Axions and Other Hypothetical Particles

1. Axions: The Invisible, Lightweight Particle Hypothesized to Explain Dark Matter

Axions are hypothetical particles proposed in the 1970s to solve a problem known as the strong CP problem in quantum chromodynamics (QCD). The term CP refers to the combination of charge (C) and parity (P) symmetries, which dictate how particles behave if their charges and spatial orientations are reversed. According to theoretical predictions, certain reactions involving quarks (the particles that make up protons and neutrons) should violate CP symmetry. However, experimentally, CP violation does not occur in strong interactions, suggesting an unknown mechanism behind this symmetry preservation. Physicists Roberto Peccei and Helen Quinn introduced the axion concept to explain this mystery.

Properties of Axions:

• Mass: Axions are expected to have extremely low masses, ranging from micro-electronvolts (µeV) to milli-electronvolts (meV).
• Charge and Spin: They are electrically neutral and are considered to have no intrinsic spin, making them scalar particles.
• Weak Interactions: Axions interact only very weakly with other particles, meaning they are nearly invisible and hard to detect.

Mathematical Representation of Axions

The interaction of axions with electromagnetic fields can be represented by the axion-photon coupling term in the Lagrangian (the function describing a system's dynamics). This term is often written as:

$$\mathcal{L}_{a\gamma} = -\frac{g_{a\gamma}}{4} a F_{\mu\nu} \tilde{F}^{\mu\nu}$$

where:

• $g_{a\gamma}$ is the axion-photon coupling constant,
• $a$ is the axion field,
• $F_{\mu\nu}$ is the electromagnetic field tensor, and
• $\tilde{F}^{\mu\nu}$ is the dual of the electromagnetic field tensor.

This coupling term implies that axions could convert into photons (and vice versa) in the presence of a strong magnetic field, a feature that scientists attempt to exploit in detection experiments.

Axion Experiments

Several ongoing experiments aim to detect axions:

• Axion Dark Matter Experiment (ADMX): This experiment looks for axions converting into microwave photons within a resonant cavity under a magnetic field.
• Haloscope Searches: These experiments use microwave cavities in high magnetic fields to detect potential axion-photon conversions.
• Helioscope Searches: For example, the CERN Axion Solar Telescope (CAST) looks for axions coming from the Sun, which would convert into photons when they pass through a magnetic field.

Axions and Dark Matter

One of the most exciting aspects of axions is that they could make up dark matter, the mysterious, unseen matter that appears to constitute around 27% of the universe’s mass-energy content. Since axions are very stable, nearly invisible, and weakly interacting, they fit the profile of a good dark matter candidate.

2. Supersymmetric Particles: Theoretical Partners of Known Particles

Supersymmetry (SUSY) is a proposed extension of the Standard Model that postulates each particle has a “superpartner” with different spin properties. This theory attempts to solve some critical issues in particle physics, such as:

• Hierarchy Problem: Why the Higgs boson has a much lower mass than expected based on quantum corrections.
• Dark Matter Candidate: Some supersymmetric particles could account for dark matter.

In SUSY, each fermion (particles like quarks and electrons that make up matter) has a bosonic partner (particles that mediate forces), and each boson has a fermionic partner. For example:

• Electron (fermion) ↔ Selectron (bosonic superpartner)
• Quark ↔ Squark
• Photon (boson) ↔ Photino (fermionic superpartner)

Supersymmetric Particles and the Minimal Supersymmetric Standard Model (MSSM)

The MSSM is the simplest version of SUSY, extending the Standard Model by introducing superpartners for all Standard Model particles. It also introduces a symmetry-breaking mechanism, adding a Higgs sector to give mass to these particles.

Theoretical Equations and Predictions in SUSY

Supersymmetry involves complex algebraic structures and fields. The Wess-Zumino model is one example, which introduces a Lagrangian for a simple supersymmetric system. Mathematically, SUSY transformations involve anticommuting spinor fields and are represented by the equation:

$$\delta \phi = \bar{\epsilon} \psi, \quad \delta \psi = \partial_\mu \phi \gamma^\mu \epsilon$$

where $\phi$ is a scalar field, $\psi$ is a fermion, and $\epsilon$ is a small spinor parameter.

Experimental Searches for Supersymmetric Particles

To date, no supersymmetric particles have been observed. However, experiments at Large Hadron Collider (LHC) at CERN continue to search for these particles, especially looking for signs of particles like the neutralino—a stable, neutral SUSY particle that could be a dark matter candidate.

3. Other Theoretical Particles: Gravitons, Sterile Neutrinos, and WIMPs

Beyond axions and SUSY particles, other hypothetical particles are considered in various theories aiming to unify forces or explain dark matter.

Gravitons: Hypothetical Particles for Quantum Gravity

In quantum field theory, each fundamental force has a corresponding particle:

• The photon mediates electromagnetism,
• Gluons mediate the strong force, and
• W and Z bosons mediate the weak force.

By analogy, a particle known as the graviton is proposed to mediate gravity, though no gravitons have been detected. A potential graviton's field could be described in theoretical frameworks like string theory, but it is challenging to reconcile with general relativity due to issues like renormalization (handling infinities in calculations).

Sterile Neutrinos and Dark Matter

Sterile neutrinos are a proposed type of neutrino that does not interact via the weak force, unlike known neutrino types. Sterile neutrinos could explain dark matter or contribute to phenomena observed in neutrino oscillations.

WIMPs (Weakly Interacting Massive Particles)

WIMPs are another popular candidate for dark matter. These particles, which have higher masses and weak interactions, have been the target of numerous direct-detection experiments like XENON1T and LUX-ZEPLIN, which look for signs of WIMPs scattering off nuclei.

4. Baryon Asymmetry Problem: Why Is There More Matter Than Antimatter?

One of the unsolved mysteries in cosmology is the Baryon Asymmetry Problem, which asks why the universe appears to be made mostly of matter, with very little antimatter. According to the Standard Model, matter and antimatter should have been created in equal amounts at the Big Bang, leading to their mutual annihilation.

Possible Explanations for Baryon Asymmetry

Some hypotheses attempt to explain this imbalance:

1. CP Violation in the Early Universe: Small CP violations, particularly in quark interactions, may have led to a slight excess of matter over antimatter.
2. Leptogenesis: Proposed by researchers such as M. Fukugita and T. Yanagida, this theory suggests that CP-violating decays of heavy neutrinos in the early universe created an excess of leptons over antileptons, which later transferred to baryons.
3. Electroweak Baryogenesis: This theory proposes that interactions involving the Higgs field at high temperatures in the early universe may have broken baryon symmetry.

References for Further Exploration

For further reading and current research updates:

1. Peccei, R. D., & Quinn, H. R. (1977). CP Conservation in the Presence of Instantons. Physical Review Letters, 38(25), 1440–1443.
2. Arkani-Hamed, N., Dimopoulos, S., & Dvali, G. (1998). The Hierarchy Problem and New Dimensions at a Millimeter. Physics Letters B, 429(3–4), 263–272.
3. Ellis, J. R., & Gaillard, M. K. (1979). Higgs Bosons in GUTs. Nuclear Physics B, 150(1), 141–162.
4. Aghanim, N., et al. (2020). Planck 2018 Results. VI. Cosmological Parameters. Astronomy & Astrophysics, 641, A6.

The discovery of any of these particles would represent a paradigm shift in physics, potentially leading to new laws and a deeper understanding of the universe. 

What Happens After Death? Understanding from Physics, Mathematics, and Hypotheses

What Happens After Death? An Exploration Through Mathematics and Physics

The question of what happens after death has intrigued philosophers, theologians, scientists, and laypeople for centuries. In this exploration, we will investigate this question from the perspectives of mathematics and physics. While science has not yet fully explained what occurs after death, many theories attempt to approach it by considering consciousness, energy, and the nature of reality, including the concept of spacetime.

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Part I: Physics Theories About Life and Death

Physics provides a foundation for understanding the nature of life and the universe, including theories about energy, consciousness, and time.

1. The Law of Conservation of Energy

• According to the First Law of Thermodynamics, energy cannot be created or destroyed, only transformed. When a person dies, the biological processes halt, but the energy within the body disperses into the surroundings. The energy that once powered our bodies doesn’t simply vanish; it transforms.
• This transformation of energy is sometimes used to explain concepts like reincarnation or the persistence of consciousness, although it is not conclusive evidence.

2. Quantum Mechanics and Consciousness

• Quantum mechanics, which governs subatomic particles, introduces fascinating ideas that challenge our understanding of reality. Some theories suggest that consciousness might be connected to quantum processes in the brain. When we die, this quantum process ends, but whether this impacts consciousness remains unknown.
• The Quantum Consciousness Theory, proposed by physicist Sir Roger Penrose and anesthesiologist Stuart Hameroff, suggests that consciousness is the result of quantum processes in the brain’s microtubules. While this theory remains controversial, it adds an interesting layer to our understanding of life, suggesting a quantum-based foundation for consciousness.

3. Spacetime and the Block Universe Theory

• Albert Einstein’s theory of relativity provides a unique framework for considering life and death. In relativity, spacetime is a single, four-dimensional structure where past, present, and future exist simultaneously.
• The Block Universe Theory suggests that time is a dimension similar to space. From this perspective, each moment in time – including all moments of our lives – exists permanently. When a person dies, they still exist in a certain location in spacetime. This could imply that, in a certain way, people continue to exist in the spacetime “block” where they once lived.

Part II: Mathematics and Death

Mathematics allows us to model, quantify, and understand the universe, often through abstract concepts that reveal insights into life and existence.

1. Entropy and the Arrow of Time

• Entropy, a concept from thermodynamics, refers to disorder or randomness in a system. The Second Law of Thermodynamics states that entropy tends to increase over time in an isolated system. Life creates order within the chaos, but after death, entropy gradually disperses our bodily order into the environment.
• Mathematically, entropy $S$ can be expressed by: $$S = k \cdot \ln(W)$$ where $k$ is Boltzmann's constant, and $W$ represents the number of possible microscopic configurations of the system. After death, biological processes cease, and entropy in the body increases, leading to a natural return to disorder.

2. Mathematical Models of Consciousness

• Neuroscientists and mathematicians have developed models to understand how neural connections create consciousness. Some theories suggest consciousness is a network or graph of neurons interacting in complex ways. After death, the network ceases to function, leading to the cessation of consciousness.
• Although no formula fully explains consciousness, mathematical tools, such as graph theory, have provided insights into how neurons interact and form thought. This raises interesting questions about whether consciousness could be mathematically described as a complex pattern within the brain.

Part III: Hypotheses About Life After Death

Many researchers have offered hypotheses that mix philosophy, science, and metaphysics, although they remain unproven. 

1. The Simulation Hypothesis

• Physicist Nick Bostrom and others have proposed that reality, including our lives and deaths, might be part of a vast simulation. According to this idea, death could mean simply the end of our program or consciousness within the simulation.
• This hypothesis raises questions about the nature of reality, time, and even consciousness. However, no definitive evidence supports it, making it more of a thought experiment than a proven theory.

2. Biocentrism

• Proposed by scientist Robert Lanza, Biocentrism argues that life and consciousness are fundamental to the universe. From this perspective, life does not end at death because consciousness cannot be destroyed. Instead, consciousness exists outside of linear time and physical constraints, potentially existing indefinitely.
• Biocentrism merges ideas from physics, biology, and philosophy to suggest that death may not be the final end of consciousness. Although this theory lacks concrete evidence, it challenges us to rethink the relationship between life and the universe.

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Part IV: Experiments and Observations

Although we cannot directly measure what happens after death, some experiments provide insight into related phenomena:

1. Near-Death Experiences (NDEs)

• Some individuals who have been close to death report near-death experiences (NDEs), often including visions of light or feelings of peace. Scientists have studied these experiences, and although no definitive conclusion exists, some theories suggest that NDEs result from brain activity during dying.
• Experiments have found similarities between NDEs and effects from specific neural stimulation, possibly indicating that NDEs are natural processes in the brain rather than glimpses of an afterlife.

2. Quantum Biology and Microtubules

• Hameroff and Penrose’s Quantum Consciousness Theory suggests that microtubules within cells could contain quantum processes that contribute to consciousness. Experiments in quantum biology seek to uncover how quantum effects influence living systems, although we still have much to learn.
• This area of research is in its early stages, but the possibility of quantum processes contributing to consciousness provides a new lens to consider life and death.

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Part V: Curiosities and Fun Facts

1. Time Slows Down in Space: Time dilation, a concept from Einstein’s relativity, means that time moves more slowly in stronger gravitational fields. This hints that time as we perceive it might not end as simply as we imagine, possibly influencing our ideas of life and death in high-energy conditions like black holes.

2. The “Holographic Principle”: Some physicists propose that our three-dimensional reality could be a projection of information on a two-dimensional surface. This would mean that death and life might be states within this projection.

3. Black Hole Paradox: When matter falls into a black hole, information theoretically cannot escape. This paradox raises questions about the persistence of information, and by extension, the “information” of our lives, which some speculate could never truly be erased.

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Conclusion

Death remains one of humanity’s greatest mysteries, and while mathematics and physics have not answered the question conclusively, they have provided interesting insights and avenues for exploration. From the structure of spacetime to the conservation of energy and quantum mechanics, science hints that life’s energy and information may persist in ways we are only beginning to understand. Whether consciousness or a form of our existence endures remains unanswered, but each theory offers a glimpse into what might be possible.

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References for Further Reading

1. Penrose, R. and Hameroff, S. (1996). "Consciousness in the Universe: Neuroscience, Quantum Space-Time Geometry and Orch OR Theory."
2. Einstein, A. (1915). “The Foundation of the General Theory of Relativity.” Annalen der Physik.
3. Bostrom, N. (2003). "Are You Living in a Computer Simulation?" Philosophical Quarterly.
4. Lanza, R. (2010). Biocentrism: How Life and Consciousness are the Keys to Understanding the Universe.

Why is the Tower of Pisa Leaning?

Is the Tower of Pisa Leaning?

Everybody knows that in the city of Pisa in Italy, there is a beautiful tower that "leans" Very ew people know the reason of its leaning Every year thousands of people go there to see the der made of white marble The walls are four meters thick at its base. It has eight story and in 55 meters high. There is a stairway which leads to the top and has 300 steps From as top one can have a magnificent view of the city and the sea which is ten kilometer away.   

Leaning Tower of Pisa, Italy.

Now the question arises: What makes this tower lean and why it does not fall? At the top, the tower is five  meters away from the perpendicular. It leans over by five meters If we drop ball from it's top, a would hit the ground five meters away from its base. It was intended as a bell tower for the cathedral which is nearby. Its construction was started in 1174 and completed in 1350 When the construction started nobody thought that it would lean, but it started leaning after the third story was completed. The foundations of the tower were laid sand and this may explain why it leans. Since the tower started leaning, the plans of its constructs were modified and the tower was completed. During the last one hundred years the tower has leaned another 30 cm.

Now the question arises: Even while leaning, why does it not tall?  According to science anything well remain stable till the vertical line drawn from its center of gravity passes through The center of gravity is that point where the whole of the mass of the body is  supposed to be concentrated. Till today the vertical line from the center of gravity has been falling within the base of the tower. That is why it has not fallen. It is believed that when the tower leans further and the line from its center of gravity pass out of its base, it will fall down According to some engineers the tower will definitely fall one day.

"Rome Wasn't Built In A Day. " 

Sir Isaac Newton and The Foundations of Physics

Introduction

    Isaac Newton, one of the most brilliant minds in the history of science, is renowned for his groundbreaking contributions to physics. His profound insights into the laws of motion and universal gravitation laid the foundation for classical mechanics and revolutionized our understanding of the physical world. In this article, we will explore the life and achievements of this iconic physicist, as well as his profound influence on the field of physics. 

Sir Isaac Newton (1643-1727) 

Early Life and Education

Isaac Newton was born on January 4, 1643, in Woolsthorpe, England. His early life was marked by hardship, as he grew up in a farming family following the premature death of his father. However, his exceptional intellect soon became evident, and he attended The King's School in Grantham, where his interest in mathematics and science first took root.

In 1661, Newton enrolled at Trinity College, Cambridge, where he embarked on a journey that would change the course of scientific history. At Cambridge, he delved into the study of mathematics and physics, laying the groundwork for his future groundbreaking discoveries.

Laws of Motion

Newton's three laws of motion, often referred to as Newton's Laws, are the cornerstone of classical mechanics. They describe the fundamental principles governing the motion of objects and remain integral to our understanding of the physical universe.

1. Newton's First Law of Motion: The Law of Inertia

Newton's first law states that an object at rest will stay at rest, and an object in motion will stay in motion at a constant velocity unless acted upon by an external force. In other words, an object will maintain its state of motion unless compelled to change by an unbalanced force.

This law fundamentally altered the way we perceive motion, introducing the concept of inertia, which is the tendency of objects to resist changes in their state of motion.

2. Newton's Second Law of Motion: The Law of Force and Acceleration

The second law of motion relates force, mass, and acceleration. It can be expressed mathematically as F = ma, where F represents force, m is the mass of the object, and a is its acceleration. This law elucidates the relationship between force and the rate of change of an object's velocity.

Newton's second law allowed for precise calculations of how forces influence the motion of objects, making it an invaluable tool in both science and engineering.

3. Newton's Third Law of Motion: The Law of Action and Reaction

Newton's third law posits that for every action, there is an equal and opposite reaction. In simpler terms, when one object exerts a force on another, the second object exerts an equal and opposite force on the first. This law is the foundation of the conservation of momentum and explains phenomena as diverse as rocket propulsion and walking.

Universal Gravitation

Newton's law of universal gravitation was a milestone in the history of science. Published in his work "Philosophiæ Naturalis Principia Mathematica" in 1687, it revolutionized our understanding of the force that governs the motion of celestial bodies.

The law of universal gravitation states that every mass attracts every other mass in the universe with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. This discovery provided a unified explanation for the motion of the planets, the behavior of tides, and the falling of objects on Earth. It effectively merged terrestrial and celestial mechanics into a single coherent framework.

The Impact of Newton's Work

Isaac Newton's laws and theories radically transformed our understanding of the natural world. His work became the cornerstone of classical physics, and it still forms the basis of our scientific endeavors today. His influence is immeasurable, and here are a few areas where his legacy is most pronounced:

1. Astronomy: Newton's law of universal gravitation made it possible to calculate the orbits of planets and predict astronomical events, leading to the eventual discovery of Neptune and the exploration of outer space.

2. Engineering: Newton's laws of motion are foundational principles in engineering, allowing us to design everything from bridges to spacecraft with precision.

3. Modern Science: His methods of inquiry and mathematical rigor laid the groundwork for the scientific method and critical thinking in science.

4. Mathematics: Newton made significant contributions to mathematics, including the development of calculus, which is a fundamental branch of mathematics.

5. Physics: Newton's laws are still taught in every physics classroom, and while they have been refined with the advent of relativity and quantum mechanics, they remain incredibly accurate in everyday situations.

Conclusion

Isaac Newton's work revolutionized our understanding of the physical universe. His laws of motion and the law of universal gravitation have stood the test of time, remaining as critical pillars in the edifice of modern physics. Beyond his scientific contributions, Newton's methods of inquiry, dedication to empirical evidence, and commitment to mathematical rigor continue to inspire scientists and thinkers to this day. His life and work serve as a testament to the power of human intellect and the enduring impact of scientific exploration. As we celebrate the genius of Isaac Newton, we are reminded of the endless possibilities that await those who dare to inquire and explore the mysteries of the cosmos. 

"No Great Discovery Was Ever Made Without A Bold Guess. "--Sir Isaac Newton. 

Explanation of Photoelectric Effect and their Laws

The experimentally observed facts of photoelectric effect can be explained the help of Einstein's photoelectric equation. 

Photo-electric Effect

i) Each incident photon liberates one electron, then the increase of intensity of the light (the number of photons per unit area per unit time) increases the number of electrons emitted thereby increasing the photo-current, The same has been experimentally observed.

ii) From K(max)=h v—Φ•, it is evident max that K is proportional to the frequency max of the incident light and is independent of intensity of the light.

iii) There must be minimum energy (equal to the work function of the metal) for incident photons to liberate electrons from the metal surface. ( h v= h v 1/2 m v^2 ). 

Below this value of energy, emission of electrons is not possible. Correspondingly, there exists minimum frequency called threshold frequency below which there is no photoelectric emission.

iv) According to quantum concept, the transfer of photon energy to the electrons is instantaneous so that there is no time lag between incidence of photons and ejection of electrons. Thus, the photoelectric effect is explained on the basis of quantum concept of light.

Laws of Photoelectric Effect :

i) For a given metallic surface, the emission of photo-electrons takes place only if the frequency of incident light is greater than a certain minimum frequency called the threshold frequency.

Photo-electric Effect

ii) For a given frequency of incident light above threshold value, the number of photo-electrons emitted is directly proportional to the intensity of the incident light. The saturation current is also directly proportional to the intensity of incident light. 

iii) Maximum kinetic energy of the photo electrons is independent of intensity of the incident light.

iv) Maximum kinetic energy of the photo electrons from a given metal is directly proportional to the frequency of incident light.

v) There is no time lag between incidence of light and ejection of photo-electrons.

" When you change the way you look at things, the things you look at change. " --- Max Planck.--- 

The History Of Australia (From Land to Sea)

 The History Of Australia:

🦘 Australia became inhabitant over 40,000 years ago by the Indigenous Australians or Aborigines, who are believed to have come to Australia by land bridges and short sea crossing from Southeast Asia. These people were hunters and gathers. During that time, oral history was passed down through the generations in the form of tales, myths, and songs. Over the centuries that followed, multiple colloquial language, culture and lifestyle survived in different regions of the continent.

 Map of The Commonwealth of Australia.

🦘 In the 17th Century, the European explorers began to frequent the west and north coast of Australia.

Willam Janszoon (Dutch Explorer).

William Janszoon, a Dutch navigator sighted the Cape York Peninsula in 1606, but made no attempt at settling there. In the mid 18th century. The British had an overcrowded prison population and required a new penal colony. 

James Cook (British Explorer).

In 1770, Captain James Cook sailed along the east coast of Australia and claimed it for Britain, naming it New South Wales.

The First Fleet By  Captain James Cook.

In 1788, the first fleet arrived carrying 750 convicts. This was the first penal colony that is now the Sydney.

The Second Fleet Struggle in Port Arthur.

🦘 The second penal colony was called Port Arthur, which is a tourist attraction now. The number of colonies grew over the following decades. Australia grew into a productive farming land and a major wool producer. The mid 19th century witnessed a gold rush in Victoria and New South Wales.

James Cook Landed on Australia.

🦘 In January 1st 1901, the six colonies were federated to form one nation, and the commonwealth of Australia was born. The new constitution aimed at creating a new social, cultural,and economical atmosphere, leaving the pitfalls of the old times behind. Over the following decades, Australia continued to expand and after World War II, there was a mass immigration from Europe. At one point in time, Melbourne became the largest Greek populated city outside of the Athens. the immigration has come from Asian neighbors.

🦘 Now, Australia is flourishing in terms of its national media and international business reputation. Both as a nation and as a continent.

🦘 And Australia is a continent and a country. It is known as the land down under because it is below the Equator.

"Don't worry about the world ending today. It's already tomorrow in Australia" — Charles M. Schulz.

Story of Motor Car

Daimler, Maybach and Benz introduce the first practical gasoline-engine automobile.

It is difficult, if not impossible, to imagine a world without the motorcar. When German engineer Karl Benz ( 1844-1929 ) drove a motorcar tricycle in 1885 and

                          Karl Benz 

 fellow Germans Gottlieb Daimler (1834-1900) and

                    Gottlieb Daimler

 Wilhelm Maybach (1846-1929) converted a horse-drawn carrige into a four-wheeled motorcar in August 1886, 

                     Wilhelm Maybach

none of them could have foreseen the effects of their new invention.

Benz recognized the great potential of petrol as a fuel. His three-wheeled car had a top speed of just ten miles (16 km) per hour with its four-stroke, one cylinder engine. After receiving his patent in January 1886, he began selling the Benz Velo, but the public doubted it's reliability. 

The Patent Document awarded to Karl Benz in 1886.

Benz's wife Bertha had a brilliant idea to advertise the new car. In 1888 she took it on a 60-mile (100 km) trip from Mannheim to near Stuttgart. Despite having to push the car up hills, the success of the journey proved to a skeptical public that this was a reliable mode of transport.

            First motor car by Benz & Co.

Daimler and Maybach did not produce commercially feasible cars until 1889. Initially the German inventions did not meet with much demand, and it was French companies like Panhard et Levassor that redesigned and popularized the automobile.

          Panhard et Levassor Car (French).

 In 1926 Benz's company merged to form the Daimler-Benz company. Benz had left his company in 1906 and, remarkably, he and Daimler never met. Due to higher incomes and cheaper, mass-produced cars, the United States led in terms of motorization for much of the twentieth century.

           Daimler Benz Car Company.

This kind of movement has, however, come at a cost. Some 25 million people are estimated to have died in car accidents worldwide during the twentieth century. Climate-changing exhaust gases and suburban sprawl are but two more of the consequences of a heavy reliance on the automobile.

" If I had asked people what they wanted, they would have said faster horses." — Henry Ford.

What is Space?

Space holds many secrets. It contains places  where human beings can be stretched into spaghetti shapes, or boiled, or frozen solid: that's  why astronauts wear protective clothing in the  space. 

Welcome to a mysterious — and endlessly fascinating — world. 

♦ What is space?

                               When people think of space,  they think of:

                      ♠ Weightlessness — everything  floats as if there's no gravity.

                       ♠ Nothingness — vast areas of  space are completely empty.

                        ♠ Stars —  every star is a burning ball of gas. Our Sun is a star.

                         ♠  Astronauts — people who  explore the world beyond our Earth.

                          ♠ Rockets and Satellites — These  are what scientists use to explore space.

                           ♠ Silence — there is no air in  space, so there is absolutely no sound.

 

♦ Is that space?

                              On a cloudless night, you can see  thousands of stars. Space is the name we give to  the huge empty areas in between the  atmospheres of stars and planets. Apart from the odd rock, space is sprinkled only with dust and  gas.

♦ Why is space so dark?

                                            Space is black because  there is nothing there to reflect light. From space,  Earth looks lit up because light from our Sun  reflects off sea, and land, and the particles in our  atmosphere.

♦ How the distance is measure in space?

                                                                         The  distance measure in space in light years. One light year is the distance light travels in one year: that's  10 million million km ( 6 million million miles ). 

♦ Is anyone there?

                                  • If there are aliens, it is unlikely they will speak the languages of Earth, so  communication may be a problem. Coded signals  have been sent into space. People are also  listening for signals from space.

           

                                   • SETI ( The search for Extra Terrestrial Intelligence ) uses powerful radio  telescopes to scan for alien signals. However, so  far nothing has been found. 

         

                                   • Message into space:

                                                                         In 1974,

 astronomers at Arecibo, Puerto Rico, sent a radio  message from us to the stars. It was sent towards 

a cluster of stars called M13, where it will arrive  in 25,000 years. We may then get a reply after  another 25,000 years.( Is anyone there to read it ! )

                                    

 The Arecibo message lasts  three minutes. It is consists of 1,679 pulses,  which when arranged from a pictogram. The  pictogram explains the basis of life.

♦ Is a black hole may be a doorway to another  universe?

                 Some people think a black hole may be a doorway to another universe. But it's all just  speculation. Nobody really knows. However, it is  doubtful someone could survive the journey  through the hole to find out. An astronaut unfortunate enough to try would be stretched out  like a piece of spaghetti... 

            

              

“ Two Possibilities Exist: Either We Are  Alone In The Universe Or We Not Both Are Equally Terrifying. ”

                                — Arthur C. Clark.