Why Light Bends by Gravity?

Introduction to General Relativity:

The Equivalence Principle

Einstein's theory of General Relativity builds on the Equivalence Principle, which states that the effects of gravity are indistinguishable from the effects of acceleration. This principle implies that a uniform gravitational field is locally equivalent to an accelerated frame of reference. 

Einstein's Field Equations

The heart of General Relativity is encapsulated in Einstein's field equations:

where:

• is the Ricci curvature tensor,
• is the Ricci scalar,
• is the metric tensor,
• is the cosmological constant,
• is the gravitational constant,
• is the speed of light,
• is the stress-energy tensor.

These equations describe how matter and energy influence the curvature of spacetime.

Spacetime Curvature and Geodesics:

Metric Tensor

The metric tensor gμν​ defines the geometry of spacetime. In the presence of a massive object, this tensor describes how distances and times are measured differently compared to flat spacetime.

Geodesics

In curved spacetime, the path that light follows is called a geodesic. Mathematically, a geodesic is the curve that minimizes the spacetime interval:

Light Bending.

Gravitational Lensing:

Bending of Light

When light passes near a massive object, its path bends due to the curvature of spacetime. This bending can be calculated using the lens equation:

where:

• is the observed position of the lensed image,
• is the true position of the source,
• is the deflection angle,
• is the distance between the lens and the source,
• is the distance to the source.

Deflection Angle

The deflection angle α can be derived from the Schwarzschild metric for a point mass M:

where, b is the impact parameter, the closest approach of the light ray to the massive object.

Historical Verification:

1919 Solar Eclipse

The first observational confirmation of light bending by gravity was made by Sir Arthur Eddington during the solar eclipse of 1919. Eddington measured the positions of stars near the Sun and found them to be shifted, confirming Einstein's prediction. 

Types of Gravitational Lensing:

Strong Lensing

Occurs when the alignment of source, lens, and observer is very close, resulting in multiple images, arcs, or Einstein rings.

Weak Lensing

Involves slight distortions in the images of background objects. This type is used to study the distribution of dark matter.

Microlensing

Causes temporary brightening of a background star when a smaller object like a star or planet passes in front of it. This technique is often used to detect exoplanets.

Mathematical Representation and Calculations:

Deflection Angle in a Weak Field

For weak gravitational fields, the deflection angle α is small, and the bending can be approximated using linearized gravity.

Exact Solutions

For strong fields near black holes or neutron stars, exact solutions to Einstein's field equations are required. The Schwarzschild and Kerr metrics are commonly used for these purposes. 

Applications and Implications:

Astrophysics

Gravitational lensing is used to study distant galaxies and quasars, revealing information about their mass and structure.

Cosmology

By observing the lensing of distant objects, scientists can map the distribution of dark matter and study the expansion of the universe. 

References and Further Reading:

1. Einstein, A. (1916). The Foundation of the General Theory of Relativity. Annalen der Physik, 354(7), 769-822.
2. Carroll, S. M. (2004). Spacetime and Geometry: An Introduction to General Relativity. Addison-Wesley.
3. Weinberg, S. (1972). Gravitation and Cosmology: Principles and Applications of the General Theory of Relativity. Wiley.
4. Misner, C. W., Thorne, K. S., & Wheeler, J. A. (1973). Gravitation. W. H. Freeman.
5. Schneider, P., Ehlers, J., & Falco, E. E. (1992). Gravitational Lenses. Springer-Verlag.
6. Dyson, F. W., Eddington, A. S., & Davidson, C. (1920). A Determination of the Deflection of Light by the Sun's Gravitational Field, from Observations Made at the Total Eclipse of May 29, 1919. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 220(571-581), 291-333.  

The Toughest Predators Ever: Tyrannosaurus Rex.

    Tyrannosaurus Rex was one of the most ferocious creature to ever roam the Earth. With a gigantic body, keen teeth, and jaws powerful enough to smash a vehicle, this renowned carnivore controlled the forested river valleys of western North America during the late Cretaceous period, 68 million years ago.

    T. Rex is a well-known Tyrannosaur, yet our understanding of him is continually changing. Improved technologies, including as biomechanical modelling and x-ray imaging, have helped scientists obtain a better understand of how this apex predator lived.

    Tyrannosaurus rex, which means "King of the Tyrant Lizards," was designed to take control. This dinosaur's massive body covered up to 40 feet—roughly the length of a school bus—from its nose to the tip of its powerful tail. T. rex, weighing up to eight tonnes, raised headfirst across its territory with two powerful legs. These dinosaurs most likely hunted living animals and collected cadavers, and they occasionally ate one another.

    Tyrannosaurus rex had a good sense of smell, which helped it find its prey. While scientists have long known that this dinosaur's brain was dedicated to scent processing, current research has revealed that T. rex has nearly as many genes encoding its olfactory receptors as a house cat does today. This strong nostrils most likely helped T. rex find mates and identify other predators.

    The head of a Tyrannosaurus dinosaur was very terrifying. This ruthless carnivore was designed to crush through its prey, with a hard cranium that allowed it to concentrate all of its muscle power into a single bite, making a up to six tonnes of pressure. This dinosaur utilised its 60 hooked teeth, each about eight inches long, to puncture and hold flesh before throwing it into the air and eating it whole. To protect from overheating while crushing prey with its powerful jaws, the gigantic animal developed openings in its head to keep its brain cool, similar to those found in alligators.

Tyrannosaurus Rex.

    Tyrannosaurus rex, a ferocious dinosaur, had tiny arms that biologists debated. Some believe they were evolutionary leftovers or served non-predatory purposes, while others argue they were evolved for "cruel cutting" in close quarters. Considering their powerful thighs, these dinosaurs could only walk at 12 miles per hour, which scientists believe would have fractured their feet if they travelled faster.

    Tyrannosaurus rex, a dangerous predator with a life expectancy of 28 years, suffered a growth rise during its adolescent years. A 2020 analysis of Nano Tyrannus fossils found that the bones belonged to a young T. rex rather than another species. This shows that Tyrannosaurus rex's growth rate varied as it aged, and that it could slow down when food was limited. Despite its advantages, T. rex was unable to equal the 66 million-year-old catastrophe that killed three-quarters of all species on Earth. This catastrophe occurred when an asteroid or comet collided with Earth, destroying Tyrannosaurus rex and other non-avian dinosaurs and marking the end of the Cretaceous epoch. 

The Photoelectric Effect.

    A process known as the photoelectric effect occurs when a substance, usually a metal, absorbs enough light to cause electrons to be expelled from its surface. This phenomenon made a fundamental contribution to the advancement of contemporary physics and offered vital data in support of the quantum theory of light. 

Scientific Principles:

Photon Concept:

• Light consists of particles called photons, each carrying a discrete amount of energy determined by its frequency (E=hv), where "h" is Planck's constant and "v" is the frequency of the light.

Energy Threshold:

• For electrons to be ejected from a material, the energy of the incident photons must exceed a certain minimum value known as the work function (ϕ) of the material.

Electron Emission:

• When a photon hits the material, its energy is transferred to an electron. If the energy is greater than the work function, the electron is emitted from the surface with kinetic energy given by Ek=hv−ϕ.

Intensity Independence:

• The number of ejected electrons depends on the intensity of the light, but the energy of the ejected electrons depends only on the frequency of the incident light.

Historical Development

Heinrich Hertz (1887):

    While researching electromagnetic waves, the photoelectric effect was discovered. Hertz noted that sparks may jump across metal electrodes more readily in the presence of UV light, but he did not investigate the underlying mechanism.

Wilhelm Hallwachs (1888):

    It was discovered that a negatively charged zinc plate would lose its charge when light fell on it, offering preliminary proof for the photoelectric effect.

J.J Thomson (1899):

    Photoelectrically released electrons' charge-to-mass ratio was measured, and it was determined that these particles were identical to those seen in cathode rays.

Albert Einstein (1905):

    Used the quantum theory to provide a theoretical justification for the photoelectric effect. According to Einstein's theory, the energy of the quanta—later referred to as photons—in light is proportional to the frequency of the light. He was awarded the 1921 Nobel Prize in Physics for this achievement.

Robert Millikan (1916):

    Millikan's work, which involved precise tests to validate Einstein's theory, cleared the air for the linear relationship between the frequency of incident light and the kinetic energy of released electrons. Millikan was first sceptical of the hypothesis.

Impacts:

Quantum Theory of Light

    The photoelectric effect provided evidence in favour of the fundamental tenet of quantum mechanics—that light possesses both wave and particle characteristics.

Useful Applications:

   Numerous technologies, such as photovoltaic cells (solar panels), photomultiplier tubes, and photoelectron spectroscopy, rely on the principles underlying the photoelectric effect.

   One of the key ideas in comprehending how light and matter interact, bridging the gap between classical and quantum physics, is the photoelectric effect. 

The Brief History of The Sun.

The Sun:

The Sun is the star at the centre of our solar system. Its gravity holds the solar system together, keeping everything from the - biggest planets to the smallest bits of debris - in its orbit.

Heat and light are produced by nuclear events that occur deep beneath. In order to produce this energy, The Sun has been using four million tonnes of hydrogen fuel each second since its formation, or around 4.6 billion years ago.

Solar Flares:

A solar flare is a massive eruption that occurs on the Sun when energy that has been trapped in "twisted" magnetic fields- which are typically found above sunspots, Chromosphere -is suddenly released.

They may heat materials to millions of degrees in a matter of minutes, resulting in a burst of radiation that includes: radio waves, X-rays, and gamma rays.

Sun Spots:

Sunspots are areas where the magnetic field is about 2,500 times stronger than Earth's, much higher than anywhere else on the Sun. Because of the strong magnetic field, the magnetic pressure increases while the surrounding atmospheric pressure decreases.

This in turn lowers the temperature relative to its surroundings because the concentrated magnetic field inhibits the flow of hot, new gas from the Sun's interior to the surface.

Sunspots tends to occur in pairs that have magnetic fields pointing in opposite directions.

Why Sun Spots are Dark?

The sunspots are large concentrations of strong magnetic field. Some energy is partially prevented from passing through the surface by this magnetic field.

As a result, sunspots experience a lower surface temperature than other areas of the surface. It appears darker when the temperature is lower.

Coronal Mass Ejections (CMEs):

Coronal mass ejections (CMEs) are large expulsions of plasma and magnetic field from the sun's atmosphere the corona.

Compared to solar flares bursts of electromagnetic radiation that travel at the speed of light, reaching Earth in just over 8 minutes.

Formation of CMEs:

The more explosive CMES generally begin when highly twisted magnetic field structures (flux ropes) contained in the Sun's lower corona become too stressed and realign into a less tense configuration - a process called magnetic reconnection.

Near Earth CMEs Effects:

Auroras:

The CMEs causes stunning light displays known as auroras, visible in the polar regions of the earth.

Geomagnetic Storms:

CMEs can cause significant disturbances in Earth's magnetosphere, leading to geomagnetic storms which are; Satellite Operations, Power Grids, Communication Systems.

Radiation Hazards:

It Increases radiation levels at high altitudes, especially near the poles.

Preventing & Monitoring:

SPACE WEATHER FORECASTING:

To provide early alerts of possible CMEs, organisations such as NASA and NOAA's Space Weather Prediction Centre (SWPC) track solar activity.

AID:

Continuous monitoring and improved prediction models are essential to prevent the bad impacts of CMEs.

How to Find the Sun Spots Area:

To find the area of sunspots, I use the manual formula to calculate the area of the sunspots.

As = ((Af x n) / cos (B) x cos (L))

Where,

As - Area of the sunspot,

Af - Area factor constant for the solar chart image (i.e., 63.66),

n - Number of grid sares occupying the sunspot,

B- Heliographic latitude,

L - Angular distance of the sunspot from the solar disk centre.

The physical unit for the calculated area is a millionth of a hemisphere (MHS). 

Solar Cycle:

About every 11 years, the Sun's magnetic field gradually changes polarity, a process known as the solar cycle. This reversal causes changes in solar activity.

The solar cycle has been observed and recorded since the mid-18th century, with the current cycle being Solar Cycle 25. 

 "Sun, in fact, is the center of the universe" -Nicolaus Copernicus. 

Nicolaus Copernicus's: Revolutionary the Mind

    On February 19, 1473, in Toruń, Poland, Nicolaus Copernicus—the man who dared to change the centre of the cosmos from Earth to the Sun—was born. Though his life was filled with many varied hobbies and endeavours outside of space exploration, his revolutionary work in astronomy permanently changed our knowledge of the universe.

    Copernicus was raised in a secure and intellectually stimulating atmosphere because his parents were merchants and clergy. Following his father's premature death, Lucas Watzenrode, his uncle, assumed responsibility for his upbringing and education. Prominent clergyman Watzenrode sent Copernicus to study at the University of Kraków in 1491 to make sure he had the greatest education possible. Here, Copernicus was introduced to the complexities of philosophy, astronomy, and mathematics, which stoked his interest in astronomical occurrences.

Copernicus.

    In order to further his education at the University of Bologna in Italy in 1496, Copernicus moved there and resided with the well-known astronomer Domenico Maria Novara. Copernicus's criticism of the geocentric model of the universe—which put Earth at its center—was greatly affected by this mentorship. He pursued further education at the University of Padua, where he studied law and medicine. Later, the University of Ferrara awarded him a doctorate in canon law.

    The widely accepted geocentric model promoted by Claudius Ptolemy was boldly replaced by Copernicus's heliocentric theory. For centuries the accepted wisdom in astronomy was the Ptolemaic system, with its intricate epicycles and deferents. In his more straightforward theory, Copernicus put the Sun at the centre of the cosmos, with Earth and the other planets revolving around it. In 1543, the year of his death, he released his ground-breaking treatise, De revolutionibus orbium coelestium (On the Revolutions of the Heavenly Spheres), which laid forth his thesis.

    A heliocentric cosmos was not just a scientific theory; it was a significant departure from the previous worldview that was influenced by religious and scientific beliefs. Copernicus waited years to reveal his findings because he was worried about what might occur. When he did, many were curious about his views but also opposed to them. With the help of later scientists like Johannes Kepler and Galileo Galilei, the heliocentric theory took decades to become widely accepted.

    Although being mostly recognised for his contributions to astronomy, Copernicus was a true Renaissance man with a wide range of skills and passions. He oversaw the financial and administrative matters of the Frombork (formerly Frauenburg) cathedral chapter while serving as a canon. In addition to controlling the grain supply and keeping an eye on the finances, he also practiced medicine. His medical expertise was especially wanted during plague and other disease epidemics. In addition to his work in mathematics, Copernicus wrote a treatise on the value of money and the depreciation of currency. His understanding of the economy was predicted and reflects his wide-ranging intellectual interest.

Helio-Centric Model.

Astronomer and Artist: Copernicus was not only a skilled mathematician and scientist but also an amateur artist, producing illustrations of his astronomical theories in the form of drawings and diagrams.

Astronomical Tools: In order to make accurate observations of the sky, he built his own astronomical equipment, such as an armillary sphere and a triquetrum.

Delayed Fame: Copernicus's contributions took time to become well-known. His heliocentric concept was not fully understood until much later, thanks to the efforts of other astronomers and the invention of the telescope.

Deathbed Publication: It is reported that Copernicus saw the result of his life's labours before he passed away, as he was given a copy of his published De revolutionibus on his deathbed.

    The legacy of Nicolaus Copernicus is evidence of the value of curiosity and the courage to go against conventional wisdom. In addition to changing astronomy, his heliocentric theory cleared the path for the scientific revolution, which altered our understanding of the cosmos and our place in it. His biography serves as a reminder that genuine innovation often requires having the courage to see past conventional wisdom and journey into unknown spaces.

"To know that we know what we Know, and to know that we do not know what we do not know, Chat is true knowledge." -N. Copernicus.

The mysteries behind the extinction of dinosaurs: A voyage through time.

Introduction: The Jurassic World: 

                        The extinction of the dinosaurs remains a deep mystery. This historical voyage looks into the interesting subject of the dinosaur extinction, uncovering fascinating information and a wealth of archaeological evidence related to the mysterious extinction of these amazing species. 

Dinosaurs in Jurassic Period.

The Rise and Fall of the Dinosaurs:

During the Mesozoic Era, dinosaurs first appeared and ruled the earth for millions of years. They changed over time, becoming anything from the massive Brachiosaurus to the speedy Velociraptor. They evolved in many habitats throughout thousands of years, affecting the path of evolution. 

But disaster came at the end of the Jurassic Period, some 66 million years ago. A fatal extinction caused by a terrible disaster eliminated many other species in addition to dinosaurs. The change that occurred between the Mesozoic and Cenozoic Eras was signalled by this event, which also cleared the way for the creation of mammals.

Theories of Extinction:

Among the many ideas that explain why dinosaurs became extinct, two have received a lot of attention.

Asteroid Impact: 

                            The most well-known idea suggests that Earth was struck by a huge asteroid or comet that caused widespread destruction. Massive amounts of energy would have been released by this impact, resulting in the destabilisation of the food chain, wildfires, tsunamis, and a nuclear winter-like state as dust and debris blanketed the sky and blocked sunlight.

Volcanic Activity: 

                            Another convincing argument argues that the extinction of dinosaurs was mostly caused by volcanic eruptions, especially those of the Deccan Traps in modern-day India. Large amounts of greenhouse gases would have been emitted during these eruptions, causing environmental disturbance and climate change.

                           Scientists are still deeply divided about the exact order of events and how they contributed to the extinction disasters.

Tyrannosaurus rex (T. rex) went extinct around 65 million years ago.

Curious Archaeological Finds:

Secrets into the past are provided by archaeological finds, such as fossilised bones and geological data that provide light on the mystery surrounding the demise of the dinosaurs.

 Chicxulub Crater: 

                              Buried beneath Mexico's Yucatán Peninsula, the Chicxulub crater is one of the most significant pieces of evidence in support of the asteroid impact idea. This massive crater, which is over 180 km in diameter and was discovered in the 1970s, is dated to around 66 million years ago, which matches with the period of the extinction disasters.

Fossil Record:

                            The record of fossils documents the wide range of dinosaur species that once roamed the earth, providing an understanding of life before to the extinction disasters. By analysing these fossils, one may learn more about the anatomy, behaviour, and ecological functions of these prehistoric beings and get insight into their environment.

Asteroid impact, Volcanic activity are the causes that how Dinosaurs are extinction.

Geochemical study: 

                                Exceptions related to asteroid impacts and volcanic activity in the late Cretaceous have been found by geochemical study of sediment layers. The trace elements and geochemical traces provide important hints regarding the environmental conditions and probably catastrophic events that led to the extinction disasters. 

Conclusion: Solving the Mystery:

Scientists are still fascinated by the mysterious surrounding the eventual extinction of dinosaurs, which motivates investigation and study. Although hypotheses such as volcanic activity and asteroid impact theories exist, the actual origin is still unknown. Each archaeological find that reveals more about Earth's past helps us to solve this puzzle and highlights the strength and danger of life on our planet... 

 

“All the explanations proposed seem to be only partly satisfactory. They range from massive climatic change to mammalian predation to the extinction of a plant with apparent laxative properties, in which case the dinosaurs died of constipation.” 

---CARL SAGAN. 

  

Napoléon Bonaparte: Un voyage de victoire et de poursuite.

Les exploits extraordinaires et l'ascension rapide au pouvoir du grand homme politique et tacticien militaire Napoléon Bonaparte ont laissé une impression durable dans l'histoire. Napoléon, né en Corse le 15 août 1769, est sorti d'une relative obscurité pour devenir l'un des personnages les plus marquants de l'histoire européenne. Ce blog explorera l'étonnant récit de la vie de Napoléon, le suivant depuis son petit enfant corse jusqu'à l'empereur français. 

Le passé instable de la Corse et l'impact de ses ancêtres italiens ont façonné les premières années de Napoléon là-bas. Napoléon fut poussé à devenir un grand homme par la mort prématurée de son père et l'annexion de l'île à la France. À neuf ans, il se lance dans une aventure qui marquera sa vie : quitter la Corse et se rendre en France métropolitaine.

Napoléon Bonaparte.

Le succès futur de Napoléon fut pavé de sa formation militaire à l'Ecole Militaire de Paris. Même s'il était issu d'une éducation modeste, son génie et sa ruse le distinguaient immédiatement des autres. 

Napoléon a eu l’occasion idéale de gravir les échelons de l’establishment militaire et politique lors de la Révolution française de 1789. Ses compétences militaires ont été démontrées par ses victoires en Égypte et en Italie, qui lui ont valu non seulement une notoriété mais aussi une influence politique.

L'événement crucial s'est produit en 1799 lorsque Napoléon a mené un coup d'État, renversant le gouvernement français et assumant le poste de Premier Consul. Ce fut le début de la consolidation de son pouvoir, qui aboutit finalement à la déclaration de l'Empire français en 1804. 

Les exploits militaires de Napoléon sont légendaires. Il fut le plus grand tacticien et stratège de tous les temps, remportant à la fois la bataille d'Austerlitz et la conquête de la péninsule ibérique. Le génie administratif de Napoléon a été démontré par le Code Napoléon, un code juridique complet et la restructuration des gouvernements européens.

Cependant, avec la terrible invasion de la Russie en 1812, les choses ont commencé à changer. L'effondrement de Napoléon a commencé lorsque la Grande Armée a subi un coup dur en raison du rude hiver et des difficultés logistiques. 

La chute de Napoléon a commencé avec la bataille de Leipzig en 1813 et l'invasion de la France par la Sixième Coalition. Il abdiqua en 1814 et fut envoyé à l'île d'Elbe. Il réussit néanmoins sa fuite malheureuse et rentre en France au cours des Cent Jours de 1815.

Le destin de Napoléon fut scellé lors de la bataille cruciale de Waterloo, et il fut de nouveau emprisonné, cette fois sur l'île isolée de Sainte-Hélène, dans l'Atlantique Sud. Il y a vécu ses dernières années, en repensant à son incroyable voyage et à l'impact qu'il a laissé derrière lui. 

La vie de Napoléon Bonaparte est une histoire fascinante d'aspirations, de réussites et d'échecs éventuels. Son influence sur le développement de l’histoire européenne est immense et son héritage fait encore l’objet de recherches et de discussions aujourd’hui. Napoléon Bonaparte, critiqué pour son leadership autocratique et loué pour ses prouesses militaires, continue d'être un personnage important dans l'histoire de l'humanité et un symbole des difficultés liées à l'accès au pouvoir et au désir...

L'histoire est un ensemble de mensonges convenus.

History of Cinema: Beyond Screens.

Cinema is the most widely acclaimed means of entertainment in the world today. It is a combination of various equipments, techniques and art which constitutes cinema. But the most important things needed to experience cinema are camera, film reel and a projector. "Wheel of life' or 'zoopraxiscope' was the first machine to show animated pictures. It was patented in 1867 by William Lincoln. In a zoopraxiscope, moving photographs were watched through a slit. 

Zoopraxiscope

"The cinema is an invention without a future." - Louis Lumière. The Lumiere brothers-Auguste and Louise - are credited for inventing the first motion picture camera in the year, 1895. But even prior to Lumiere brothers, many others had made similar inventions. Lumiere brothers  invented a portable motion-picture camera, film processing unit and a projector called the Cinematographe. Here, three functions were covered in one invention. 

Lumiere Brothers

Cinematographe

The first footage shot by Lumiere brothers was that of workers leaving the Lumiere factory.

Cinematographe or Cinematography brought a revolutionary change in the world of cinema and made motion pictures popular. Though, prior in 1891, the Edison Company came up with a kinetoscope which allowed to watch cinema one person at a time, Edison's vitascope (1896) was the first commercially successful projector in USA. 

Kinetoscope

A camera shoots an activity on a film roll, also known as a film negative. This film negative is then edited. An editor removes away unnecessary scenes by cutting away that portion of the film role. Then the edited film roll is processed in a lab with required effects. The final film footage is then mounted on a projector. A projector is a device which projects the film running on the film roll on a blank white screen with the help of light. There are two pulleys on a projector. The film reel is mounted on the first projector and is run through the first to the second projector with the help of a motor. 

Advertising of Edson's  Vitascope

The film reel passes between a magnifying lens and a light bulb. The lens increases the size of the image on the blank white screen.

Cinematography is an art form unique to motion pictures. Although the exposing of images on light-sensitive elements dates back to the early 19th century, motion pictures demanded a new form of photography and new aesthetic techniques. In the infancy of motion pictures, the cinematographer was usually also the director and the person physically handling the camera. As the art form and technology evolved, a separation between the director and the camera operator emerged. With the advent of artificial lighting and faster (more light sensitive) film stocks, in addition to technological advancements in optics and new techniques such as colour film and widescreen, the technical aspects of cinematography necessitated a specialist in that area. 

It was a key during the silent movie era no sound apart from background music, no dialogue the films depended on lighting, acting and set. 

In 1919, in Hollywood, the new motion picture capital of the world, one of the first (and still existing) trade societies was formed: the American Society of Cinematographers (ASC), which stood to recognise the cinematographer's contribution to the art and science of motion picture making. 

Films are made up of a series of individual images called frames. When these images are shown rapidly in succession, a viewer has the illusion that motion is occurring. The viewer cannot see the flickering between frames due to an effect known as persistence of vision, whereby the eye retains a visual image for a fraction of a second after the source has been removed. Viewers perceive motion due to a psychological effect called the beta movement. 

 

A Film Projector

CINEMA 4D is a 3D modelling, animation and rendering application developed by MAXON Computer GmbH of Friedrichsdorf, Germany. It is capable of procedural and polygonal/subd modelling, animating, lighting, texturing, rendering and common features found in 3d modelling applications.  

"IF A MILLION PEOPLE SEE MY MOVIE, I HOPE THEY SEE A MILLION DIFFERENT MOVIES."            ---QUENTIN TARANTINO--- 

QUENTIN TARANTINO. 

Discovery of Radium:

Radium is one the of the few elements that constantly emit invisible radiations. Such elements are called radioactive elements and the radiations they emits are called "radioactive" rays.

Radium Metal

 There are three types of radioactive rays-alpha, beta and gamma. Radium, due to the emission of the radioactive rays, disintegrates and finally gets converted into lead. Half of this radioactive element gets converted into lead in 1622 years. 

This is called the 'half life' of the radioactive element. In the next 1622 years, half of the remaining substance decays into lead. This process continues indefinitely. The radioactive rays are so powerful that they can pass through different kinds of substances including the human body. These rays are very useful in the treatment of cancer. Do you know who discovered radium?

Marie Curie 

All the credit of the discovery of radium goes to a married couple, Pierre Curie and Marie Curie. The story of its discovery is very interesting.

In 1896 Henri Becquerel discovered the phenomenon of radioactivity. He found that the uranium emits a kind of invisible radiations which are even more powerful than the X-rays. Pierre Curie and Marie Curie, in 1898, also found that thorium also emits similar radiations. They also thought that pitchblende, which is the ore of uranium, must contain some other radioactive substance too. 

 They started refining pitchblende in order to obtain the new radioactive element. They had to work in a tin-shed because they could not afford a proper laboratory on account of limited means. Without caring for rains and storms, they worked day and night Finally, they succeeded in extracting 100 milligrams of radium from several tons of pitchblende. They found that this new element was much more powerful than uranium.

Pure radium is white in colour. It is quite heavy and thousands of times costlier than gold. The quantity of pure radium available in the world is very small. Radioactive rays are very harmful to the body. If handled carelessly its radioactive rays can wound the body. So be careful guys. 

"Nuclear Power Is One Hell Of A Way To Boil Water" - Albert Einstein.

The Four Fundamental Forces in Physics.

 The Four Fundamental Forces in Physics.

There are four fundamental forces in physics:

They are Gravitational, Electromagnetic, Strong Nuclear and Weak Nuclear forces.

The Four Fundamental Forces in Physics.

Gravitational Force:

Gravitational force is a force between two masses and it is universal in nature. Our planets are bound to the sun through gravitational force of the sun. We are in the earth because of Earth's gravitational attraction on our body.

Electromagnetic Force:

Electromagnetic force is a force between two charges, and We are standing on the earth's surface because of the Electromagnetic force between atoms of the surface of the earth with atoms in our feet.

Strong Nuclear Force:

The force between two nucleons, there exists a strong nuclear force and this force is responsible for stability of nucleus. Strong Nuclear force holds the protons and neutrons together in the nucleus of an atom. The atoms in our body are stable is due to strong nuclear force. 

Weak Nuclear Force:

Weak force is even shorter in the range than the strong nuclear force. During the fusion of hydrogen into helium in the sun, neutrinos and enormous radiations are produced through weak force.

" A Physicist is just an atom's way of looking itself " 

                   --Niels Bohr-- 

Rutherford's Alpha Particles Scattered with Scattering Angle

 Rutherford's Alpha Particles Scattered with Scattering Angle.

In 1911, Geiger and Marsden did the experiment based on the Rutherford's scattering alpha particles by gold foil.

A source of Alpha particles are kept inside a thick lead box with with a hole. The alpha particles coming through the hole made of lead box pass through another hole made on the lead screen. These particles are now allowed to fall on a thin gold foil and it is observed that the alpha particles passing through gold foil are scattered through different angles. A movable screen (from 0° to 180°) which is made up of zinc sulphide (ZnS) is kept on the other side of the gold foil to collect the scattered alpha particles. Whenever alpha particles strike the screen, a flash of light is observed which can be seen through a microscope. 

Rutherford's Alpha Particles Scattered with Scattering Angle 

Rutherford proposed an atom model based on the results of the alpha scattering experiment. In this experiment alpha particles were allowed to fall on the atoms of a metallic gold foil.

(a) Most of the alpha particles were un-deflected through the gold foil and went straight.

(b) Some of the alpha particles were deflected through a small angle.

(c) A few alpha particles (one in thousand) were deflected through the angle more than 90°.

(d) Very few alpha particles returned back (back scattered) - that is, deflected back by 180°.

" An alleged scientific discovery has no merit unless it can be explained to a barmaid. " 

                                          ---Ernest Rutherford--- 

Astronauts Living In Space.

 Astronauts Living In Space : 

A bed on the wall, baby wipes for a wash, footholds, and edible  toothpaste! Life on the space station is very different from life on earth.  

 

Life in Space Station. 

Ordinary Days :

                                             Astronauts need to do everything that you do. They eat, exercise, sleep, work, and play, but they have to do all these things in a home without the gravity

Astronaut Chris Hanfield in Space.

.      

New Arrivals :

                                          When astronauts arrive at a space station, they bring supplies with them. Imagine trying to unpack your suitcase when you are floating. some astronauts suffer temporary hearing problems after living on a space station, this is because the necessary air filters, fans, and pumps make it very noisy.          

Keeping Healthy :

                                                   Astronaut's muscles don't work very hard in micro gravity, so they quickly lose strength, so astronauts exercise for about two hours a day. This athlete completed a marathon on the International Space Station treadmill.  

     

Astronaut on Treadmill.

   

Time for Work :

                                             Experienced scientists regularly jion the astronauts in the space station to carry out a variety of experiments and record the results.  

 

Astronaut in space station.

A Tasty Food :

                                          Food is supplied in sealed packets and some of it is dehydrated. That means that water has to be added before the food can be eaten.   

 Nutritional Food for Astronauts. 

Time for Bed :

                                Most of the crew use sleeping bags, which have to be strapped to the walls of the space station. The bag holds astronauts' arms in place. Otherwise they would float above their head.   

Bed for Astronauts.

     

They like to keep clean, like us !

                                                                                         Astronauts use combs and toothbrushes, and toothpaste. But the toothpaste doesn't froth, and gets swallowed. Wet wipes are useful for a speedy wash...  

      

Bathing in Space.

Showering in Space Station.

" Building One Space Station For Everyone Was And Is Insane: We Should Have Built A Dozen. "  

                                                                    ---Larry Niven.---           

      

Journey To The Moon

MOON JOURNEY  :  

During the 1960s there was a race between the USA and the former Soviet Union to put a man on the moon. The USA landed the first man on the moon with APOLLO 11 in 1969.     

Apollo 11's mission crew members (1969).
Left side -  Commander Neil Armstrong ; Middle - Command module Michael Collins ; Right side - Lunar module pilot Buzz Aldrin.  

What was Apollo 11 ?  

                                       🌕  Apollo 11 was made up of three modules, or parts: the tiny command module, the service module, and the lunar module.Apollo 11 mission reached the moon because of a huge rocket called SATURN V. Most of SATURN V contained the fuel needed to blast it into space. 

The  Journey Plan for the Moon Landing {1969}.  

                  🌕 Three astronauts sat in a tiny capsule at the top of the rocket. The service module contained the power and life-support systems. The three astronauts worked and slept in the command  module. And the Mission commander Neil Armstrong struggled to find a flat landing site. He succeeded with just seconds to spare. 

   

The Body Parts of Saturn V's that was carried the Lunar Module called Eagle.  

The Eagle has landed : 

                                           🌕  The lunar module ( the part of apollo 11 that landed ) was also known as the Eagle.It touched down on the moon on 20 July, 1969.  

Lunar Module named Eagle.  

The Different Stages of Apollo 11 Mission : 

                                                                                           🚀  STAGE 1 :  Five F1 engines blast the SATURN V rocket into space from the Kennedy Space Center.  

                                     🚀  STAGE 2 : The rocket's engines fire to set the craft on a course to the moon. 

                                     🚀  STAGE 3 : The command and service modules separate from the rocket and perform a 180° turn.   

                                     🚀 STAGE 4 :  The command and service modules reattach to the lunar module, which is still connected to the rocket.  

                                     🚀 STAGE 5 :  The rest of the rocket is discarded while the commanded, service, and lunar modules  continue to the moon.  

                                     🚀  STAGE 6 :  The journey has taken 102 hours, 45 minutes. The lunar module is ready to land.  

                                     🚀  STAGE 7 :  The command and service modules orbit the moon ( one astronaut remains on board ) while the lunar module lands. Two astronauts walk on the moon.    

                                     🚀  STAGE 8 :  The lunar module joins the command and service modules so the two lunar astronauts can climb through. The lunar module is then abandoned.   

                                     🚀  STAGE 9 :  The service module is ejected before re-entry into Earth's atmosphere.    

                                     🚀  STAGE 10 :  The command module is the only part of the mission to return to Earth.

   

Stages of Moon Landing Mission. 

   "  THE ORIGIN AND EVOLUTION OF LIFE ARE CONNECTED IN THE MOST INTIMATE WAY WITH THE ORIGIN AND EVOLUTION OF THE STARS .  "   

                     ______ CARL SAGAN. ______