A natural disaster is a major adverse event resulting from natural processes of the Earth; examples include floods, hurricanes, tornadoes, volcanic eruptions, earthquakes, tsunamis, and other geologic processes. A natural disaster can cause loss of life or property damage,^[1] and typically leaves some economic damage in its wake, the severity of which depends on the affected population's resilience, or ability to recover and also on the infrastructure available.^[2]

An adverse event will not rise to the level of a disaster if it occurs in an area without vulnerable population.^[3][4] In a vulnerable area, however, such as Nepal during the 2015 earthquake, an earthquake can have disastrous consequences and leave lasting damage, requiring years to repair.

Volcanoes can cause widespread destruction and consequent disaster in several ways. The effects include the volcanic eruption itself that may cause harm following the explosion of the volcano or falling rocks. Second, lava may be produced during the eruption of a volcano, and so as it leaves the volcano the lava destroys many buildings, plants and animals due to its extreme heat . Third, volcanic ash generally meaning the cooled ash – may form a cloud, and settle thickly in nearby locations. When mixed with water this forms a concrete-like material. In sufficient quantity ash may cause roofs to collapse under its weight but even small quantities will harm humans if inhaled. Since the ash has the consistency of ground glass it causes abrasion damage to moving parts such as engines. The main killer of humans in the immediate surroundings of a volcanic eruption is the pyroclastic flows, which consist of a cloud of hot volcanic ash which builds up in the air above the volcano and rushes down the slopes when the eruption no longer supports the lifting of the gases. It is believed that Pompeii was destroyed by a pyroclastic flow. A lahar is a volcanic mudflow or landslide. The 1953 Tangiwai disaster was caused by a lahar, as was the 1985 Armero tragedy in which the town of Armero was buried and an estimated 23,000 people were killed.

A specific type of volcano is the supervolcano. According to the Toba catastrophe theory, 75,000 to 80,000 years ago a supervolcanic event at Lake Toba reduced the human population to 10,000 or even 1,000 breeding pairs, creating a bottleneck in human evolution.^[8] It also killed three-quarters of all plant life in the northern hemisphere. The main danger from a supervolcano is the immense cloud of ash, which has a disastrous global effect on climate and temperature for many years.

Representatives from Mexico, the USA and Canada met in Alberta, Canada, to examine the impact of scientific change on society and its governance. Preparing for the 1999 World Conference on Science, the group looked at many aspects of the links between science and society — strengths, weaknesses, benefits, pitfalls and possible future directions. The full report and its appendices summarizes the group’s reflections and is addressed to the World Conference on Science.

Brief presentations on four selected topics where the applications of science affect virtually everyone — agriculture and food production, genetic research in medicine, global change, and energy — helped to ground the discussion in real issues. By intention, many points raised cut across the specific introductory topics. The report groups the resulting discussion under six broad themes: science in transition; communication and education; North-South issues; economics versus sustainable development; science policy and ethics; and integrating issues.

The meeting was not intended to define an official North American position; rather, participants were invited in their capacity as professional scientists, to present their personal perspectives on the changing role of science in society and governance in an open forum. From this frank and penetrating exchange, a number of general observations and conclusions emerged that are relevant to the concept and agenda of the World Science Conference. These are accompanied by suggestions for action recommended by some or several participants.

Science in Transition

In the past, our scientific methods and institutions have tended to emphasize the study of individual natural processes rather than systems, analysis more than synthesis, and understanding nature more than predicting its behaviour. And in many instances, science has focussed on short-term, small-scale problems, often in monodisciplinary mode, rather than on long-term, large-scale or integrated problems. While these approaches and perspectives have built up a considerable base of knowledge and led to a vast portfolio of useful technologies, especially in the 20th century, many of the problems now facing humankind can be solved only if we approach science more holistically. Greater effort is needed to understand integrated natural systems on multiple time and space scales.

Scientific findings must also be applied at the right scales. The impact of technological interventions on individual people, communities and the environment must also be carefully considered. To do this, science needs to become more multidisciplinary and its practitioners should continue to promote cooperation and integration between the social and natural sciences. A holistic approach also demands that science draw on the contributions of the humanities (such as history and philosophy), local knowledge systems, aboriginal wisdom, and the wide variety of cultural values.

The influence of science on people’s lives is growing. While recent benefits to humanity are unparalleled in the history of the human species, in some instances the impact has been harmful or the long-term effects give causes for serious concerns. A considerable measure of public mistrust of science and fear of technology exists today. In part, this stems from the belief by some individuals and communities that they will be the ones to suffer the indirect negative consequences of technical innovations introduced to benefit only a privileged minority. The power of science to bring about change places a duty on scientists to proceed with great caution both in what they do and what they say. Scientists should reflect on the social consequences of the technological applications or dissemination of partial information of their work and explain to the public and policy makers alike the degree of scientific uncertainty or incompleteness in their findings. At the same time, though, they should not hesitate to fully exploit the predictive power of science, duly qualified, to help people cope with environmental change, especially in cases of direct threats like natural disasters or water shortages.

The current trend toward privatization in many countries is influencing the focus and practice of science. While in some instances the net result may be to increase research capacity and knowledge in selected areas, there is major concern that the trend may be undermining public-sector science, especially fundamental research and efforts to solve socially important problems of no interest to commercial enterprises. Patent protection of private intellectual property, for example, makes the job of public research more difficult. There is also concern over the social implications of private ownership and control of technology, and its effect on broad public scientific literacy, and on options for public choice.

Another major trend shaping science is globalization. The end of the Cold War, growing technology demand from emerging economies, world recognition of the interconnectedness of the planet’s biophysical systems and improved communications, especially via the Internet -- all these forces are boosting cross-border scientific cooperation and information exchange between individual researchers, institutions and governments. However, much of the expansion is occurring in just a handful of scientifically advanced countries. For science to be truly global, more effort is needed to ensure all countries, rich and poor, and a wide range of world cultures are included in collaborative research and technology transfer. This is especially important in areas like global climate change which will affect, sooner or later, all human beings. With the right policies in place, joint scientific work in critical areas such as the Arctic, for example, could serve as a model for other types of global cooperation.

A major challenge for global science is to find institutional arrangements conducive to success. The proliferation of international networks and programs, the so-called "acronym jungle", reflects a rather ad hoc approach, necessitated in part by the narrowness of purposes of established scientific institutions and the lack of strategic, integrated support by national governments in areas like global change or international aid. What is needed is the formation of true international partnerships that allow scientists in different disciplines and countries to fully support each other’s aims and share resources and management duties to mutual advantage.

Fifty years ago, the tools we rely upon to communicate today were only science fiction. Today, you can purchase a smartphone and make calls, surf the Web, play games, run applications and accomplish more than most speculative fiction authors dared to dream. So what's next?

In the short term, we'll likely see basic cell phones slowly fade away. As smartphones become more common and less expensive, more people will adopt them. The process is gradual. As with most new technologies, a group of enthusiastic adopters lead the way. Sometimes, the general population will follow the early pioneers -- the compact disc is a good example of such technology. In other cases, the early adopters end up owning technology that becomes obsolete without ever finding wide acceptance -- like LaserDiscs.

Smartphones seem to be in the first category. Products like the Apple iPhone and Google's Android operating system have pushed the smartphone out of the world of gadget geeks and into the mass market. In 2010, the first 4G smartphone for a major carrier in the United States made an appearance. It was the HTC EVO 4G, running on Sprint's WiMAX network [source: CNET]. The 4G network allows for faster data transfer speeds than other networks.

The Internet will continue to play an increasing role in communication. Voice over Internet protocol (VoIP) already plays a large role in several communication products and services. Sites like Facebook and Twitter allow users to communicate with networks of people. With the rise of the Web, people now have a platform from which they can address the world. In the past, only celebrities and politicians could address so many people at one time. Now, anyone with an Internet connection can do the same thing.

This may lead to changes in everything from entertainment to politics. Using the Web as a communication tool, people with aspirations may be able to find an audience more easily than ever before. It may not be long until a relatively unknown person uses the Internet to win enough support to be elected president of the United States.

So far we've looked at some fairly mundane advances in communication. But what about the distant future?

How many countries use English?

How is English important?

................ cx normal thôi mak

ngày thứ nhất bán được
          1245 x 1/3 = 415 ( cái áo )
còn lại số cái áo là :
          1245 - 415 = 830 ( cái áo )
ngày thứ 2 bán được
           830 x 2/5 = 332 ( cái áo )
2 ngày còn lại cửa hàng còn :
           1245 - 332 = 913 ( cái áo )
                      đáp số : 913 cái áo
​**** cho nhá 

bn thử search google chưa?

lấy vài ý rồi mik viết cho//

Phân số chỉ số quần áo còn lại là :

\(1-\frac{1}{3}=\frac{2}{3}\)( tổng số áo )

Sau lần bán thứ nhất cửa hàng còn lại số áo là :

\(1245\times\frac{2}{3}=830\)( cái áo )

Lần thứ 2 bán số ao là :

\(830\times\frac{2}{5}=332\)( cái áo )

Sau 2 ngày bán còn lại số áo là :

\(830-332=498\)( cái áo )