatory in Antarctica.

Ice Cube Neutrino Observatory Credit: South Pole Doc)
Ice Cube Experiment Layout (Credit: Inspire.hep)

But now MiniBooNE has found the same signature of sterile neutrinos as the LSND had making physicists scratch their heads and wonder, what’s going on here? Perhaps one clue is that both LSND and MiniBooNE employ photomultiplier tubes to detect the energy released by a neutrino interacting with another particle while Ice Cube and the Underground Oscillation Project use other techniques. But whether the photomultiplier tubes are enabling the detection of sterile neutrinos, or are causing a false signal that is being interpreted as sterile neutrinos is as yet completely unknown. The image below shows the photomultiplier Tube array in the LSND. When in use the chamber is filled with water for the neutrinos to interact with.

Photomultiplier Tubes are a common technique for detecting Neutrino interactions (Credit: Amusing Universe)

Neutrinos have been leading physicists on both an exciting and yet very twisted journey ever since Wolfgang Pauli first predicted their existence back in the 1930s. I’m certain that there are a few more twists still to come.

 

 

 

Paleontology News for June 2018.

Two new fossils have been discovered recently of new species that are both very important in our understanding of the evolutionary history of life on our planet. Following the rule of age before beauty I’ll begin by discussing the earliest known ancestor of the group of reptiles known as the lizards.

Most people know lizards as simply any reptile that obviously isn’t either a crocodile or a turtle or a snake but lizards are actually the largest family of reptiles having over 6,000 species. Lizards range in size from tiny geckoes only a couple of centimeters long to the Komodo dragon that can exceed 3m in length.

The ‘new’ species has been named Megachirella wachtleri and the specimen was actually found twenty years ago in the Dolomites region of Northern Italy. As is the case with many recent fossil discoveries it was only when M. wachtleri was re-examined with new, more powerful instruments, a CT scan in the instance, that the features of M. wachtleri that made it important could be seen. The image below shows the fossil of Megachirella wachtleri.

Fossil of Megachirella wachtleri (Credit: Live Science)

 

The study of M. wachtleri was co-authored by Tiago Simoes of the University of Alberta in Canada who had spent more than 400 days visiting over 50 university and museum fossil collections in 17 different countries. Doctor Simoes is one of a number of researchers making important discoveries among the forgotten and misidentified specimens locked away in museum drawers.

Megachirella wachtleri lived some 240 million years ago making it the oldest fossil lizard by about 75 million years. Just as importantly, since M. wachtleri shows so many classic lizard features it probably pushes the common ancestor of lizards and other reptiles back to more than 252 million years.

Why is that important? Well you see 252 million years ago was the Permian / Triassic extinction when more than 95% of all of the different species of living creatures vanished. If the lizards split off from the other reptiles before then that means that at least one species of lizard survived the Permian extinction. The image below shows an artist’s impression of what M. wachtleri looked like.

Artists view of Megachirella wachleri (Credit: Live Science, Davide Bonadonna)

Our second discovery this month comes from a fossil site in the state of Utah and consists of a well preserved skull of an early relative of the mammals from an extinct group known as the haramiyidan. Named Cifelliodon wahkarmoosuch the fossil is thought to be between 139 and 124 million years old. The image below shows the fossil skull.

Skull of Cifelliodon wahkarmoosuch(Credit: Utah Geological Survey)

As I mentioned above the haramiyidan were a group of creatures that broke away from the reptiles at about the same time as the mammals and which share certain characteristics with our ancestors such as hairy fur but which retained other reptilian characteristics like giving birth via eggs. The exact nature of haramiyidans is still largely unknown since the group of animals did not last long and most of what we know comes from fossil teeth. Larger bones and especially skulls are often so smashed that little can be learned from them.

Paleontologists appear to have gotten lucky this time because the skull of C. wahkarmoosuch was well preserved enough to reveal an enormous amount of detail under X-rays and CT scans. Again, we see how newer more sophisticated instruments are leading to ever more discoveries! The excellent preservation of the fossil was despite the fact that the skull of C. wahkarmoosuch was found beneath the foot of a new species of iguanodon type dinosaur named Hippodraco.

C. wahkarmoosuch was a very small animal, less than 15 centimeters in length and weighing little more than a kilo. Based upon an examination of its eye sockets and large olfactory cavities the animal probably had poor eyesight but a very good sense of smell. The image below shows an artist’s impression of what C. wahkarmoosuch may have looked like.

Artist’s Impression of Cifelliodon wahkarmoosuch trying to scare off a dinosaur(Credit: Utah Geological Survey)

With every new discovery we are filling in the details of the tree of life and finding it to be far more complex and detailed than we had ever imagined.

 

 

Giant Carnivorous Worms are Invading France. No, that’s not the Plot of the Latest Disaster Movie.

Before you get too frightened the ‘Giant’ worms invading France are less than half a meter in length and while they are meat-eaters they mostly eat other, more familiar worms. However that doesn’t mean that they aren’t a big problem.

What we’re talking about are Hammerhead Flatworms, see images below. Creatures that are native to Asia but that have been unintentionally been brought to Europe and have now become established in southern France. This news raises two important issues, how human activity has enabled invasive species to harm environments around the world and, what do we actually mean when we talk about worms?

Diversibipalium multilineatum (Credit: Live Science)
Bipalium kewense eating an Earthworm (Credit: Live Science)

I’ll consider the second issue first. We humans tend to call any small creature that is long and narrow with no noticeable appendages, legs or head or etc., a worm. Now the typical earthworm that we can dig up in our backyard and use as bait when we go fishing is a species, in fact an entire class of species within the phylum Annelid, the segmented worms, see image below.

Common Earthworm, Lumbricus terrestris, Segmented Worm (Credit: Mira.com)

While Annelid worms may look simple on the outside they are really rather complex creatures with a full range of internal organs including both a circulatory and respiratory system. Indeed the internal structure of the segmented worms is so similar to that of the Arthropods, insects and crustaceans etc., that the two phyla are considered to be evolutionary cousins.

On the other hand the animals invading France are Flatworms, members of the phylum Platyhelminthes which are far simpler creatures having no internal body cavity at all. Without either a circulatory or respiratory system flatworms have to be flat because every cell in their body has to be near its skin surface in order to get its oxygen from the outside world.

So from now on we should all bear in mind that ‘worm’ can really mean a lot of very different animals, segmented worms, flatworms and oh, there is an entire phylum of roundworms as well.

So now let’s consider the problem of species of animals that ‘ride along’ with human beings as we travel around the world. These creatures often establish themselves in new environments were they have no natural predators to keep them in check so they breed out of control and end up destroying many native species. Examples of this phenomenon are so numerous I’ll only mention a few.

Before humans came, the island of Guam had no snakes so many of the species of birds there evolved to nest on the ground. Once Humans brought some snakes as pets a few got loose and within just a couple of decades all those birds were extinct, which actually hurt the snakes themselves as they had destroyed their own food source.

Right now the Asian carp is an invasive species spreading throughout the Mississippi river region and that are now threatening to get into the Great Lakes. The carp simply crowd out more valuable, well to us more valuable, native fish species destroying both recreational and industrial fishing wherever they spread. Also the carp have the habit of jumping out of the water whenever they are startled which has actually caused injuries to a few people. The image below shows how violent this habit can be.

Asian Carp (Credit: NPR)

The surprising thing about the Hammerhead Flatworms in France is that gardeners in southern France have been telling the ‘smart’ professional biologists about the flatworms for a couple of decades but the professionals weren’t really listening. Yes, the scientists admitted, some of these animals could hitch a ride on shipments of vegetables and fruit from south Asia but they couldn’t survive in France’s colder climate. This is one actual case where the professional scientists should have paid more attention to the ordinary, average person.

And the Hammerhead Flatworms are more than a slight embarrassment, they do real damage. You see the native segmented worms are responsible for a lot of the aeration and mixing of the soil we use for agriculture. Studies have shown that fields without earthworms are as much as 10% less productive.

Since the Hammerhead Flatworms can quickly decimate the earthworm population in an area we could be dealing with a very big problem. Any program to eradicate the flatworms would be very expensive and would probably still have little effect. Scientists are at least now determined to keep a closer watch on these creatures to see how quickly and how far they spread along with getting a better idea of the damage they do.

We like to think that we rule this world and take advantage of other creature for our purposes but the Hammerhead Flatworms are just one more example of how other species can sometimes take advantage of us for their purposes.

 

TV Movie Review: Fahrenheit 451.

Fahrenheit 451 (Credit: Ballantine Books)

Fahrenheit 451 is the temperature at which books burn and of course it is also the title of the classic novel by Ray Bradbury about a future society where books are burned as a way to keep the populace happy, and dumb, and controlled. Now HBO productions has released an new, updated version of Bradbury’s tale for our divided and angry age.

For the most part the HBO version sticks to the original. Guy Montag is a fireman who doesn’t put out fires, he starts them in order to burn books but in keeping with our modern age he also burns VHS tapes, DVDs and even computers with literature on them. Legally allowed entertainment in this age consists of lame, interactive videos and games, a lot like what we do have.

One mistake HBO makes right from the start is eliminating Montag’s wife who Bradbury used to good purpose in illustrating the vapid, lifeless. anti-intellectual life in the society of Fahrenheit 451. Indeed the only characters we meet in the new version are either book burning firemen or book reading criminals. We never get any feel for the vast majority of the people in this society.

The HBO version also tries to make itself more exciting by adding a healthy dose of violence. Right at the beginning we see a boxing match between Montag and his fire chief, a couple minutes of action that has nothing to do with the plot. Cutting out a few scenes of firemen hitting book readers could have freed up some time to show how censorship is used to control people.

Montag, with flame thrower, and his Chief (Credit: HBO)

Going by the sets and visuals either the producer or director, probably both, are big fans of Blade Runner because there are a lot of shots of tall skyscrapers with videos being shown on their sides. Also everything is very poorly lighted and has a high-tech but still grimy feel to it.

A couple of the most memorable scenes from the novel are shown pretty much as Bradbury wrote them. Probably the best known scene is when the fireman burst into a house with huge library of books, maybe even more than in my house. After the firemen have doused all of the books with kerosene the little old lady whose books they are refuses to leave. Instead she sets the books, and herself alight with a match.

Ready to Burn (Credit: HBO)

Scenes like that are powerful, they are the reason why Fahrenheit 451 is still such a good read after 65 years. However instead of just sticking to their source material the script writers decided to ‘improve’ Fahrenheit 451 by adding Omnis. What’s Omnis you ask? Well I don’t like to give away too much so let’s just say that Omnis has something to do with the recent discovery that you can store data, even a book, on DNA.

With the addition of Omnis the writers are then able to drop Bradbury’s quiet, yet very profound ending and replace it with five minutes of pyrotechnics. It’s an ending that disappoints at best.

While HBO’s version of Fahrenheit 451 isn’t great, it isn’t bad either. The cast and crew obviously realize that Bradbury had something important to say not just for the McCarthy era when he wrote the novel, but something that applies to today’s world as well.

 

 

Astronomers declare Asteroid near Jupiter to be an Interstellar Immigrant.

It was only last October that astronomers discovered the first known interstellar visitor to our Solar System. (See my post of  4Nov17) The asteroid, which was discovered by the Panoramic Survey Telescope and Rapid Response System or Pan-STARRS telescope in Hawaii, was moving much too fast for the Sun’s gravity to keep it in a permanent orbit so it must have come from interstellar space and only spent a short period of time going around our Sun.

Astronomers named the asteroid Oumuamua, Hawaiian for scout, and we learned quite a lot about it in the few months Oumuamua was close enough to study. Astronomers found the composition of Oumuamua was like that of an iron-nickel meteorite than a dirty snowball like a comet. They also discovered that Oumuamua possessed a very unusual cigar shape being at least ten times longer than it was wide. The image below is an artist’s impression of Oumuamua.

The Interstellar Visitor Oumuamua (Credit: Space.com)

Now the astronomers at Pan-STARRS have discovered another asteroid that, while it is a permanent member of our Solar System, its orbit is so strange that it may not be an original member. Orbital simulations suggest that it could be an interstellar immigrant.

The new find hasn’t been given a name yet so I’ll be using its astronomical designation, which is 2015 BZ509. Now 2015 BZ509 orbits the Sun with a semi-major axis (Average distance) only slightly less than that of Jupiter. The most unusual thing about its orbit however is that 2015 BZ509 orbits in the opposite direction of nearly every other object in the Solar System. It has what is called retrograde motion. The image below shows a telescopic view of 2015 BZ509, it’s in the yellow circle.

Two pictures of the Asteroid 2015 BZ509, in yellow circle (Credit: Los Angeles Times)

To understand what retrograde means let’s imagine ourselves looking down on the Solar System from the Sun’s north pole (which happens to correspond to Earth’s north pole). Looking at the image below of the inner Solar System ( the whole thing is too big to really illustrate my point), the orbits of the planets, the spin of the Sun and the spins of all of the planets, even the motions of the major moons all go counterclockwise. The reason for this is simple; the original gas and dust cloud that formed our Solar System must have had a counterclockwise spin and so the Sun, the planets and all of the moons shared that counterclockwise motion.

The Inner Solar System (Credit: University of Rochester)

Objects that orbit in a clockwise motion are very rare, but not completely unknown. There is an entire class of objects known as Centaurs who orbit the Sun between the orbits of the gas giant planets (Jupiter, Saturn, Uranus and Neptune). This small number of asteroids are of great interest to astronomers simply because of their unusual orbits and astronomers have done an enormous amount of computer modeling trying to understand how those asteroids got those orbits. What they found was that the powerful gravity of the gas giants could capture an object out of the Ort cloud and an object so captured could on occasion wind up going the wrong way. Astronomers also found that such orbits are unstable, lasting less than 100 million years. The image below shows a few of the crazy orbits of the Centaur asteroids.

Centaur asteroid Orbits (Credit: Nick Fiorenza, Lunar Planner.com)

2015 BZ509 isn’t a Centaur however, it’s not between two gas giants its in an orbit very similar to Jupiter’s only backward. And when researchers F. Namouni of the Universite Cote d’Azur in Nice France and M. H. M. Morais of the Universidade Estadual Paulista in Sao Paulo Brazil carried out one million simulations of the orbit of 2015 BZ509 they found that its orbit was stable going back to the very beginning of our Solar System four and a half billion years ago.

So if 2015 BZ509 has been sitting around Jupiter pretty much since the formation of Jupiter and the other planets how did it get its backwards orbit. Doctors Namouni and Morais theorize that, back when the Solar System was very young and we were a part of a star cluster like the Pleiades or the Orion nebula 2015 BZ509 could have been grabbed from another star system that was also in the process of formation.

Personally I think that claiming that 2015 BZ509 is interstellar in origin just because it has a very unusual, but nevertheless stable orbit is a bit of a stretch. I want to see some more evidence, and I expect I’ll get my wish as astronomers continue to study this fascinating object.

P.S. Orbital dynamics isn’t my forte but I do know how to calculate the difference between the specific energy of an object (that’s the energy per kilogram of mass) between being free of the Sun’s gravity and being captured at Jupiter’s orbit. I calculate that 2015 BZ509 would have to have somehow lost 85 million Joules of energy for every kilogram of its mass if it is an interstellar immigrant. That’s lot so you can see why I’m more than a little doubtful!

 

Movie Review: Avengers, Infinity War.

 

Poster: Avengers Infinity War (Marvel / Disney)

How many superheroes can you cram into a single movie before it becomes an unwieldy mess? That was my fear before I went to see the new Avengers movie from Marvel / Disney Productions.

I’m happy to report that my worries were groundless. Even with by my count twenty-one superheroes, Avengers Infinity War is both a very exciting and actually very well constructed story. Not only did the writers and production crew manage to give all the big named stars at least a few scenes where they get to say some important lines. They also succeeded in keeping the story flowing along without making it look like they were giving all the big named stars etc. etc.

Part of the secret is just following the old formula KISS (Keep It Simple Stupid). The plot is really simple. The bad guy Thanos is on a mission to acquire (i.e. steal) the six Infinity Stones that will give him infinite power. Can’t get much simpler than that.

Thanos The Bad Gut (Credit: Marvel / Disney)

Another trick is to break your twenty-one superheroes into separate groups. Thor meets up with The Guardians of the Galaxy, the God of Thunder and Rocket the raccoon actually work really well together. Then Iron Man, Doctor Strange and Spiderman are on a spaceship toward the Bad Guy’s home planet while Captain America is back on Earth getting everybody else organized for the big battle at the end. It’s important that the writer’s keep the scenes moving back and forth seamlessly between these groups but if they can do so it can actually keep the audience from getting confused, or bored.

Thor with Rocket and Groot (Credit: Marvel / Disney)
Iron Man with Spiderman and Doctor Strange (Credit: Marvel Disney)
Captain America Takes Command (Credit: Marvel / Disney)

One thing you can’t make simple is the characterizations and that’s one of the advantages of a series of movies like the Marvel Universe. With one exception all of these actors have already played their character several times and hence knows how to play the character and how the public expects their character to behave.

The one exception is the bad guy Thanos; he may have made a couple of brief appearances in earlier Marvel Movies but this is the first time he’s a major character so it’s important that Thanos doesn’t become just a cardboard villain. Once again the writers have done their job by making Thanos crazy, psychopathic and absolutely certain that he’s the good guy!

Now I’m not going to give away too much of what happens in Avengers Infinity War but I will say that the ending was quite unexpected. I will give away one little secret however. Marvel movies often have a short scene either during or at the very end of the credits. This scene gives a clue to what’s to what’s going to happen in a future movie. Well in Avengers Infinity War you have to wait until the very end of the credits if you want to see it!

Avengers Infinity War was undoubtedly a difficult movie to make, there really is just a lot going on. However, it is definitely a success both as a story and as a spectacle. If the writer’s, producers and production teams at Marvel / Disney keep up the quality it seems to me as if the Marvel Universe will be turning out the blockbusters for quite a few more years to come.

 

The Coriolis “Force”, it’s what makes Hurricanes, Tornadoes and the water in your Toilet spin.

Did you ever take a ride on a Merry-Go-Round with a friend and while the ride was spinning you tried to toss something, let’s say a piece of candy to them? Well I bet the candy took off in a sharp turn and you missed by a mile! You’re left with a surprised look on your face as the candy flies off as if it had a mind of its own!

Think about it, because of the motion of the Merry-Go-Round both you and your friend are moving in a circle! That means that by the time the candy gets to where your friend was when you threw it, they’re not there anymore! And because of the circular motion of the Carousel your candy appears to you to take a sharp turn in the opposite direction of the spin of the Merry-Go-Round! Click on the link below to be taken to a youtube video of a very nice demonstration of what I’m describing from a freshman physics course at MIT.

This effect is commonly known as the Coriolis “Force” although any physicist will point out that there’s really no force acting on the candy. Technically what’s happening is that you are in a rotating frame of reference, the Carousel, but once you let go of the candy it no longer is. This makes the candy’s straight line motion look to you as if it’s curved. That’s right the candy is moving in a straight line, you’re on the Merry-Go-Round, you’re the one going in a circle!

Now we all live our lives on a great big Merry-Go-Round, better known as the spinning globe of the Earth, so the coriolis effect has a major influence on many of the phenomena we see every day. (That’s right you flat Earth loonies, the Earth is a spinning globe and the phenomena I’m about to talk about are demonstrations of that fact!!!). Since the Earth’s equator is 40,000 km in circumference and the planet rotates once every 24 hours that means that a person standing on the equator is actually moving at 1666.6 kilometers per hour (40,000km / 24 hours=1666.6 kph). On the other hand someone standing at the north or south pole isn’t moving at all (relative to the center of the Earth at least) but simply turning around once every 24 hours. In between you can calculate your speed if you know your latitude using the formula:

v=1666.6 x sin(Latitude)

For example I live in Philadelphia at a latitude of 40º N so I’m moving at a speed of 1071 kph. The image below illustrates this.

Your speed due to the Earth’s spin depends on your latitude.

This difference in velocities has a major effect on our weather and to see how let’s look at how a LOW pressure system behaves. Now I hope you remember that a low pressure system is also a storm system because it pulls in and condenses moisture laden air leading to rain and strong winds.

Looking at the image below we see that a super strong Low Pressure system is sitting right over me in Philadelphia. This low is so strong it’s pulling in air all the way from the equator and the north pole. Now as I said above Philadelphia is moving at 1071 kph and so is the air above it. The air at the equator is moving much faster however, 1666 kph so when it get pulled toward the low it misses, going in front of the low, to the east. The air at the pole however is moving much slower so it misses the low to the rear, the west. The result is a counter-clockwise flow of air around the low pressure system giving hurricanes and tornados their familiar spiral shape, see image of a hurricane below. That is why you often hear your local meteorologist, in the northern hemisphere, talk about storms having a counterclockwise motion while a fair weather system has a clockwise spin.

Hurricane Irma Spinning Counter-Clockwise (Credit: National Geographic)

The mirror image of this happens in the southern hemisphere. The air from the equator still misses to the front of the low and the air from the pole misses to the rear but because the equator and pole have flipped positions, see image below, the low now has a clockwise flow. The very movements of the weather systems on Earth are due to our planet being a spinning globe.

Before I go I’ll mention one more example of the coriolis effect that you probably see several times a day, whenever you flush your toilet in fact. Think about it, isn’t all that water flowing out causing a low pressure system, and doesn’t the water spin counter-clockwise north of the equator and clockwise south of it. That’s the coriolis effect right inside your own home.

And you don’t have to be very far north or south of the equator to see the spinning. Click on the link below to be taken to a youtube video shot at the equator in Uganda. The presenter demonstrates the coriolis effect just a few feet north of, right on and a few feet south of the equator.

https://www.youtube.com/watch?v=_xqtXBnuXiA

So remember, the next time some you arguing with a flat Earth idiot just flush the toilet and tell them the spinning globe of the Earth is causing the spin in the water. Then you can flush their nonsense down the toilet as well.

 

 

The SuperCDMS Experiment and the Search for Dark Matter.

It was back in my undergraduate days (early 1980s) that the topic of Dark Matter first began to be seriously considered by astro-physicists and cosmologists. The idea that there was some kind of matter in the Universe that was for some reason invisible to our telescopes was considered as a solution to two of the biggest problems in our study of the Universe.

The first problem concerned the stability of all of the rotating spiral galaxies we were studying. The idea that the stars in the outer reaches of a galaxy, like our own sun, would orbit around the center of the galaxy made perfect sense. After all, it was just Newton’s laws of gravity at work we thought. However, when we estimated the mass a galaxy, basically counting the numbers of stars, and measured the speed at which the stars were orbiting we found that there wasn’t enough mass, the galaxies should fly apart! There had to be some mass that we weren’t seeing, some invisible matter whose gravitational attraction was holding galaxies together. See image below.

Spiral Galaxy Rotation (Credit: Giphy)

At the same time other astronomers were studying the Cosmic Microwave Background (CMB), the leftover radiation from the original big bang, and used that data to calculate how the Universe should look today. Problem was that the calculations didn’t match the reality, not based on the amount of mass we could see. In order to make the calculations work the Universe had to have about four times as much invisible matter as the matter we could see.

O’k so the Universe had a lot of matter that didn’t emit light the way normal matter did in the stars, some sort of Dark Matter. The search was on to discover just what this Dark Matter was. The astro-physicists, with some help from the high-energy physicists, came up with a lot of ideas: Cold Dark Matter, Hot Dark Matter, MACHOS (Mass Concentrations) and WIMPs (Weakly Interacting Massive Particles).

That was almost forty years ago now, and we’re still waiting for direct experimental evidence of any kind of dark matter. Oh, we’ve made some progress, everybody pretty much agrees on WIMPs as Dark matter but that doesn’t mean everybody’s right. We need good hard evidence.

Hopefully soon we’ll get some from the Super Cryogenic Dark Matter Search now under construction by the Stanford Linear Accelerator Center (SLAC) at Stanford University and which will be set up over 2000 meters underground at SNOLAB at the Vale Inco Mine in Sudbury, Canada.

Setting up sophisticated, delicate physics experiments deep down in an old mine because all of the rock above the instruments helps insulate them from the interference of cosmic ray particles. And the SuperCDMS needs to eliminate all of the interference it can, it’s trying to measure the tiny amount of energy produced when a WIMP bounces against a normal atom. The image below shows the Sudbury neutrino telescope already in operation at Sudbury.

Neutrino Telescope in Sudbury Mine (Credit: Pinterest)

Physicists calculate that such collisions are very rare, you may have to wait many trillions of trillions of years for a particular atom to experience such a collision. Rather than waiting so long physicists will use trillion of trillions of atoms and then ‘listen’, that’s right listen for the sound of any collisions. Technically the intent is to detect the minute phonon signals of the collisions with germanium crystal detectors. The image below shows one of SuperCDMS’s detectors.

SuperCDMS Detector (Credit: SuperCDMS)

But in order to ‘hear’ the sound of a WIMP hitting an atom the physicists have to eliminate as much as possible the racket caused by all of the atoms hitting each other caused by thermal vibrations and the only way to do that is to reduce the detector’s temperature down to a small fraction of a degree above absolute zero, hence Super Cryogenic Dark Matter Search.

The experimental setup is shown in the image below. The cyrostat and detector section is modular in design allowing more detectors to be installed in the future. Around the detectors is a lining of lead (Pb) shielding with water shielding around that. The entire apparatus is then mounted on seismic isolators because even the slightest outside movement could be picked up as an erroneous signal. It’s often true that in today’s physics experiments, eliminating the unwanted signals can be a bigger job than detecting the minuscule signal you’re looking for!

SuperCDMS Experimental Layout (Credit: SuperCDMS)

SuperCDMS is scheduled to be up and running by the year 2020 but it will take four or five years of data collection before any results can be announced but I’ll let you in on my opinion. Now I’ll be very happy to be proven wrong but I’ve always been skeptical of WIMPs, we’ve been looking for them for forty years and have no evidence so far. Personally I was a MACHO supporter, basically the idea here was that for every star we can see there would be dozens of smaller brown dwarfs, objects just too small to start nuclear fusion and so don’t glow, and on top of that there would be literally thousands of planetary sized objects in interstellar space. I still think we need to consider MACHOS as a possible solution to the Dark Matter problem.

Fossil Reveals First Steps in the Evolution of the Beaks of Birds.

In today’s world the taxonomic group we call birds have two unique anatomic characteristics that no other animals possess, feathers and beaks. Trying to understand how these distinct features evolved has been a goal of paleontologists since Darwin’s days.

Considerable progress has been made in the study of feathers with the discovery not only of early birds with feathers like Archaeopteryx but also of new evidence that some species of dinosaurs sported primitive feathers for insulation. The images below show archaeopteryx and a feathered T-rex (yes some paleontologists think the mighty T-rex might have been partially covered by feathers).

Archaeopteryx: Feathers and Teeth! (Credit: Independent)
T-rex with Feathers? (Credit: American Museum of Natural History)

Evidence for the evolution of the bird’s beak however is much sparser; and the development of the beak is mostly unknown. Beaks by the way are composed of bony upper and lower mandibles (jaws) that are covered by a thin later of keratin (the protein in your hair and fingernails) and which lack teeth composed of dentine. Although similar in some ways to the mouths of other vertebrates the avian beak is a structure unique to birds.

The big problem in studying the development of the beak is that usually the delicate bones making up the skull of an early bird are so squashed that little can be learned from them. One thing we were certain of however was that feathers came first; there are many fossil specimens, again like Archaeopteryx, of early birds covered with feathers but sporting a mouthful of teeth.

Now a new study, combining both recent fossil finds and a reexamination of older specimens with the latest instruments, is changing that. It started in 2014 when Kristopher Super, then an undergraduate student at Fort Hays State University in Kansas, found an almost complete fossil of the well know early bird Ichthyornis dispar encased in limestone. A transitional species between the dinosaurs and birds I. dispar was a seagull sized creature that lived between 66 and 100 million years ago.

When the find was shown to Yale Professor of Paleontology Bhart-Anjan Bhullar he suggested that instead of trying to remove the specimen from the limestone it should be scanned by computerized tomography (CT scanning). What they found led them to perform CT scans on three other fossils for conformation. There, right at the very end of a long bony jaw filled with very sharp teeth sat a tip covered in keratin, a beak. Professor Bhullar suggests that even a tiny tip of a beak may have given I. dispar a greater ability to manipulate its food and preen its feathers. Exactly the behavioral activities that modern birds use their beaks for. The image below shows a composite of the CT scans of I. dispar.

Ichthyornis CT Scan (Keratin Beak is at tip) (Credit: Science Magazine)

The scientists also found that the skull of I. dispar shared a mixture of dinosaur and bird like features, a large brain case like that of a bird along with the powerful jaw muscles of a velociraptor like dinosaur. The evidence provided by I. dispar pushes back by millions of years the development of the bird’s beak while at the same time indicating that birds may have existed for millions of years with both a partial beak and a mouthful of teeth. The image below shows an artists rendering of the head of Ichthyornis dispar.

Ichthyornis Head (Artist’s Rendering) (Credit: Science Magazine)

The first fossils of Ichthyornis were discovered in the 1870s by the US paleontologist Othniel C. Marsh, famous for his ‘Dinosaur Wars’ with Edward D. Cope. Even after almost 150 years we’re still leaning more about these amazing dino-birds.

Space News for May2018.

Several stories of interest have been happening in space exploration over the past month so let’s get to it!

Once again Space X is rewriting the rules on how to get into orbit cheaply and efficiently. Elon Musk’s Falcon 9 rocket has now been successfully launched more than fifty times with Space X recovering more than twenty of the first stages. For the last two years the Falcon 9 has flown more often than any other rocket making Space X the leader in the drive to commercialize space travel.

The latest Falcon 9 rockets have been considerably improved and updated from the first vehicle that was launched in 2010. Lighter, more powerful engines combined with larger fuel tanks have nearly doubled the Falcon 9’s payload to orbit.

Now Space X is rolling out a new version of the Falcon 9, referred to as Block 5 by Space X. The Block 5  version has been optimized for recovery and reuse. The intention is to reuse the Falcon 9 first stages at least ten times each in order to maximize the cost savings. The first launch of the new, improved Falcon 9 is scheduled for next week but since this is a new design there may be delays as Space X wants to be certain that everything is a go for launch. The image below shows the new, optimized Falcon 9 Block 5.

Falcon 9 Block 5 Rollout (Credit: Space X)

Perhaps the success of Space X is making their competitors a little nervous because just this past week Boeing saw fit to publicly remind everyone that their Space Launch System (SLS), which hasn’t flown yet, is bigger than Space X’s Falcon heavy, which has. I think that ‘my rocket is gonna be bigger than your rocket’ doesn’t quite match the success Space X has had recently. The image below shows what the SLS will look like when it is finally tested, hopefully next year.

Illustration of the Space Launch System (Credit: NASA)

My second story is actually an update of a story I blogged about back on 27Jan2018. In that post I described the small nuclear power plant that was developed by NASA’s Glenn Research Center in Cleveland Ohio. Called the Kilopower Reactor Using Stirling Technology (KRUSTY) the prototype has been undergoing testing to the Department of Energy’s Nevada National Security Site. The image below shows the prototype KRUSTY.

NASA’s kilowatt Nuclear Reactor KRUSTY (Credit: Youtube)

The first two tests to be carried out were simple environment checkouts without the reactor being powered up in any way. During the third test the reactor’s core was slowly powered up in order to heat the core. The final test consisted of a full power test of 28-hour duration intended to simulate an actual mission.

The prototype KRUSTY reactor is designed to output one kilowatt of electrical power but the concept is intended to be scalable up to ten kilowatts. NASA scientists are of the opinion that four such ten-kilowatt units would be sufficient to power a manned outpost on either the Moon or Mars. The image below shows what a KRUSTY unit could look like deployed on the Moon.

KRUSTY on the Moon (Credit: Popular Mechanics)

Over the last forty years NASA has initiated several programs for the design and testing of a small nuclear reactor for use in outer space. However all of those programs were canceled before testing had even begun primarily because of public aversion to nuclear power. Hopefully the day will soon come where KRUSTY is providing the electrical needs of NASA astronauts on another world.

 

My final story concerns a brand new NASA program for an initial design of the space telescope of the future. What scientists at Cornell are proposing is a modular concept of a telescope that will build itself piece by piece in orbit until it is about thirty meters across. The image below shows both a single module and a partially assembled telescope.

Modular Active Self Assembling Space Telescope design concept (Credit: NASA, Cornell University)

Professor of mechanical engineering Dmitry Savransky leads a team of fifteen scientists and engineers who have been awarded a Phase I NASA Innovative Advanced Concept grant of $125,000 for an initial feasibility study.

The basic idea is for the Telescope to be constructed from one thousand or more identical pieces that can be placed into orbit one at a time. Since the larger a telescope is the more light it can gather to study we want to put the largest possible into orbit but also the larger a telescope is the more difficult it is to get into space.

This certainly makes the idea of putting the telescope into orbit in pieces and assembling them there is a logical way to go. However the final configuration of the optics of any telescope has to be so precise that the concept of a prefabricated space telescope may simply be unworkable. Only time and study will tell if a modular space telescope is the way to go or not. This is a Phase I study after all.