Sunday, March 21, 2010
STETHOSCOPE
The stethoscope was invented by the French physician R.T.H. Laënnec. René Théophile Hyacinthe Laënnec is generally considered to be the father of chest medicine.
History of the Stethoscope
The history of the monaural stethoscope and the binaural stethoscope.
Docteur Laennec
One day in 1816, Laennec is invited by urchins to hear to the scratching of a pin transmitted through the length of a wooden beam. He is thereby inspired to fashion a paper tube to listen to the chests of his patients.
History of the Stethoscope
The history of the monaural stethoscope and the binaural stethoscope.
Docteur Laennec
One day in 1816, Laennec is invited by urchins to hear to the scratching of a pin transmitted through the length of a wooden beam. He is thereby inspired to fashion a paper tube to listen to the chests of his patients.
INVENTION OF MOUSE
In 1964, the first prototype computer mouse was made to use with a graphical user interface (GUI), 'windows'. Engelbart received a patent for the wooden shell with two metal wheels (computer mouse U.S. Patent # 3,541,541) in 1970, describing it in the patent application as an "X-Y position indicator for a display system." "It was nicknamed the mouse because the tail came out the end," Engelbart revealed about his invention. His version of windows was not considered patentable (no software patents were issued at that time), but Douglas Engelbart has over 45 other patents to his name.
Throughout the '60s and '70s, while working at his own lab (Augmentation Research Center, Stanford Research Institute), Engelbart dedicated himself to creating a hypermedia groupware system called NLS (for oNLine System). Most of his accomplishments, including the computer mouse and windows, were part of NLS.
In 1968, a 90-minute, staged public demonstration of a networked computer system was held at the Augmentation Research Center -- the first public appearance of the mouse, windows, hypermedia with object linking and addressing, and video teleconferencing.
Douglas Engelbart was awarded the 1997 Lemelson-MIT Prize of $500,000, the world's largest single prize for invention and innovation. In 1998, he was inducted into the National Inventors Hall of Fame.
Currently, Douglas Engelbart is the director of his company, Bootstrap Institute in Fremont, California, which promotes the concept of Collective IQ. Ironically, Bootstrap is housed rent free courtesy of the Logitech Corp., a famous manufacturer of computer mice.
Throughout the '60s and '70s, while working at his own lab (Augmentation Research Center, Stanford Research Institute), Engelbart dedicated himself to creating a hypermedia groupware system called NLS (for oNLine System). Most of his accomplishments, including the computer mouse and windows, were part of NLS.
In 1968, a 90-minute, staged public demonstration of a networked computer system was held at the Augmentation Research Center -- the first public appearance of the mouse, windows, hypermedia with object linking and addressing, and video teleconferencing.
Douglas Engelbart was awarded the 1997 Lemelson-MIT Prize of $500,000, the world's largest single prize for invention and innovation. In 1998, he was inducted into the National Inventors Hall of Fame.
Currently, Douglas Engelbart is the director of his company, Bootstrap Institute in Fremont, California, which promotes the concept of Collective IQ. Ironically, Bootstrap is housed rent free courtesy of the Logitech Corp., a famous manufacturer of computer mice.
PYRAMIDS
Ancient Egypt was the home of one of the most advanced civilizations of its time.
Today, many historians are held in our memories in statues and paintings. However, the Ancient Egyptian Leaders held themselves in memory in a different way. Obsessed with the afterlife, years ago Egyptian rulers ordered thousands of slaves to move stone and rocks forming what we call today, the Pyramids. The pyramids were created to assist the kings of their time in walking on through the afterlife.
The beginning of the Old Kingdom is believed to be the construction of Djoser's monument. The construction project of Pharaoh Djoser's Step Pyramid started around 2620 B.C. It was created to amaze the ancient Egyptians, and amaze them is exactly what it did. The Step Pyramid rises to a height of 60 meters. Its base being 120 meters by 108 meters. Inside is a system of underground corridors and rooms. The main feature of the Step Pyramid is a central shaft 25 meters deep and 8 meters wide.
However, Djoser's pyramid was not exactly a pyramid. It was made more like steps, and not smooth on all sides like other pyramids. As the pyramids evolved, there where failures. Glorious failures, until they finally got the design just right. The first smooth sided, true pyramid was built at Meidum. When Snefru took the throne sometime near 2575 BC, Djoser's Step Pyramid was the only large royal pyramid that was completed. Snefru then became the greatest pyramid builder in Egyptian history by completing not one pyramid, but three. Many believe that building Djoser's pyramid, which was done by hundreds of workers, served to join the provinces into the world's first nation-state. During the Old Kingdom, which began around 2700 BC and lasted some 550 years, each pharaoh after Djoser marshaled a vast portion of his country's manpower and wealth to build his own tomb and ensure his immortality.
Two generations after Djoser's reign, the center of the Old Kingdom moved to the barren plateau of Giza. Three 4th dynasty pyramids were erected here; they are included among the Seven Wonders of the World. The one the farthest north and the oldest was built by Khufu (2558-2532 BC), the second king during the 4th dynasty. It was called the Great Pyramid. The middle pyramid was built by Khafre (2520 - 2494 BC), the fourth king of the 4th dynasty. The southern and last pyramid to be construction was of Menkaure (2532-2503 BC), the sixth king of the 4th dynasty.
Near 2465 B.C, about halfway through the Old Kingdom, pyramids suddenly became less important. No one knows why, but many scholars have suggested that after Khufu's pyramid, which took roughly 23 years to build, the kingdom grew weary with each Pharaoh's effort to outdo the last, several pharaohs died before the completion of their pyramids. A king would never again build a pyramid on a truly colossal scale. Instead the religious focus shifted from the pyramid itself toward the mortuary temple that stood to the east of it. As the culture grew more sophisticated, even the Pharaoh's unlimited power was beginning to fade.
To this very day, we continue to look in awe at the amazing marvels. For many years onward, they will remain important to all who see them. Just is it was important so many years ago.
Today, many historians are held in our memories in statues and paintings. However, the Ancient Egyptian Leaders held themselves in memory in a different way. Obsessed with the afterlife, years ago Egyptian rulers ordered thousands of slaves to move stone and rocks forming what we call today, the Pyramids. The pyramids were created to assist the kings of their time in walking on through the afterlife.
The beginning of the Old Kingdom is believed to be the construction of Djoser's monument. The construction project of Pharaoh Djoser's Step Pyramid started around 2620 B.C. It was created to amaze the ancient Egyptians, and amaze them is exactly what it did. The Step Pyramid rises to a height of 60 meters. Its base being 120 meters by 108 meters. Inside is a system of underground corridors and rooms. The main feature of the Step Pyramid is a central shaft 25 meters deep and 8 meters wide.
However, Djoser's pyramid was not exactly a pyramid. It was made more like steps, and not smooth on all sides like other pyramids. As the pyramids evolved, there where failures. Glorious failures, until they finally got the design just right. The first smooth sided, true pyramid was built at Meidum. When Snefru took the throne sometime near 2575 BC, Djoser's Step Pyramid was the only large royal pyramid that was completed. Snefru then became the greatest pyramid builder in Egyptian history by completing not one pyramid, but three. Many believe that building Djoser's pyramid, which was done by hundreds of workers, served to join the provinces into the world's first nation-state. During the Old Kingdom, which began around 2700 BC and lasted some 550 years, each pharaoh after Djoser marshaled a vast portion of his country's manpower and wealth to build his own tomb and ensure his immortality.
Two generations after Djoser's reign, the center of the Old Kingdom moved to the barren plateau of Giza. Three 4th dynasty pyramids were erected here; they are included among the Seven Wonders of the World. The one the farthest north and the oldest was built by Khufu (2558-2532 BC), the second king during the 4th dynasty. It was called the Great Pyramid. The middle pyramid was built by Khafre (2520 - 2494 BC), the fourth king of the 4th dynasty. The southern and last pyramid to be construction was of Menkaure (2532-2503 BC), the sixth king of the 4th dynasty.
Near 2465 B.C, about halfway through the Old Kingdom, pyramids suddenly became less important. No one knows why, but many scholars have suggested that after Khufu's pyramid, which took roughly 23 years to build, the kingdom grew weary with each Pharaoh's effort to outdo the last, several pharaohs died before the completion of their pyramids. A king would never again build a pyramid on a truly colossal scale. Instead the religious focus shifted from the pyramid itself toward the mortuary temple that stood to the east of it. As the culture grew more sophisticated, even the Pharaoh's unlimited power was beginning to fade.
To this very day, we continue to look in awe at the amazing marvels. For many years onward, they will remain important to all who see them. Just is it was important so many years ago.
HISTORY OF PYTHAGORAS
The History of Pythagoras and his Theorem
In this section you will learn about the life of Pythagoras and how it is that the theorem is known as the Pythagorean Theorem.
Be aware that there are no good records about the life of Pythagoras, so the exact dates and other issues are not known with certainty. In addition, the names of some of the people as well as the places where Pythagoras lived may have different spellings.
Pythagoras was born in the island of Samos in ancient Greece1. There is no certainty regarding the exact year when he was born, but it is believed that it was around 570 BC That is about 2,570 years ago! Those were times when a person believed in superstitions and had strong beliefs in gods, spirits, and the mysterious. Religious cults were very popular in those times.
Pythagoras of Samos
Pythagoras' father's name was Mnesarchus and may have been a Phoenician. His mother's name was Pythais. Mnesarchus made sure that his son would get the best possible education. His first teacher was Pherecydes, and Pythagoras stayed in touch with him until Pherecydes' death. When Pythagoras was about 18 years old he went to the island of Lesbos where he worked and learned from Anaximander, an astronomer and philosopher, and Thales of Miletus, a very wise philosopher and mathematician.
Thales had visited Egypt and recommended that Pythagoras go to Egypt. Pythagoras arrived in Egypt around 547 BC when he was 23 years old. He stayed in Egypt for 21 years learning a variety of things including geometry from Egyptian priests . It was probably in Egypt where he learned the theorem that is now called by his name.
By the time he was about 55 years old he returned to his native land and started a school on the island of Samos. However, because of the lack of students he decided to move to Croton in the south of Italy.
In Croton he started a school which concentrated in the teaching and learning of Mathematics, Music, Philosophy, and Astronomy and their relationship with Religion. It is said that as many as 600 of the worthiest people in the city attended the school, including Theana whom he married when he was 60. The school reached its highest splendor around the year 490 BC. He taught the young to respect their elders and to develop their mind through learning. He emphasized justice based on equality. Calmness and gentleness were principles encouraged at the school. Pythagoreans became known for their close friendships and devotion to each other. More than anyone before him Pythagoras combined the spiritual teachings with the pursuit of knowledge and science.
Pythagoras also headed a cult known as the secret brotherhood that worshiped numbers and numerical relationships. They attempted to find mathematical explanations for music, the gods, the cosmos, etc. Pythagoras believed that all relations could be reduced to number relations.
At some point Pythagoras was exiled from Croton and had to move to Tarentum. After 16 years he had to move again, this time to Metapontus where he lived four years before he died at the age of 99.
Here we have a picture of a statue of Phytagoras in the island of Samos. If you click on the figure you'll be able to see a larger picture. On the bottom of the statue the text is "". The literal translation is "Pythagoras the Samosan", but the preferred translation is "Pythagoras of Samos".
Now let's talk a bit about the theorem that bears his name. The Egyptians knew that a triangle with sides 3, 4, and 5 make a 90o angle. As a matter of fact, they had a rope with 12 evenly spaced knots like this one:
that they used to build perfect corners in their buildings and pyramids. It is believed that they only knew about the 3, 4, 5 triangle and not the general theorem that applies to all right triangles.
The Chinese also knew this theorem. It is attributed to Tschou-Gun who lived in 1100 BC. He knew the characteristics of the right angle. The theorem was also known to the Caldeans and the Babylonians more than a thousand years before Pythagoras. A clay tablet of Babylonian origin was found with the following inscription: "4 is the length and 5 the diagonal. What is the breadth?"
So why is it called the Pythagorean Theorem? Even though the theorem was known long before his time, Pythagoras certainly generalized it and made it popular. It was Pythagoras who is attributed with its first geometrical demonstration. That is why it is known as the Pythagorean Theorem. There are hundreds of purely geometric demonstrations as well as an unlimited (that is right -- an infinite number) of algebraic proofs.
The Pythagorean Theorem is one of the most important theorems in the whole realm of geometry. We will conclude this section by stating the theorem in words:
The square described upon the hypotenuse of a right-angled triangle is equal to the sum of the squares described upon the other two sides.
Another way of saying the same thing is:
When the two shorter sides in a right triangle are squared and then added, the sum equals the square of the longest side or hypotenuse.
LARGEST EARTHQUAKES SINCE 1990
Location Date UTC Magnitude Lat. Long. Reference
1. Chile 1960 05 22 9.5 -38.29 -73.05 Kanamori, 1977
2. Prince William Sound, Alaska 1964 03 28 9.2 61.02 -147.65 Kanamori, 1977
3. Off the West Coast of Northern Sumatra 2004 12 26 9.1 3.30 95.78 Park et al., 2005
4. Kamchatka 1952 11 04 9.0 52.76 160.06 Kanamori, 1977
5. Offshore Maule, Chile 2010 02 27 8.8 -35.846 -72.719 PDE
6. Off the Coast of Ecuador 1906 01 31 8.8 1.0 -81.5 Kanamori, 1977
7. Rat Islands, Alaska 1965 02 04 8.7 51.21 178.50 Kanamori, 1977
8. Northern Sumatra, Indonesia 2005 03 28 8.6 2.08 97.01 PDE
9. Assam - Tibet 1950 08 15 8.6 28.5 96.5 Kanamori, 1977
10. Andreanof Islands, Alaska 1957 03 09 8.6 51.56 -175.39 Johnson et al., 1994
11. Southern Sumatra, Indonesia 2007 09 12 8.5 -4.438 101.367 PDE
12. Banda Sea, Indonesia 1938 02 01 8.5 -5.05 131.62 Okal and Reymond, 2003
13. Kamchatka 1923 02 03 8.5 54.0 161.0 Kanamori, 1988
14. Chile-Argentina Border 1922 11 11 8.5 -28.55 -70.50 Kanamori, 1977
15. Kuril Islands 1963 10 13 8.5 44.9 149.6 Kanamori, 1977
Updated 2010 March 01
1. Chile 1960 05 22 9.5 -38.29 -73.05 Kanamori, 1977
2. Prince William Sound, Alaska 1964 03 28 9.2 61.02 -147.65 Kanamori, 1977
3. Off the West Coast of Northern Sumatra 2004 12 26 9.1 3.30 95.78 Park et al., 2005
4. Kamchatka 1952 11 04 9.0 52.76 160.06 Kanamori, 1977
5. Offshore Maule, Chile 2010 02 27 8.8 -35.846 -72.719 PDE
6. Off the Coast of Ecuador 1906 01 31 8.8 1.0 -81.5 Kanamori, 1977
7. Rat Islands, Alaska 1965 02 04 8.7 51.21 178.50 Kanamori, 1977
8. Northern Sumatra, Indonesia 2005 03 28 8.6 2.08 97.01 PDE
9. Assam - Tibet 1950 08 15 8.6 28.5 96.5 Kanamori, 1977
10. Andreanof Islands, Alaska 1957 03 09 8.6 51.56 -175.39 Johnson et al., 1994
11. Southern Sumatra, Indonesia 2007 09 12 8.5 -4.438 101.367 PDE
12. Banda Sea, Indonesia 1938 02 01 8.5 -5.05 131.62 Okal and Reymond, 2003
13. Kamchatka 1923 02 03 8.5 54.0 161.0 Kanamori, 1988
14. Chile-Argentina Border 1922 11 11 8.5 -28.55 -70.50 Kanamori, 1977
15. Kuril Islands 1963 10 13 8.5 44.9 149.6 Kanamori, 1977
Updated 2010 March 01
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