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Bok Globules

November 30, 2009 Leave a comment

The birth of a baby is one of the most amazing miracles to behold in the natural world. From conception to birth, the change that a baby endures beginning as a single cell and ending up as a full grown and functioning human being in the short span of forty weeks is unrivaled in nature. Stellar birth, however, is also an extremely amazing event. Although the birth of a star takes an eternity in comparison to the human gestational cycle, it is one of the most amazing processes that occur within the celestial realms. One place where the birth of stars occurs is within dark molecular clouds called Bok Globules.

A pair of Bok Globules

Bok globules are dark, dense clouds of dust and gas found within H II regions, which are low density clouds of gas and plasma that can be as big as several hundred light-years in diameter. These Bok globules typically have a mass that ranges between 0.1 and 2000 solar masses, a unit of astronomical mass measurement that is equal to the mass of the Sun.  They are contained with an area of about a light year or so in diameter. Molecular hydrogen, carbon dioxide, helium, and a small percentage of silicate dust are found within these clouds.

These astronomical phenomena where first observed by astronomer Bart Bok in the 1940s. Bok and his researcher partner E.F. Reilly published a paper in 1947 that stated these clouds were similar to the cocoons of insects. They hypothesized that these clouds were undergoing gravitational collapse to form protostars from which star clusters and star systems were formed. This hypothesis was difficult to verify due to the fact that the clouds obscure all visible light being emitted from within the cloud. However, infrared analysis observations published in 1990 confirmed that stars were being formed within the Bok globules.

Bok globules are the smallest manifestations of dark nebulae, which are interstellar clouds that contain a very high concentration of dust that allows them to scatter and absorb visible light. Bok globules support both the inflow and outflow of material, a process common in the development of protostars. These clouds are known to have a temperature of around 10 Kelvin.

Bok globules are still being intensely researched and their inmost properties are still being analyzed. While there is still much information to be garnered from Bok globules, what is known is that they actually serve as a cocoon protecting infant protostars from being stripped by radioactive stellar winds from other nearby stars and the block all visible light. Bok globules are an amazing phenomena and the understanding of these clouds will give us an even greater insight into the birth of stars.

References

http://astronomy.swin.edu.au/cms/astro/cosmos/B/Bok+Globule

http://www.universetoday.com/2009/02/02/journey-inside-a-bok-globule/

Binary Stars

November 26, 2009 Leave a comment

Stars are the visual masterpieces of the sky that have captivated humanity for untold centuries. Many believe that the alignment of these celestial bodies can bring good and bad luck or that their positions can assist in predicting the future. Sailors have used the celestial star map as a guide for as long as humanity has struck out across the ocean. What makes these astronomical bodies so amazing? The fact is that they produce such an amazing visual display and are the most abundant feature in our sky. No stagnant show, however, is quite as captivating as a binary star.

Binary stars

A binary star is a system of two stars that orbit a common center mass. Within the coupling, the brightest star is known as the primary star and the other star is the secondary or companion star. The term double star can be used synonymously with the term binary star, but more often than not the term refers to optical double stars. The term binary star is not to be confused with an optical double star, which is a coupling of stars that appear visually close together but share no physical connection. The double star may be defined as optical if the stars being measured have significantly different proper motions, which are the angular changes of a star in relationship to the Sun, or radial velocities, which is the velocity of an object either toward or away from the observer. Another way that the optical double star is defined depends on whether the measured parallaxes of the individual stars are significantly different distances from Earth.

Binary stars were first theorized in 1767 by John Michell, but the first observation and cataloguing of double stars began in 1779. The term binary star was first used in context by Sir William Herschel when he stated, “If, on the contrary, two stars should really be situated very near each other, and at the same time so far insulated as not to be materially affected by the attractions of neighboring stars, they will then compose a separate system, and remain united by the bond of their own mutual gravitation towards each other. This should be called a real double star; and any two stars that are thus mutually connected, for the binary sidereal system which we are to now consider.” The first orbit of a binary star was not computed until 1827 when the orbit of Xi Ursae Majoris was calculated by Felix Savary. The Washington Double Star Catalogue is a database of known binary and optical double stars containing more than 100,000 couplings. Only several thousand of these pairs have their orbits calculated.

There are four categories of binary stars: visual binaries, spectroscopic binaries, eclipsing binaries, and astrometric binaries. These categories of binary stars are defined by the way in which the coupling is observed. The observations, however, are not mutually exclusive as several binary stars fall within more than one category. A visual binary is a pair of stars in which the angular separation of the bodies is enough for each individual star to be observed by a telescope. Within each visual binary, the brightness of the primary star plays a key role in the identification of the secondary star. If the primary star is extremely brighter than the secondary, the light pollution emitted by the primary will make the secondary unobservable.

The second type of binary star is the spectroscopic binary. Sometimes the only evidence of this pairing comes from the Doppler Effect, or the change in frequency of the light wave as the source moves, on its emitted light. In these cases, the binary pair emits light beginning in the blue spectrum of light which shifts into the red spectrum as the stars revolve around the center mass. Commonly, the separation between these types of stars is extremely small and the orbital velocity is high. The vast majority of these star couplings cannot be detected with a telescope.

Eclipsing Binary Star

The next category of coupling is called the eclipsing binary. This star pair is categorized due to the fact that the orbital plane of the stars parallels the observation point so nearly that the stars eclipse one another as they revolve around the center mass. Eclipsing binaries are variable stars due to the fact that the light emitted is expressed by an almost constant emission with a significant noticeable change in intensity as the stars eclipse one another. If one star in the pairing is significantly smaller than the other, the smaller star will be eclipsed totally by the larger, but as the smaller star eclipses the larger star an annular eclipse occurs.

The final category of binary star is called an astrometric binary. This binary was first discovered when astronomers noted stars that seemingly orbited around empty space. These are stars that are relatively nearby to the Earth and seem to wobble around a point in space with no visible companion star. Mathematicians use the properties of know binaries to calculate the mass of the missing companion star which might be too dim to be seen or simply out of the observer’s vantage point.

Mass transfer in a binary star

A mass transfer can occur within binary stars as the main sequence star increases in mass, it may at some point exceed its Roche lobe and the companion star may begin to absorb the mass of the other star. The mass may be absorbed by direct impact or through an accretion disc, which is a circumstellar disk formed by diffused material in orbital motion around a central body. When this occurs, the accretion disc often becomes the brightest observable point of the binary, sometimes even becoming the only observable point due to light pollution caused by the disc itself.

Binary stars are an amazing phenomenon to be observed in the heavens. One thing remains certain about star observation, it will continue to captivate humanity and motivate science for many generations to come, whether or not the stars can be used to predict the future or bring us luck.

References

http://www.astro.cornell.edu/academics/courses/astro201/binstar.htm

http://www.universetoday.com/guide-to-space/stars/what-is-a-binary-star/

http://www.midnightkite.com/binstar.html

Categories: Astronomy Tags: , ,

Externalizing Behavior: A Journal Article Review

November 23, 2009 1 comment

Developmental Psychology, Vol.45, 2009

Infancy Parenting and Externalizing Psychopathology from Childhood through Adulthood: Developmental Trends

Michael F. Forber and Byron Egeland

SUMMARY:

This article attempted to answer the question, does poor-quality early parenting have a correlation with externalization of behavior as a child continues to progress developmentally toward adulthood? Previous findings were suggestive that poor-quality early parenting was more strongly associated with externalization or behavior problems in early childhood than in adolescence. The results of this study also suggested a similar result with the added inference that externalization during adulthood is more directly correlated to early parenting. There were two theories offered to explain the lack of exhibition of the behavior during adolescence.

The first theory offered to explain the regression of parental influence on behavior during adolescence is called the developmental period explanation which states that during adolescence, it is normal for the adolescent to exhibit a greater predisposition toward externalization of behavior regardless of parental upbringing. This is thought to be caused by increased pressure by deviant peers. Even children with a history of externalization from late preschool age to preadolescence are exposed to the same deviant peer groups. During this adolescent period, poor-quality early parenting has less of an impact than peer pressure according to the results. Conversely, behavioral externalization is relatively low in the late preschool age to preadolescent group, so incidences may be more heavily related to early parenting.

The second salient theory to explain why externalization associated with early parenting decreases during adolescence is called the decaying relation explanation, which attributes the decrease to a longer interval separating risk and outcome. The keystone of this theory is that successful adaptation in previous encounters serves as a tool to cope with future experiences. This coping ability, however, can be affected by future circumstances. This means that successful adaptation in a given situation does not always lead to better coping skills for future encounters if significant events have altered the adolescent’s coping mechanism. For example, negative experiences outside of the early parent-child relationship may cause the adolescent to exhibit more psychopathology than is proportional to the quality of interaction in early childhood.

The results of the tests−parental surveys for kindergarteners, first-graders, and 16-year-olds, and participant surveys for 16-, 23-, and 26-year-olds−indicated that externalization of behavior related to poor-quality early parenting is more prevalent in preadolescent children and adults. This result is suggestive that in stages where externalization is not normative, as in preadolescence or adulthood, those incidences of the behavior are more directly linked to poor-quality early parenting. In adolescence, the major contributing factor is not early parenting. Rather, it is more based on peer interaction and individual choice. Further, researchers suggest that infancy, characterized by rapid development of the ability to regulate emotion, pattern relational abilities, and other internal representations of relationships, may be a sensitive period for future environmental influence. The authors also introduce the idea of a genetic link regarding externalization between the parent and child due to similar results regarding antisocial behavior. Preadolescent and adult antisocial behaviors show a stronger genetic link than that of adolescent antisocial behavior. It is plausible to suggest that, due to these findings, externalization of behavior may be linked to a genetic liability shared between parent and child.

REFLECTION:

This was a very interesting article about how early parenting has the potential to lead to externalization of behavior; i.e. hyperactivity, delinquency, and aggression. It is apparent that the parenting style taken in the early formative years has a direct effect on the child for the remainder of his/her life. The effect is most pronounced in preadolescence and adulthood, but it still affects adolescence, albeit a more muted effect within that age range.  The most interesting factor of the study was the drop in level for 16-year-olds. In both sets of surveys, the participants and the parents believed that poor-quality early parenting had little to do with the externalization of behavior, but the numbers rebound back to comparable levels between preadolescent parental surveys and adult participant surveys. This could mean that in preadolescence, parents believe that they are responsible for their children’s behavior, but after a certain age of maturity, the parents believe that society, peer influence, and individual choice have more to do with the adolescent’s behavior. Similarly, the surveyed adolescents responded in a way that leads the reader to believe that they agree that their early parental experience has little to do with incidences of externalizing behavior during adolescence, but after a few more years of gained maturity, the adults cite poor-quality parenting as a reason for acting out.

After reading the survey, I was stunned to see the percentage of adults who personally cite early parental influence as the reason behind their externalization of behavior. I believe that adults are completely responsible and accountable for their actions. I understand that nurture during formative years has much to do with the adult that you become, but honestly, I have a strong belief that if a person has the desire to overcome the shortcomings of early life that one cannot control, the shortcomings can and will be overcome. I seriously ask myself, “What happened to personal responsibility? When did it become the normal course of action to blame someone else when something goes wrong?”

The data collected within the survey is good, but further studies are needed to correlate whether there is truth in what the data suggests. If other studies find the same result, then the data might useful as early intervention for preadolescent and adults prone to externalization of behavior. Also, a survey could be useful for school age children to identify which students might need more individual attention based on early parental relationships.

Antimatter

November 19, 2009 Leave a comment

Antimatter

Science fiction often borrows from scientific fact in order to make entertaining and scientifically relevant media. Such was the case with Dan Brown’s Angels and Demons, which brought antimatter to the limelight as the latest public craze in science fiction. Antimatter has long been a source for entertainment. Originally, it was represented in the light of alternate universes and antimatter galaxies to becoming the latest terror device in the aforementioned movie.

Antimatter is an extension to the concept of antiparticle matter in the study of physics. The basic premise of study of antimatter revolves around the principle that antimatter is composed of antiparticles in the same way that matter is composed of regular particles. For example, if an anti-electron and an anti-proton combined, it is conceivable that they could for an anti-hydrogen particle in the same way that an electron and proton combine to form hydrogen.

The root of the antimatter discussion goes back several scientific generations. Although the discussion of antimatter spans over one hundred years, the actual history of the modern antimatter theory stems form a paper written by Paul Dirac in 1928. Dirac realized that applying the theory of relativity to the Schrodinger wave equation for electrons predicted the possibility of anti-electrons. The particle was then discovered by Carl Anderson four years later. Dirac did not use the term antimatter in his paper, but the term had existed for three decades after being coined by Arthur Schuster in two fanciful letters to Nature in 1898. Although Dirac did not use the term antimatter when predicting the existence of the antiparticles, it was a natural extension of the proposed concept so the terminology stuck.

Antihydtogen

The majority of the known universe is composed of matter. This has been explained by scientists in relation to the Big Bang theory by stating that matter had a slight edge in overall mass after the proposed Big Bang. This would give matter the edge by sheer number. When matter and antimatter particles contact one another, they go through a process called annihilation. When this process occurs, the matter and antimatter particles are reorganized into new particles completely as neither could be destroyed due to fact that energy and momentum must be conserved within the reaction. In the case of the collision between matter and antimatter, the particles become high energy protons such as gamma rays, or other particle-antiparticle pairs. Due to the process of annihilation after the Big Bang, whichever particle had the edge in overall particle count would become the dominant universal particle.

Antiparticles can be produced in any environment with a sufficiently high temperature. It is believed that when the universe was very young, it was an extremely hot and dense environment. In this environment, matter and antimatter were constantly being produced and annihilated. The final asymmetry of matter to antimatter remains a mystery as to the root cause. Positrons are also produced via beta decay, but this mechanism is considered both natural and artificial. Antimatter was created in the mid 1990s in the form of antihydrogen, but the particles were very hot and unsuitable for study. In 2002, a solar flare produced about a pound of antimatter according to a NASA led research project. This small amount of antimatter could power the United States for two days.

Antimatter is still under intense research. The energy potential of this antiparticle is something that cannot be ignored by science. Although only small amounts of antimatter have been produced artificially by science, the study of the potential energy and the possible destructive force of this little known particle will continue to press scientists to better understand the amazing and unknown properties of antimatter.

References

http://www.space.com/scienceastronomy/antimatter_sun_030929.html

http://www.livescience.com/technology/090514-antimatter-angels-demons.html

Nebulae: An overview

November 16, 2009 Leave a comment

Pillars of Creation Nebula

A nebula is an interstellar cloud of dust, hydrogen gas, helium gas, and plasma. The word nebula is derived from the Latin word for cloud. Originally the word nebula was used to describe any extended astronomical object including galaxies. The older use of the word survives in modern usage in some confusing ways. Various star clusters and galaxies are still referred to as nebulae. Strictly speaking, the word nebula should be reserved for clouds composed of gas and dust. There are several types of nebulae.

Omega Emission Nebula

The first type of nebula is called an emission nebula. These are clouds of ionized gas that emit various colors. The most common color expressed by an emission nebula is red due to the ionizing hydrogen. There are other colors as well, but none as abundant as red due to the great amount of hydrogen within these clouds. The most common cause for the ionization of the gas is a result of high-energy photons from a nearby hot star, as in the case of emission nebulae located in H II regions where there are new stars being born or dying stars which are in the process of expelling their outer layers exposing the hot core. The majority of emission nebulae are not caused by a single star as the star would have to be massive to ionize a significant part of the cloud. Instead, the ionization occurs due to an entire cluster of high temperature stars.

Witch Head Reflecting Nebula

The next type of nebulae is the reflecting nebula. These are similar to emission nebulae in the regard that they are both visible due to light. Within a reflecting nebula, there is not enough energy to ionize the gas to form an emission nebula. However, there is enough to scatter the light and make the dust within the cloud visible. Therefore, the reflecting nebula takes on the color characteristic of the star that the nebula is reflecting. There are around 500 known reflection nebulae. Many times, emission and reflecting nebulae occur within the same dust cloud where one part of the cloud is hot enough to ionized the gas, but there are sections where the temperature is lower and the light is reflected.

Horse Head Dark Nebula

The final type of nebulae is the dark nebula. A dark nebula is a nebula that is so dense that it obscures the light that attempts to pass through it from emission nebulae or background stars. The extinction of light is caused by the interstellar dust located at the coldest, densest places within the nebula. Large dark nebulae are associated with Giant Molecular Clouds, whereas smaller dark nebulae are called Bok globules. Within these nebulae, stellar events such as the formation of new stars occur as the gravitational forces act within the clouds.

Nebulae offer a spectacular celestial show as they interact with outside energy forces. Much research is still being invested into these phenomena, and the more we discover helps us to discern better the origins of our own corner of the universe.

References

http://astro.nineplanets.org/twn/types.html

http://www.daviddarling.info/encyclopedia/R/reflectionneb.html

http://abyss.uoregon.edu/~js/glossary/dark_nebula.html

Bible Study Friday: Humility

November 13, 2009 1 comment

La BibliaOne of the most important aspects of walking alongside God is making sure that you are continually reading and meditating on His word. I am planning on starting a new installment on the blog called Bible Study Friday. Here I will relay what I am studying and how God is moving in my life based on His amazing word. I hope that publishing this study will help you as much as it helps me to prepare for this installment. Without further ado…

What is Humility? Some would say humility is an attitude, but I would venture to say that, while an attitude of humility is extremely important, God desires much more from the Church. At the most basic level of faith, God desires a lifestyle of humility from His people.

In Matthew 23, Jesus is talking with his disciples and the crowds that were following him. In the previous chapter, he had been challenged by the Pharisees and Sadducees. In each instance, Jesus had taken the challenge issued by the men of the law and refuted it so that each group of challengers had nothing left to say. Jesus put them in their place so decisively, verse 22:46 states that, “No one could say a word in reply, and from that day on no one dared to ask him any more questions.” With his spiritual enemies firmly silenced, Jesus was able to address the crowds freely.

For the next few verses, Jesus rips into the Pharisees and teachers of the law regarding their outward shows of spiritualism and their love of human recognition. He tells the crowds, “Everything they do is done for men to see: They make their phylacteries wide and the tassels on their garments long; they love the place of honor at the banquets and the most important seats in the synagogues; they love to be greeted in the marketplaces and to have men call them Rabbi” (Matt 23:5-7).

Are we not there today? We love ourselves to a fault and we love to be exalted before men.  This is not what God desires. God would have us to live humble lives as servants. Jesus himself said, “The Son of Man did not come to be served, but to serve, and to give his  life as a ransom for many” (Matt 20:28 ). Today, we live in a society that preaches the need to take care of number one. To exalt yourself to stand out.  We have a corporate world that would have you lie, cheat, and steal to advance up the next rung of the ladder. But Jesus himself stated that he came to serve, even to the point of death on a cross in obedience to the Father as a sacrifice for us. So where does that leave us today? If the Son of Man came as a servant unto this world, how crazy is it for us to be so self-serving! This attitude is even prevalent within the walls of churches today! This has to break God’s heart. We, the body of Christ, are to be His living message to the world today, but it seems like we have forgotten what that message is.

The attitudes that we express are clearly outside of what Jesus lays out in verse 11 and 12.  “The greatest among you will be your servant. For whoever exalts himself will be humbled, but he who humbles himself will be exalted.” See how our self-importance and Christ do not mix? If you want to be exalted before God, you have to humble yourself before men. As Christians, our rewards in heaven clearly outweigh any reward that we could receive here. Earthly reward is fleeting, while heavenly rewards are eternal. I don’t know about you, but I would rather invest in my eternal home rather than the temporal home I have here on Earth.

God lays it out for us. If we want to be within His will here on Earth, we have to find humility. Let go of your pride. It only serves to hold you back from where God wants you to be. The gains of surrender greatly surpass the penalty of retaining your self-serving nature. The call on our lives is to love the people of the world as Christ did. And how did Jesus love? Through service. How are we then called to love the world? As humble servants putting others above ourselves. Remember, he who exalts himself will be humbled, but he who humbles himself will be exalted.

All for His glory.

Jeremy

Categories: Faith Tags: , , , , ,

What are neutrinos and how are they detected?

November 12, 2009 1 comment

Often in the study of astronomy, the focus of many research programs and independent study revolves around the hulking celestial bodies that have captured humanity’s imagination for thousands of years. Oft forgotten are the small particles of matter that are the basic essentials for physical existence. The study of these tiny particles has evolved from studying atoms to studying subatomic particles and finally to studying elementary particles. Elementary particles are particles that are not know to have any substructure, which means, if this remains true under scientific scrutiny, that elementary particles are the basic building blocks of which all matter in the universe in composed. One such elementary particle is called the neutrino.

Image of a Neutrino

Neutrinos are elementary particles that are similar to the more commonly known electron. The difference, however, between the electron and the neutrino is in the particle’s charge. This difference is crucial in determining the behavior of the particle. Electrons are affected greatly by electromagnetic forces due to the particle’s negative charge. Neutrinos on the other hand carry no charge making them mostly impervious to strong force electromagnetism. Instead, these particles are only affected by weak nuclear force and gravitation although the effect from gravity has been shown to be negligible in laboratory study. The name neutrino literally means “small neutral one.”

The vast majority of the neutrinos that pass through Earth come from the Sun. Since the particles are electrically neutral and are not affected by strong force, the neutrinos pass through the Earth relatively unaffected. It can be said that during the daytime, solar neutrinos shine down on humanity, but during the night, these neutrinos shine up from underneath! More than fifty trillion solar neutrinos pass through the human body every second. There are three types, or “flavors,” of neutrinos. These are electron neutrinos, muon neutrinos, and tauon neutrinos, which each have a unique antimatter particle called an antineutrino. Electron neutrinos and antineutrinos are created when a proton becomes a neutron or vice versa through the process of beta decay, which is a type of radioactive decay in which a beta particle, an electron or positron, is emitted.

The proposed existence of the neutrino was first theorized in 1930 by Wolfgang Pauli. This idea was formulated to preserve the laws of conservation of energy, conservation of momentum, and the conservation of angular momentum in regards to beta decay. Pauli stated that an undetected particle was carrying away the observed difference in regards to the energy, momentum, and angular momentum of the initial and final particle. Upon first theorizing the existence of the neutrino, Pauli named the unknown particle the neutron, but a more massive sub atomic particle with no charge was found two years later and was also named the neutron. The naming confusion was remedied by Enrico Fermi as he changed the name to neutrino when proposing the theory of beta decay.

Observation of Neutrinos

The neutrino particle remained only a proposed idea until 1956 when a group of researchers published the article “Detection of the Free Neutrino: a Confirmation” in Science. This discovery was awarded the Nobel Prize in physics almost 40 years later in 1995. The experiment, now known as the neutrino experiment, took neutrinos created in a nuclear reactor by beta decay and shot them into protons which produced neutrinos and positrons of which both were able to be detected. Further, in 1962 a team of researchers found that there were different types of neutrinos when they identified the already hypothesized muon neutrino. A third lepton, the tau, was discovered at Stanford in 1975. It was theorized that there would be an associated neutrino with this particle as well, but this was not confirmed until 2000 by the DONUT.

SNO neutrino detector at work

Neutrinos are detected in several ways. As previously stated, the first detection of neutrinos was accomplished in the neutrino experiment in 1956 using induced beta decay to observe the particles. In the modern scientific era, a neutrino detector is used to identify and study neutrinos. These apparatus must be very large in order to detect neutrinos because of the weak-reacting nature that neutrinos exhibit. They are often built underground in order to differentiate cosmic rays from background radiation. These apparatus take on several different incarnations from large volumes of water that are watched by phototubes for the Cherenkov radiation, which occurs when electromagnetic radiation is emitted as a charged particle passes through an insulator at a constant speed greater than the speed of light in that medium, to detectors made of large volumes of chlorine or gallium which are then checked for argon or germanium, respectively.

The study of the massive celestial bodies will continue to captivate the mind and imagination of humanity for many generations to come. Discovering new stars and planetary bodies will continue to drive the study of astronomy outward, but let science not forget that the inward study of the very particles that make up every physical body in the universe will garner us much insight into the great celestial bodies that surround us.

References

http://www.ps.uci.edu/~superk/neutrino.html

http://hyperphysics.phy-astr.gsu.edu/Hbase/particles/neutrino.html