Could an exploding star have been responsible for the death of the dinosaurs? This idea has become popular again as an explanation for the disappearance of the dinosaurs. An exploding star can blast material enormous distances into space. If this material reached Earth’s atmosphere, changes may have occurred that were harmful to life.
We call an exploding star a supernova. Nova is the Latin word for new, and in ancient times, when an exploding star was observed, people often thought a new star was being born. The plural form of nova is novae. So when we talk of more than one supernova, we say supernovae.
When a star has used all it’s nuclear fuel, the gravitational force that pulls the star’s material towards it’s center no longer has an opposing force to act against it. As a result the star collapses. A star that once had eight times as much matter as our sun and was 1,000,000 miles across, becomes a sphere only ten to fifteen miles across. As the star collapses, very small particles (called neutrinos) escape into space. After the star becomes a very small sphere, it explodes like a giant nuclear bomb and becomes a billion times as bright as our own sun. All kinds of matter and radiation are blasted into space. This matter and radiation travels through space at nearly the speed of light (186,000 miles per second)
Now, if one of these supernovae were to occur within about 130 light years of Earth, some scientists feel that life on earth would be drastically affected.
Since a light year is the distance light travels in one year, 130 light years is about
760,000,000,000,000 (760 quadrillion miles!).
So, suppose a supernova had occurred sixty-five million years ago within 130 light years of Earth, how exactly would it cause the death of the dinosaurs? Some scientists think neutrinos and galactic cosmic rays would cause extremely high
At the opening of the book Borderlands, La Frontera, Gloria Anzaldua conceptualizes the borderlands as being a burden and a cause of her pain and hopelessness. Anzaldua expresses her feelings towards the boarder using physical traits, but also using non-material descriptions. Anzaldua then goes on to talk about the experiences of oppression and, violence and discrimination of those queer folks of color and how her metaphors used in this book help understand better the meaning of such experiences. She also examines how the queer bodies are marked as locations for all kinds of violence through the power of gender binaries. In the first chapter of her book, Anzaldua explores many aspects of the borderline, and she portrays strong feelings about this matter.
In particular, the use of Florence Nightingale’s theory of nursing as the basis of my new practice had allowed me to begin with the basics and work my way forward toward a more modern and holistic approach to nursing care. While Florence’s work focused mainly on the military and her care of soldiers, she began to establish schools of nursing to promote nursing education and to encourage people to view nursing as a viable profession, (Alligood, 2014. 63). Nightingale’s focus may have been care of the military, but she made great strides on getting recognition for nursing and her theories still affect the practice of nursing today. In the article, Nurses as Leaders, the author proposes that nurse leaders have made great strides since Nightingale’s time when nurses were conscripted to help care for wounded soldiers. Such a setting required these early nurse pioneers to rely on critical thinking and quick action in order to save lives. The author goes on to discuss how a change in nursing occurred in the early 20th century as new management styles emerged, most notable the “Scientific Management,” model. This style placed doctors at the top, then nurse managers, and on down to bedside care staff. Though this did allow some nurses the ability to move upward, nurses resented a doctor being in charge of their teams as the work of a physician and that of a nurse are two very different practices, ("Nurses as Leaders," 2016). This is quite different from the modern concept of a nurse executive as leader of
Most stars in the universe are main sequence stars (average mass stars) which begin their life as moderately sized stars, burn their hydrogen for about 10 billion years after which they become “red giants”. Red giants form when the amount of hydrogen in an average star is lower than what is needed for fusion to continue. The outer layers of such stars expand and cool, and their helium cores contract. Over time, the outer layers are shed and the remaining helium core of the now dead star shines as a small white dwarf star. It is the remnant of the
Have you ever heard the phrase “We are stardust”? Chances are you have, but what exactly does that mean? As an Astronomy major and someone whose always been fascinated by the wonders of space, including the wonder of supernovas. I want to pass some of the information I have learned to you today by telling you the different types of supernova and what happens during a supernova.
...leted of its nuclear fuel and lost its outer layers. When a small to medium (less than 10 solar masses) main-sequence star begins to run out of fuel in its core, the core will begin to collapse where hydrogen on the edges of the collapsed core can be compressed and heated (Chandra 2012). The nuclear fusion of this new hydrogen will create a new gush of power that will make the outer layers of the star to expand out; this is known as the red giant phase. In the red giant phase over millions of years, all of the stars energy supplies are used up leaving behind a hot core that is still surrounded by the expanded outer layers. The outer layers are eventually expelled by stellar winds which end up creating a planetary nebula and the hot core left behind forms a white dwarf star where the pull of gravity is supported by degeneracy pressure (p. 538 Bennett en al. 2013).
Stars explode at the end of their lifetime, sometimes when they explode the stars leave a remnant of gasses and, dust behind. What the gasses come together to form depend on the size of the remnant. If the remnant is less than 1.4 solar masses it will become a white dwarf, a hot dead star that is not bright enough to shine. If the remnant is roughly 1.4 solar masses, it will collapse. “The protons and electrons will be squashed together, and their elementary particles will recombine to form neutrons”. What results from this reaction is called a neut...
When women migrate from one nation or culture to another they carry their knowledge and expressions of distress with them. On settling down in the new culture, their cultural identity is most likely going to change and that encourages a degree of not belonging; they also attempt to settle down by either assimilation or biculturalism. Consider identity issues of women from the borderlands like feminist Gloria Anzaldua. Her life in the borderlands was a constant battle of discrimination from the Anglo, she was caught in a world of two cultures, various languages, and male domination, “She realized she had two options, to be the victim or to take control of her own destiny” (Borderlands). In her book, Borderlands/La Frontera, she discusses conflicts of linguistic, sexual, and ethnic identity that exists on the border of Mexico and the United States. Gloria Anzaldúa articulates in one of her chapters, “How to Tame a Wild Tongue”, that “ethnic identity is twin skin to linguistic identity;” the languages she possess wield extraordinary influence over her cultural identification (Borderlands). In her book she combines both Spanish and English to emphasize the significance of the position from which she writes, yet Anzaldúa also depicts the near impossibility of reconciling the cultures her speech reflects. When she speaks English, she speaks “the oppressor’s language” (Borderlands); when she speaks Chicano Spanish, she speaks “an orphan tongue” (Borderlands). As a result, the implications of language on her identity are, at times, problematic. Since the English speakers she must accommodate deem her tongue “illegitimate,” she deems herself illegitimate (Borderlands). Her life struggles in the borderlands compelled Gloria Anzaldúa to be resilient and even hopeful. She will use her native tongue to “overcome the tradition of
To this day, the most admired person in nursing history would be Florence Nightingale. She will forever be an influential figure in the world of nursing due to her perseverance and critical thinking skills that saved so many lives during the Crimean War. There is no way to tell how long it could have taken nursing to evolve without the help of Nightingale. In her book, Notes on Nursing: What It Is and What It Is Not, Nightingale described a multitude of factors that must be considered when helping the ill to recover and to have the healthy maintain their well-being (Nightingale, 1860/1969). Four chapters in her book are of high importance, chapter two, on Health of Homes, chapter
The eternal endeavor of obtaining a realistic sense of selfhood is depicted for all struggling women of color in Gloria Anzaldua’s “Borderlands/La Frontera” (1987). Anzaldua illustrates the oppressing realities of her world – one that sets limitations for the minority. Albeit the obvious restraints against the white majority (the physical borderland between the U.S. and Mexico), there is a constant and overwhelming emotional battle against the psychological “borderlands” instilled in Anzaldua as she desperately seeks recognition as an openly queer Mestiza woman. With being a Mestiza comes a lot of cultural stereotypes that more than often try to define ones’ role in the world – especially if you are those whom have privilege above the “others”.
Nebula away so that it can avoid certain things. In the short story, “The Star,” the priest stated,
of species due to a variety of causes. Included is out competition, depletion of resources
Nursing is more than merely a job, an occupation, or a career; it is a vocation, a calling, a frame of mind and heart. As a nurse, one must value the general good of others over his own. He must devote of himself nobly to ensure the well-being of his patient. However, today’s well-recognized nurses are notably different from nurses of the recent past. Service is the core of the nursing profession, and the essential evolution of the vocation reflects the ever-changing needs of the diverse patient population that it serves. As a profession, nursing has evolved progressively, particularly in its modernization throughout the past two centuries with the influence of Florence Nightingale. The field of nursing continues to grow and diversify even today, as nurses receive greater medical credibility and repute, as its minority representations
Realism is one of the important perspectives on global politics, it is a notion about the conservative society and political philosophy (Heywood 2011: 54; Shimko 2013: 36). Besides, Gilpin (1996) claims that “realism…, it is not a scientific theory that is subject to the test of falsifiability, therefore, cannot be proved and disproved.” (Frankel 1996: xiii). The components of the realist approach to international relations will be discussed.
Liberalism has contributed to the understanding of International Relations as an academic discipline and through organizations such as the United Nations, the European Union, the League of Arab States, and others in what many consider to be a very influential manner.
Supernovae occur when a star can no longer resist the force of gravity and collapse. There are two types of supernovae. Type II supernovae have hydrogen absorption lines in their light spectrum. Type II supernovae occur in stars with masses much greater than our sun. They are an implosion-explosion event. During fusion, outward pressure is created to balance the inward pull of gravity. However once the star runs out of fuel, the star will expand into a red supergiant. While the star is still a red supergiant, the core become hotter and denser. During this time more nuclear reactions occur, delaying the collapse of the core. However once the core is out of fuel this time, it has nothing left to fuse and the core collapses. The implosions, or collapse, of the iron cores of massive stars are caused from extreme pressure. When the core collapses, the core will rise to over 100 billion degrees. The energy from the iron crushing together will be overcome by gravity at first, but will bounce back through the layers of the star. When it reached the hydrogen envelope of the star, it explodes and a shock wave occurs. Many heavy elements are released by the explosion and are dispersed throughout the galaxy to form new stars