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2417) Donald Glaser

Gist:

Life

Donald Glaser was born in Cleveland, Ohio to Russian immigrants. His father was a businessman. After first studying at Case School of Applied Science in Cleveland, he later received his PhD in physics from California Institute of Technology, Pasadena, in 1949. He then moved to the University of Michigan in Ann Arbor, where he carried out the research that led to his Nobel Prize, before moving to the University of California, Berkeley, in 1959. Beginning in the 1960s, Glaser devoted himself to molecular biology. He was married twice and had two children from his first marriage.

Work

Our ability to study the smallest components of our world took a giant leap forward when C.T.R. Wilson invented the cloud chamber, where the trails of charged particles can be observed. Donald Glaser's invention of the bubble chamber in 1952 made it possible to study particles with higher energies. When charged particles rush forward through the chamber filled with a liquid at near-boiling point, they ionize atoms they pass by. When the pressure inside the chamber is then reduced, bubbles form around these charged atoms. The particles' tracks can then be photographed and analyzed.

Summary

Donald A. Glaser (born September 21, 1926, Cleveland, Ohio, U.S.—died February 28, 2013, Berkeley, California) was an American physicist and recipient of the 1960 Nobel Prize for Physics for his invention (1952) and development of the bubble chamber, a research instrument used in high-energy physics laboratories to observe the behaviour of subatomic particles.

After graduating from Case Institute of Technology, Cleveland, in 1946, Glaser attended the California Institute of Technology, Pasadena, where he received a Ph.D. in physics and mathematics in 1950. He then began teaching at the University of Michigan, where he became a professor in 1957.

Glaser conducted research with Nobelist Carl Anderson, who was using cloud chambers to study cosmic rays. Glaser, recognizing that cloud chambers had a number of limitations, created a bubble chamber to learn about the pathways of subatomic particles. Because of the relatively high density of the bubble-chamber liquid (as opposed to the vapour that filled cloud chambers), collisions producing rare reactions were more frequent and were observable in finer detail. New collisions could be recorded every few seconds when the chamber was exposed to bursts of high-speed particles from particle accelerators. As a result, physicists were able to discover the existence of a host of new particles, notably quarks. At the age of 34, Glaser became one of the youngest scientists ever to be awarded a Nobel Prize.

In 1959 Glaser joined the staff of the University of California, Berkeley, where he became a professor of physics and molecular biology in 1964. In 1971 he cofounded the Cetus Corp., a biotechnology company that developed interleukin-2 and interferon for cancer therapy. The firm was sold (1991) to Chiron Corp., which was later acquired by Novartis. In the 1980s Glaser turned to the field of neurobiology and conducted experiments on vision and how it is processed by the human brain.

Details

Donald Arthur Glaser (September 21, 1926 – February 28, 2013) was an American physicist and biologist who received the Nobel Prize in Physics in 1960 for his invention of the bubble chamber.

Personal life

Donald Arthur Glaser was born on September 21, 1926, in Cleveland, Ohio, to Russian Jewish immigrants, Lena and William J. Glaser, a businessman. He enjoyed music and played the piano, violin, and viola. He went to Cleveland Heights High School, where he became interested in physics as a means to understand the physical world.  He died in his sleep at the age of 86 on February 28, 2013, in Berkeley, California.

Education and career

Glaser attended Case School of Applied Science (now Case Western Reserve University), where he completed his Bachelor of Science degree in physics and mathematics in 1946.  During the course of his education there, he became especially interested in particle physics. He played viola in the Cleveland Philharmonic while at Case, and taught mathematics classes at the college after graduation. He continued on to the California Institute of Technology (Caltech), where he pursued his PhD in physics. His interest in particle physics led him to work with Nobel laureate Carl David Anderson, studying cosmic rays with cloud chambers.  He preferred the accessibility of cosmic ray research over that of nuclear physics. While at Caltech he learned to design and build the equipment he needed for his experiments,  and this skill would prove to be useful throughout his career. He also attended molecular genetics seminars led by Nobel laureate Max Delbrück;  he would return to this field later. Glaser completed his doctoral thesis, The Momentum Distribution of Charged Cosmic Ray Particles Near Sea Level, after starting as an instructor at the University of Michigan in 1949.  He received his PhD from Caltech in 1950, and he was promoted to professor at Michigan in 1957  He joined the faculty of UC Berkeley in 1959 as a professor of physics. During this time, his research concerned short-lived elementary particles. The bubble chamber enabled him to observe the paths and lifetimes of the particles. Starting in 1962, Glaser changed his field of research to molecular biology, starting with a project on ultraviolet-induced cancer. In 1964, he was given the additional title of professor of molecular biology. Glaser's position (since 1989) was professor of physics and neurobiology in the graduate school.

Bubble chamber

While teaching at Michigan, Glaser began to work on experiments that led to the creation of the bubble chamber.  His experience with cloud chambers at Caltech had shown him that they were inadequate for studying elementary particles. In a cloud chamber, particles pass through gas and collide with metal plates that obscure the scientists' view of the event. The cloud chamber also needs time to reset between recording events and cannot keep up with accelerators' rate of particle production.

He experimented with using superheated liquid in a glass chamber. Charged particles would leave a track of bubbles as they passed through the liquid, and their tracks could be photographed. He created the first bubble chamber with ether.  He experimented with hydrogen while visiting the University of Chicago, showing that hydrogen would also work in the chamber.

It has often been claimed that Glaser was inspired to his invention by the bubbles in a glass of beer; however, in a 2006 talk, he refuted this story, saying that although beer was not the inspiration for the bubble chamber, he did experiments using beer to fill early prototypes.

His new invention was ideal for use with high-energy accelerators,  so Glaser traveled to Brookhaven National Laboratory with some students to study elementary particles using the accelerator there. The images that he created with his bubble chamber brought recognition of the importance of his device, and he was able to get funding to continue experimenting with larger chambers. Glaser was then recruited by Nobel laureate Luis Alvarez,  who was working on a hydrogen bubble chamber at the University of California at Berkeley. Glaser accepted an offer to become a professor of physics there in 1959.

Nobel Prize

Glaser was awarded the 1960 Nobel Prize for Physics for the invention of the bubble chamber. His invention allowed scientists to observe what happens to high-energy beams from an accelerator, thus paving the way for many important discoveries.

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2686.

2476) The Alps

The Alps

Gist

The Alps are Europe's highest and most extensive mountain range, forming a crescent across eight countries (France, Switzerland, Italy, Austria, Germany, Slovenia, Liechtenstein, Monaco), famous for Mont Blanc, Matterhorn, stunning scenery, skiing, biodiversity, and unique climate zones, originating from tectonic plate collision and providing vital water sources for Europe.

Which countries are in the Alps?

They stretch across eight countries: France, Switzerland, Italy, Monaco, Liechtenstein, Austria, Germany and Slovenia. The mountains were formed millions of years ago as two giant tectonic plates collided, creating some of the highest mountains in Europe, like the Matterhorn, Mont Blanc, and the Eiger.

Summary

The Alps are some of the highest and most extensive mountain ranges in Europe, stretching approximately 1,200 km (750 mi) across eight Alpine countries (from west to east): Monaco, France, Switzerland, Italy, Liechtenstein, Germany, Austria, Slovenia, and Hungary.

The Alpine arch extends from Nice on the western Mediterranean to Trieste on the Adriatic and Vienna at the beginning of the Pannonian Basin. The mountains were formed over tens of millions of years as the African and Eurasian tectonic plates collided. Extreme shortening caused by the event resulted in marine sedimentary rocks rising by thrusting and folding into high mountain peaks such as Mont Blanc and the Matterhorn.

Mont Blanc spans the French–Italian border, and at 4,809 m (15,778 ft) is the highest mountain in the Alps. The Alpine region area contains 82 peaks higher than 4,000 m (13,000 ft).

The altitude and size of the range affect the climate in Europe; in the mountains, precipitation levels vary greatly and climatic conditions consist of distinct zones. Wildlife such as ibex live in the higher peaks to elevations of 3,400 m (11,155 ft), and plants such as edelweiss grow in rocky areas in lower elevations as well as in higher elevations.

Evidence of human habitation in the Alps goes back to the Palaeolithic era. A mummified man ("Ötzi"), determined to be 5,000 years old, was discovered on a glacier at the Austrian–Italian border in 1991.

By the 6th century BC, the Celtic La Tène culture was well established. Hannibal notably crossed the Alps with a herd of elephants, and the Romans had settlements in the region. In 1800, Napoleon crossed one of the mountain passes with an army of 40,000. The 18th and 19th centuries saw an influx of naturalists, writers, and artists, in particular, the Romanticists, followed by the Golden Age of Alpinism as mountaineers began to ascend the peaks of the Alps.

The Alpine region has a strong cultural identity. Traditional practices such as farming, cheese making, and woodworking still thrive in Alpine villages. However, the tourist industry began to grow early in the 20th century and expanded significantly after World War II, eventually becoming the dominant industry by the end of the century.

The Winter Olympic Games have been hosted in the Swiss, French, Italian, Austrian and German Alps. As of 2010, the region is home to 14 million people and has 120 million annual visitors.

Details

Alps, a small segment of a discontinuous mountain chain that stretches from the Atlas Mountains of North Africa across southern Europe and Asia to beyond the Himalayas. The Alps extend north from the subtropical Mediterranean coast near Nice, France, to Lake Geneva before trending east-northeast to Vienna (at the Vienna Woods). There they touch the Danube River and meld with the adjacent plain. The Alps form part of France, Italy, Switzerland, Germany, Austria, Slovenia, Croatia, Bosnia and Herzegovina, Montenegro, Serbia, and Albania. Only Switzerland and Austria can be considered true Alpine countries, however. Some 750 miles (1,200 kilometres) long and more than 125 miles wide at their broadest point between Garmisch-Partenkirchen, Germany, and Verona, Italy, the Alps cover more than 80,000 square miles (207,000 square kilometres). They are the most prominent of western Europe’s physiographic regions.

Though they are not as high and extensive as other mountain systems uplifted during the Paleogene and Neogene periods (i.e., about 65 million to 2.6 million years ago)—such as the Himalayas and the Andes and Rocky mountains—they are responsible for major geographic phenomena. The Alpine crests isolate one European region from another and are the source of many of Europe’s major rivers, such as the Rhône, Rhine, Po, and numerous tributaries of the Danube. Thus, waters from the Alps ultimately reach the North, Mediterranean, Adriatic, and Black seas. Because of their arclike shape, the Alps separate the marine west-coast climates of Europe from the Mediterranean areas of France, Italy, and the Balkan region. Moreover, they create their own unique climate based on both the local differences in elevation and relief and the location of the mountains in relation to the frontal systems that cross Europe from west to east. Apart from tropical conditions, most of the other climates found on the Earth may be identified somewhere in the Alps, and contrasts are sharp.

A distinctive Alpine pastoral economy that evolved through the centuries has been modified since the 19th century by industry based on indigenous raw materials, such as the industries in the Mur and Mürz valleys of southern Austria that used iron ore from deposits near Eisenerz. Hydroelectric power development at the end of the 19th and beginning of the 20th centuries, often involving many different watersheds, led to the establishment in the lower valleys of electricity-dependent industries, manufacturing such products as aluminum, chemicals, and specialty steels. Tourism, which began in the 19th century in a modest way, became, after World War II, a mass phenomenon. Thus, the Alps are a summer and winter playground for millions of European urban dwellers and annually attract tourists from around the world. Because of this enormous human impact on a fragile physical and ecological environment, the Alps are likely the most threatened mountain system in the world.

Physical features:

Geology

The Alps emerged during the Alpine orogeny, an event that began about 65 million years ago as the Mesozoic Era was drawing to a close. A broad outline helps to clarify the main episodes of a complicated process. At the end of the Paleozoic Era, about 250 million years ago, eroded Hercynian mountains, similar to the present Massif Central in France and Bohemian Massif embracing parts of Germany, Austria, Poland, and the Czech Republic, stood where the Alps are now located. A large landmass, formed of crystalline rocks and known as Tyrrhenia, occupied what is today the western Mediterranean basin, whereas much of the rest of Europe was inundated by a vast sea. During the Mesozoic (about 250 million to 65 million years ago) Tyrrhenia was slowly leveled by the forces of erosion. The eroded materials were carried southward by river action and deposited at the bottom of a vast ocean known as the Tethys Sea, where they were slowly transformed into horizontal layers of rock composed of limestone, clay, shale, and sandstone.

About 44 million years ago, relentless and powerful pressures from the south first formed the Pyrenees and then the Alps, as the deep layers of rock that had settled into the Tethys Sea were folded around and against the crystalline bedrock and raised with the bedrock to heights approaching the present-day Himalayas. These tectonic movements lasted until 9 million years ago. Tyrrhenia sank at the beginning of the Quaternary Period, about 2.6 million years ago, but remnants of its mass, such as the rugged Estéral region west of Cannes, are still found in the western Mediterranean. Throughout the Quaternary Period, erosive forces gnawed steadily at the enormous block of newly folded and upthrust mountains, forming the general outlines of the present-day landscape.

The landscape was further modeled during the Quaternary by Alpine glaciation and by expanding ice tongues, some reaching depths of nearly 1 mile (1.6 kilometres), that filled in the valleys and overflowed onto the plains. Amphitheatre-like cirques, arête ridges, and majestic peaks such as the Matterhorn and Grossglockner were shaped from the mountaintops; the valleys were widened and deepened into general U-shapes, and immense waterfalls, like the Staubbach and Trümmelbach falls in the Lauterbrunnen Valley of the Bernese Alps, poured forth from hanging valleys hundreds of feet above the main valley floors; elongated lakes of great depth such as Lake Annecy in France, Lake Constance, bordering Switzerland, Germany, and Austria, and the lakes of the Salzkammergut in Austria filled in many of the ice-scoured valleys; and enormous quantities of sands and gravels were deposited by the melting glaciers, and landslides—following the melting of much of the ice—filled in sections of the valley floors. The hills east of Sierre in the Rhône valley are an example of this last phenomenon, and they mark the French–German language divide in this area.

When the ice left the main valleys, there was renewed river downcutting, both in the lateral and transverse valleys. The river valleys have been eroded to relatively low elevations that are well below those of the surrounding mountains. Thus, Aosta, Italy, in the Pennine Alps, and Sierre, Switzerland, look up to peaks that tower a mile and a half above them. In the valley of the Arve River near Mont Blanc, the difference in relief is more than 13,100 feet.

Glaciation therefore modified what otherwise would have been a harsher physical environment: the climate was much milder in the valleys than on the surrounding heights, settlement could be established deeper into the mountains, communication was facilitated, and soils were inherently more fertile because of morainic deposits. Vigorous glacial erosion continues in modern times. Many hundreds of square miles of Alpine glaciers, such as those in the Ortles and Adamello ranges and such deep-valley glaciers as the Aletsch Glacier near Brig, Switzerland, are still found in the Alps. The summer runoff from these ice masses is instrumental in filling the deep reservoirs used to generate hydroelectricity.

Physiography

The Alps present a great variety of elevations and shapes, ranging from the folded sediments forming the low-lying pre-Alps that border the main range everywhere except in northwestern Italy to the crystalline massifs of the inner Alps that include the Belledonne and Mont Blanc in France, the Aare and Gotthard in Switzerland, and the Tauern in Austria. From the Mediterranean to Vienna, the Alps are divided into Western, Central, and Eastern segments, each of which consists of several distinct ranges.

The Western Alps trend north from the coast through southeastern France and northwestern Italy to Lake Geneva and the Rhône valley in Switzerland. Their forms include the low-lying arid limestones of the Maritime Alps near the Mediterranean, the deep cleft of the Verdon Canyon in France, the crystalline peaks of the Mercantour Massif, and the glacier-covered dome of Mont Blanc, which at 15,771 feet (4,807 metres) is the highest peak in the Alps. Rivers from these ranges flow west into the Rhône and east into the Po.

The Central Alps occupy an area from the Great St. Bernard Pass east of Mont Blanc on the Swiss-Italian border to the region of the Splügen Pass north of Lake Como. Within this territory are such distinctive peaks as the Dufourspitze, Weisshorn, Matterhorn, and Finsteraarhorn, all 14,000 feet high. In addition, the great glacial lakes—Como and Maggiore in the south, part of the drainage system of the Po; and Thun, Brienz, and Lucerne (Vierwaldstättersee) in the north—fall within this zone.

The Eastern Alps, consisting in part of the Rätische range in Switzerland, the Dolomite Alps in Italy, the Bavarian Alps of southern Germany and western Austria, the Tauern Mountains in Austria, the Julian Alps in northeastern Italy and northern Slovenia, and the Dinaric Alps along the western edge of the Balkan Peninsula, generally have a northerly and southeasterly drainage pattern. The Inn, Lech, and Isar rivers in Germany and the Salzach and Enns in Austria flow into the Danube north of the Alps, while the Mur and Drau (Austria) and Sava (Balkan region) rivers discharge into the Danube east and southeast of the Alps. Within the Eastern Alps in Italy, Lake Garda drains into the Po, whereas the Adige, Piave, Tagliamento, and Isonzo pour into the Gulf of Venice.

Differences in relief within the Alps are considerable. The highest mountains, composed of autochthonous crystalline rocks, are found in the west in the Mont Blanc massif and also in the massif centring on Finsteraarhorn (14,022 feet) that divides the cantons of Valais and Bern. Other high chains include the crystalline rocks of the Mount Blanche nappe—which includes the Weisshorn (14,780 feet)—and the nappe of Monte Rosa Massif, sections of which mark the frontier between Switzerland and Italy. Farther to the east, Bernina Peak is the last of the giants over 13,120 feet (4,000 metres). In Austria the highest peak, the Grossglockner, reaches only 12,460 feet; Germany’s highest point, the Zugspitze in the Bavarian Alps, only 9,718 feet; and the highest point of Slovenia and the Julian Alps, Triglav, only 9,396 feet. Some of the lowest areas within the Western Alps are found at the delta of the Rhône River where the river enters Lake Geneva, 1,220 feet. In the valleys of the Eastern Alps north of Venice, elevations of only about 300 feet are common.

Climate of the Alps

The location of the Alps, as well as the great variations in their elevations and exposure, give rise to extreme differences in climate, not only among separate ranges but also within a particular range itself. Because of their central location in Europe, the Alps are affected by four main climatic influences: from the west flows the relatively mild, moist air of the Atlantic; cool or cold polar air descends from northern Europe; continental air masses, cold and dry in winter and hot in summer, dominate in the east; and, to the south, warm Mediterranean air flows northward. Daily weather is influenced by the location and passage of cyclonic storms and the direction of the accompanying winds as they pass over the mountains.

Temperature extremes and annual precipitation are related to the physiography of the Alps. The valley bottoms clearly stand out because generally they are warmer and drier than the surrounding heights. In winter nearly all precipitation above 5,000 feet is in the form of snow, and depths from 10 to 33 feet or more are common. Snow cover lasts from approximately mid-November to the end of May at the 6,600-foot level, blocking the high mountain passes; nevertheless, relatively snowless winters can occur. Mean January temperatures on the valley floors range from 23 to 39 °F (−5 to 4 °C) to as high as 46 °F (8 °C) in the mountains bordering the Mediterranean, whereas mean July temperatures range between 59 and 75 °F (15 and 24 °C). Temperature inversions are frequent, especially during autumn and winter, and the valleys often fill with fog and stagnant air for days at a time. At those times the levels above 3,300 feet can be warmer and sunnier than the low-lying valley bottoms. Winds can play a prominent role in daily weather and microclimatic conditions.

A foehn wind can last from two to three days and blows either south–north or north–south, depending on the tracking of cyclonic storms. The air mass of such a wind is cooled adiabatically as it passes upward to the mountain crests, which precipitates either rain or snow and retards the rate of cooling. When this drier air descends on the lee side, it is adiabatically warmed by compression at a constant rate and therefore has a higher temperature at the same altitude than when it began its upward flow. Snow in the affected areas disappears rapidly.

Avalanches, one of the great destructive forces of nature, are an ever-present danger during the period from late November to early June. Most follow well-defined paths, but much of the fear of avalanches is related to the difficulty of predicting where and when they will strike. Avalanches are a greater threat to human life and property in the Alps than in other mountain ranges because of the region’s relatively high population density and the tens of millions of tourists who visit each year. The development of ski resorts also has depleted many forests, which serve as natural barriers against avalanches.

Additional Information:

Geography:

The Alps are the highest and most extensive mountain range system that lie in south-central Europe. The mountain range stretches approximately 750 miles (1,200 kilometers) in a crescent shape across eight Alpine countries: France, Switzerland, Monaco, Italy, Liechtenstein, Austria, Germany, and Slovenia.

Ecology:

The Alps are an interzonal mountain system (Orobiome), or a “transition area” between Central and Mediterranean Europe. The Alps have high habitat diversity, with 200 habitats classified throughout the mountain range. This mountain range is home to a high level of biodiversity.

According to the World Wildlife Fund (WWF), there are over 4,500 species of plants, 200 bird species, 21 amphibian species, 15 reptile species, and 80 mammal species. Many of these species have made adaptations to the harsh cold conditions and high altitudes.

None of the 80 mammal species found in the Alps are “strictly” endemic, meaning they occur in the Alps and nowhere else in the world. Some of the larger carnivore species found in the Alps include the Eurasian lynx, the wolf, and the brown bear, and herbivores include the Alpine ibex, the chamois. These populations have been reduced in size or fragmented into small groups. There are also numerous rodent species found in the Alps, such as voles and marmots.

There are about 200 breeding bird species, as well as an equal number of migratory species, in the Alps. The largest bird species found in the Alps are the golden eagle and the bearded vulture. The alpine chough is the most common bird found in the region.

Of the 21 total species of amphibians, only one is endemic, Salamandra lanzai. There are fifteen reptile species present, including adders and vipers.

According to WWF, the Alps are one of the regions with the richest flora and fauna in Europe, second only to the Mediterranean. There are about 4,500 species of vascular plants, 800 species of mosses, 300 liverworts, 2500 lichens and more than 5000 fungi found in the Alps. About 8 percent of the vascular species are endemic. The variety of habitats in the Alps helps to promote the uniqueness of Alpine flora, along with the harsh environmental conditions that drive species to change and adapt.

Highest peak:

Mont Blanc is the highest peak at 15,776 feet (4,808 m). It is the second-highest and second most prominent mountain in Europe and the eleventh most prominent mountain summit in the world. The Mont Blanc massif spans across France, Italy, and Switzerland, while the summit itself lies on the border between France and Italy. There are about a hundred peaks higher than 13,000 ft (4,000 m) in the Alpine region.

Rivers:

The Alps provide lowland Europe with drinking water, irrigation, and hydroelectric power. Although the area is only about 11% of the surface area of Europe, the Alps provide up to 90% of water to lowland Europe. Major European rivers flow from the Alps, including the Rhine, the Rhône, the Inn, and the Po.

Glaciers:

The major glacierized areas in the Alps are situated along the crest of the mountain chain, with the largest glaciers often found at the highest elevations. There are smaller glaciers scattered throughout the Alps.

The Swiss Alps is known for glaciers, containing around 1,800 glaciers. The region’s glaciers include the longest glacier in the Alps: the Aletsch Glacier.

Additional Facts:

* At over 12 miles long and about a half-mile thick, the famous Aletsch valley glacier is the longest in the Alps, but due to climate change, the Aletsch is shrinking and predicted to completely melt by the end of this century.
* The Alps are Europe’s highest and most extensive mountain range.
* Mont Blanc is the highest mountain in the Alps, spanning 3 countries. Its granite ramparts distinguish it from other peaks. Mont Blanc’s ranges rose straight from the deep and are still rising, a phenomenon caused by glacial movement.
* The limestone Dolomites in Italy are half as high as Mont Blanc and were created as Africa’s collision with Europe pushed together an ancient tropical seafloor with the ancient skeletons of marine organisms into the sky.
* Humans have been living in the Alps since Paleolithic times, about 60,000 to 50,000 years ago. The Alpine region continues to have a strong cultural identity and its traditional culture of farming, cheesemaking, and woodworking still exists in Alpine villages. However, the tourism industry has been growing since the 20th century. While the region is home to 14 million people, it has 120 million annual visitors.

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#10711. What does the term in Geography Corrasion mean?

#10712. What does the term in Geography Coulee mean?

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#2550. What does the medical term Medulloblastoma mean?

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#9834.

Hi,

2685.