A steam turbine
with the case opened. Such turbines produce most of the electricity used today. Electricity consumption and living standards are highly correlated. Electrification is believed to be the most important engineering achievement of the 20th century.
Technology ("science of craft", from Greek τέχνη, techne, "art, skill, cunning of hand"; and -λογία, -logia) is the collection of techniques, skills, methods, and processes used in the production of goods or services or in the accomplishment of objectives, such as scientific investigation. Technology can be the knowledge of techniques, processes, and the like, or it can be embedded in machines to allow for operation without detailed knowledge of their workings.
The simplest form of technology is the development and use of basic tools. The prehistoric discovery of how to control fire and the later Neolithic Revolution increased the available sources of food, and the invention of the wheel helped humans to travel in and control their environment. Developments in historic times, including the printing press, the telephone, and the Internet, have lessened physical barriers to communication and allowed humans to interact freely on a global scale.
Technology has many effects. It has helped develop more advanced economies (including today's global economy) and has allowed the rise of a leisure class. Many technological processes produce unwanted by-products known as pollution and deplete natural resources to the detriment of Earth's environment. Innovations have always influenced the values of a society and raised new questions of the ethics of technology. Examples include the rise of the notion of efficiency in terms of human productivity, and the challenges of bioethics.
Philosophical debates have arisen over the use of technology, with disagreements over whether technology improves the human condition or worsens it. Neo-Luddism, anarcho-primitivism, and similar reactionary movements criticize the pervasiveness of technology, arguing that it harms the environment and alienates people; proponents of ideologies such as transhumanism and techno-progressivism view continued technological progress as beneficial to society and the human condition.
is a test page published and promoted by the Web Standards Project
to expose web page rendering
flaws in web browsers
and other applications that render HTML
. It was developed in the spirit of Acid1
, a relatively narrow test of compliance with the Cascading Style Sheets
1.0 (CSS1) standard
, and was released on April 13, 2005. Like Acid1, an application passes the test if the way it displays the test page matches a reference image. Acid2 tests aspects of HTML markup, CSS 2.1 styling, PNG
images, and data URIs
. The Acid2 test page will be displayed correctly in any application that follows the World Wide Web Consortium
and Internet Engineering Task Force
specifications for these technologies. These specifications are known as web standards
because they describe how technologies used on the web are expected to function. While at the time of Acid2's release no web browser passed the test, Acid2 was designed with Microsoft Internet Explorer
particularly in mind. The creators of Acid2 were dismayed that Internet Explorer did not follow web standards and, consequently, Internet Explorer was prone to display web pages differently from other browsers. Acid2 represented a challenge to Microsoft to bring Internet Explorer in line with web standards, making it easier to design web pages that work as intended in any web browser.
In this month
Did you know...
was a pioneering American
scientist and one of the world's most distinguished cytogeneticists
. McClintock received her PhD
from Cornell University
in 1927, where she was a leader in the development of maize
cytogenetics; the field remained the focus of her research for the rest of her career. Her work was groundbreaking: she developed the technique to visualize maize chromosomes and used microscopic analysis to demonstrate many fundamental genetic concepts, including genetic recombination
—a mechanism by which chromosomes exchange information. She produced the first genetic map for maize, linking regions of the chromosome with physical traits, and she demonstrated the role of the telomere
, regions of the chromosome that are important in the conservation of genetic information. During the 1940s and 1950s, McClintock discovered transposition and using this system showed how genes
are responsible for turning on or off physical characteristics. Awards and recognition of her contributions to the field followed, including the Nobel Prize in Physiology or Medicine
awarded to her in 1983 for the discovery of genetic transposition
; she was the first and only woman to receive an unshared Nobel Prize in that category.
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