Friday, October 5, 2012

Borderline Personality Disorder

Borderline Personality Disorder (BPD) is a condition by roughly 1 to 3% of the population and affects women three times more often as men.  But what is BPD and how can it be treated?  To find out more, follow the link to my latest article on the very subject over at Mad Mikes America.
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Wednesday, July 4, 2012

CERN's Announcement

As many of you are no doubt aware, earlier today CERN made an announcment about the discovery of a new Boson that fits the bill for the Higgs Boson.  While it has yet to be confirmed with complete certainty that it is the Higgs, it is in the right energy range as has been expected for the Higgs and is being called a "Higgs-like Boson".

For further information, follow the link to my latest post over at Mike's Mad America.
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Tuesday, June 26, 2012

Europa, The Frozen Ocean

The Moon Europa as seen by the Galileo probe, via NASA.
Between 1609 and 1610, using his improved telescope design, Galileo Galilei observed four bodies orbiting Jupiter.  These bodies, later named the Galilean Moons, are the largest satellites of the Jovian System (Jupiter and its moons).  The second of these moons and the smallest of the first four observed, Europa has become one of the focal points for the search for life outside of Earth.

Despite most sources giving credit to Galileo for its discovery, Europa and the other three Galilean Moons were also likely discovered at the same time by Simon Marius.  Originally Galileo named the moons the Medician Stars, partly out of his initial uncertainty of their nature and as a way of faltering his future patrons.  Marius, however, named the moons according to the suggestion of fellow astronomer Johannes Kepler, invoking the names of the mistresses of Zeus (who was later renamed Jupiter according to Roman mythology), a tradition that has been used in the naming of all of Jupiter's moons since.

Europa was named after a Cretan moon goddess who was absorbed into Greek mythology as a Phoenician Princess who was abducted and raped by Zeus as he took the form as Bull.  Sought out by Zeus for her beauty, the Jovian moon of Europa follows in the steps of its namesake.

The first human probe to observe Europa was Pioneer 10 in 1973 and was followed the next year by Pioneer 11.  The first images of this sixth moon of Jupiter were grainy and lacked any distinguishing detail.  It wasn't until 1979 when the first Voyager probe passed by that images detailed enough to discern surface features were available.  It was with these first images that scientific curiosity and debate surrounding Europa bloomed.

While studying images obtained from both Voyager 1 and 2, certain anomalous features were noticed.  The most striking were striations that seemed to cover the moon.  Named Lineae, these features reached widths of 20 kms (12 mi) across and hundreds to thousands of kilometers in length. 

Europa with its prominent Lineae, via NASA.
To confound things further, the surface of Europa was surprisingly smooth.  Few craters were observed which suggests that the surface is constantly being remade.  In the cosmic shooting gallery that is the solar system, craters are a common feature.  The older the visible surface, the more craters that will be observed as only changes in surface features will wipe away craters that form.  A quick look at Mercury or our own moon Luna and you will see how a geologically inactive body collects craters.  Europa, on the other hand, has very few craters and those few that do exist are visibly 'young'.  Combined with Europa having a very high reflectivity, or albedo, at 0.64, the surface of the moon can be estimated to be between 20 and 180 million years.  In comparison, regions of the Martian surface have been dated to around 3.3 billion years.

These and other unexpected features seen by future missions such as the the Galileo mission to the Jovian system and the New Horizon probe as it passed by Europa on its way to visit Pluto suggested that the source of the strange features was ice, water ice.  But these surface structures suggests something more then just a cold frozen moon.  The renewing of the surface and the formation of the long Lineae lent credence to the hypothesis that there was liquid water hidden beneath the icy surface.  Not just a little water, but a vast, possibly global ocean.

But with an average surface temperature of 110 K (−160 °C; −260 °F) at the equator, how could there be a subsurface ocean of liquid water?  The answer seems to come from the same process that causes the tides here on Earth.  As Europa and the other Jovian moons orbit Jupiter, they are pulled on gravitationally at different rates at different times.  Similar to the processes that cause the nigh constant volcanism on the innermost of the Galilean Moons of Io, Jupiter's gravity causes tidal forces that heat up the plant.  This could, potentially, cause volcanism akin to the deep ocean hydrothermal vents on Earth.

The 'Ice Rafts' of the Conamara Chaos, via Wikipedia Commons.
With such internal heating, a warm, liquid water ocean is likely to exist.  This isn't a fringe idea either, it has become the leading hypothesis to explain the observable features of Europa.  The liquid ocean has been calculated to have an average depth of 100 km (over 62 miles) with depths up to 170 km (over 105 miles).  This liquid ocean would exist below a cold, hard cap of ice reaching 10 -30 km (6 - 19 miles) slowly becoming a more ductile warm ice before eventually becoming the liquid water below.  This warm ice would be capable of moving up into any cracks that form in the hard surface ice, creating the Linaea.  Still further evidence from the chaoses suggest that there may even be liquid water 'lakes' trapped in the ice.

The amount of water that can be found on Europa is staggering.  If one takes the average depth of 100 km, there is a volume of 3 × 1018 miles cubed of liquid water.  This is over two times the amount of water that can be found here on Earth.

Europa next to Earth, along with the comparable spheres of water contained by each, via NASA.
In the search for life elsewhere in our solar system, Mars tends to steal the show in the popular media.  With its relatively close proximity, potential for human colonization, and its history of once possessing large quantities of liquid water on the surface, it is understandable.  Liquid water seems to be the key for life as we know it.  Everywhere on Earth that it is found, life can be observed as well.  This being considered, Europa seems to be one of the best sites for the future search for life and the astronomical community knows this.  While there have been many probes proposed to visit Europa, most have fallen through until JUICE.

JUICE is the somewhat tortured acronym for the planned European Space Agency (ESA) probe known as the JUpiter ICy moon Explorer.  Planned for a 2022 launch, JUICE would reach the Jovian system in 2030 where it will serve out at least a three year mission to visit Europa and two other of the Galilean moons, Callisto and Ganymede.  Like Europa, Callisto and Ganymede also appear to have liquid water as well as the observed water ice.  While all have the potential for harboring conditions that could be conducive to life, Europa is seen as the most likely to contain such an environment due to its larger amounts of water, hotter internal environments and a far more dynamic surface.

Artist rendition of the JUICE probe, via ESA.
As a final boost to the potential for the development of life is the oxygen content of Europa.  Oxygen is, as far as we know, required for the development of complex life and was directly responsible for the explosion of multicellular life here on Earth.  Based on new calculations by Richard Greenberg, there could be enough oxygen to support a biomass of around 3 billion kilograms if such multicellular life had developed on Europa.  Even better, the proliferation of oxygen most likely occurred later in its existence which would be required for the formation of life based on how life progressed here on Earth.

--------------------------------------------
Citations:
Complete Dictionary of Scientific Biography. New York: Charles Scribner's Sons, 2007. ISBN 0-684-31559-9.

Geissler, Paul E.; Greenberg, Richard; et al. (1998). "Evolution of Lineaments on Europa: Clues from Galileo Multispectral Imaging Observations".

McFadden, Lucy-Ann; Weissman, Paul; and Johnson, Torrence (2007). The Encyclopedia of the Solar System. Elsevier. pp. 432. ISBN 0-12-226805-9.

Schmidt BE, Blankenship DD, Patterson GW, & Schenk PM. (2011) Active formation of 'chaos terrain' over shallow subsurface water on Europa. Nature, 479(7374), 502-5. PMID: 22089135

Cosmos Magazine. http://www.cosmosmagazine.com/news/3069/jupiter-moon%E2%80%99s-ocean-rich-oxygen.

Hartmann, William K., and Gerhard Neukum. "Cratering Chronology and the Evolution
of Mars." Space Science Reviews 96 (2001): 165-194.
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Friday, June 15, 2012

The Kakapo

Evolution is a strange thing.  Change the selective pressures on a species a bit and it will take take any path to survival it can, no matter how absurd.  Familiar body plans begin to diverge and change and every so often, these adaptations add up to what can only be called odd.

Approximately 85 million years ago, the microcontinent of Zealandia -the tectonic plate containing New Zealand- split from the super continent East Gondwana.  As it did so, the resident organisms became isolated from their mainland relatives.  One group of birds, the ancestors to the New Zealand Parrots (superfamily Strigopoidea) became trapped on the islands.  While most of the parrot species retained a recognizable, if unique form, one species adapted itself to its new environment in the most unexpected of ways.

Enter Strigops habroptila, more commonly known as the Kakapo.  The Kakapo is what a parrot would look like, if it were to be described by someone who had only the vaguest idea of what one was.  Instead of flying through the trees seeking food in the light of the sun, the Kakapo prefer to run about the underbrush at night using their wings for little more then as a means to fall a bit slower.

When flight is no longer an issue, neither is size.
Meaning Night Parrot in Maori, the Kakapo is a rotund bird that inhabits both the underbrush and trees.  An avid climber, it has not lost its preference for high places despite the lack of any native land predators that could threaten the bird.  The only native predators are diurnal (active during the day) birds of prey which have helped push the species towards its flightless and nocturnal nature to escape the threat.

While flightless birds tend to be relatively uncommon, the Kakapo is even more so as no other known species of parrot, living or extinct, has lost the ability to fly.  Since weight is of little concern for the Kakapo any longer, it has been able to grow into the heaviest of all parrots, weighing up to 8 lbs (3.5 kg).  Instead of flight, they will use their strong legs to 'jog' about.  While not exceedingly fast, they are able to cover a few kilometers a night if need be, as can be seen both when females leave their nest in search of food and during the mating season.

Generally solitary, the Kakapo only gathers for breeding purposes.  The mating rituals of the Kakapo also set it aside as it is the only flightless bird to have what is known as a lek mating system.  A lek is a gathering of indiviudals in an area for breeding purposes.  When available food is abundant, the males will leave their territories to gather around hilltops and ridges specifically for breeding.   Here they will compete with other males to attract females.  Each male attempts to control their own patch of ground that is typically seperated by around 160 ft (50 m) from any other male.  While direct confrontation does occur between males, females tend to pick mates based on the loudness of the males calls.  During mating seasons, the males will let out a series of loud 'booms' that can be heard for miles.  The males call out on average 1,000 times an hour for 6 to 7 hours each night.  After finding a mate, the female will leave the lek and retains no connection to the male.

Kakapo chicks, courtesy TerraNature.org.

While the Kakapo was once revered by the Maori and even kept as pets due to their calm and curious nature, the species now faces an uncertain future.  As humans began to arrive on New Zealand, they brought with them new species that began to threaten the Kakapo.  Starting with rats brought to the island by the Maori's Polynesian ancestors and continuing to include domestic cats and stoats, the introduction of mammalian predators along with changes to the environment led to a dramatic drop in the Kakapo population. 

Now critically endangered, only 126 individuals survive in both captivity and the wild.  While there have been multiple attempts at reintroduction of Kakapo to various islands with minimal predators, success has been limited.  This is not helped by the fact that Kakapo typically breed only once every 3 to 4 years.  Since the start of programs to save the Kakapo, its plight has gained a certain amount of attention with multiple books and television programs being made about the dying species.  While its future is uncertain, continued research and breeding programs have made it possible for the Kakapo to, at the very least, hold on for a bit longer.  If you wish to aid in the survival of this unusual species, the Kakapo Recovery Program accepts donations to help maintain the future of the Kakapo.
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Wednesday, May 23, 2012

SpaceX's Falcon 9 headed for ISS

The Falcon 9 launching from Cape Canaveral (courtesy SpaceX).

On Tuesday, May 22, at 3:44 a.m. EDT (0744 GMT) SpaceX successfully launched its Falcon 9 rocket from Cape Canaveral, Florida.  This third flight of the independently designed and operated rocket system carries along with it the Dragon capsule for its second flight.  While the first two launches of the Falcon 9 and the previous launch with the Dragon were for test purposes, this flight has a different mission.  It is to be the first commercial resupply of the International Space Station (ISS).

Based out of Hawthorne, California, Space Exploration Technologies Corporation, or SpaceX, won a $278 million contract with NASA to develop their Falcon rocket systems for eventual resupply mission to ISS.  Since the retirement of NASA's Space Shuttle program, the space station has not had a single American spacecraft dock and all resupply missions have been carried out by other ISS member nations.  Currently SpaceX has a contract with NASA that runs until 2015 and includes 12 resupply visits to ISS. 

This launch is actually the second attempt for the Falcon 9 to deliver the Dragon to ISS.  The first attempt, on May 19, was canceled when an on-board computer detected an error with one of the engine's check valves.  After repairs were made to the Merlin 1C engine, the launch was rescheduled for the early morning of May 22, making for the first night launch of the Falcon 9.

The Dragon capsule (PDF) is set to deliver its payload to ISS on May 25.  While the CRS version of the Dragon that was launched is unmanned, other capsules are being built that will be capable of carrying up to nine individuals.  The CRS Dragon is composed of two storage sections.  The main pressurized section which can carry 7,300 lbs (2,210 kg) and a unpressurized section known as the trunk which can carry 7,300 lbs (3,310 kg).  The Dragon was named after the 1963 song by Peter, Paul and Mary "Puff, the Magic Dragon".

Computer Model of the Dragon approaching ISS (courtesy NASA).

The Falcon 9, named after the Millennium Falcon from Star Wars, is a two stage, medium-lift rocket system.  It utilizes nine of SpaceX's Merlin 1C rockets to power the first stage and a tenth Merlin engine that has been modified for use in a vacuum.  The Falcon 9 is capable of carrying 23,00 lbs (10,450 kg) to low Earth orbit and 9,800 lbs (4,450 kg) to a geostationary transfer orbit (this carries payloads through a specific trajectory to safely insert it into a geostationary orbit).

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Wednesday, May 2, 2012

How to make a black hole




Black holes are, well, odd.  They are the place where common sense goes to die.  Physics takes such a beating when it comes to black holes that when it comes to the central point of a black hole, its singularity, physicists are often left smiling and nodding as their equations are chewed up and turned into useless infinities.

But don't let this make you think that we know nothing about these cosmic anomalies.  We have gone from the days of black holes being nothing more than mathematical oddities to one of the most intriguing areas of studies in modern cosmology.

The idea of an object so dense as to have a mass greater than the escape velocity of light was first proposed in 1783 by John Michell, but it wasn't until 1916 that mathematical evidence for such an object was proposed.  Using Einstein's Theory of General Relativity (which was published a year earlier), Karl Schwarzchild was able to show that black holes were, at the very least, mathematically consistent.  But for the longest time, the process that led to stellar mass black holes was a mystery.  It was believed to involve dying stars, but little else was known.

With an increasing array of tools that are constantly becoming more sensitive and precise, physicists have been able to assemble a basic recipe for a stellar mass black hole.  Before I go on, I should clarify what I mean by a stellar mass black hole.  There are multiple kinds of black holes, each sharing the same physics but with a difference of scale.  From the supermassive black holes lurking in the cores if nearly, if not all major galaxies to the hypothetical primordial black holes left over from the big bang, there is more variety than the uninitiated would expect.  The best studied form is the stellar black hole.  These are all made through a similar process in the core of dying stars.

But not any star can form a black hole.  In fact, the theoretical lower limit of a star large enough to produce one of these stellar black holes is around 20 times the mass of our own sun.  Anything smaller just doesn't have the mass required to form a black hole.  They will either cool down into a white dwarf like our sun or form another bizarre stellar remnant such as a neutron star.  However, there are a lot of stars in the universe.  In our galaxy, the Milky Way, there is predicted to be around 100 million stellar black holes.

Now that we have a star of the right size, how does it become a black hole?  The answer lies in the core of a star.  Stars work by fusing matter together using their enormous gravity.  Normally, the nuclei of atoms are kept apart thanks to the electromagnetic force.  But with enough energy, the electromagnetic force can be overcome allowing things such as the strong nuclear force to take over.  When this happens, the atomic nuclei are forced together into a new, more massive nuclei.  Thanks to a little equation known as E=MC2, some of that mass is converted to energy.  This left over energy is what powers a star.

Stars primarily are composed of hydrogen and, as such, fuse more hydrogen into helium than anything else.  Our sun alone fuses 700 million tons of hydrogen into 695 million tons of helium every second.  The remaining 5 million tons is the left over energy that powers our sun and helps to keep us from, you know, dying.  But not all stars fuse at the same rate, it all depends on mass.  A star twice as massive as our sun will fuse hydrogen at ten times the rate of our sun, while a star twenty times will fuse 36,000 times as quickly.  The larger the star, the shorter the life time.

But a star never uses up all its hydrogen.  It is only in its core that the environment is right for nuclear fusion.  As the star's life continues, eventually the available hydrogen in its core begins to dwindle.  Soon helium has to be fused into carbon, carbon into neon, and so on.  The denser material settling at the core with the easy to fuse hydrogen being pushed further out.  Each step takes less time then the last with every element forming a ring around its denser counterpart.  Eventually, if a star is massive enough, it will fuse atomic nuclei all the way up to iron, but this is as far as it can go. 

Unfortunately for such massive stars, iron resists fusion and outside extreme conditions such as supernovae and hypernovae, iron nuclei cannot be fused into heavier elements.  For such massive stars, this is the beginning of the end.  For lighter stars that cannot fuse up to iron, the process is quite similar, the only difference is that the masses required to fuse up to iron are lacking and a lighter element will become the dense core that cools or collapses into one of a variety of stellar remnants.

The iron core, as I mentioned, cannot be fused inside a star.  Stars are kept from collapsing by the energy released through the fusion of its mass.  Since the iron cannot fuse, the star begins to lose its internal support, placing even greater force on the core.  This force, coupled with the cores already massive size, begins to cause the electrons that have been stripped from their atoms due to the extreme temperature and forces to be crammed together when the iron nuclei.  Thanks to the Pauli exclusion principle, these particles cannot inhabit the same locations in time-space and begin to form a counter pressure known as degeneracy pressure.  This pressure helps to keep the star together, but only for a time.

Once this degenerate matter core reaches a mass of at least 1.4 solar masses, it can no longer hold back the massive pressures and the pull of gravity. The core then collapses in an extraordinary way.  In a thousandth of a second this core collapses at speeds of around 45,000 miles a second, shrinking a core thousands of miles across to just a few miles across.  The resulting vacuum causes the remaining shell of the star to collapse, adding further pressure, before rebounding.  The star would continue to collapse, rebound and shrink again if not for the affects of a ghost like particle known as the neutrino.

Neutrinos are very weakly interacting particles.  About 65 billion of these particles are passing through every square centimeter of the Earth every second and nearly all of these particles pass through it as if there was nothing there.  But in the conditions found inside a dying star, the 10 to the 58th power neutrinos released in a ten second burst from the core are enough to shred the outer star leading to a supernova.  It is only here, in the final moments of a dying star, that the core of a massive enough star collapses into a black hole.

First the degenerate core will see such extreme pressure and gravity to force the electrons and protons together into neutrons.  This new material, neutronium, is the component of neutron stars.  If there is enough mass, the core will continue to collapse all the way into a black hole.  The resulting black hole will then begin to feed on the remnants of its parent star with an accretion disk forming around it.  Some of this material may find a stable orbit around the black hole while the rest is heated up through friction to the point of emitting light across the electromagnetic spectrum.

With thanks to Phil Plait, Ph.D. and his book Death From The Skies.
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Wednesday, April 11, 2012

The Mantidflies, family Mantispidea

For those who are afraid of insects, the above image will probably haunt your dreams for years to come.  For the rest who are unfamiliar with this unusual insect, your first reaction may be to stare in disbelief at what, for the sake of your sanity, you hope must be photoshopped.  But it is a very real insect.  Appearing to be what happens when you graft the front end of a Praying Mantid on to the body of a wasp, this bizarre amalgamate of a creature is actually not closely related to either.

The Mantidflies or Mantsipids, family Mantispidae, are a group of insects who are most closely related to the Lacewings and Antlions.  Belonging to order Neuroptera (the net-winged insects), these predatory insects are, despite their potentially disturbing appearance, harmless to humans.  With over 400 species currently recognized and with ranges throughout much of the world, they are a surprisingly common, if poorly known group of insects. 

Nearly all Mantidflies have an appearance closer to a fusion between Lacewings and Mantids, but a couple species have developed a form of mimicry to avoid their own predators.  These, like the above Climaciella brunnea, have an appearance that is close enough to those of wasps to deter most predators.  Their Batesian Mimicry --the process of a harmless species having the appearance of a dangerous one-- has gone so far as to take on the form of whatever the most populous species of paper wasp from the genus Polistes is in their area.  Because of this, their appearance will vary from region to region despite all being members of the same species.

The Green Mantidfly, Zeugomantispa minuta

The larvae of Mantidflies are, like their adult form, strict carnivores.  In some species, the larvae will actively hunt the larvae of other insects, such as beetles and flies, where as others are known to be parasitoids of wasps, bees, and even spiders.  It is the case of the spider parasitoids there is a disturbingly high degree of specialization to be found.

Those species that target spiders can be divided into those with two distinct strategies.  The egg penetrators and the spider boarders.  The egg penetrators, like the above Green Mantidfly, have active larvae that seek out spider egg cases and, upon finding one, chew through the top and climb inside.  They then begin to feed on the developing spiders as they go through their various stages of metamorphosis safe within the spider's egg sac.  Eventually, an adult emerges from the empty cocoon and flies off.

The spider boarders, however, have lost the ability to chew into a spider's egg case and instead waits for a spider to walk by.  While this may seem close to suicidal, the tiny larvae can often climb on to a spider and latch on without difficulty.  The small, flattened larvae attaches itself to the underside of the abdomen where it can patiently wait.  It nourishes itself by feeding on the hemolymph, the blood, of the spider.  If the larvae has found itself on an immature spider, some species are known to simply crawl into the book lungs of the spider where it will be safe from being dislodged when the spider molts.

If the larvae is lucky, it will have found a female, but it will make do with a male as well.  Here, it will simply wait for the male to find a female to mate with and jump ship as the two mate.  Once on the female, it waits for its host to lay its eggs.  As the spider is spinning the silken cocoon around the eggs, the Mantidfly larvae crawls inside undetected.  It then enters its next stage, a grub-like form that has only one goal, feed.  Once it has consumed the contents of the egg cocoon, it will spin its own cocoon and metamorphosize into its adult form.

Such spider parasitoid Mantidflies are far from rare.  They are so common that all major groups of hunting spiders are attacked by these spider boarding larvae.  While web building spiders are safe from this fate, many still end up being the targets of the egg penetrating species.

Such spider boarders are so common that a fossil of one has actually been recently found.  Discovered by Michael Ohl of Berlin's Museum of Natural History, the larvae was found attached to a spider that had been unlucky enough to find itself not only with the parasitoid Mantidfly larvae but also caught in tree sap.  As the sap hardened over time, the two were preserved perfectly in amber.  Dating to around 44 million years ago, the specimen shows that this form of symbiosis has been used in what is essentially its present form for quite some time.  It is possible that this tactic goes back even farther as the earliest Mantidfly fossils date to the early Jurassic, 180 million years ago.

A spider in amber with a Mantidfly larvae still clinging to its host.

Images courtesy of WeedsWorth.com, BugGuide.net and Discover Magazine.
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