Squall

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Squall

A squall is a sudden, sharp increase in wind speed lasting minutes, as opposed to a wind gust, which lasts for only seconds. They are usually associated with active weather, such as rain showers, thunderstorms, or heavy snow. Squalls refer to the increase of the sustained winds over that time interval, as there may be higher gusts during a squall event. They usually occur in a region of strong sinking air or cooling in the mid-atmosphere. These force strong localized upward motions at the leading edge of the region of cooling, which then enhances local downward motions just in its wake.

Etymology

There are different versions of the word's origins:

• By one version, the word appears to be Nordic in origin, but its etymology is considered obscure. It probably has its roots in the word skvala an Old Norse word meaning literally to squeal.
• By another version, it is an alteration of squeal influenced by bawl.

Character of the wind

The term "squall" is used to refer to a sudden wind-speed increase lasting minutes. In 1962 the World Meteorological Organization (WMO) defined that to be classified as a "squall", the wind must increase at least 8 m/s and must attain a top speed of at least 11 m/s, lasting at least one minute in duration. In Australia, a squall is defined to last for several minutes before the wind returns to the long-term mean value. In either case, a squall is defined to last about half as long as the definition of sustained wind in its respective country. Usually, this sudden violent wind is associated with briefly heavy precipitation as squall line.

Regional terms

Argentina

Known locally as pamperos, these are characterized as strong downsloped winds that move across the pampas, eventually making it to the Atlantic Ocean.

Australia

In southeastern Australia, the colloquial name for a squall is southerly buster, which is an abrupt southerly wind change in the southern regions of New South Wales and Victoria, Australia, which approaches from the southeast, mainly on a hot day, bringing in cool, usually severe weather and a dramatic temperature drop, thus ultimately replacing and relieving the prior hot conditions.

Central America

Offshore Central America, a gully squall is characterized by strong increases of the wind forced through sharp mountain valleys on the Pacific Ocean side of the isthmus.

Cuba

A bayamo is a squall emanating from tropical thunderstorms near the Bight of Bayamo.

East Indies

In the East Indies, brubu is a name for a squall

Pacific Northwest (North America)

In the Pacific Northwest, a squall is a short but furious rainstorm with strong winds, often small in area and moving at high speed, especially as a maritime term. A strong Katabatic outflow occurring in fjords and inlets is referred to by mariners as a squamish.

South Africa

Bull's Eye Squall is a term used offshore South Africa for a squall forming in fair weather. It is named for the appearance of the small isolated cloud marking the top of the squall.

Philippines (West Pacific)

In most parts of the country, squalls are called subasko and are characterized by heavy rains driven by blustery winds. Local fishermen at sea are often on the lookout for signs of impending squalls on the open water and rush to shore at its early signs.

South-East Asia

"Barat" is a term for a northwest squall in Manado Bay in Sulawesi.

"Sumatra squall" is a term used in Singapore and Peninsular Malaysia for squall lines that form over the island of Sumatra and move east across the Straits of Malacca. Gusts can reach up to 28 m/s (100 km/h).

Severe weather

A shelf cloud such as this one can be a sign that a squall is imminent

A squall line is an organized line of thunderstorms. It is classified as a multi-cell cluster, meaning a thunderstorm complex comprising many individual updrafts. They are also called multi-cell lines. Squalls are sometimes associated with hurricanes or other cyclones, but they can also occur independently. Most commonly, independent squalls occur along front lines, and may contain heavy precipitation, hail, frequent lightning, dangerous straight line winds, and possibly funnel clouds, tornadoes and waterspouts. Squall lines require significant low-level warmth and humidity, a nearby frontal zone, and vertical wind shear from an angle behind the frontal boundary. The strong winds at the surface are usually a reflection of dry air intruding into the line of storms, which when saturated, falls quickly to ground level due to its much higher density before it spreads out downwind. Significant squall lines with multiple bow echoes are known as derechos.

Squall line life cycle

There are several forms of mesoscale meteorology, including simplistic isolated thunderstorms unrelated to advancing cold fronts, to the more complex daytime/nocturnal mesoscale convective system (MCS) and mesoscale convective complex (MCC), to squall line thunderstorms.

Formation

The main driving force behind squall line creation is attributed to the process of in-filling of multiple thunderstorms and/or a single area of thunderstorms expanding outward within the leading space of an advancing cold front.

Pressure perturbations

Pressure perturbations within an extent of a thunderstorm are noteworthy. With buoyancy rapid within the lower and mid-levels of a mature thunderstorm, one might believe that low pressure dominates in the mesoscale environment. However, this is not the case. With downdrafts ushering colder air from mid-levels, hitting ground and propagating away in all directions, high pressure is to be found widely at surface levels, usually indicative of strong (potentially damaging) winds.

Wind shear

A summer squall line in Southern Ontario, producing lightning and distant heavy rains.

Wind shear is an important aspect to measuring the potential of squall line severity and duration. In low to medium shear environments, mature thunderstorms will contribute modest amounts of downdrafts, enough to turn will aid in create a leading edge lifting mechanism – the gust front. In high shear environments created by opposing low level jet winds and synoptic winds, updrafts and consequential downdrafts can be much more intense (common in supercell mesocyclones). The cold air outflow leaves the trailing area of the squall line to the mid-level jet, which aids in downdraft processes.

Evolution

Updrafts

The leading area of a squall line is composed primarily of multiple updrafts, or singular regions of an updraft, rising from ground level to the highest extensions of the troposphere, condensing water and building a dark, ominous cloud to one with a noticeable overshooting top and anvil (thanks to synoptic scale winds). Because of the chaotic nature of updrafts and downdrafts, pressure perturbations are important.

As thunderstorms fill into a distinct line, strong leading-edge updrafts – occasionally visible to a ground observer in the form of a shelf cloud – may appear as an ominous sign of potential severe weather.

Beyond the strong winds because of updraft/downdraft behavior, heavy rain (and hail) is another sign of a squall line. In the winter, squall lines can occur albeit less frequently – bringing heavy snow and/or thunder and lightning – usually over inland lakes (i.e. Great Lakes region).

Bow echoes

Following the initial passage of a squall line, light to moderate stratiform precipitation is also common. A bow echo is frequently seen on the northern and southernmost reaches of squall line thunderstorms (via satellite imagery). This is where the northern and southern ends curl backwards towards the middle portions of the squall line, making a "bow" shape. Bow echoes are frequently featured within supercell mesoscale systems.

Mesolow

A wake low is a mesolow

The poleward end of the squall line is commonly referred to as the cyclonic end, with the equatorward side rotating anticyclonically. Because of the coriolis force, the poleward end may evolve further, creating a "comma shaped" mesolow, or may continue in a squall-like pattern.

A wake low is another kind of mesoscale low-pressure area to the rear of a squall line near the back edge of the stratiform rain area. Due to the subsiding warm air associated with the system's formation, clearing skies are associated with the wake low. Severe weather, in the form of high winds, can be generated by the wake low when the pressure difference between the mesohigh preceding it and the wake low is intense enough. When the squall line is in the process of decay, heat bursts can be generated near the wake low. Once new thunderstorm activity along the squall line concludes, the wake low associated with it weakens in tandem.

Dissipation

As supercells and multi-cell thunderstorms dissipate due to a weak shear force or poor lifting mechanisms, (e.g. considerable terrain or lack of daytime heating) the squall line or gust front associated with them may outrun the squall line itself and the synoptic scale area of low pressure may then infill, leading to a weakening of the cold front; essentially, the thunderstorm has exhausted its updrafts, becoming purely a downdraft dominated system. The areas of dissipating squall line thunderstorms may be regions of low CAPE, low humidity, insufficient wind shear, or poor synoptic dynamics (e.g. an upper-level low filling) leading to frontolysis.

From here, a general thinning of a squall line will occur: with winds decaying over time, outflow boundaries weakening updrafts substantially and clouds losing their thickness.

Signs in the sky

Shelf clouds and roll clouds are usually seen above the leading edge of a squall, also known as a thunderstorm's gust front. From the time these low cloud features appear in the sky, one can expect a sudden increase in the wind in less than 15 minutes.

Tropical cyclones

Tropical cyclones normally have squalls coincident with spiral bands of greater curvature than many mid-latitude systems due to their smaller size. These squalls can harbor waterspouts and tornadoes due to the significant vertical wind shear which exists in the vicinity of a tropical cyclone's outer bands.

Winter weather

Snow squalls can be spawned by an intrusion of cold air aloft over a relatively warm surface layer. Lake-effect snows can be in the form of a snow squall.

Control engineering

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Control_engineering 

Control systems play a critical role in space flight.

Control engineering or control systems engineering is an engineering discipline that deals with control systems, applying control theory to design equipment and systems with desired behaviors in control environments. The discipline of controls overlaps and is usually taught along with electrical engineering and mechanical engineering at many institutions around the world.

The practice uses sensors and detectors to measure the output performance of the process being controlled; these measurements are used to provide corrective feedback helping to achieve the desired performance. Systems designed to perform without requiring human input are called automatic control systems (such as cruise control for regulating the speed of a car). Multi-disciplinary in nature, control systems engineering activities focus on implementation of control systems mainly derived by mathematical modeling of a diverse range of systems.

Overview

Modern day control engineering is a relatively new field of study that gained significant attention during the 20th century with the advancement of technology. It can be broadly defined or classified as practical application of control theory. Control engineering plays an essential role in a wide range of control systems, from simple household washing machines to high-performance fighter aircraft. It seeks to understand physical systems, using mathematical modelling, in terms of inputs, outputs and various components with different behaviors; to use control system design tools to develop controllers for those systems; and to implement controllers in physical systems employing available technology. A system can be mechanical, electrical, fluid, chemical, financial or biological, and its mathematical modelling, analysis and controller design uses control theory in one or many of the time, frequency and complex-s domains, depending on the nature of the design problem.

Control engineering is the engineering discipline that focuses on the modeling of a diverse range of dynamic systems (e.g. mechanical systems) and the design of controllers that will cause these systems to behave in the desired manner. Although such controllers need not be electrical, many are and hence control engineering is often viewed as a subfield of electrical engineering.

Electrical circuits, digital signal processors and microcontrollers can all be used to implement control systems. Control engineering has a wide range of applications from the flight and propulsion systems of commercial airliners to the cruise control present in many modern automobiles.

In most cases, control engineers utilize feedback when designing control systems. This is often accomplished using a PID controller system. For example, in an automobile with cruise control the vehicle's speed is continuously monitored and fed back to the system, which adjusts the motor's torque accordingly. Where there is regular feedback, control theory can be used to determine how the system responds to such feedback. In practically all such systems stability is important and control theory can help ensure stability is achieved.

Although feedback is an important aspect of control engineering, control engineers may also work on the control of systems without feedback. This is known as open loop control. A classic example of open loop control is a washing machine that runs through a pre-determined cycle without the use of sensors.

History

See also: Control systems § History

Control of fractionating columns is one of the more challenging applications.

Automatic control systems were first developed over two thousand years ago. The first feedback control device on record is thought to be the ancient Ktesibios's water clock in Alexandria, Egypt, around the third century BCE. It kept time by regulating the water level in a vessel and, therefore, the water flow from that vessel. This certainly was a successful device as water clocks of similar design were still being made in Baghdad when the Mongols captured the city in 1258 CE. A variety of automatic devices have been used over the centuries to accomplish useful tasks or simply just to entertain. The latter includes the automata, popular in Europe in the 17th and 18th centuries, featuring dancing figures that would repeat the same task over and over again; these automata are examples of open-loop control. Milestones among feedback, or "closed-loop" automatic control devices, include the temperature regulator of a furnace attributed to Drebbel, circa 1620, and the centrifugal flyball governor used for regulating the speed of steam engines by James Watt in 1788.

In his 1868 paper "On Governors", James Clerk Maxwell was able to explain instabilities exhibited by the flyball governor using differential equations to describe the control system. This demonstrated the importance and usefulness of mathematical models and methods in understanding complex phenomena, and it signaled the beginning of mathematical control and systems theory. Elements of control theory had appeared earlier but not as dramatically and convincingly as in Maxwell's analysis.

Control theory made significant strides over the next century. New mathematical techniques, as well as advances in electronic and computer technologies, made it possible to control significantly more complex dynamical systems than the original flyball governor could stabilize. New mathematical techniques included developments in optimal control in the 1950s and 1960s followed by progress in stochastic, robust, adaptive, nonlinear control methods in the 1970s and 1980s. Applications of control methodology have helped to make possible space travel and communication satellites, safer and more efficient aircraft, cleaner automobile engines, and cleaner and more efficient chemical processes.

Before it emerged as a unique discipline, control engineering was practiced as a part of mechanical engineering and control theory was studied as a part of electrical engineering since electrical circuits can often be easily described using control theory techniques. In the very first control relationships, a current output was represented by a voltage control input. However, not having adequate technology to implement electrical control systems, designers were left with the option of less efficient and slow responding mechanical systems. A very effective mechanical controller that is still widely used in some hydro plants is the governor. Later on, previous to modern power electronics, process control systems for industrial applications were devised by mechanical engineers using pneumatic and hydraulic control devices, many of which are still in use today.

Control systems

The centrifugal governor is an early proportional control mechanism.

A control system manages, commands, directs, or regulates the behavior of other devices or systems using control loops. It can range from a single home heating controller using a thermostat controlling a domestic boiler to large industrial control systems which are used for controlling processes or machines. The control systems are designed via control engineering process.

For continuously modulated control, a feedback controller is used to automatically control a process or operation. The control system compares the value or status of the process variable (PV) being controlled with the desired value or setpoint (SP), and applies the difference as a control signal to bring the process variable output of the plant to the same value as the setpoint.

For sequential and combinational logic, software logic, such as in a programmable logic controller, is used.

Control theory

Control theory is a field of control engineering and applied mathematics that deals with the control of dynamical systems in engineered processes and machines. The objective is to develop a model or algorithm governing the application of system inputs to drive the system to a desired state, while minimizing any delay, overshoot, or steady-state error and ensuring a level of control stability; often with the aim to achieve a degree of optimality.

To do this, a controller with the requisite corrective behavior is required. This controller monitors the controlled process variable (PV), and compares it with the reference or set point (SP). The difference between actual and desired value of the process variable, called the error signal, or SP-PV error, is applied as feedback to generate a control action to bring the controlled process variable to the same value as the set point. Other aspects which are also studied are controllability and observability. Control theory is used in control system engineering to design automation that have revolutionized manufacturing, aircraft, communications and other industries, and created new fields such as robotics.

Extensive use is usually made of a diagrammatic style known as the block diagram. In it the transfer function, also known as the system function or network function, is a mathematical model of the relation between the input and output based on the differential equations describing the system.

Control theory dates from the 19th century, when the theoretical basis for the operation of governors was first described by James Clerk Maxwell. Control theory was further advanced by Edward Routh in 1874, Charles Sturm and in 1895, Adolf Hurwitz, who all contributed to the establishment of control stability criteria; and from 1922 onwards, the development of PID control theory by Nicolas Minorsky.

Although a major application of mathematical control theory is in control systems engineering, which deals with the design of process control systems for industry, other applications range far beyond this. As the general theory of feedback systems, control theory is useful wherever feedback occurs - thus control theory also has applications in life sciences, computer engineering, sociology and operations research.

Education

At many universities around the world, control engineering courses are taught primarily in electrical engineering and mechanical engineering, but some courses can be instructed in mechatronics engineering, and aerospace engineering. In others, control engineering is connected to computer science, as most control techniques today are implemented through computers, often as embedded systems (as in the automotive field). The field of control within chemical engineering is often known as process control. It deals primarily with the control of variables in a chemical process in a plant. It is taught as part of the undergraduate curriculum of any chemical engineering program and employs many of the same principles in control engineering. Other engineering disciplines also overlap with control engineering as it can be applied to any system for which a suitable model can be derived. However, specialised control engineering departments do exist, for example, in Italy there are several master in Automation & Robotics that are fully specialised in Control engineering or the Department of Automatic Control and Systems Engineering at the University of Sheffield or the Department of Robotics and Control Engineering at the United States Naval Academy and the Department of Control and Automation Engineering at the Istanbul Technical University.

Control engineering has diversified applications that include science, finance management, and even human behavior. Students of control engineering may start with a linear control system course dealing with the time and complex-s domain, which requires a thorough background in elementary mathematics and Laplace transform, called classical control theory. In linear control, the student does frequency and time domain analysis. Digital control and nonlinear control courses require Z transformation and algebra respectively, and could be said to complete a basic control education.

Careers

A control engineer's career starts with a bachelor's degree and can continue through the college process. Control engineer degrees are well paired with an electrical or mechanical engineering degree. Control engineers usually get jobs in technical managing where they typically lead interdisciplinary projects. There are many job opportunities in aerospace companies, manufacturing companies, automobile companies, power companies, and government agencies. Some places that hire Control Engineers include companies such as Rockwell Automation, NASA, Ford, and Goodrich. Control Engineers can possibly earn $66k annually from Lockheed Martin Corp. They can also earn up to $96k annually from General Motors Corporation.

According to a Control Engineering survey, most of the people who answered were control engineers in various forms of their own career. There are not very many careers that are classified as "control engineer," most of them are specific careers that have a small semblance to the overarching career of control engineering. A majority of the control engineers that took the survey in 2019 are system or product designers, or even control or instrument engineers. Most of the jobs involve process engineering or production or even maintenance, they are some variation of control engineering.

Recent advancement

Originally, control engineering was all about continuous systems. Development of computer control tools posed a requirement of discrete control system engineering because the communications between the computer-based digital controller and the physical system are governed by a computer clock. The equivalent to Laplace transform in the discrete domain is the Z-transform. Today, many of the control systems are computer controlled and they consist of both digital and analog components.

Therefore, at the design stage either digital components are mapped into the continuous domain and the design is carried out in the continuous domain, or analog components are mapped into discrete domain and design is carried out there. The first of these two methods is more commonly encountered in practice because many industrial systems have many continuous systems components, including mechanical, fluid, biological and analog electrical components, with a few digital controllers.

Similarly, the design technique has progressed from paper-and-ruler based manual design to computer-aided design and now to computer-automated design or CAD which has been made possible by evolutionary computation. CAD can be applied not just to tuning a predefined control scheme, but also to controller structure optimisation, system identification and invention of novel control systems, based purely upon a performance requirement, independent of any specific control scheme.

Resilient control systems extend the traditional focus of addressing only planned disturbances to frameworks and attempt to address multiple types of unexpected disturbance; in particular, adapting and transforming behaviors of the control system in response to malicious actors, abnormal failure modes, undesirable human action, etc.

Kola Superdeep Borehole

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Kola_Superdeep_Borehole

 

Kola Superdeep Borehole

Superstructure of the Kola Superdeep Borehole, 2007
Location
Location	Pechengsky District
Province	Murmansk Oblast
Country	Russia
Coordinates	69.3965°N 30.6100°E
Production
Type	Scientific borehole
Greatest depth	12,262 metres (40,230 ft)
History
Opened	1965
Active	1970–1983 1984 1985–1992
Closed	1995

The Kola Superdeep Borehole (Russian: Кольская сверхглубокая скважина, romanized: Kol'skaya sverkhglubokaya skvazhina) SG-3 is the result of a scientific drilling project of the Soviet Union in the Pechengsky District, near the Russian border with Norway, on the Kola Peninsula. The project attempted to drill as deep as possible into the Earth's crust.

Drilling began on 24 May 1970 using the Uralmash-4E, and later the Uralmash-15000 series drilling rig, and it became the deepest manmade hole in history in 1979. The 23 centimetres (9 in) diameter boreholes were drilled by branching from a central hole. The deepest reached 12,262 metres (40,230 ft; 7.619 mi) in 1989, the deepest human-made hole on Earth, and remains so as of 2023.

In terms of true vertical depth, it remains the deepest borehole in the world. For two decades, it was also the world's longest borehole in terms of measured depth along the well bore (that is, borehole length) until it was surpassed in 2008 by the 12,289 metres (40,318 ft; 7.636 mi) long Al Shaheen Oil Well in Qatar.

Drilling

Kola Superdeep Borehole, commemorated on a 1987 USSR stamp

Drilling began on 24 May 1970 using the Uralmash-4E, a serial drilling rig used for drilling oil wells. The rig was slightly modified to be able to reach a 7,000-meter (23,000 ft) depth. In 1974, the new purpose-built Uralmash-15000 drilling rig was installed onsite, named after the new target depth, set at 15,000 metres (49,000 ft).

On 6 June 1979, the world depth record held by the Bertha Rogers hole in Washita County, Oklahoma, United States, at 9,583 meters (31,440 ft), was broken. In October 1982, the first hole reached 11,662 metres (38,261 ft), and the second hole was started in January 1983 from a 9,300 metres (30,500 ft) depth of the first hole.

In 1983, the drill passed 12,000 metres (39,000 ft) in the second hole, and drilling was stopped for about a year for numerous scientific and celebratory visits to the site.

This idle period may have contributed to a breakdown after drilling resumed; on 27 September 1984, after drilling to 12,066 metres (39,587 ft), a 5 metres (16 ft) section of the drill string twisted off and was left in the hole. Drilling was restarted in September 1986, 7,000 metres (23,000 ft) from the first hole.

The third hole reached 12,262 metres (40,230 ft) in 1989. In that year, the hole depth was expected to reach 13,500 metres (44,300 ft) by the end of 1990 and 15,000 metres (49,000 ft) by 1993.

In June 1990, a breakdown occurred in the third hole at 12,262 metres (40,230 ft) of depth. The drilling of the fourth hole was started in January 1991 from 9,653 metres (31,670 ft) of depth of third hole. The drilling of the fourth hole was stopped in April 1992 at 11,882 metres (38,983 ft) of depth. Drilling of the fifth hole started in April 1994 from 8,278 metres (27,159 ft) of depth of the third hole. Drilling was stopped in August 1994 at 8,578 metres (28,143 ft) of depth due to lack of funds and the well itself was mothballed.

During the drilling process, unexpectedly no basaltic layers were found at seven kilometers down or at any depth in the borehole. Prior to that, geological information about the earth's crust was mostly based on analyzing seismic waves that indicated discontinuity. Scientific models had previously suggested basalt should be seen. Instead, the actual geological evidence from the borehole revealed there were more granites, and at much greater depths than scientists had considered. It was then thought by scientists that seismic discontinuity was caused by granite metamorphosis instead of basalts. In addition to this, water was unexpectedly found at three to six kilometers deep. Water was not naturally vaporizing at any depth in the borehole. Instead, water was found at these greater depths. Scientific models previously had not predicted water to be found at such great depths. It was discovered that deep granites can be fractured and receive water this deep. As a result of these findings, many scientists now theorize that aquifers of water can be found at much greater depths than older scientific models had previously thought possible.

Research

The Kola Superdeep Borehole penetrated about a third of the way through the Baltic Shield continental crust, estimated to be around 35 kilometres (22 mi) deep, reaching Archean rocks at the bottom. The project has been a site of extensive geophysical examinations. The stated areas of study were the deep structure of the Baltic Shield, seismic discontinuities and the thermal regime in the Earth's crust, the physical and chemical composition of the deep crust and the transition from upper to lower crust, lithospheric geophysics, and to create and develop technologies for deep geophysical study.

To scientists, one of the more fascinating findings to emerge from this well is that no transition from granite to basalt was found at the depth of about seven kilometres (4.3 mi), where the velocity of seismic waves has a discontinuity. Instead, the change in the seismic wave velocity is caused by a metamorphic transition in the granite rock. In addition, the rock at that depth had been thoroughly fractured and was saturated with water, which was surprising. This water, unlike surface water, must have come from deep-crust minerals and had been unable to reach the surface because of a layer of impermeable rock.

Microscopic plankton fossils were found six kilometres (3.7 mi) below the surface.

Another unexpected discovery was a large quantity of hydrogen gas. The drilling mud that flowed out of the hole was described as "boiling" with hydrogen.

In 1992, an international geophysical experiment obtained a reflection seismic crustal cross-section through the well. The Kola-92 working group consisted of researchers from the universities of Glasgow and Edinburgh in the United Kingdom, the University of Wyoming in the United States, and the University of Bergen in Norway, as well as several Russian earth science research institutions. The experiment was documented in a video recorded by Professor David Smythe, which shows the drilling deck in action during an attempt to recover a tool dropped down the hole.

Status

The borehole site in 2012

 

The borehole (welded shut), August 2012

The drilling terminated in 1995 due to a lack of funds. The scientific team was transferred to the federal state unitary subsidiary enterprise "Kola Superdeep", reduced and reoriented to a thorough study of the exposed section. In 2007, the scientific team was dissolved and the equipment was transferred to a private company and partially liquidated.

In 2008, the company was liquidated due to unprofitability, and the site was abandoned. The site is still visited by curious sightseers, who have reported that the structure over the borehole has been partially destroyed or removed.

Similar projects

• The United States had embarked on a similar project in 1957, dubbed Project Mohole, which was intended to penetrate the shallow crust under the Pacific Ocean off of Mexico. After initial drilling, the project was abandoned in 1966 when funding was cut off. This program inspired the Ocean Drilling Program, Integrated Ocean Drilling Program, and the present International Ocean Discovery Program.
• The KTB superdeep borehole (German Continental Deep Drilling Programme, 1987–1995) at Windischeschenbach in northern Bavaria was drilled to a depth of 9,101 metres (29,859 ft), reaching temperatures of more than 260 °C (500 °F). Its ambitious measuring program used high-temperature logging tools that were upgraded specifically for KTB.
• In 2023, China embarked on a 10,000 m super-deep borehole in the Tarim Basin in the Xinjiang region for scientific, oil and gas exploration.

Records

The Kola Superdeep Borehole was both the longest and deepest borehole in the world from 1989 to 2008. In May 2008, the Kola Superdeep Borehole's record length (but not record depth) was surpassed by a curved borehole of the extended reach drilling well BD-04A in the Al Shaheen Oil Field in Qatar, with a total length of 12,289 metres (40,318 ft) and a horizontal reach of 10,902 metres (35,768 ft). In terms of depth below the surface, the Kola Superdeep Borehole SG-3 retains the world record at 12,262 metres (40,230 ft) reached in 1989 and is still the deepest artificial point on Earth.

Scientific literacy

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Scientific_literacy 

Scientific literacy or science literacy encompasses written, numerical, and digital literacy as they pertain to understanding science, its methodology, observations, and theories. Scientific literacy is chiefly concerned with an understanding of the scientific method, units and methods of measurement, empiricism and understanding of statistics in particular correlations and qualitative versus quantitative observations and aggregate statistics, as well as a basic understanding of core scientific fields, such as physics, chemistry, biology, ecology, geology and computation.

Definition

The OECD PISA Framework (2015) defines scientific literacy as "the ability to engage with science-related issues, and with the ideas of science, as a reflective citizen." A scientifically literate person, therefore, is willing to engage in reasoned discourse about science and technology which requires the competencies to:

• Explain phenomena scientifically – recognize, offer and evaluate explanations for a range of natural and technological phenomena.
• Evaluate and design scientific inquiry – describe and appraise scientific investigations and propose ways of addressing questions scientifically.
• Interpret data and evidence scientifically – analyze and evaluate data, claims and arguments in a variety of representations and draw appropriate scientific conclusions.

According to the United States National Center for Education Statistics, "scientific literacy is the knowledge and understanding of scientific concepts and processes required for personal decision making, participation in civic and cultural affairs, and economic productivity". A scientifically literate person is defined as one who has the capacity to:

• Understand, experiment, and reason as well as interpret scientific facts and their meaning.
• Ask, find, or determine answers to questions derived from curiosity about everyday experiences.
• Describe, explain, and predict natural phenomena.
• Read articles with understanding of science in the popular press and engage in social conversation about the validity of the conclusions.
• Identify scientific issues underlying national and local decisions and express positions that are scientifically and technologically informed.
• Evaluate the quality of scientific information on the basis of its source and the methods used to generate it.
• Pose and evaluate arguments based on evidence and to apply conclusions from such arguments appropriately.

Scientific literacy may also be defined in language similar to the definitions of ocean literacy, Earth science literacy and climate literacy. Thus a scientifically literate person can:

• Understand the science relevant to environmental and social issues.
• Communicate clearly about the science.
• Make informed decisions about these issues.

Finally, scientific literacy may involve particular attitudes toward learning and using science. Scientifically-literate citizens are capable of researching matters of fact for themselves.

History

Reforms in science education in the United States have often been driven by strategic challenges such as the launch of the Sputnik satellite in 1957 and the Japanese economic boom in the 1980s. The phrase "science literacy" was popularized by Paul Hurd in 1958, when he charged that the immediate problem in education was "one of closing the gap between the wealth of scientific achievement and the poverty of scientific literacy in America". For Hurd, rapid innovation in science and technology demanded an education "appropriate for meeting the challenges of an emerging scientific revolution." Underlying Hurd's call was the idea "that some mastery of science is essential preparation for modern life."

Initial definitions of science literacy included elaborations of the content that people should understand, often following somewhat traditional lines (biology, chemistry, physics). Earth science was somewhat narrowly defined as expanded geological processes. In the decade after those initial documents, ocean scientists and educators revised the notion of science literacy to include more contemporary, systems-oriented views of the natural world, leading to scientific literacy programs for the ocean, climate, earth science, and so on.

Since the 1950s, scientific literacy has increasingly emphasized scientific knowledge being as socially situated and heavily influenced by personal experience. Science literacy is seen as a human right and a working knowledge of science and its role in society is seen as a requirement for responsible members of society, one that helps average people to make better decisions and enrich their lives. In the United States, this change in emphasis can be noted in the late 1980s and early 1990s, with the publication of Science for All Americans and Benchmarks for Science Literacy.

The National Science Education Standards (1996) defined scientific literacy as "the knowledge and understanding of scientific concepts and processes required for personal decision making, participation in civic and cultural affairs, and economic productivity". In addition, it emphasized that scientific literacy was not simply a matter of remembering specific scientific content. It involved the development of key abilities or skills. "Scientific literacy means that a person can ask, find, or determine answers to questions derived from curiosity about everyday experiences. It means that a person has the ability to describe, explain, and predict natural phenomena."

Some emphasize the importance of an underlying "ethos" that makes it possible to participate in scientific debates and communities. Key norms are that the observations and hypotheses of scientific discovery are part of a communally shared process; that ideas are important, not the status of the person who voices them; that what matters is disinterested evidence, not desired outcomes; and that statements that go beyond observations should be subject to testing.

More recently, calls for "scientific literacy" have identified misinformation and disinformation as dangers. They suggest that civic science literacy, digital media science literacy, and cognitive science literacy are all important components of education, if individuals are to be scientifically informed and engage in individual and collective decision-making in a democratic society.

Comparisons of the views of citizens and scientists by the Pew Research Center suggest that they hold very different positions on a range of science, engineering and technology-related issues. Both citizens and scientists rate K-12 STEM education in the U.S. poorly.

Science, society, and the environment

The interdependence of humans and our natural environment is at the heart of scientific literacy in the Earth systems. As defined by nationwide consensus among scientists and educators, this literacy has two key parts. First, a literate person is defined, in language that echoes the above definition of scientific literacy. Second, a set of concepts are listed, organized into six to nine big ideas or essential principles. This defining process was undertaken first for ocean literacy, then for the Great Lakes, estuaries, the atmosphere, and climate. Earth science literacy is one of the types of literacy defined for Earth systems; the qualities of an Earth science literate person are representative of the qualities for all the Earth system literacy definitions.

According to the Earth Science Literacy Initiative, an Earth-science-literate person:

• understands the fundamental concepts of Earth’s many systems
• knows how to find and assess scientifically credible information about Earth
• communicates about Earth science in a meaningful way
• is able to make informed and responsible decisions regarding Earth and its resources

All types of literacy in Earth systems have a definition like the above. Ocean literacy is further defined as "understanding our impact on the ocean and the ocean's impact on us". Similarly, the climate literacy website includes a guiding principle for decision making; "humans can take action to reduce climate change and its impacts". Each type of Earth systems literacy then defines the concepts students should understand upon graduation from high school. Current educational efforts in Earth systems literacy tend to focus more on the scientific concepts than on the decision-making aspect of literacy, but environmental action remains as a stated goal.

The theme of science in a socially-relevant context appears in many discussions of scientific literacy. Ideas that turn up in the life sciences include an allusion to ecological literacy, the "well-being of earth". Robin Wright, a writer for Cell Biology Education, laments "will [undergraduates'] misunderstandings or lack of knowledge about science imperil our democratic way of life and national security?" A discussion of physics literacy includes energy conservation, ozone depletion and global warming. The mission statement of the Chemistry Literacy Project includes environmental and social justice. Technological literacy is defined in a three-dimensional coordinate space; on the knowledge axis, it is noted that technology can be risky, and that it "reflects the values and culture of society". Energy Literacy boasts several websites, including one associated with climate literacy.

Attitudes as part of scientific literacy

Attitudes about science can have a significant effect on scientific literacy. In education theory, understanding of content lies in the cognitive domain, while attitudes lie in the affective domain. Thus, negative attitudes, such as fear of science, can act as an affective filter and an impediment to comprehension and future learning goals. In the United States, student attitudes toward science are known to decline beginning in fourth grade and continue to decline through middle and high school. This beginning of negative feelings about science stems from a greater emphasis put on grades. Students begin to feel that they are achieving less which causes them to lose motivation in the classroom and student participation drops. It has been well documented that students who retain high motivation for learning will have a more positive attitude toward the subject. Studies of college students' attitudes about learning physics suggest that these attitudes may be divided into categories of real world connections, personal connections, conceptual connections, student effort and problem-solving.

The decision-making aspect of science literacy suggests further attitudes about the state of the world, one's responsibility for its well-being and one's sense of empowerment to make a difference. These attitudes may be important measures of science literacy, as described in the case of ocean literacy.

In the K-12 classroom, learning standards do not commonly address the affective domain due to the difficulty in developing teaching strategies and in assessing student attitude. Many modern teaching strategies have been shown to have positive impacts on student attitudes toward science including the use of student-centered instruction, innovative learning strategies and utilizing a variety of teaching techniques. Project-based learning has also been shown to improve student attitudes about a subject and improve their scientific processing skills.

Teachers can use Likert scales or differential scales to determine and monitor changes in student attitudes towards science and science learning.

Promoting and measuring

Proponents of scientific literacy tend to focus on what is learned by the time a student graduates from high school. Science literacy has always been an important element of the standards movement in education. All science literacy documents have been drafted with the explicit intent of influencing educational standards, as a means to drive curriculum, teaching, assessment, and ultimately, learning nationwide. Moreover, scientific literacy provides an important basis for making informed social decisions. Science is a human process carried out in a social context, which makes it relevant as a part of our science education. In order for people to make evidence-informed decision, everyone should seek to improve their scientific literacy.

Relevant research has suggested ways to promote scientific literacy to students more efficiently. Programs to promote scientific literacy among students abound, including several programs sponsored by technology companies, as well as quiz bowls and science fairs. A partial list of such programs includes the Global Challenge Award, the National Ocean Sciences Bowl and Action Bioscience.

Some organizations have attempted to compare the scientific literacy of adults in different countries. The Organisation for Economic Co-operation and Development found that scientific literacy in the United States is not measurably different from the OECD average. Science News reports "The new U.S. rate, based on questionnaires administered in 2008, is seven percentage points behind Sweden, the only European nation to exceed the Americans. The U.S. figure is slightly higher than that for Denmark, Finland, Norway and the Netherlands. And it’s double the 2005 rate in the United Kingdom (and the collective rate for the European Union)."

University educators are attempting to develop reliable instruments to measure scientific literacy, and the use of concept inventories is increasing in the fields of physics, astronomy, chemistry, biology and earth science.

Colonization of the asteroid belt

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Colonization_of_the_asteroid_belt 

 

See also: List of exceptional asteroids

Main Asteroid Belt 42 largest asteroids

  Amor asteroid belt

  Apollo asteroid belt

  Aten asteroid belt

Asteroids, including those in the asteroid belt have been suggested as a possible site of human colonization. Some of the driving forces behind this effort to colonize asteroids include the survival of humanity, as well as economic incentives associated with asteroid mining. The process of colonizing asteroids does have many obstacles that must be overcome for human habitation, including transportation distance, lack of gravity, temperature, radiation, and psychological issues.

Space habitats

Main article: Space habitat

Most asteroids have minerals that could be mined. Because these bodies do not have substantial gravity wells, only a low delta-V is needed to haul materials to a construction site.

There is estimated to be enough material in the main asteroid belt alone to build enough space habitats to equal the habitable surface area of 3,000 Earths.

Ceres

Ceres is a dwarf planet and the largest body in the asteroid belt. As it is cryovolcanic it has potential for asteroid mining of resources for colonization. Its gravitational pull is stronger than other bodies in the asteroid belt, making surface colonization a more realistic possibility.

Driving forces

Main article: Space and survival

One of the primary arguments for space colonization is to ensure the long-term survival of the human species. In the event of worldwide artificial or natural disaster a space colony would allow the human species to continue on. Michael Griffin, the NASA administrator in 2006, stated the case as follows:

“... the goal isn't just scientific exploration ... it's also about extending the range of human habitat out from Earth into the solar system as we go forward in time ... In the long run a single-planet species will not survive ... If we humans want to survive for hundreds of thousands or millions of years, we must ultimately populate other planets.” 

A specific argument for asteroid colonization is the potential economic gain from asteroid mining. Asteroids contain a significant amount of valuable materials, including rare minerals and precious metals, which can be mined and transported back to Earth to be sold. With approximately as much iron as the world produces in 100,000 years, 16 Psyche is one such asteroid worth approximately $10 quintillion in metallic iron and nickel. NASA is planning a mission for October 10, 2023 for the Psyche orbiter to launch and get to the asteroid by August 2029 to study. 511 Davida could have $27 quadrillion worth of minerals and resources.

NASA estimates that between 1.1 and 1.9 million asteroids in the asteroid belt are larger than 1 kilometer in diameter. Millions are smaller. Approximately 8% of known main belt asteroids are similar in composition to 16 Psyche. One company, Planetary Resources, is already aiming to develop technologies with the goal of using them to mine asteroids. Planetary Resources estimates some 30-meter long asteroids to contain as much as $25 to $50 billion worth of platinum.

Transportation

Ceres space elevator concept
Surface gravity is

• 0.284 m/s²
• 0.029 g

less than 3% of Earth's

Ceres gravity train concept

Interplanetary spaceflight is a challenge because the asteroid belt is far, hundreds of millions of miles or km away. A human mission to Mars, tens of millions of miles or km, is similarly challenging. The Mars rover mission, for example, took 253 days to get to Mars. Russia, China, and the European Space Agency ran an experiment, called MARS-500, between 2007 and 2011 to gauge the physical and psychological limitations of crewed space flight. The experiment concluded that 18 months of solitude was the limit for a crewed space mission. With current technology the journey to the asteroid belt would be greater than 18 months, suggesting that a crewed mission may be beyond our current technological capabilities.

Landing

See also: List of minor planets and comets visited by spacecraft

Asteroids are not large enough to produce significant gravity, making it difficult to land a spacecraft. Humans have yet to land a spacecraft on an asteroid in the asteroid belt, but uncrewed spacecraft have temporarily landed on a few asteroids, the first of which in 2001 was 433 Eros, a NEA from the Amor group, more recently 162173 Ryugu, another NEA of the Apollo group. This was part of the Hayabusa2 mission that was conducted by the Japanese Space Agency. The landing used four solar ionic thrusters and four reaction wheels for orientation control and orbit control of the spacecraft to land on Ryugu. These technologies may be applied to complete a successful similar landing in the asteroid belt.

Mining the Asteroid Belt from Mars

See also: Category:Main-belt_asteroids, Amor asteroids, and Apollo asteroids

The asteroids of the inner Solar System and Jupiter: The belt is located between the orbits of Jupiter and Mars.

Sun   Jupiter trojans   Orbits of planets

Asteroid belt   Hilda asteroids (Hildas)   Near-Earth objects (selection)

Since Mars is much closer to the Asteroid belt than Earth is, it would take less Delta-v to get to the Asteroid belt and return minerals to Mars. One hypothesis is that the origin of the Moons of Mars (Phobos and Deimos) are actually Asteroid captures from the Asteroid belt. Using the moon Phobos to launch spacecraft is energetically favorable and a useful location from which to dispatch missions to main belt asteroids. Mining the asteroid belt from Mars and its moons could help in the Colonization of Mars.

A space elevator based on Phobos could reduce the cost of transport. See Colonization_of_Mars#Transportation

• 

  Space elevator Phobos

• 

  Earth vs Mars vs Moon gravity at elevation

Challenges for human habitation

Gravity

Lack of gravity has many adverse effects on human biology. Transitioning gravity fields has the potential to impact spatial orientation, coordination, balance, locomotion, and induce motion sickness. Asteroids, without artificial gravity, have relatively little gravity in comparison to earth. Without gravity working on the human body, bones lose minerals, and bone density decreases by 1% monthly. In comparison, the rate of bone loss for the elderly is between 1-1.5% yearly. The excretion of calcium from bones in space also places those in low gravity at a higher risk of kidney stones. Additionally, a lack of gravity causes fluids in the body to shift towards the head, possibly causing pressure in the head and vision problems.

Overall physical fitness tends to decrease as well, and proper nutrition becomes much more important. Without gravity, muscles are engaged less and overall movement is easier. Without intentional training, muscle mass, cardiovascular conditioning and endurance will decrease.

Artificial gravity

Artificial gravity offers a solution to the adverse effects of zero gravity on the human body. One proposition to implement artificial gravity on asteroids, investigated in a study conducted by researchers at the University of Vienna, involves hollowing out and rotating a celestial body. Colonists would then live within the asteroid, and the centrifugal force would simulate Earth's gravity. The researchers found that while it may be unclear as to whether asteroids would be strong enough maintain the necessary spin rate, they could not rule out such a project if the dimensions and composition of the asteroid were within acceptable levels.

Currently, there are no practical large-scale applications of artificial gravity for spaceflight or colonization efforts due to issues with size and cost. However, a variety of research labs and organizations have performed a number of tests utilizing human centrifuges to study the effects of prolonged sustained or intermittent artificial gravity on the body in an attempt to determine feasibility for future missions such as long-term spaceflight and space colonization. A research team at the University of Colorado Boulder found that they were able to make all participants in their study feel comfortable at approximately 17 revolutions per minute in a human centrifuge, without the motion sickness that tends to plague most trials of small-scale applications of artificial gravity. This offers an alternative method which may be more feasible considering the significantly reduced cost in comparison to larger structures.

Temperature

Most asteroids are located in the asteroid belt, between Mars and Jupiter. This is a cold region, with temperatures ranging from -73 degrees Celsius to -103 degrees. Human life will require a consistent energy source for warmth.

Radiation

In space, cosmic rays and solar flares create a lethal radiation environment. Cosmic radiation has the potential to increase risk of heart disease, cancer, central nervous system disorder, and acute radiation syndrome. On Earth, we are protected by a magnetic field and our atmosphere, but asteroids lack this defense.

One possibility for defense against this radiation is living inside of an asteroid. It is estimated that humans would be sufficiently protected from radiation by burrowing 100 meters deep inside of an asteroid. However, the composition of asteroids creates an issue for this solution. Many asteroids are loosely organized rubble piles with very little structural integrity.

Psychology

Space travel has a huge impact on human psychology, including changes to brain structure, neural interconnectivity, and behavior.

Cosmic radiation has the ability to impact the brain, and has been studied extensively on rats and mice. These studies show the animals suffer from decreases in spatial memory, neural interconnectivity, and memory. Additionally, the animals had an increase in anxiety and fear.

The isolation of space and difficulty sleeping in the environment also contribute to psychological impacts. The difficulty of speaking with those on earth can contribute to loneliness, anxiety, and depression. A Russian study simulated the psychological impacts of extended space travel. Six healthy males from various countries but with similar educational backgrounds to astronauts lived inside an enclosed module for 520 days in 2010–11. The members of the survey reported symptoms of moderate depression, abnormal sleep cycles, insomnia, and physical exhaustion.

In addition, NASA reports that missions on the global scale have ended or been halted due to mental issues. Some of these issues include shared mental delusions, depression, and becoming distressed from failed experiments.

However, in many astronauts, space travel can actually have a positive mental impact. Many astronauts report an increase of appreciation for the planet, purpose, and spirituality. This mainly results from the view of Earth from space.