Assignment Example | Topics and Well Written Essays - 500 words - 44

Assignment Example These two ends help the cells mix properly with water. Phospholipid bilayers contain transport and receptor proteins, which help the transport substances in and out of the cell. The plasma membrane is a semi-permeable membrane; it allows the substances needed for the functioning of the cell to enter, while filters out the rest. Also, the membrane helps maintain a cell potential inside the cell that assists in communication and the exchange of signals from outside the cell (Pandey, 2010) The three steps for cellular respiration are glycolysis, The Krebs cycle, and the electron transport chain. Glycolysis is the process in which glucose molecules are broken down from carbohydrates into pyruvates. In this process, a phosphate is removed from ATP, which becomes ADP, and is given to the glucose molecule, making it more chemically reactive. The Krebs cycle is an aerobic process, which means that it requires oxygen. It is a sequence of steps using enzymes as catalysts, which results in the complete oxidization of the Acetyl CoA molecule. The electron transport chain is the process in which most energy is released that has been trapped in the glucose molecule. The electron transport chain is a system of electron-carrying proteins that are found in the inner membrane of the mitochondria. The electrons are passed along these proteins and are finally joined with oxygen, which is the last electron acceptor (â€Å"Understanding Cellular Respiration†, n.d.) Respiration makes use of oxygen to perform the function of electron acceptor to form ATP. During fermentation, inorganic electron donors are used to form ATP such as sulfur and methane. Although both the processes use the same substances to produce ATP, they vary in their respective processes and the amount of energy that is released. Respiration results in the production of 38 ATP, while fermentation only manages to produce 2 ATP.

Management accountiong Essay Example | Topics and Well Written Essays - 2000 words

Management accountiong - Essay Example asure of two projects, this project favors the project with which has a higher present value though its likely to have a higher initial capital outlay, its not dependable when projects have different capital outlays. It's difficult to calculate as well as to understand and use in comparison with the pay back method or even the returns on the capital employed. Advantages of internal rate of return It considers the time value of money. It takes into account the total cash flows and outflows. It's easy to understand It's consistent with the overall objective of maximizing the shareholders wealth. Limitation of the internal rate of return It involves tedious calculation. It produces multiple rates which can be confusing. 3. ACTIVITY BASED COSTING This is a controlling and a planning tool which allocates costs to products in value chain analysis. It enables the overhead costs to be allocated to the respective product which incurred it rather than using the traditional methods where by the overhead costs were allocated as a percentage of the total overhead costs. It enables the managers to identify the products which incur higher costs therefore to charge them at a higher price or look for means to control these costs. 4. PEST ANALYSIS Political environment: These affect the operations of the business in UK; these laws encourage the existence of free markets where the market forces set the equilibrium hence there is fair competition. This encourages the supermarket to compete at a fair ground with its competitors. Economic environment: this affects the consumer consumption depending with the disposable income; this affects the way in which the supermarket will stock its products. Corporate taxes will also determine the manner in which it will price its products. If the...It enables the overhead costs to be allocated to the respective product which incurred it rather than using the traditional methods where by the overhead costs were allocated as a percentage of the total overhead costs. It enables the managers to identify the products which incur higher costs therefore to charge them at a higher price or look for means to control these costs. Political environment: These affect the operations of the business in UK; these laws encourage the existence of free markets where the market forces set the equilibrium hence there is fair competition. This encourages the supermarket to compete at a fair ground with its competitors. Economic environment: this affects the consumer consumption depending with the disposable income; this affects the way in which the supermarket will stock its products. Corporate taxes will also determine the manner in which it will price its products. If the taxes are very high then this will be reflected in the prices. Technology: the level of technology used in production affects the prices of the products of the supermarket, if the competitors are well off with better technology then are likely to have higher returns if the market prices are equal. Performance related pay is known to improve manager's production due to the fact that they have a budget against which controls them in using the firm resources.

Impact of Communication Technology on Politics and Economics

Impact of Communication Technology on Politics and Economics Impact of Communication Technologies on Political and Economic Development Joe Owczarski Introduction Modern-day society is witnessing the continuous creation of innovative mediums concerning communications technology that are not only convenient to use but inexpensive as well. Such digital communication tools include mobile phones, smart phones, and the Internet. It is not a secret that they have been successful in bringing a drastic revolution in the methods of information-sharing and communication. It is not surprising that these innovative technologies have impacted every aspect of peoples’ lives, be it political, religious, educational, professional, social, or economical. Innovations in information and communication technologies (ICTs) have not only increased the availability of innumerable products and services but have also reduced their prices. As a result, the inexpensiveness of and accessibility to ICTs have caused a great reduction in â€Å"the costs associated both with doing business and with organizing social and political movements† (Hart, 2010). The cheap availability of ICTs has also declined the costs of communication and transportation. From an economic point of view, there have been declines in the costs related to coordination and transaction. These declining patterns have consequently made the international trade and capital investment to reach extremely high levels. In addition, the cost reductions have also lessened the significance of geographical distances in international business. As distance has lost its importance in today’s digitalized world, there has been an increase in both political and economic activities due to the trending globalization (Hart, 2010). Impact of Cheap Communication Technologies on Politics and Political Development As far as politics is concerned, the inexpensive communication technologies have made a tremendous impact on both domestic and worldwide political phenomenon. In particular, the Internet and social media has contributed greatly in the development of political context and understanding. The blogs as well as the discussions and arguments that are conducted on the Web have provided people a platform to openly voice their views and beliefs regarding political aspects. Although a lot of people argue that social media and related communication technologies have nothing to contribute to politics; many oppose this point of view. Cheap communication technologies have played a major role in the contemporary era for making political processes more free, autonomous, and independent (Unwin, 2012). It would not be incorrect to state that the ICTs have offered exceptional liberties to the common man who is now able to dramatically impact the political phenomenon through cell phones, the Internet, and the social media sites. Communication technologies have emerged as a powerful tool for the politicians and governments as well. The political leaders and governmental authorities are capable of spreading their messages, agendas, and policies to the general public, directly and cheaply. For instance, mobile text messaging is now used by both political parties and governments to encourage public to vote for them in elections (Unwin, 2012). Likewise, the Internet and the social media is also playing a central role in making people aware about the current incidents that take place worldwide. Detailed stories and images enable people to receive the latest information about political movements and happenings around the world. In this manner, cheap communication technologies have enhanced global awareness. The example of Syria is an important one. This is because social media sites and other communication mediums have made people aware of the continuing conflicts in Syrian regime (Unwin 2012). It is true that the globalization phenomenon has interconnected the states and people. This interconnectedness has also influenced the opinions of people who use communication technologies to share their opinions with others. On a global level, globalization has also undermined the concept of a sovereign state. States are now interdependent due to global policies that have made it impossible for them to shield themselves from external influences. As people are beginning to use cheap communication technologies more progressively, there have been improvements in the overall communication between people belonging to diverse political regimes. These enhancements in ICTs have made it possible for people to share information and knowledge rapidly and easily. Moreover, the cheap communication technologies have also enhanced the fusion of different cultures. In addition, the acquired awareness has made people question the governmental authorities. As a matter of fact, revolutionary innovations in ICTs have undermined the autonomous and monarch status of particular political systems, such as the one in Middle East (Unwin, 2012). It can be concluded that the contemporary ICTs have offered remarkable opportunities to people to modify the rules of the long-established political game. On the other hand, even though cheap ICTs have tremendously changed the international political map, this revolution has not particularly affected the marginalized and poor people. Without a doubt the use of cheap communication technologies has impacted the political development and processes. Nevertheless, it completely depends on the individual’s observation whether he considers it a good or bad change (Healey, 2011). Impact of Cheap Communication Technologies on Economy and Economic Development As mentioned, communication technology in the current era has become extraordinarily cheap, user-friendly, and accessible. Although ICTs are taken for granted by people, communication devices and services have been triumphant in transforming economies as well as the lives of millions of people throughout the world. It is significant to mention that cheap communication technologies are being used by people in the developing countries in greater ways as compared to people belonging to the developed world. The penetration of information and communication technologies has a considerable impact on the economic development. ICTs have opened up new avenues for supporting economy in the recent times. Cheap communication technologies are acknowledged to have a significant impact on economic growth as they are affecting education, health sectors, agricultural output, income, poverty, and living standards. Communication technologies have tremendously facilitated the attainment and taking in of knowledge. They have offered extraordinary opportunities to developing countries for the enhancement of their educational systems, improvement of policy making and implementation, and widening of the assortment of opportunities for both affluent and the poor. It is important to highlight that ICTs have contributed in reducing the sense of isolation tolerated by poorest members of the society. It is not a secret that when poor are provided sufficient opportunities, they also contribute in the economic development of the country by playing their productive part. Thus, cheap communication technologies have opened access to knowledge, education, and employment in ways that could not be imagined in the past times (Reddi, 2011). The issues prevalent in society today mostly revolve around poverty. The economic development of a region principally depends on the standard and acquisition of education. This is because an educated society can efficiently and effectively work for the progression and development of its country. This realization has made almost every country to expand its demand for education at every level for the political, social, and economic development. However, many countries give limited budgets to their education sectors after facing the contrasting demand for better investment in resources that are necessary for human survival (food, shelter, etc.). However, the utilization and employment of communication technologies have offered alternate solutions to provide access and impartiality to students and teachers. ICTs have also suppressed the need for building schools and colleges. Instead, they have provided the concept of e-learning for convenient teaching and learning (Reddi, 2011). Cheap information and communication technologies have provided agriculturalists and farmers with opportunities to increase their yield and productivity, thus leading to economic progression. Mobile technology is considered to be an outstandingly critical tool for the improvement and enhancement of the competence of the agriculture and food sectors. Not only this, it is also regarded as a potential catalyst to help in raising the incomes of innumerable poor farmers found all over the world. This augmented efficiency is exceedingly important as it could lead to food losses in smaller quantity. A decrease in food losses means the growing demand for sufficient and inexpensive supplies of healthy food could be met eventually. When people are provided with self-sufficient resources, economy develops and grows automatically (Kirk, Steele, Delbà © Crow, 2011). The cheap communication technologies, especially mobile services, have enabled businesses, companies and organizations to directly contact and interact with different members in the value chain. This interrelation has also helped in visibility of issues, competence and excellence. The best potential benefits for the smallholder farmers can be spawned by enabling them to take advantage of mobile financial payments and mobile information provision. In India, for instance, the smallholder farmers of remote areas have benefitted from this service greatly as the mentioned services have each brought approximately 40% of the total anticipated raise in agricultural revenues (Kirk, Steele, Delbà © Crow, 2011). As a result, the country’s economy has grown significantly. In short, ICTs have enabled poor families to diminish their everyday expenditures related to physical labor, time, and energy. As a result, communication technologies have caused an exceptional positive impact on the i ncomes and livelihoods of many rural families. Communication technologies have also facilitated the reduction of â€Å"information gaps and restrictions inherent in marketplaces where consumers and producers have little means of comparing commodity prices between distant markets† (Zambrano Seward, 2010). ICTs are presently working as a catalytic tool in the improvement and expansion of development programming. In addition, the advancement in mobile technologies and their accessibility to rural areas have also contributed towards sustainable development. Thus, the technological change has introduced ways that have made the economic growth sustainable. The communication technologies are, in fact, sustainable technologies that are helping people and governments meet â€Å"the needs of the present without compromising the ability of future generations to meet their own needs† (Beder, 2006). Communication technologies have offered equal economic and employment opportunities to people who reside in cosmopolitan and rural areas. ICTs have not only increased productivity but have also made the market work extremely efficient. However, it is important to highlight that the extent of the economic growth outcomes can be different. ICT is a platform that has reached and will reach populations that have low literacy and income levels. Consequently, ICT is emerging as the leading distribution platform that provides public and private services to innumerable people. As there was no or negligible connectivity mediums in rural areas, the underdeveloped areas did not receive the deserved services and facilities. However, the emergence of ICTs has made it possible for underprivileged people to access financial services, market information, health services, and education services. In contrast, it is evident in the present times that the wireless platform has promoted new and innovative social and economic opportunities for the poor populace at all levels. Conclusion In closing, cheap communication technologies have brought significant changes in the traditional ways of socialization, business tasks’ execution, education attainment, and delivery of services. High-speed Internet, in particular, has changed the ways of doing businesses, transformation of public service delivery, and democratization of innovation. There is no doubt in the fact that the businesses that are using cheap communication technologies have demonstrated more production, faster growth, increased investment, and high profits. Similarly, governments and political parties that have employed cheap communication technologies are also receiving better outcomes in the development of democratic political structure. In short, cheap information and communication technologies have revealed a transformative power on a global level. It is important for the governments to realize the importance of ICT potentials and educate the populations about them in order to reduce poverty, increase economic development, and develop a fine political sense. Therefore, steps must be taken to educate people about the significance of employing ICTs in positive ways for the development and progression of today’s global village. Bibliography Beder, S. (2006).Environmental Principles and Policies: An Interdisciplinary Introduction. Hoboken: Taylor and Francis. Hart, J. (2010). Information Technologies and the Global Political Economy. InThe International Studies Encyclopedia. Chichester, West Sussex, U.K.: Wiley-Blackwell. Healey, J. (2011).Social Impacts of Digital Media. Thirroul, N.S.W.: Spinney Press. Reddi, U. R. V. (2011).Primer 1: An Introduction to ICT for Development. Asian and Pacific Training Centre for Information and Communication Technology for Development (APCICT). Unwin, T. (2012, September 1). Social Media and Democracy: Critical Reflections. Retrieved November 28, 2014, from http://www.cpahq.org/cpahq/cpadocs/Unwin CPA Social media and democracy.pdf Kirk, M., Steele, J. Delbà ©, C. Crow, L. (2011). Connected Agriculture: The Role of Mobile in Driving Efficiency and Sustainability in the Food and Agriculture Value Chain.Vodafone. Retrieved November 29, 2014, from http://www.vodafone.com/content/dam/vodafone/about/sustainability/2011/pdf/connected_agriculture.pdf Zambrano, R., Seward, R. (2010). Mobile Technologies and Empowerment: Enhancing Human Development Through Participation and Innovation. Retrieved November 29, 2014, from http://unpan1.un.org/intradoc/groups/public/documents/un-dpadm/unpan048480.pdf

Jesus Christ :: essays research papers

Jesus Christ   Ã‚  Ã‚  Ã‚  Ã‚  I think a great person to put on the postage stamp would be Jesus Christ. There are many reasons why Jesus would be a good choice. He was very influential to many people in the world. He was also a great person and a role model for a lot of people. Jesus changed a lot of peoples live and countless people praise him and honor him everyday. Jesus was a great person and leader to many. I think since Jesus Christ is such an influence he deserves the honor of being on a postage stamp.   Ã‚  Ã‚  Ã‚  Ã‚  Jesus would be a great person for a postage stamp because he was a huge influence. Jesus Christ is one of the main figures of the Christianity religion branch. Jesus inspired many and was the son of God. He was perfect. Mostly everyone in the world knows that Jesus is an icon for the Christian faith and since over forty percent of the world’s population believes in Christianity, he is defiantly something many admire. There are an immense amount of places of worship called churches for Christians to praise Christianity. There are also radio stations and music as well as television channels and even movies. Vast amounts of people put Jesus to play major role as an influence to their life.   Ã‚  Ã‚  Ã‚  Ã‚  Another reason Jesus is a great person to put on postage stamps is because he was a great person and role model. Jesus was the only perfect human being. Jesus could do the impossible and make miracles happen. He was a supreme being. Jesus was the son of God and lived a simple life. He was not greedy, or selfish or promiscuous. Jesus was a wise and simple man who made all the right choices with the best intentions, he did not hate anyone. He only loved. Jesus would always end up being the better of the bunch by making good and righteous decisions. I think this is a very good reason why Jesus is a great role model. He was a kind, fair, and loving man. A man like Jesus should be on a postage stamp because he is an idol to many.   Ã‚  Ã‚  Ã‚  Ã‚  Jesus should be on a postage stamp on account of the fact that he is a commendable person who many people look up to and are influenced by.

Web Quest

Context clues Directions: Answer each question for the politician Huey Long. Use the internet and your favorite search engine to answer each of the questions. Each complete response for each author is worth 5 points 1. What was happening politically during the time this author was writing? During his time, there was poverty and homelessness due to the Great Depression. 2. Where was the author located? What nationality is the author? He was located in Louisiana and his nationality was the US 3. When was the author born? And, when did he die? August 30, 1893 – September 10, 1935 . What kinds of social problems would the author have observed? Name and explain three. It also extends to the ends his strategies and schemes for dealing with the social problems he identified by redistributing wealth. He didn't like the rich, and he expanded the freeway system.. redistributing wealth 5. What novels, short stories or articles did the author write which reflected those problems? List a m inimum of two. Every Man A King and My First Days in the White House 6. What were the author’s political beliefs and how might they have shaped his writing?He was highly liberal and very anti-Standard Oil. He pushed high taxes and wealth redistribution. 7. Did the author earn his living through writing alone or did he earn an additional income doing something else? What was the alternative employment if any? Huey Long earned money in many jobs. He won a debating scholarship, he spent four years as a traveling salesman, selling books, canned goods and patent medicines, as well as working as an auctioneer. In 1915, he passed the state bar exam in Louisiana and began private practice.

IEP Module for SED 104 Essays - Special Education, Free Essays

IEP Module for SED 104 Essays - Special Education, Free Essays IEP Module for SED 104 objectives: 1. familiarize yourself with the basic information of an IEP (who it is for, what it is for, when it is written, how it is written, how long it is viable) 2. identify the parts on an IEP and their purpose (PLAAFP, goals, SDI/SAS) 3. develop a plan for creating IEPs in the future (knowing what documents are needed, expectations and requirements) What you need to do to complete this module: Access the required resources KDE IEP documents access this link and download the following documents: Guidance Document for IEP Development IEP and Lesson Plan Development Handbook IEP PPT by Dr. Clarke Watch the videos on our expectations for developing IEPs: PLAAFP video Goals and Objectives video SDI and SAS video Using the information you reviewed above, answer the following questions in the column on the right. Upload your response into the Assignment section in Blackboard. IEP QuestionsAnswer the prompts in this column What does IEP stand for?Individualized Education Program How does a student qualify for an IEP?A student must undergo evaluation and go through assessments. Who writes an IEP? (Is it written by the Special Education teacher, General Education teacher, committee, etc.?) List the author/authors.a What types of information should you use to create an IEP? Define PLAAFP - what information should be included here?Present Level of Academic Achievement and Functional Performance. To establish a baseline of measurable information that serves as the starting point for developing goals. Fix these sentences and identify why it is not acceptable in a PLAAFP: John wont listen to the teachers. Kalil never does his work. Sada doesnt read at grade level. John will listen to the teachers Kalil always does his work Sada does read at grade level. In the PLAAFP, what kind of data should be included?Statement of how disability affects the students involvement and progress in the general curriculum, a description of how the disability affects the students academic achievement and functional performance in the relevant skill areas, logical cues for writing the accompanying goals. What is included in the considerations of special factors section?Positive behavioral interventions, language needs, If the student is blind or visually impaired they must be provided Braille or appropriate reading and writing media, Consider communication needs, Consider whether the child needs assistive technology devices and services. Why should we have measurable goals?It tells what a student can accomplish in 1 year. How often are IEPs written and reviewed?IEPs are reviewed at least once a year but they may be revised more often than just once a year. What is the difference between annual goals and benchmarks?Annual goals are goals that should be met over a years time. Benchmarks are a breakdown of goals by intervals. How often are we required to report progress?Depends on district, usually weekly data collection is required. Why dont we use the term regular education? What term do we use instead?The term we use now Is General Education because the term Regular places a label on being regular or irregular. What is specially designed instruction? What does it pertain to?SDI describes the types of unique instructional services needed by a child or youth with a disability to accomplish their IEP goals and objectives. What are supplementary aids and services? Who does it pertain to?Focus on student needs in the classroom/school, Emphasis on leveling the playing field for LRE, Helps provide adjustments to general curriculum in order to meet IEP goals. What are assessment accommodations, and when should they be used?Accommodations provide access to the same curriculum. What are program modifications and supports for school personnel?Modifications change the general curriculum by decreasing expectations and/or the complexity. What is least restrictive environment and how should it be recorded in an IEP? A Least Restrictive Environment is when a student with a disability has the opportunity to be educated with non-disabled peers. When including time for special education services, who is the service provider?The special educators, Educational Professionals, Counselors. When including time for related services, who could the providers be?Therapist, Social work services, Speech Pathology services, Physical Therapy. How do students qualify for extended school year services?The decision will be made by the childs IEP team. A meeting would be set up by the team. Who is required to have transition services? Include the age according to IDEA (federal requirements) and the age/grade listed in KY requirements (note: KY has chosen a different age than is required in federal regulations,

Five Great Problems in Theoretical Physics

Five Great Problems in Theoretical Physics In his controversial 2006 book The Trouble with Physics: The Rise of String Theory, the Fall of a Science, and What Comes Next, theoretical physicist Lee Smolin points out five great problems in theoretical physics. The problem of quantum gravity: Combine general relativity and quantum theory into a single theory that can claim to be the complete theory of nature.The foundational problems of quantum mechanics: Resolve the problems in the foundations of quantum mechanics, either by making sense of the theory as it stands or by inventing a new theory that does make sense.The unification of particles and forces: Determine whether or not the various particles and forces can be unified in a theory that explains them all as manifestations of a single, fundamental entity.The tuning problem: Explain how the values of the free constants in the standard model of particle physics are chosen in nature.The problem of cosmological mysteries: Explain dark matter and dark energy. Or, if they dont exist, determine how and why gravity is modified on large scales. More generally, explain why the constants of the standard model of cosmology, including the dark energy, have the values they do. Physics  Problem 1: The Problem of Quantum Gravity Quantum gravity is the effort in theoretical physics to create a theory that includes both general relativity and the standard model of particle physics. Currently, these two theories describe different scales of nature and attempt to explore the scale where they overlap yield results that dont quite make sense, like the force of gravity (or curvature of spacetime) becoming infinite. (After all, physicists never see real infinities in nature, nor do they want to!) Physics  Problem 2: The Foundational Problems of Quantum Mechanics One issue with understanding quantum physics is what the underlying physical mechanism involved is. There are many interpretations in quantum physics the classic Copenhagen interpretation, Hugh Everette IIs controversial Many Worlds Interpretation, and even more controversial ones such as the Participatory Anthropic Principle. The question that comes up in these interpretations revolves around what actually causes the collapse of the quantum wavefunction.   Most modern physicists who work with quantum field theory no longer consider these questions of interpretation to be relevant. The principle of decoherence is, to many, the explanation interaction with the environment causes the quantum collapse. Even more significantly, physicists are able to solve the equations, perform experiments, and practice physics without resolving the questions of what exactly is happening at a fundamental level, and so most physicists dont want to get near these bizarre questions with a 20-foot pole. Physics  Problem 3: The Unification of Particles and Forces There are four fundamental forces of physics, and the standard model of particle physics includes only three of them (electromagnetism, strong nuclear force, and weak nuclear force). Gravity is left out of the standard model. Trying to create one theory which unifies these four forces into a unified field theory is a major goal of theoretical physics. Since the standard model of particle physics is a quantum field theory, then any unification will have to include gravity as a quantum field theory, which means that solving problem 3 is connected with the solving of problem 1. In addition, the standard model of particle physics shows a lot of different particles   18 fundamental particles in all. Many physicists believe that a fundamental theory of nature should have some method of unifying these particles, so they are described in more fundamental terms. For example, string theory, the most well-defined of these approaches, predicts that all particles are different vibrational modes of fundamental filaments of energy, or strings. Physics  Problem 4: The Tuning Problem A theoretical physics model is a mathematical framework that, in order to make predictions, requires that certain parameters are set. In the standard model of particle physics, the parameters are represented by the 18 particles predicted by the theory, meaning that the parameters are measured by observation. Some physicists, however, believe that fundamental physical principles of the theory should determine these parameters, independent of measurement. This motivated much of the enthusiasm for a unified field theory  in the past and sparked Einsteins famous question Did God have any choice when he created the universe? Do the properties of the universe inherently set the form of the universe, because these properties just wont work if the form is different? The answer to this seems to be leaning strongly toward the idea that there is not only one universe that could be created, but that there are a wide range of fundamental theories (or different variants of the same theory, based on different physical parameters, original energy states, and so on) and our universe is just one of these possible universes. In this case, the question becomes why our universe has properties that seem to be so finely tuned to allow for the existence of life. This question is called the fine-tuning problem and has promoted some physicists to turn to the anthropic principle for an explanation, which dictates that our universe has the properties it does because if it had different properties, we wouldnt be here to ask the question. (A major thrust of Smolins book is the criticism of this viewpoint as an explanation of the properties.) Physics Problem 5: The Problem of Cosmological Mysteries The universe still has a number of mysteries, but the ones that most vex physicists are dark matter and dark energy. This type of matter and energy is detected by its gravitational influences, but cant be observed directly, so physicists are still trying to figure out what they are. Still, some physicists have proposed alternative explanations for these gravitational influences, which do not require new forms of matter and energy, but these alternatives are unpopular to most physicists. Edited by Anne Marie Helmenstine, Ph.D.