SCIENCE AND
TECHNOLOGY
Science (from the Latin scientia, meaning "knowledge") is an enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the natural world. An older meaning still in use today is that of Aristotle, for whom scientific knowledge was a body of reliable knowledge that can be logically and convincingly explained .Since classical antiquity science as a type of knowledge was closely linked to philosophy, the way of life dedicated to discovering such knowledge. And into early modern times the two words, "science" and "philosophy", were sometimes used interchangeably in the English language. By the 17th century, "natural philosophy" (which is today called "natural science") could be considered separately from "philosophy"
>ALBERT EINSTEIN -ONE OF THE FATHERS OF MODERN SCIENCE
> Thomas Alva Edison
The Improvement of the Electric Light Bulb Hands On Activity: Make Your Own Light Bulb
The Perfection of the Light Bulb
In 1875 Herman Sprengel invented the mercury vacuum pump making it possible to develop a practical electric light bulb by making a really good vacuum inside the bulb possible.
In 1878 Sir Joseph Wilson Swan, an English physicist, was the first person to invent a practical and longer-lasting electric light bulb (13.5 hours). Swan used a carbon fiber filament derived from cotton.
Many others contributed to the development of the light bulb during the years.
It Is clear that Tomas Alva Edison could not be credited with the invention of the electric light bulb (incandescent lamp). Nevertheless, his contribution to the perfection of this device is really impressing.
Until 1878 when Edison decided to throw the bulk of his attention and resources into the perfection of the light bulb the best source of lighting was gas. Unfortunately it was far from convenient. It was dirty, unhealthy, uncomfortable and dangerous. When gas burned it created soot everywhere. It degraded the air quality by emitting soot and depleting oxygen. During the summer it made the air even hotter and more uncomfortable. It caused explosions, fires and its care could not be trusted to children. But the major deficit of gas was that it could not serve as a source of power. The appliances we take for granted today - fans, refrigerators, electric irons and computers - could not be powered by gas, at least not in a convenient way.
On the other hand, light bulbs existing prior to Edison’s efforts burned for a short time – the best achievement was Swan’s, 13.5 hours, though a great breakthrough, not commercially yet.
Thomas Alva Edison, a prolific inventor, and his team (yes, he did not work alone!) experimented with thousands of different filaments to find just the right materials to glow well and be long-lasting. In 1879 Edison obtained an improved Sprengel vacuum pump, and it proved to be the catalyst for a breakthrough. Edison discovered that a carbon filament in an oxygen-free bulb glowed for 40 hours. Soon, by changing the shape of the filament to a horseshoe it burned for over 100 hours and later, by additional improvements, it lasted for 1500 hours.
Edison and his colleagues had invented a practical light bulb and by doing so they opened up the way for the establishment of the electrical power system.
It was this power system that became Edison's real achievement. It beget a huge new industry that would radically effect everyone.
By September of 1882 he had opened a central station on Pearl Street in Manhattan and was eventually supplying electricity to a one mile square section of New York.
It’s important to mention that Edison's method for generating and transmitting electricity employed direct current (DC) whereas modern power stations employ alternating current (AC ) introduced by George Westinghouse based on Nikola Tesla, and others’, patents.
Nevertheless, this and other obstacles, Edison’s power station is regarded by many as the first practical power station ever because the Pearl Street station provided reliable central power generation, safe and efficient distribution, and a successful end use - Edison’s long-lasting incandescent light bulb - at a price that competed successfully with gas lighting.
What Did Isaac Newton Invent?Differential and Integral Calculus, Universal Gravitation, Telescope, White Light Composition Hands On Activities: Mathematics, Mechanics, Astronomy and Optics Science Fair Projects and Experiments
In Mathematics
Newton laid the foundations for differential and integral calculus, several years before its independent discovery by Leibniz. The 'method of fluxions', as he termed it, was based on his crucial insight that the integration of a function is merely the inverse procedure to differentiating it. Taking differentiation as the basic operation, Newton produced simple analytical methods that unified many separate techniques previously developed to solve apparently unrelated problems such as finding areas, tangents, the lengths of curves and the maxima and minima of functions.
Mathematics fair projects links:
Mathematics Science Fair Projects and Experiments
In Mechanics and Gravitation
In his Principia Newton explained a wide range of previously unrelated phenomena: the eccentric orbits of comets, the tides and their variations, the precession of the Earth's axis, and motion of the Moon as perturbed by the gravity of the Sun. This work made Newton an international leader in scientific research.
The first part of the Principia is devoted to dynamics and includes Newton's three famous laws of motion; the second part to fluid motion and other topics; and the third part to the explanation of Kepler's laws of planetary motion.
Physics and astronomy fair projects links:
Mechanics Science Fair Projects and Experiments
Astronomy Science Fair Projects and Experiments
Galileo Galilei: The Falling Bodies Experiment
Leonardo da Vinci: The Invention of the Parachute
In Optics
He also observed Newton's rings, which are actually a manifestation of the wave nature of light which Newton did not believe in.
Optics science fair projects links:
The Discovery of the Spectrum of Light
Optics Science Fair Projects and Experiments
In Theology and Alchemy
Newton devoted much of his time to the study of chemistry, a great number of his experiments still remain in manuscript.
The Invention of the Parachute Hands On Activity: Compare a Modern Parachute Performance to that of Leonardo da Vinci’s design.
Leonardo da Vinci Inventions and Discoveries
The History of the Invention of the Parachute
Some think that a form of a primitive parachute was mentioned by Chinese texts 21 centuries ago. In 9th century Abbas Ibn Firnas and Ali Ben Isa (of Arabic origin) also created one of the earliest versions of a parachute which John H. Lienhard described as "a huge winglike cloak to break his fall" [1].
A conical parachute appears for the first time in the 1470s in an Italian manuscript, slightly preceding Leonardo da Vinci's conical parachute designs [2]. It was intended as an escape device to allow people to jump from burning buildings, but there is no evidence that it was actually ever used.
Many think that the first modern conical parachute design had been imagined and sketched by Leonardo Da Vinci in the 15th century.
Leonardo's parachute design consists of sealed linen cloth held open by a pyramid of wooden poles, about seven metres long. The original design was scribbled by Da Vinci in a notebook in 1483. An accompanying note read: "If a man is provided with a length of gummed linen cloth with a length of 12 yards on each side and 12 yards high, he can jump from any great height whatsoever without injury."
Maybe the first implemented parachute was created in 1595 by the Croatian inventor Faust Vrančić, who named it Homo Volans (Flying Man). Twenty years later, he implemented his design and tested the parachute by jumping from a tower in Venice in 1617 [3].
Credit for the invention of the first practical parachute frequently goes to Sebastien Lenormand who demonstrated the parachute principle in 1783.
A French aeronaut (pilot of a balloon or lighter-than-air aircraft), Jean Pierre Blanchard, claimed the invention of the parachute in 1785, and the first successful parachute descent from a great height was made in 1797 by the French aeronaut Jacques Garnerin, who dropped 3,000 ft (920 m) from a balloon. Parachutes began as an escape system for persons aboard balloons or aircraft unable to land safely. In 1887, Captain Thomas Baldwin invented the first parachute harness and in 1890, Paul Letteman and Kathchen Paulus invented the method of folding or packing the parachute in a knapsack to be worn on the back before its release.
On Tuesday, 27 June, 2000 BBC News Online's Dr Damian Carrington reported that Leonardo Da Vinci was proved right, over 500 years after he sketched the design for the first parachute.
A British man, Adrian Nicholas, dropped, with a Da Vinci implemented parachute, from a hot air balloon 3,000 metres (10,000 feet) above the ground, after ignoring expert advice that the canvas and wood contraption would not fly beacuse of weight.
The parachute's great weight was due to the use of materials that would have been available in medieval Milan like canvas and wood.
Mr Nicholas said he thought Da Vinci would have been pleased, even if the vindication of his idea came five centuries late.
http://news.bbc.co.uk/1/hi/sci/tech/808246.stm
Experiments with Parachutes
We suggest two main options:
Make a Parachute - Schlumberger
Science Projects with Toy Parachutes - Dr. Jean Potvin
Falling from the Sky - Charlotte Burns
Parachutes: Is It Surface Area or Shape? - The National Museum of the United States Air Force
Leonardo's Parachute - National Museum of Science and Technology Leonardo da Vinci
Leonardo da Vinci: Parachute - The British Library
Make a Parachute - The Royal Aeronautical Society (RAES)
General Leonardo da Vinci Links
Leonardo da Vinci - Museum of Science, Boston
Leonardo da Vinci - WebMuseum, Paris
The Drawings of Leonardo da Vinci
Archimedes of Syracuse The Discovery of Archimedes' Principle Hands On Activity: Demonstrate Archimedes' Principle
Archimedes' Inventions and Discoveries
Archimedes was born in Syracuse, Sicily. He lived there most of his life. When the Romans attacked Syracuse, Archimedes invented weapons to defend the city. He is said to have suggested a method of employing mirrors to set enemy ships afire. After a two-year siege the Romans finally entered the city, and Archimedes was killed in the battle that followed. Among his other important inventions: the lever, the compound pulley and Archimedes’ screw.
But his greatest fame lies in the field of mathematics. Archimedes was able to apply the method of exhaustion, which is the early form of integration, by which he calculated different areas and volumes of geometric shapes and solids. Archimedes also gave an accurate approximation to π and showed that he could approximate square roots accurately. He invented a system for expressing large numbers.
In mechanics Archimedes discovered fundamental theorems concerning the centre of gravity of plane figures and solids. His most famous theorem gives the weight of a body immersed in a liquid, called after him, Archimedes' principle - that a body immersed in a fluid is subject to an upward force (buoyancy) equal in magnitude to the weight of fluid it displaces.
Legend says that Archimedes discovered the principle of displacement while stepping into a full bath. He realized that the water that ran over equaled in volume the submerged part of his body. Through further experiments, he deduced the above mentioned Archimedes' principle.
The legends goes further and tells that Archimedes was so excited with his discovery that he hopped out of the bath, and rushed naked into the street yelling triumphantly, "Eureka!" "Eureka!" (Greek word for 'I have found it!).
Another legend describes how Archimedes uncovered a fraud against King Hieron II of Syracuse using his principle of buoyancy. The king suspected that a solid gold crown he ordered was partly made of silver. Archimedes took two pieces of pure gold and of pure silver that had weights identical to the weight of the crown. He then successively immerses the gold, the silver, and the crown in a container filled to the brim with water and measured the volume of water that overflowed with each material. He found that the crown displaced more water than the gold but less than the silver, thereby proving that the crown contained some other metal which was less dense than gold.
Demonstrate Archimedes' Principle For science fair projects, class activities, lesson plans and interest
Stage a:
Suspend objects of various sizes and masses from a spring scale.
Note the reading of the scale in air for each object. Note the level of the water in the beaker.
Stage b:
Lower the objects into the beaker, record for each object the new reading on the spring scale and the new level of the water in the beaker.
Stage c:
Calculate the weight of water displaced by the object. Devise a rule relating the change in the reading of the scale and the weight of the displaced water.
More about this subject:
Archimedes Principle: Observation Experiment - Etkina, A Van Heuvelen, D. Brookes
Buoyancy Basics - PBS
Density and Archimedes Principle - Front Range Community College
Grandpa Pencil Discovers Archimedes' Principle
Buoyancy: Archimedes Principle - NASA
Buoyancy and Scuba Diving - aquaholic.com
Properties of Liquids - SEED
Why do Helium Filled Balloons Rise? - Yerkes Winter Institute
Newton’s Laws and Archimedes’s Principle - LPC Physics
Archimedes Principle - Donald E. Simanek
Can I Make Lead Float? - California State Science Fair
How Fish Achieve Neutral Buoyancy - California State Science Fair
Heavy Things Sink, Right? Not Always! - Michael Fenton
Buoyancy - Hyperphysics
Submarines: How They Work - ONR Science & Technology Focus
Fluid Physics Experiments - Rice University
Liquid Science Fair Projects and Experiments
Charles Darwin Orchids and Evolution For the Advanced Science Hobbyist: Repeat Charles Darwin's Orchid Pollination Experiments
Charles Darwin's Evolution Theory
Under the constant struggle to exist, inferior organisms are more likely to die before they can reproduce. On average, superior living things with useful traits are more likely to survive and reproduce and thus to pass on their helpful features. As a result, the next generation changes slightly, the struggle for survival goes on among the descendants and the process is repeated. In other words, the struggle for existence selects organisms with helpful variations but makes others die out.
Another useful definition of evolution: A gradual development, from a less adaptable to a more adaptable form through the process of natural selection.
Darwin outlined his theory in his book On the Origin of Species by Means of Natural Selection in 1859 which was met with ridicule, antagonism and skepticism before it was accepted.
Charles Darwin's Experiments With Orchids
Less known are Darwin's botany experiments, especially with orchids.
In 1862 Darwin showed that orchid's beauty was not “designed” by God to please humans but honed by natural selection to attract insect cross-pollinators.
But why the importance of cross-pollination? Darwin's botanical work was always related to his evolutionary mechanism. He believed that cross-pollinated plants would produce fitter offspring than self-pollinators, and he used considerable ingenuity in conducting thousands of crossings to prove the point.
Darwin published his results in a few books:
The Various Contrivances by which British and Foreign Orchids are Fertilised by Insects (1862)
The Effects of Cross and Self Fertilization in the Vegetable Kingdom (1876)
The Different Forms of Flowers on Plants of the Same Species (1877)
More resources about Darwin’s experiments with orchids:
Charles Darwin - Botany Online, University of Hamburg
Darwin Correspondence Project (Vol. 10) - University Library, Cambridge
Darwin Correspondence Project (Vol. 11) - University Library, Cambridge
On the various contrivances by which British and foreign orchids are fertilised by insects (Chap. VI)
Reasonings February 2002
Darwin from Orchids to Variation - Wikipedia
Ironically named 'Star of Bethlehem' orchid supports Darwin's theory of evolution - gizmodo.com.au
Orchids Profit From False Advertising - James Owen, National Geographic News
Pollen Carryover, Geitonogamy, And The Evolution Of Deceptive Pollination Systems In Orchids
The effects of nectar addition on pollen removal and geitonogamy in the non-rewarding orchid Anacamptis Morio
Darwin also studied insectivorous plants, climbing plants, and the response of plants to gravity and light (sunlight, he thought, activated something in the shoot tip, an idea that guided future work on growth hormones in plants).
A few good general links about Darwin and evolution:
Darwin - American Museum of Natural History
AboutDarwin.com
Evolution Website - BBC
The Complete Work of Charles Darwin Online - John van Wyhe
Evolution - PBS
Do You Believe in Evolution? - Bob Riggins
Rocky Road: Charles Darwin - Strange Science
Robert Fitzroy: The Captain of the HMS Beagle
Darwin Jokes and Evolution - Jokes and Science
Evolution Science Fair Projects and Experiments
Wright Brothers The Invention of the Airplane Early Experiments With Kites and Gliders For the Advanced Science Hobbyist: Repeat Wright Brothers' Early Experiments With Kites and Gliders
Wright Brothers' Early Experiments With Kites and Gliders
The scientific foundations of aviation and aerodynamics were laid between 1799 and 1809 by an English baronet, Sir George Cayley. Cayley abandoned the ornithopter tradition, in which both lift and thrust are provided by the wings, and designed airplanes with rigid wings to provide lift, and with separate propelling devices to provide thrust. He demonstrated, both with models and with full-size gliders, the use of the inclined plane to provide lift - action of air upon a flat, inclined surface like that of a kite.
In 1853, in his third full-size machine, Cayley sent his unwilling coachman on the first gliding flight in history.
In 1842 the Englishman W. S. Henson, inspired by Cayley, patented a design for a monoplane (has only one set of wings) which he called an aerial steam carriage. Although only unsuccessful models of it were built, it was a brilliant prophetic idea.
In 1890 French engineer Clement Ader built a steam-powered airplane and made the first actual flight of a piloted, heavier-than-air craft. However, the flight was not sustained, and the airplane brushed the ground over a distance of 50 m (160 ft).
Inventors continued to pursue the dream of sustained flight. Between 1891 and 1896 German aeronautical engineer Otto Lilienthal made thousands of successful flights in hang gliders of his own design. Lilienthal hung in a frame between the wings and controlled his gliders entirely by swinging his torso and legs in the direction he wished to go. While successful as gliders, his designs lacked a control system and a reliable method for powering the craft. He was killed in a gliding accident in 1896.
Wright Brothers' Early Experiments With Kites and Gliders
First, for a few months, the Wrights built and flew several kites, testing and perfecting their new ideas about a flight control system.
In 1900, they used this system on a man-carrying glider for the first time. Before they risked their own necks, they flew the glider as a kite, controlling it from the ground.
They flew three biplane (has two wings, one above the other) gliders from the sand-hills near Kitty Hawk, North Carolina, and by 1902 had developed a fully practical biplane glider.
Their great innovation was that their glider could have been balanced and controlled in every direction, by combining the actions of warping (twisting) the wings and turning the rudder for lateral control, and by using a device called an elevator for up and down movements without any need for the pilot to swing his torso and legs in order to control the flight direction. All flight control today has developed from this 1902 Wright glider.
After mastering gliding they developed a biplane with a 12 horsepower engine and two propellers and made the world’s first true powered, sustained and controlled flight on 17 December 1903, this flight lasted for 59 seconds.
But only in 1905 they had the world first practical plane, which could be banked, turned, circled and flown easily for an half an hour at a time.
Though the Wright brothers were not the first to fly a heavier-than-air machine, their control system enabled the development of a practical and reliable airplane.
This control system was developed through a few crucial experiments they have carried out with kites in 1899.
Wright Brothers' kite and glider experiments and building instructions:
Kite Construction and Basics- NASA
Reproducing a Lost Machine - Wright Experience
In Depth: The 1899 Kite - Wright Experience
1899 Wright Kite - Wright Brothers Aeroplane Museum
1899 Kite Plans - Wright Brothers Aeroplane Museum
Flying the Kite - Wright Brothers Aeroplane Museum
The Wright Story 1912 - Wright Experience
Wright Brothers 1899 Kite - The Virginia Aviation Museum
1900: The Wrights' First Efforts - Gary Bradshaw
Aviation School Projects and Resources:
Aviation Science Fair Projects and Experiments
Aviation Resources
Radio and Wireless Patent and Invention Milestones Ward, Dolbear, Edison, Lodge, Baviera, Stone, Bose, Shoemaker, Murgas, Hulsmeyer, Fleming
Collins,Pickard, De Forest, Stubblefield, Alexanderson, Armstrong, Koch, Tesla, Marconi
Science (from the Latin scientia, meaning "knowledge") is an enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the natural world. An older meaning still in use today is that of Aristotle, for whom scientific knowledge was a body of reliable knowledge that can be logically and convincingly explained .Since classical antiquity science as a type of knowledge was closely linked to philosophy, the way of life dedicated to discovering such knowledge. And into early modern times the two words, "science" and "philosophy", were sometimes used interchangeably in the English language. By the 17th century, "natural philosophy" (which is today called "natural science") could be considered separately from "philosophy"
>ALBERT EINSTEIN -ONE OF THE FATHERS OF MODERN SCIENCE
| 1905 | Ph.D. | Einstein received his doctorate from the University of Zurich for a theoretical dissertation providing a new way of calculating the size of molecules. |
| 1905 | Brownian Motion | In 1827 the botanist Robert Brown observed under the microscope the movement or motion of plant spores floating in water and moving about randomly all the time. The explanation for this was already thought to be the random motion of molecules "hitting" the spores. But the first satisfactory theoretical treatment of the Brownian motion was made by Albert Einstein in 1905. Einstein's theory enabled significant statistical predictions about the motion of particles that are randomly distributed in a fluid. These predictions were later confirmed by experiment. |
| 1905 | Photoelectric Effect | It was known that when light was shone on certain substances, the substances gave out electrons, but that only the number of electrons emitted, and not their energy, was increased when the strength of the light was increased. According to classical theory, when light, thought to be composed of waves, strikes substances, the energy of the liberated electrons ought to be proportional to the intensity of light. In other words, the energy emitted by the irradiated substance is changing in a discrete quantities rather than in a continuous manner. Einstein proposed that under certain circumstances light can be considered as consisting of particles, but he also hypothesized that the energy carried by any light particle, called a photon, is proportional to the frequency of the radiation. This proposal, that the energy contained within a light beam is transferred in individual units, or quanta, contradicted a hundred-year-old tradition of considering light energy a manifestation of a continuous processes or of its wave nature. Virtually no one accepted Einstein's proposal until a decade later when the American physicist Robert Andrews Millikan experimentally confirmed the theory. This Einstein's efforts helped out with the development of the quantum theory (mechanics). For this contribution, Einstein was awarded the Nobel Prize in physics for 1921 (see below). |
| 1905 | Special Theory of Relativity | This theory provides a consistent explanation for the way radiation (light, for example) and matter interact when viewed from different inertial frames of reference, that is, an interaction viewed simultaneously by an observer at rest and an observer moving at uniform speed. Einstein based this theory on two postulates: the principle of relativity, that physical laws are the same in all inertial reference systems, and the principle of the invariance of the speed of light, that the speed of light in a vacuum is a universal constant for all observers regardless of the motion of the observer or of the source of the light. He was thus able to provide a consistent and correct description of physical events in different inertial frames of reference without making special assumptions about the nature of matter or radiation, or how they interact. Among the theory's main assertions and consequences are the propositions that the maximum velocity attainable in the universe is that of light; that objects appear to contract in the direction of motion and vice versa; that the rate of a moving clock seems to decrease as its velocity increases; the results of observers in different systems are equally correct; and that mass and energy are equivalent and interchangeable properties according to Einstein's famous formula: |
| 1911 | Why Is The sky Blue? | The case, "Why is the sky blue?", was finally settled by Einstein in 1911, who calculated the detailed formula for the scattering of light from molecules; and this was found to be in agreement with experiment. |
| 1916 | General Theory of Relativity | Einstein expanded the special theory of relativity into the general theory of relativity that applies to systems in nonuniform (accelerated) motion as well as to systems in uniform motion (like in the special theory of relativity). The general theory is principally concerned with the large-scale effects of gravitation and therefore is an essential ingredient in theories of the universe as a whole, or cosmology. The theory recognizes the equivalence of gravitational and inertial mass. It asserts that material bodies produce curvatures in space-time that form a gravitational field and that the path of a body in the field is determined by this curvature. In other words, according to this theory, space becomes curved in the vicinity of matter (this is the meaning of gravity); the greater the concentration of matter, the greater the curvature and the greater the gravity. The geometry of a given region of space and the motion in the field can be predicted from the equations of the general theory. |
| 1922 | Nobel Prize | On December 10, 1922, Einstein received the Nobel prize in physics for the year 1921, especially for his discovery of the law of the photoelectric effect (see above). |
| 1924 | Bose-Einstein Condensate | The Bose-Einstein condensate (BEC) is a phase of matter, in the sense that solid, liquid, gas and plasma are phases of matter. In 1924 the Indian physicist Satyendra Nath Bose sent Einstein a paper in which he derived the Planck law for black-body radiation by treating the photons as a gas of identical particles. Einstein generalized Bose's theory to an ideal gas of identical atoms or molecules for which the number of particles is conserved and, in the same year, predicted that at sufficiently low temperatures the particles would become locked together, or overlap, in the lowest quantum state of the system. The result of Einstein's and Bose's efforts is the so called Bose Einstein statistics. We now know that this phenomenon, (BEC), only happens for "bosons". What does it mean to say that atoms overlap? The coins in a stack of pennies don’t overlap, and neither do the gas molecules in the air we breathe. As a gas becomes colder and colder, quantum mechanics tells us that the wavelike behavior of the atoms becomes more and more important. At the lowest temperatures, within a few hundred billionths of absolute zero (-273.15°C), the waves of the atoms in a gas can overlap and create, in effect, one super-atom. In this state, it hardly even makes sense to talk about individual atoms because they all behave as one collective object. This is much like the output of a laser, since all the light is the same wavelength (same color) and the waves are all in step and you can’t tell one light particle (a photon) from another. In recent developments, BECs are being used to create atom lasers, the equivalent of a laser made of light; in the study of superconductivity (the ability of some materials to conduct electrical current without any resistance); superfluidity (the ability of some materials to flow without resistance) and in refining measurements of time and distance. |
| 1926 | Einstein Refrigerator | Only few know that Albert Einstein was also a practical man and invented a refrigerator. The Einstein refrigerator is an absorption refrigerator which has no moving parts and requires only a heat source to operate - it does not require electricity to operate, needing only a heat source, e.g. a small gas burner, suitable for poor countries and outdoor activities. It was jointly invented in 1926 by Albert Einstein and his former student Leó Szilárd and patented in the US on November 11, 1930 (U.S. Patent 1,781,541). |
| 1945 | The First Atomic Bomb Was Dropped | The first atomic bomb, nicknamed "Little Boy", was dropped on Hiroshima on August 6, 1945. Although Einstein did not invent the bomb and did not participate in the Manhattan Project, his theories laid the foundation for it. The Relativity Theory showed that mass could be converted directly into energy (E=mc²), and that a minute piece of mass could release a vast amount of energy. In 1939 Einstein collaborated with several other physicists in writing a letter to President Franklin D. Roosevelt, pointing out the possibility of making an atomic bomb and the likelihood that the German government was embarking on such a course. The letter, which bore only Einstein's signature, helped lend urgency to efforts in the U.S. to build the atomic bomb, but Einstein himself played no role in the work and knew nothing about it at the time. |
> Thomas Alva Edison
The first electric light was made in 1809 by Humphry Davy, an English scientist. He experimented with electricity and when he connected wires and a piece of carbon to a battery, the carbon glowed, producing light.
In 1875 Herman Sprengel invented the mercury vacuum pump making it possible to develop a practical electric light bulb by making a really good vacuum inside the bulb possible.
In 1878 Sir Joseph Wilson Swan, an English physicist, was the first person to invent a practical and longer-lasting electric light bulb (13.5 hours). Swan used a carbon fiber filament derived from cotton.
Many others contributed to the development of the light bulb during the years.
It Is clear that Tomas Alva Edison could not be credited with the invention of the electric light bulb (incandescent lamp). Nevertheless, his contribution to the perfection of this device is really impressing.
Until 1878 when Edison decided to throw the bulk of his attention and resources into the perfection of the light bulb the best source of lighting was gas. Unfortunately it was far from convenient. It was dirty, unhealthy, uncomfortable and dangerous. When gas burned it created soot everywhere. It degraded the air quality by emitting soot and depleting oxygen. During the summer it made the air even hotter and more uncomfortable. It caused explosions, fires and its care could not be trusted to children. But the major deficit of gas was that it could not serve as a source of power. The appliances we take for granted today - fans, refrigerators, electric irons and computers - could not be powered by gas, at least not in a convenient way.
On the other hand, light bulbs existing prior to Edison’s efforts burned for a short time – the best achievement was Swan’s, 13.5 hours, though a great breakthrough, not commercially yet.
Thomas Alva Edison, a prolific inventor, and his team (yes, he did not work alone!) experimented with thousands of different filaments to find just the right materials to glow well and be long-lasting. In 1879 Edison obtained an improved Sprengel vacuum pump, and it proved to be the catalyst for a breakthrough. Edison discovered that a carbon filament in an oxygen-free bulb glowed for 40 hours. Soon, by changing the shape of the filament to a horseshoe it burned for over 100 hours and later, by additional improvements, it lasted for 1500 hours.
Edison and his colleagues had invented a practical light bulb and by doing so they opened up the way for the establishment of the electrical power system.
It was this power system that became Edison's real achievement. It beget a huge new industry that would radically effect everyone.
By September of 1882 he had opened a central station on Pearl Street in Manhattan and was eventually supplying electricity to a one mile square section of New York.
It’s important to mention that Edison's method for generating and transmitting electricity employed direct current (DC) whereas modern power stations employ alternating current (AC ) introduced by George Westinghouse based on Nikola Tesla, and others’, patents.
Nevertheless, this and other obstacles, Edison’s power station is regarded by many as the first practical power station ever because the Pearl Street station provided reliable central power generation, safe and efficient distribution, and a successful end use - Edison’s long-lasting incandescent light bulb - at a price that competed successfully with gas lighting.
What Did Isaac Newton Invent?
Newton laid the foundations for differential and integral calculus, several years before its independent discovery by Leibniz. The 'method of fluxions', as he termed it, was based on his crucial insight that the integration of a function is merely the inverse procedure to differentiating it. Taking differentiation as the basic operation, Newton produced simple analytical methods that unified many separate techniques previously developed to solve apparently unrelated problems such as finding areas, tangents, the lengths of curves and the maxima and minima of functions.
Mathematics fair projects links:
Mathematics Science Fair Projects and Experiments
In 1687 Newton summarized his discoveries in terrestrial and celestial mechanics in his Principia (mathematical principles of natural philosophy), one of the greatest milestones in the history of science. In it he showed how his principle of universal gravitation provided an explanation both of falling bodies on the earth and of the motions of planets, comets, and other bodies in the heavens.
In his Principia Newton explained a wide range of previously unrelated phenomena: the eccentric orbits of comets, the tides and their variations, the precession of the Earth's axis, and motion of the Moon as perturbed by the gravity of the Sun. This work made Newton an international leader in scientific research.
The first part of the Principia is devoted to dynamics and includes Newton's three famous laws of motion; the second part to fluid motion and other topics; and the third part to the explanation of Kepler's laws of planetary motion.
Physics and astronomy fair projects links:
Mechanics Science Fair Projects and Experiments
Astronomy Science Fair Projects and Experiments
Galileo Galilei: The Falling Bodies Experiment
Leonardo da Vinci: The Invention of the Parachute
In Optics (1704), Newton observed that white light could be separated by a prism into a spectrum of different colors, each characterized by a unique refractivity, and proposed the corpuscular theory of light. Newton's views on optics were born out of the original prism experiments he performed at Cambridge. In his "experimentum crucis" (crucial experiment), Newton had proved that white light was made up of colors mixed together, and the prism merely separated them - he was the first person to understand the rainbow.
He also observed Newton's rings, which are actually a manifestation of the wave nature of light which Newton did not believe in.
Optics science fair projects links:
The Discovery of the Spectrum of Light
Optics Science Fair Projects and Experiments
In the 1690s, Newton wrote a number of religious tracts dealing with the literal interpretation of the Bible. Henry More's belief in the Universe and rejection of Cartesian dualism may have influenced Newton's religious ideas. A manuscript he sent to John Locke in which he disputed the existence of the Trinity was never published. Later works – The Chronology of Ancient Kingdoms Amended (1728) and Observations Upon the Prophecies of Daniel and the Apocalypse of St. John (1733) – were published after his death.
Newton devoted much of his time to the study of chemistry, a great number of his experiments still remain in manuscript.
> THE Leonardo da Vinci (THE GENIUS MIND)
Leonardo da Vinci, the most versatile genius of the Renaissance, is best remembered as the painter of the Mona Lisa (c. 1503) and The Last Supper (c. 1495). But he is almost equally famous for his astonishing multiplicity of talents: architecture, sculpture, music, engineering, geology, hydraulics and the military arts, all with success, and in his spare time doodled sketches for working parachutes and flying machines like helicopters that resembled inventions of the 19th and 20th centuries. He made detailed drawings of human anatomy which are still highly regarded today. Was also known for his engineering of canal locks, cathedrals, and engines of war. Leonardo also was quirky enough to write notebook entries in mirror (backwards) script, a trick which kept many of his observations from being widely known until decades after his death.
Some think that a form of a primitive parachute was mentioned by Chinese texts 21 centuries ago. In 9th century Abbas Ibn Firnas and Ali Ben Isa (of Arabic origin) also created one of the earliest versions of a parachute which John H. Lienhard described as "a huge winglike cloak to break his fall" [1].
A conical parachute appears for the first time in the 1470s in an Italian manuscript, slightly preceding Leonardo da Vinci's conical parachute designs [2]. It was intended as an escape device to allow people to jump from burning buildings, but there is no evidence that it was actually ever used.
Many think that the first modern conical parachute design had been imagined and sketched by Leonardo Da Vinci in the 15th century.
Leonardo's parachute design consists of sealed linen cloth held open by a pyramid of wooden poles, about seven metres long. The original design was scribbled by Da Vinci in a notebook in 1483. An accompanying note read: "If a man is provided with a length of gummed linen cloth with a length of 12 yards on each side and 12 yards high, he can jump from any great height whatsoever without injury."
Maybe the first implemented parachute was created in 1595 by the Croatian inventor Faust Vrančić, who named it Homo Volans (Flying Man). Twenty years later, he implemented his design and tested the parachute by jumping from a tower in Venice in 1617 [3].
Credit for the invention of the first practical parachute frequently goes to Sebastien Lenormand who demonstrated the parachute principle in 1783.
A French aeronaut (pilot of a balloon or lighter-than-air aircraft), Jean Pierre Blanchard, claimed the invention of the parachute in 1785, and the first successful parachute descent from a great height was made in 1797 by the French aeronaut Jacques Garnerin, who dropped 3,000 ft (920 m) from a balloon. Parachutes began as an escape system for persons aboard balloons or aircraft unable to land safely. In 1887, Captain Thomas Baldwin invented the first parachute harness and in 1890, Paul Letteman and Kathchen Paulus invented the method of folding or packing the parachute in a knapsack to be worn on the back before its release.
On Tuesday, 27 June, 2000 BBC News Online's Dr Damian Carrington reported that Leonardo Da Vinci was proved right, over 500 years after he sketched the design for the first parachute.
A British man, Adrian Nicholas, dropped, with a Da Vinci implemented parachute, from a hot air balloon 3,000 metres (10,000 feet) above the ground, after ignoring expert advice that the canvas and wood contraption would not fly beacuse of weight.
The parachute's great weight was due to the use of materials that would have been available in medieval Milan like canvas and wood.
Mr Nicholas said he thought Da Vinci would have been pleased, even if the vindication of his idea came five centuries late.
The full story:
http://news.bbc.co.uk/1/hi/sci/tech/808246.stm
We suggest two main options:
- Test scaled down parachutes' properties in general.
- Compare modern parachute performance to that of Leonardo da Vinci’s design.
- Get a stopwatch and time how long it takes for your object to fall with and without the parachute. Do several drops and see if the time is always the same or if it varies somewhat.
- Using the same weight, compare the results with a small and a large parachute.
- Using the same size parachute, compare results using two different weights or more.
- Try lengthening or shortening the length of the suspension lines.
- Try changing the number of suspension lines.
- Try different shapes for your parachute, round, oval, rectangular, square, etc.
- Try cutting holes and/or slits in the parachute fabric.
- Try different fabric materials.
Make a Parachute - Schlumberger
Science Projects with Toy Parachutes - Dr. Jean Potvin
Falling from the Sky - Charlotte Burns
Parachutes: Is It Surface Area or Shape? - The National Museum of the United States Air Force
Leonardo's Parachute - National Museum of Science and Technology Leonardo da Vinci
Leonardo da Vinci: Parachute - The British Library
Make a Parachute - The Royal Aeronautical Society (RAES)
General Leonardo da Vinci Links
Leonardo da Vinci - Museum of Science, Boston
Leonardo da Vinci - WebMuseum, Paris
The Drawings of Leonardo da Vinci
Archimedes (c. 287-212 BC) is considered as one of the greatest mathematicians and inventors of all time.
Archimedes was born in Syracuse, Sicily. He lived there most of his life. When the Romans attacked Syracuse, Archimedes invented weapons to defend the city. He is said to have suggested a method of employing mirrors to set enemy ships afire. After a two-year siege the Romans finally entered the city, and Archimedes was killed in the battle that followed. Among his other important inventions: the lever, the compound pulley and Archimedes’ screw.
But his greatest fame lies in the field of mathematics. Archimedes was able to apply the method of exhaustion, which is the early form of integration, by which he calculated different areas and volumes of geometric shapes and solids. Archimedes also gave an accurate approximation to π and showed that he could approximate square roots accurately. He invented a system for expressing large numbers.
In mechanics Archimedes discovered fundamental theorems concerning the centre of gravity of plane figures and solids. His most famous theorem gives the weight of a body immersed in a liquid, called after him, Archimedes' principle - that a body immersed in a fluid is subject to an upward force (buoyancy) equal in magnitude to the weight of fluid it displaces.
Legend says that Archimedes discovered the principle of displacement while stepping into a full bath. He realized that the water that ran over equaled in volume the submerged part of his body. Through further experiments, he deduced the above mentioned Archimedes' principle.
The legends goes further and tells that Archimedes was so excited with his discovery that he hopped out of the bath, and rushed naked into the street yelling triumphantly, "Eureka!" "Eureka!" (Greek word for 'I have found it!).
Another legend describes how Archimedes uncovered a fraud against King Hieron II of Syracuse using his principle of buoyancy. The king suspected that a solid gold crown he ordered was partly made of silver. Archimedes took two pieces of pure gold and of pure silver that had weights identical to the weight of the crown. He then successively immerses the gold, the silver, and the crown in a container filled to the brim with water and measured the volume of water that overflowed with each material. He found that the crown displaced more water than the gold but less than the silver, thereby proving that the crown contained some other metal which was less dense than gold.
The experiment goes as follows:
Stage a:
Suspend objects of various sizes and masses from a spring scale.
Note the reading of the scale in air for each object. Note the level of the water in the beaker.
Stage b:
Lower the objects into the beaker, record for each object the new reading on the spring scale and the new level of the water in the beaker.
Stage c:
Calculate the weight of water displaced by the object. Devise a rule relating the change in the reading of the scale and the weight of the displaced water.
More about this subject:
Archimedes Principle: Observation Experiment - Etkina, A Van Heuvelen, D. Brookes
Buoyancy Basics - PBS
Density and Archimedes Principle - Front Range Community College
Grandpa Pencil Discovers Archimedes' Principle
Buoyancy: Archimedes Principle - NASA
Buoyancy and Scuba Diving - aquaholic.com
Properties of Liquids - SEED
Why do Helium Filled Balloons Rise? - Yerkes Winter Institute
Newton’s Laws and Archimedes’s Principle - LPC Physics
Archimedes Principle - Donald E. Simanek
Can I Make Lead Float? - California State Science Fair
How Fish Achieve Neutral Buoyancy - California State Science Fair
Heavy Things Sink, Right? Not Always! - Michael Fenton
Buoyancy - Hyperphysics
Submarines: How They Work - ONR Science & Technology Focus
Fluid Physics Experiments - Rice University
Liquid Science Fair Projects and Experiments
Much is known about Darwin’s theory of evolution. A short description follows:
Under the constant struggle to exist, inferior organisms are more likely to die before they can reproduce. On average, superior living things with useful traits are more likely to survive and reproduce and thus to pass on their helpful features. As a result, the next generation changes slightly, the struggle for survival goes on among the descendants and the process is repeated. In other words, the struggle for existence selects organisms with helpful variations but makes others die out.
Another useful definition of evolution: A gradual development, from a less adaptable to a more adaptable form through the process of natural selection.
Darwin outlined his theory in his book On the Origin of Species by Means of Natural Selection in 1859 which was met with ridicule, antagonism and skepticism before it was accepted.
Less known are Darwin's botany experiments, especially with orchids.
In 1862 Darwin showed that orchid's beauty was not “designed” by God to please humans but honed by natural selection to attract insect cross-pollinators.
But why the importance of cross-pollination? Darwin's botanical work was always related to his evolutionary mechanism. He believed that cross-pollinated plants would produce fitter offspring than self-pollinators, and he used considerable ingenuity in conducting thousands of crossings to prove the point.
Darwin published his results in a few books:
The Various Contrivances by which British and Foreign Orchids are Fertilised by Insects (1862)
The Effects of Cross and Self Fertilization in the Vegetable Kingdom (1876)
The Different Forms of Flowers on Plants of the Same Species (1877)
More resources about Darwin’s experiments with orchids:
Charles Darwin - Botany Online, University of Hamburg
Darwin Correspondence Project (Vol. 10) - University Library, Cambridge
Darwin Correspondence Project (Vol. 11) - University Library, Cambridge
On the various contrivances by which British and foreign orchids are fertilised by insects (Chap. VI)
Reasonings February 2002
Darwin from Orchids to Variation - Wikipedia
Ironically named 'Star of Bethlehem' orchid supports Darwin's theory of evolution - gizmodo.com.au
Darwin got some support for his cross-pollination idea from modern science evidence:
Orchids Profit From False Advertising - James Owen, National Geographic News
Pollen Carryover, Geitonogamy, And The Evolution Of Deceptive Pollination Systems In Orchids
The effects of nectar addition on pollen removal and geitonogamy in the non-rewarding orchid Anacamptis Morio
Darwin also studied insectivorous plants, climbing plants, and the response of plants to gravity and light (sunlight, he thought, activated something in the shoot tip, an idea that guided future work on growth hormones in plants).
A few good general links about Darwin and evolution:
Darwin - American Museum of Natural History
AboutDarwin.com
Evolution Website - BBC
The Complete Work of Charles Darwin Online - John van Wyhe
Evolution - PBS
Do You Believe in Evolution? - Bob Riggins
Rocky Road: Charles Darwin - Strange Science
Robert Fitzroy: The Captain of the HMS Beagle
Darwin Jokes and Evolution - Jokes and Science
Evolution Science Fair Projects and Experiments
Interest in aviation (design, development, production, operation and flight of heavier-than-air machines) can be traced back as far as Leonardo da Vinci. However, real progress toward achieving flight in heavier-than-air machines only began in the middle of the 19th century.
The scientific foundations of aviation and aerodynamics were laid between 1799 and 1809 by an English baronet, Sir George Cayley. Cayley abandoned the ornithopter tradition, in which both lift and thrust are provided by the wings, and designed airplanes with rigid wings to provide lift, and with separate propelling devices to provide thrust. He demonstrated, both with models and with full-size gliders, the use of the inclined plane to provide lift - action of air upon a flat, inclined surface like that of a kite.
In 1853, in his third full-size machine, Cayley sent his unwilling coachman on the first gliding flight in history.
In 1842 the Englishman W. S. Henson, inspired by Cayley, patented a design for a monoplane (has only one set of wings) which he called an aerial steam carriage. Although only unsuccessful models of it were built, it was a brilliant prophetic idea.
In 1890 French engineer Clement Ader built a steam-powered airplane and made the first actual flight of a piloted, heavier-than-air craft. However, the flight was not sustained, and the airplane brushed the ground over a distance of 50 m (160 ft).
Inventors continued to pursue the dream of sustained flight. Between 1891 and 1896 German aeronautical engineer Otto Lilienthal made thousands of successful flights in hang gliders of his own design. Lilienthal hung in a frame between the wings and controlled his gliders entirely by swinging his torso and legs in the direction he wished to go. While successful as gliders, his designs lacked a control system and a reliable method for powering the craft. He was killed in a gliding accident in 1896.
The American brothers Wilbur and Orville Wright, inspired by Lilienthal, decided in 1899 to master gliding before attempting powered flight.
First, for a few months, the Wrights built and flew several kites, testing and perfecting their new ideas about a flight control system.
In 1900, they used this system on a man-carrying glider for the first time. Before they risked their own necks, they flew the glider as a kite, controlling it from the ground.
They flew three biplane (has two wings, one above the other) gliders from the sand-hills near Kitty Hawk, North Carolina, and by 1902 had developed a fully practical biplane glider.
Their great innovation was that their glider could have been balanced and controlled in every direction, by combining the actions of warping (twisting) the wings and turning the rudder for lateral control, and by using a device called an elevator for up and down movements without any need for the pilot to swing his torso and legs in order to control the flight direction. All flight control today has developed from this 1902 Wright glider.
After mastering gliding they developed a biplane with a 12 horsepower engine and two propellers and made the world’s first true powered, sustained and controlled flight on 17 December 1903, this flight lasted for 59 seconds.
But only in 1905 they had the world first practical plane, which could be banked, turned, circled and flown easily for an half an hour at a time.
Though the Wright brothers were not the first to fly a heavier-than-air machine, their control system enabled the development of a practical and reliable airplane.
This control system was developed through a few crucial experiments they have carried out with kites in 1899.
Wright Brothers' kite and glider experiments and building instructions:
Kite Construction and Basics- NASA
Reproducing a Lost Machine - Wright Experience
In Depth: The 1899 Kite - Wright Experience
1899 Wright Kite - Wright Brothers Aeroplane Museum
1899 Kite Plans - Wright Brothers Aeroplane Museum
Flying the Kite - Wright Brothers Aeroplane Museum
The Wright Story 1912 - Wright Experience
Wright Brothers 1899 Kite - The Virginia Aviation Museum
1900: The Wrights' First Efforts - Gary Bradshaw
Aviation School Projects and Resources:
Aviation Science Fair Projects and Experiments
Aviation Resources
Collins,Pickard, De Forest, Stubblefield, Alexanderson, Armstrong, Koch, Tesla, Marconi
|
