Gravity

Introduction

Many people, from the inquisitive, to those involved in the astronomical sciences have questioned the existence of Dark Matter. While it is called many things today, I will continue to refer to this unseen substance by its original name, Dark Matter. As it is still a theory being researched today to validate its existence and make-up, the discovery of dark matter was first presented to the world some time ago by two very intelligent astronomers. In coming to understand this matter, some of the most common questions we find ourselves asking are: What is it?

And, How was it discovered? The most difficult question we all seem to face is “Does it really exist? ” While quite tricky, this question is one that each of us have to conclude an answer to on our own. Therefore to start, I will address the more common questions first, and then I will provide my own answer to the question of its existence. Dark Matter: What is it? When first being introduced to Dark Matter, the first question we find ourselves asking is what is it? In and out of the scientific community dark matter is commonly referred to as “the source of extra gravity,” or the “mysterious form of matter that is unseen. A more refined scientific definition for dark matter is “a nonluminous, undetectable, invisible material in the universe that makes up about 70%-80% of its mass. ” In short, dark matter is an unseen form of material that contains its own gravity which affects its surrounding materials; i. e. gases, stellar, and celestial bodies. With truly dedicated astronomers and cosmologists focused on the structure and composition of the cosmos, this brings me to explaining how this invisible matter called “dark matter” was discovered. Dark Matter: How Was It Discovered?

In 1932 and 1933, astronomers Jan Hendrick Oort and Fritz Zwicky were the first to postulate the idea of the existence of dark matter. In studying the stellar motions of stars within the galactic plane of the Milky Way galaxy, Astronomer Jan Oort observed that the rotational velocity of stars on this outermost part of the galaxy (galactic plane) was actually increasing versus decreasing. This in itself presented a reason to question this stellar movement further since, based on Newton’s law of gravity, the rotational velocity of stars should steadily decrease the further they are from the galactic center.

Oort continued his observations on stellar motions, while astronomer Fritz Zwicky carried out his studies and observations on galactic clusters and how they remained gravitationally bound. During Zwicky’s observations, here is where dark matter was discovered on a much more massive scale. Through Zwicky’s research, he found that there needed to be 10 times as much mass as observed in the form of visible light in order to keep galaxies clustered together. This observation was clear to Zwicky, as it had been to Oort, that there was a large sum of mass existing within the cosmos that was simply “non-visible. At this point, astronomers simply referred to this material as “missing mass. ” Being that the peculiar stellar movement counters Newton’s law of gravity, and occurs in the outermost part of the galaxy known as “galaxy halo’s,” both Oort and Zwicky hypothesized that this “dark matter” must exist in a spherical form that enshrouds the outermost part of galaxies, thus keeping them from flying apart. In understanding how this matter was discovered, this brings me to the final and most important question, and that is determining if it really exists.

Dark Matter: Does It Really Exist? The evidence supporting the existence of dark matter today is very convincing, yet in the scientific community, it is still a theory. Giving a definite answer as to whether it exists is solely up to the individual. Despite this, astronomers are continuing to find more convincing information that supports the dark matter theory. For instance, an August 2012 article published in “Science News Today,” discussed evidence of dark matter filaments (fibers or threads of dark matter) discovered by astronomer Jorg Dietrich and his colleagues.

Dietrich and his colleague’s x-ray observations of a pair galaxy clusters called Abell 222/223, revealed a ribbon of hot gas between the clusters. This, along with the galaxies distorted shapes and how light was bent was the first hint of the presence of dark matter. Continued observation of the galaxy clusters revealed a thick cord of invisible matter with a mass comparable to that of a small galaxy cluster. Dietrich states that gas can account for only about 9 percent of that mass, dark matter appears to make up the rest. Conclusion:

In understanding that dark matter is an unseen material which contains its own gravity, the theory alone provides a unique way of understanding the structure of our universe. Most importantly, the work of astronomer’s Jan Oort and Fran Zwicky set the stage for astronomers to seek out and understand possible unseen forces at work within our cosmos. This is exactly what astronomer J. Deitrich and his colleague’s did. While there is a host of significant evidence supporting the theory of dark matter, Deitrich and his colleague’s evidence was eye-opening.

In concluding if it actually exists, in my opinion its presence is already confirmed. Works Cited Jones, Andrew, and Daniel Robbins. “The Universe’s Dark Matter and Dark Energy, String theory for dummies.

Reference

• ” Dummies. com. Dummies. biz. 2012. Web. 14 Nov. 2012. NASA. What is Dark Matter?
• Washington: Institute for Global Environmental Strategies, 23 Feb. 2012. Web. 14 Nov. 2012.
• Powell, Devin. “Dark Matter Filament Illuminated. ” Science News Magazine 11 Aug. 2012: 9+.
• Print. White, Mark. “Rotation Curves. ” Berkeley Astronomy Department. University of California at Berkeley. 2011. Web. 15 Nov. 2012.

January 4, 1643 is the time when our great mathematician and physicist, Isaac Newton, was born. His hometown was Woolsthorpe, Lincolnshire, England. His father was a noble farmer but unfortunately he died before Isaac Newton was born. After his father’s death, his mother was married again, thus he was left with his grandparent’s custody. He went to Cambridge University to study in 1661. During that year, he became interested in various fields including mathematics. He was also become interested in optics, astronomy and physics but in 1665 a plague epidemic came in the University that forces Newton to go back to his hometown.

During his two years in Cambridge, he already thought about gravity and in fact began to study optics and mathematics particularly calculus. After the plague, he returned to Cambridge. He became a second Lucasian Professor of Mathematics. In 1668, he made a reflecting telescope which attracts the attention of the scientific community and eventually he became a member of the famous Royal Society. His passion in optics and science was manifested by his series of experiments in the composition of light which resulted to the discovery of the various behavior of light.

He published “The Opticks” which consists of concepts of light and color1704. Aside from “The Opticks”, he also published several paper works in history, theology and alchemy. One of his greatest works is the “Philosophiae Naturalis Principia Mathematica” (Mathematical Principles of Natural Philosophy). This works is all about how force and gravity were applied to all objects in the universe. In 1689, he was elected to become the MP for Cambridge University and in 1696; he became the warden of the Royal Mint in London.

In 1703, he was elected as the President of the Royal Society. Before he died, he has contributed a lot of concepts, discoveries, theories and ideas on different field such as optics, physics, astronomy and mathematics. His interest in mathematics was first manifested during his undergraduate year in Cambridge University. During this time he became accustomed to various mathematical works of several mathematicians like Descartes and John Wallis. His works in mathematics include the proof and improvement of the so called “binomial theorem”.

Newton was not first to discover the formula ((a + b) n) behind the binomial theorem. In fact an Islamic mathematician namely al-Karaji made a binomial coefficient table up to n=5. Also, another Muslim mathematician namely Omar Khayyam established a method of finding nth roots using the binomial expansion. Also in Europe, a century ago, Blaise Pascal has presented his concepts of how to generate binomial coefficients. Those discoveries by various mathematicians, including Pascal, were only applicable to positive values of n.

Newton on the other hand, discovered the formula for (a+b)n that would work for any real. He arrived at this formula: (a+b)n = an + nan-1b + [n(n-1)an-2b2] / 2! + [n(n-1)(n-2)an-3b3] / 3! + . . . + bn His finding about the binomial expansion was; for values of n element of the interval (-1, 1), the formula (a+b)n generates an infinite, converging series. Newton’s discovery of binomial expansion/series was a great help in calculating pi ( ). As we all know, a binomial series recurs repeatedly which becomes a very useful instrument for mathematical analysis.

The method of fluxions was Newton’s greatest discovery in calculus. In 1671, two years before Leibnitz established his own concepts about calculus, Newton started to study fluxions which is basically include concepts, notations and ideas on Calculus. His works on calculus was well established during 1665 in which he presented symbolisms for partial derivatives which is now an important method in calculus. The idea of binomial theorem and knowledge about infinite series gave Newton a solid idea on derivatives and integrals of functions.

As a result of his studies, he showed that integral and derivatives can be expressed as a binomial expansion of infinite series particularly the power series. Newton discussed and solved problem using Method of fluxions. The problems include differentiation of algebraic function, integration of algebraic functions using inverse method, first-order differential equations, optimization problem which includes the locating the maxima and minima of a given function and lastly drawing tangent line of functions at any point. Moreover, with the aid of fluxion, Newton developed a geometric idea of “first and last” ratio of lines.

In 1660, Newton became interested to study the nature of light and vision. In fact because of his fascination on light, he actually stared directly on the sun and poked the sides of his eyeballs by a small knife to observe activities and behavior of light and which risked blinding himself. These kinds of wild experiments and other sensible ones gave way to the formulation of theories about nature, behavior of the spectrum of light. Furthermore, Newton made its great leap in the scientific world when he published his “New Theory about Light and Colors” in the Royal Society’s journal.

As a result of his various experiments, he forced to conclude that Light is a heterogeneous mixture of refrangible rays meaning light is not a homogenous entity. When he passed a white light on a glass prism, he observed that spectrum of colors were formed in opposite walls which explained the property of light known as refraction. In line with the study of optics, he constructed a reflecting telescope, the first, to overcome the distortions of chromatic dispersion. One of his greatest contributions in the field of physics was his Law of Universal Gravitation.

Isaac Newton made a comparison of the moon acceleration to the object’s acceleration on Earth. He believed that gravitational forces were accountable for the acceleration of each other. He made a vital conclusion that gravity depends mainly on distance. From his comparison, he concluded that the gravitational force of attraction between the Earth and other objects is inversely proportional to distance between the center of the earth and the object. In other words, if the object is near the center of the earth, the gravitational force of attraction is high and vise versa.

But there are other factors, aside from distance that affects the magnitude of the gravitational force. Newton knew that mass is the other factor that affects the gravity or acceleration of an object. Another important conclusion was drawn and that the gravitational force exerted by the earth on the object is directly proportional to the mass of the object. Newton’s law of universal gravitation was applied outside earth, hence gravity is really universal. With this finding, Newton was included in the gravity hall of fame. Also, with the aid of Law of Universal Gravitation, the three laws of motion were formulated.

The formulation of these three laws, particularly the second law of motion allows numerical computations of how velocity changes when force acts on it. Newton left several manuscripts and paper works about alchemy and chemistry. Most of these were part of books, bibliographies, dictionaries and many other sources however; we could count in our fingers the original one from them. He began his experiments in 1669. He wanted to know the truth about alchemical obscurity and mysticism and the nature of and structure of all matter that he believed that God created all of these.

Newton’s notable contribution on chemistry is his publication of an incomplete theory of chemical force. One of his written works is Opticks, which is first written in English. This was his most remarkable works on theories in light and color. In Opticks, he proved and explained through experiment and logical reasoning and which includes numerous axioms, theorems, propositional statements and lots of definitions. He integrated his mathematical reasoning in his works and eventually Opticks turned out to be the basis of all experimental physics.

The Opticks contained findings that light like sound is composed of waves. He obtained several criticisms from other scientist like Robert Hooke and Christian Huygens. But Newton insisted that light was composed of discrete particles that move in straight lines. Furthermore, Newton combined the ideas that light is a particle and at the same time a wave. Again, from this result he received criticisms from Hooke and other scientists. Principia, his most remarkable, notable work and considered his masterpiece was divided in three books.

The first book of the Principia contains eight definitions and three axioms. The three axioms were later known as the Three Laws of Motion. These laws were the main parts of Book I of Principia and in fact all discussions of Newton in his Book I were based on these. In the Book II of Principia, he tacked motion of fluids and other bodies. On this book, he questioned Descartes and Kepler ideas about the vortex theory. In his Book III which was subtitled the System of the World, he showed how he arrived on his famous Law of Universal Gravitation.

The Principia was considered the most influential and greatest scientific piece during Newton’s era. His laws of motion and universal gravitation were his two most popular discoveries but Newton still believes that there is a supreme being that governs and makes these phenomena possible and that is God. Newton was a religious person. In fact he has written more on religion than in natural science. As a summary, Newton was a remarkable scientist in the history of the world making remarkable scientific advancements and discoveries in mathematics, physics, astronomy, optics, alchemy, chemistry and even in the religion.

In mathematics, he contributed a lot of ideas on analytical geometry, algebra and calculus. His discovery of the binomial formula and method of fluxions were very significant in the advancement of various topics in mathematics. In physics, astronomy and optics, he made several findings and discoveries like the theories of light, Universal gravitation, laws of motion, ideas on fluid mechanics and invention of reflecting telescope. His book, “Opticks”, became the basis of many experiments in physics because of the employment of scientific method in his own experiments.

Newton also has some contribution in alchemy and chemistry although some written works were in question. Newton was a great mathematician, a great physicist, a great astronomer and a great believer of God. Although all his works were scientific, he did deny the existence of a divine being. He was really a religious person and I think this was the reason why Sir Isaac Newton was successful in his career. We owed a lot to Newton so let us thanked him for his great contribution in humanity. Work Cited “Hatch, Robert A. ” 1999. Sir Isaac Newton. 1 December 2007, <http: // www. clas.

ufl. edu/users/rhatch/pages/01-Courses/current-courses /08sr-newton. htm>. “Henderson, Tom”. 2007. Newton’s Law of Universal Gravitation. 1 December 2007, <http://www. glenbrook. k12. il. us/gbssci/phys/Class/circles/ u6l3c. html>. Newton, Sir Isaac. 1 December 2007, <http://www. phy. hr/~dpaar/fizicari/xnewton. html>. Sir Isaac Newton’s Invention of the Calculus Fluxions and Infinite Series. 1 December 2007, <http://www. polybiblio. com/bud/19178. html>. “Smoller, Laura. ” June 2001. Applications: Web-Based Precalculus. 1 December 2007 < http://ualr. edu/lasmoller/newton. html >.

What is gravity?

Gravity is a force pulling together all matter (which is anything you can physically touch). The more matter, the more gravity, so things that have a lot of matter such as planets and moons and stars pull more strongly. Mass is how we measure the amount of matter in something. The more massive something is, the more of a gravitational pull it exerts. As we walk on the surface of the Earth, it pulls on us, and we pull back.But since the Earth is so much more massive than we are, the pull from us is not strong enough to move the Earth, while the pull from the Earth can make us fall flat on our faces. In addition to depending on the amount of mass, gravity also depends on how far you are from something. This is why we are stuck to the surface of the Earth instead of being pulled off into the Sun, which has many more times the gravity of the Earth.

What is the importance of gravity?

Gravity is a very important and critical ay lives and you probably don’t even notice. Here are some things that gravity does for us evey:

1. Gravity brings us back down to the ground when we jump up.
2. t stops us from floating into space.
3. Gravity keeps our food on our plates and our drinks in our glasses.
4. Gravity keeps the Earth in orbit around the sun and keeps us warm.

It is the universal force of attraction that acts between all bodies that have mass. Though it is the weakest of the four known forces, it shapes the structure and evolution of stars, galaxies, and the entire universe. The laws of gravity describe the trajectories of bodies in the solar system and the motion of objects on Earth, where all bodies experience a downward gravitational force exerted by Earth’s mass, the force experienced as weight.

Isaac Newton was the first to develop a quantitative theory of gravitation, holding that the force of attraction between two bodies is proportional to the product of their masses and inversely proportional to the square of the distance between them. Albert Einstein proposed a whole new concept of gravitation, involving the four-dimensional continuum of space-time which is curved by the presence of matter. In his general theory of relativity, he showed that a body undergoing uniform acceleration is indistinguishable from one that is stationary in a gravitational field. * Gravity also keeps the water on the Earth, the inhabitants on Earth, and the Earth’s atmosphere in its place. Gravity Welcome to Gravity Benefits Most companies spend a significant amount of money on employee benefits, but those employee and health benefit programs are commonly underutilized and improperly structured for maximum results.Growing a company and managing employees and benefits solutions can leave little time to orchestrate the optimum employee and health benefit solution. Gravity Benefits experience and different approach guides businesses in making smart choices about their:

1. Health Benefits
2. Wellness Benefits
3. Retirement Benefits
4. Executive Benefit Programs
5. Individual Health and Life Insurance Plans
6. pulls rain and snow down to our rivers.

What is the Use of Gravity?

The obvious answer is that gravity helps to keep everything on the ground.In addition it:

1. keeps planets and moon in their orbits
2. causes tides in the ocean
3. collects material to form planets and suns
4. powers the fusion processes in stars
5. provides potential energy to run tubines at power plants
6. lets things dall “down”
7. bends light
8. provides direction for seeds to grow “up”
9. helps you balance
10. lets pendulums keep time

History of gravitational theory

Scientific revolution

Modern work on gravitational theory began with the work of Galileo Galilei in the late 16th and early 17th centuries. In his famous (though possibly apocryphal) experiment dropping balls from the Tower of Pisa, and later with careful measurements of balls rolling down inclines, Galileo showed that gravitation accelerates all objects at the same rate. This was a major departure from Aristotle’s belief that heavier objects accelerate faster. Galileo correctly postulated air resistance as the reason that lighter objects may fall more slowly in an atmosphere. Galileo’s work set the stage for the formulation of Newton’s theory of gravity.