The universe may have existed forever, according to a new model that applies quantum correction terms to complement Einstein's theory of general relativity. The model may also account for dark matter and dark energy, resolving multiple problems at once.

The widely accepted age of the universe, as estimated by general relativity, is 13.8 billion years. In the beginning, everything in existence is thought to have occupied a single infinitely dense point, or singularity. Only after this point began to expand in a "Big Bang" did the universe officially begin.

Although the Big Bang singularity arises directly and unavoidably from the mathematics of general relativity, some scientists see it as problematic because the math can explain only what happened immediately after—not at or before—the singularity.

"The Big Bang singularity is the most serious problem of general relativity because the laws of physics appear to break down there," Ahmed Farag Ali at Benha University and the Zewail City of Science and Technology, both in Egypt, told Phys.org.

Ali and coauthor Saurya Das at the University of Lethbridge in Alberta, Canada, have shown in a paper published in Physics Letters B that the Big Bang singularity can be resolved by their new model in which the universe has no beginning and no end.

Old ideas revisited

The physicists emphasize that their quantum correction terms are not applied ad hoc in an attempt to specifically eliminate the Big Bang singularity. Their work is based on ideas by the theoretical physicist David Bohm, who is also known for his contributions to the philosophy of physics. Starting in the 1950s, Bohm explored replacing classical geodesics (the shortest path between two points on a curved surface) with quantum trajectories.

In their paper, Ali and Das applied these Bohmian trajectories to an equation developed in the 1950s by physicist Amal Kumar Raychaudhuri at Presidency University in Kolkata, India. Raychaudhuri was also Das's teacher when he was an undergraduate student of that institution in the '90s.

                                                                                                              source- www.phys.org/          

Mangalyaan: India's race for space success

The orbiter lifted off from the Satish Dhawan Space Centre in Sriharikota in November 2013

Continue reading the main story\Watch

India's maiden mission to Mars, the Mangalyaan, has arrived in orbit after a 300-day marathon covering over 670 million kilometres (420 million miles). Science writer Pallava Bagla traced its journey as it neared the Red Planet.

On the morning of 24 September, the Indian Space Research Organisation (Isro) slowed down the spacecraft sufficiently so it could be caught in the orbit of Mars.

"India will become the first Asian country to have achieved this and if it happens in the maiden attempt itself, India could become the first country in the world to have reached distant Mars on its own steam in the first attempt," said Isro chairman K Radhakrishnan as it approached.

Both Russia and the US failed in their maiden attempts. The first Chinese mission to Mars, called Yinghuo-1, failed in 2011 alongside the Russian Phobos-Grunt mission with which it was launched. Earlier in 1998, the Japanese mission to Mars ran out of fuel and was lost.

Undoubtedly, India - a late starter - is way ahead of its Asian rivals in trying to get to the Red Planet.

"We are really not racing with anyone, but with ourselves to reach the next level of excellence," said Mr Radhakrishnan.

'Pink of health'

India's Mars Orbiter Mission (MOM) - an indigenously made unmanned robotic mission weighing 1,350kg (2,976lb) - was launched from the rocket port at Sriharikota on the coast of the Bay of Bengal on a balmy afternoon on 5 November last year.

Since then, the mission "has been in the pink of health", says Isro, and has been cruising at breakneck speed to reach close to Mars, half-way around the Sun.

The health of Mangalyaan is monitored from Isro's Mars mission control complex in Bangalore

The 4.5bn rupee ($74m; £45m) mission is, as Mr Radhakrishnan says, "the cheapest inter-planetary mission ever to be undertaken by the world".

On his visit to India's rocket port on 30 June, Prime Minister Narendra Modi said: "The [making of the] Hollywood movie Gravity cost more than our Mars mission - this is a great achievement."

India's low-cost and quick turnaround satellite mission has been attracting a lot of global attention from the scientific community that seeks to better understand the mysterious Mars.

On the morning of 24 September Indian time, Isro re-oriented Mangalyaan and fired its on-board rocket motor for about 24 minutes to slow the spacecraft.

It was a very tricky operation - if it did not slow down sufficiently, it would have missed being caught by the gravity of Mars and the mission could have be lost in outer space; but if the rocket engine had fired more than required it could have slowed the Mangalyaan so much that it risked crashing down on to the red soil of Mars.

Since 1960, there have been 51 global missions to Mars and the overall success rate stands at 42% so the odds were loaded against the Indian Martian entry.

M Annadurai, head of the Indian Mars mission, said he was "confident that the laws of physics will favour India and the country could have its first robotic Martian baby soon".

'Delusional dream?'

Isro dubs the mission a "technology demonstrator", essentially showcasing to the world that India is no longer a country of snake charmers but a high-tech hub that has developed its technology against the odds and stringent sanctions.

The mission also makes a big global geo-political statement ahead of Mr Modi's imminent visit to the US.

In its six-month life, the mission will study the atmosphere of Mars and search for methane gas while asking that eternal question that has dogged humanity: "Are we alone in the universe?"

Within hours of its arrival in the orbit, the spacecraft is expected to relay the first images taken by an Indian eye of the Red Planet and help decipher why and how Mars lost its liquid water.

These are important questions essential for the long-term survival of human beings on Earth.

In the sprint for the Martian marathon, India has shown its technological capability and resilience to undertake arduous inter-planetary journeys.

Many, however, say this bid to reach Mars is a "delusional dream" of India seeking super-power status since 400 million Indians still live without electricity and 600 million people still do not have access to toilets.

However, in real terms, the Mangalyaan has cost India just about four rupees (seven cents; four pence) per person. 

                                                                                              - An Article From BBC

ROCKET LAUNCH FAILURES FROM 1940 TO 2010 VIDEOS

                                               
                                                        A YouTube Video


HELLO! science lovers I am your new updater.

HERE IS AN EXCITING ROCKET LAUNCH FAILURES FROM 1940 TO 2010 VIDEOS

                                                                                      An Article by Shubham Garg

How Sunspots Form ???

                                 

We may all know that sunspots are cooler, so they appear more black than the surroundings. But do we know why they are cooler than other regions? Lets see why they are cooler.

Convective Cells

There are some convective cells or granules on the surface of the sun. They are small areas, where the hot fluid comes up to the surface, loses heat, and then sinks into the surface of the sun just like water when it is being boiled. These cells also contribute to the formation of the sunspots.

Magnetic field of the Sun

You must be knowing how magnetic field lines emerge out of a magnet, like in the picture shown below:

This same thing happens in the sun. And these field lines are formed by the hot plasma that is present inside the sun, not a bar magnet piercing through top and bottom of the sun. As you know that sun moves faster at the center than at the poles, hot plasma at the center also moves faster. So, there is not a straight magnetic field line connecting the north and south pole of the sun. Its like straight from the north pole, then a pointing structure towards the east, then again straight to the south pole. This thing continues so long that the same line takes a whole round of the sun and comes back to touch itself like a snake touching its own tail. This process makes all field lines crowded in a single area. Now, if the part of the field line in the northern hemisphere is having the positive charge, the crowded lines there repel each other due to same charge. They do this by exerting pressure, which is known as magnetic pressure.

Now the convection process (as explained above), plays its role. As heat is transferred to the surface by convection, the fluid coming up pushes the field line above. This pushing causes the field line to poke through the surface from inside, forming a loop and taking all the plasma on the part of the line above, as shown below:

Where they poke through the surface, sunspots are formed there. But why is their temperature down? That's because of magnetic pressure. Now, forget about the poking of the field line through the surface. On the surface of the sun, gas pressure is equally distributed. Now this poking happens. Then, near the area where it poked, there are many more field lines with the same polarity as the field line that is above. So, they repel each other by magnetic pressure. So, near the poked surface, there are two types of pressures - magnetic and gas pressure. So, in these area, the pressure is more than the rest of the surface. So, any how, the pressure must be equally distributed. We can't get rid of the loop until those crowded field lines are given enough time to go away from each other. So, we should lower gas pressure. But how? By inhibiting the convection process. This allows lesser heat than before, so that pressure is equally maintained. So, less heat means less temperature for those areas. So, sunspots are formed.

But they are not that cold. Only 1000 K less than other regions! (5000 K on surface and 4000 K on sunspots).  

Why sunspots are temporary?

Sunspots are of course temporary as when convection is inhibited, the field line slowly comes back inside again. And, those crowded lines also get enough time to repel each other. So, everything comes back to normal.

Now, after studying this, you can make out where sunspots are maximum in number. They will be maximum at the central region as magnetic lines get crowded there more than near the poles. But, sunspots also get formed near the poles, but less in number.

                                                                                                                       Article by - M.Santosh
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Some sources that had been helpful for the making of this article and maybe helpful to you too - 

- http://cse.ssl.berkeley.edu/segwayed/lessons/sunspots/

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Nobel Prize Physics 2013 - For Higgs and Englert

It is a pleasure to hear that the Nobel Prize 2013 went to the scientists who predicted Higgs Boson and the prediction turned out to be true! A higgs boson like particle was observed in the CERN using the Large Hadron Particle Collider before. After that event, scientists began to study it and observed properties of higgs boson as predicted. So, news became viral about it. If the discovery was true, particle physics will be hundred steps ahead. Higgs Boson is a particle that creates a Higgs field in deep space, and whenever anything interacts with it, gains mass. Only photons are the particles that never react with the Higgs Field. Particles that interact more have more mass. 

The of the discovery of the particle was confirmed on March 2013 and the credits went to Higgs and other five scientists, Kibble, Guralnik, Hagen,Englert, Brout. The discovery of the higgs boson completes the standard model of the Universe and now

scientists can briefly explain how elements gain mass to form matter.
                                                                                                                Article by - M.Santosh________________________________________________________________________

Kepler's Laws of Planetary Motion

                                                             

Johannes Kepler was a great astronomer is the 17th century, and he was the first to give true predictions and laws of planets' orbits and their properties. Below, there is a brief description of his laws and explanations, why they do so as they are mentioned:

1st Law:

                                                

First law states that when multiple planets are orbiting the sun, the planets' orbits are not circular, but an ellipse. An ellipse is a shape, like an oval, with two foci and the sun is present in one of those foci. If there was only one planet orbiting the sun, the planet's orbit would be exactly circular. But when another planets enters, the gravitational pull of both the planets can affect the orbit of each other. So, the orbits become ellipses, or an oval. For example, when only Earth is orbiting the sun, the orbit of Earth would be exactly circular, so therefore, there will be no such thing called seasons as earth won't go away from sun, or come too close to the sun. But when a massive planet like Jupiter or Saturn start orbiting the sun, the massive planet may pull earth away from the sun, when they are in a straight line, for a period of time. But still, earth would be orbiting the sun. But when earth exits the straight line between the sun and the massive planet, the massive planet stops pulling earth, and sun will be the only source, which pulls earth. So, in this period, the earth would move closer to sun. So, it is clear that earth sometimes comes close to sun, and sometimes goes away from sun, staying in orbit. So, the shape finally, is an oval or an ellipse.

2nd Law:

Second law states that the line joining the earth ans sun covers equal areas in equal intervals of time. This means that:

Consider the above picture. Sun is at position A, and Earth is in position B. After two months, Earth is in position C, and a line is connected from sun to earth. We can see that A, B and C form a sector. Take this sector as Y.

After another two months ( same time period between first two positions ), Earth is at position D. So, another sector is formed by A, C and D. Name this sector as Z.

As there is same time period gap between B,C and C,D ; the areas of sectors Y and Z is equal.

3rd Law:

The square of period of revolution of a planet around the sun is directly proportional to he cube of the average radius of the planet's orbit.

This means that the square of the time, taken by a planet to complete its orbit around the sun is directly proportional to the cube of the average radius of the planet's orbit, as it is not a circle. If only one planet orbited around the sun, we would take the average radius as the actual radius of the orbit. This law is commonly known as law of periods. The farthest point of a planet from the sun is called aphelion and the closest point is called perihelion. 

                                                                                                                         Article by M. Santosh

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Electromagnetic Induction

Michael Faraday

Electromagnetic induction is obtaining electricity from magnetism, and obtaining magnetism from electricity. This was observed by Michael Faraday. Electricity is obtained only in this was and by heating ( photoelectric effect ). This electricity is used to heat up things, run fans, ACs, lights, e.t.c. He also made an electromagnet, a coil generator, and many things that included electricity and magnetism. 

               An Electromagnet

When you make a copper coil, and move a strong bar magnet to and fro inside the coil, you induce electricity into  the wire or get electricity, which is passing through the wire. Now, this electricity is used to power gadgets at our homes and offices.

The vice versa of it is that when you loop a copper wire around any metal, and pass electricity through the wire, the metal becomes a magnet!
These magnets are known as electromagnets, and metal cleaners obtain scrap metal from garbage in this way.

                                                                                                                     Article by - M. Santosh
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Why do Planets orbit elliptical ?

Planets have a tangent velocity, and the sun's gravitational pull pulls Earth towards it. This provides balance, that keeps Earth moving around the sun. When this is clear to you, you will understand why orbits become elliptical.

An Animation from Wikipedia shows how planets

 move away in elliptical orbits

For an Example, imagine a pole fixed to a position, with a rope tied to it. A man starts to hold the rope, and start to move around the pole. When his speed increases, he will not be able to hold the rope tightly, and will fall after a period of time. The same is with planets. When they are close, that means that it is holding to the rope from the sun. When it is moving away, it's grip gets loose, and moves away from the Sun. But when it comes back again to its mean position, it is able to hold on to the rope and therefore, close to the sun. If its speed increases, it will loose the grip of the rope, and escape the orbit. When its speed is little less than the speed to escape the orbit, it moves a little bit away from the sun. Its speed is greatest when near the sun and slow, when away from the sun.

Sometimes, there may be very tiny irregularities of the path of orbit, due to the gravity of other planets like Mars and Jupiter.

                                                                                                        Answer by - M. Santosh
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Black Holes - The Mystery

Albert Einstein first predicted the existence of black holes, by his calculations of General Relativity. Black holes are never seen, they are just predicted. As even light can't escape from it, we can't see them actually. But, still scientists use advanced telescopes to see, where stars and planets move fast. It is observed that many stars are moving faster in centers of galaxies. These holes form, when stars die, and their surface gets directed to its own gravity field, making a hole. Its gravity is so powerful that the star gets crushed into its own gravitational field which is so small. This sucks everything near it, even light can't escape it.  As there is no object on universe, which is faster than light, that means that everything gets sucked through it. Black holes' size increase when they suck mass, and suck other stars and black holes. Below is a brief description, of how black holes form, and their history:

How Black holes form?

     

Stars like sun, carry out nuclear reactions in their core and on the surface. The mass of the core is so huge but the nuclear reactions taking place on the surface balances them. When the nuclear fuel is spent on the surface, only the helium atoms and the core remains. At this time, helium atoms fuse to form carbon. This creates enormous amount of energy in a very short time, which causes an explosion which is known as a supernova. 

So, the outer surface is gone, which leaves the core behind. Due to the reactions in the core which forms many elements having mass greater than hydrogen (but the total mass is the same), the core starts to shrink further and further. This shrinked core is called a neutron star as the protons and electrons combine to form neutrons at this time. If it shrinks so much to a single point, called singularity, then it is called a black hole. It bends the space time so much, which gives a impression of a hole. Its gravitational force becomes so large that light can't escape it. 

                                        

Many predict that black holes are in centers of all galaxies, but don't suck near by objects, because their mass is gravity is not so strong. Our sun's mass is very small to become a black hole, so it will become a white dwarf, which just reflects near by light, just like our moon.  

Event Horizon

Event Horizon is just an area near the black hole. If something goes through this area, it means it won't escape the black hole. Here, only entry is possible, no exit. The more mass of the black hole, larger the event horizon.

How to see a black hole

We can never see a black hole. But still we can observe by seeing where objects move faster. Where gravity is more, objects move faster. This can be proved, as Mercury closer to sun, travels faster in short distances, when Earth travels slow, even in long distances. So, scientists predict that black holes are in centers of many galaxies, as they observed that stars and objects are moving faster in centers.

Prediction of white holes

                                                                 

There was a prediction of 'white holes', as when things gets sucked into black holes, must sometime come out. They are predicted to come out through white holes, which are also never seen, and never studied about them, how they form. These white holes emit energy, which is sucked by black holes. Many scientists believe that the Big Bang was the energy coming out of the white hole, forming our galaxies and solar systems. These black and white holes are predicted to be connected by what called as ' worm holes '. 

                                                        

This wormhole is a path, that leads sucked objects by black holes, to come out through white holes. When this prediction was made, Einstein suggested that when we connect a black hole today, and a white hole in the past by a wormhole, a time machine is made. When we are sucked by black holes, we come out in past through white holes. So, everything goes into past, which are being sucked. But, there is no such explanation, by which we can go in future, by black and white holes.

Will Earth will be destroyed when The Sun becomes a black hole:

No, earth will not fall into that black hole, because Sun is not so large, to become a black hole. So, Earth will not be destroyed by Sun's Black hole.

                                                                                                                     Article by - M. Santosh
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Is there a Dead End of the Universe

There must be a dead end of the universe. When I start to study about it and make pictures and images, I usually thing that there is a black hole surrounding the universe, and a white hole at the center. When something expands and moves away, it may travel so much distance that it enters the black hole, and get out through white hole. As many scientists think that big bang was actually mass coming out of black hole, I usually think that this theory can be true. I have searched and researched, but no one has come with this opinion. If this is true, there must be a wormhole, that connects all the black holes at the edge, to a single white hole at the center. If you build a space ship to travel through space and find a dead end of the universe, you can never find it as you may have to travel billion of years, and you may die. But, if you travel faster than light, you may travel into past. and come to a place, where then universe has never expanded and traveled. So, you may find the end of the universe. If you are finding the center of the universe, and take that same ship, and travel faster than light, again you travel into past, and come again to earth, because as you are coming closer to the center, and travelling back in time, you see the universe contracting as it comes closer and closer, and land up again on earth, ancient earth. 

Many advances in science only can prove many theories of universe. Everything can't be proved now only. Many laws are recognized centuries after, when a scientist first claimed it. So, many things are being researched, and there will be a time, when humans may start to rule the universe, and know about it everything. 

                                                                                                                       Article by - M. Santosh
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Seebeck Effect

                                          
                                            Seebeck Effect                                                         Thomas Seebeck


Seebeck effect is a simple theory, of how we can generate electricity from heat. In 1821, Thomas Seebeck observed the changes of a compass needle, where it was in a round of two wires, connected to a hot body. Seebeck called this thermo-magnetic as he didn't know that it generated electricity, as it created a magnetic field but Hans Christian Orstead observed that it generated electricity. So, he called it thermo-electric effect. As heat moves from hot to cold body, hot atoms also move from hot to cold body. Atoms have electrons, so, electrons also move from hot to cold body. So electricity is generated.

Experiment you can try at home:

You can try this experiment at home also. Take any two different wires ( made up of different metals or non-metals, like copper and steel ). I used a copper wire and a nail made up of steel. Take the copper wire, and round it along one side of the nail. More rounds ( loops ), means more electricity. Connect the other end of the copper wire and the other end of the nail to an LED or a motor or any other objects like that. Take the side of the nail, rounded with copper wire, near to a candle flame ( CAUTION : Don't bring very close to the flame, or else the wire can burn) or any hot object. You can see the LED glowing, or the motor rotating.

                                                                                                                          Article By - M. Santosh

Quantum Physics

Quantum Physics deals with the science that describes and defines the indivisible units. Quantum Theories described the interaction of matter and electrons, how they absorb energy and their physical movement and interaction of atoms and matter. Quantum is the energy packet of a radiation and quanta are the energy packets of radiations. Quanta is nowadays called as photons, as described in the Standard Model of Universe. There were two Quantum theories, Old and New. The old theory was not perfect and didn't describe and give proves about the physical changes of particles. After Max Planck realized that all the elementary particles exhibit both wave and particle's properties, the New Quantum Theory was made and was perfect and logical.

Origin of Quantum Physics

Quanta

Bohr used the quantum theory to give solutions to the problems in the atomic structures. He used some of Planck's Idea also to describe the atomic structure of atoms and how electrons are orbiting around them. In 1922, Erwin and Werner developed Bohr's atomic model into modern Quantum Physics. These gave the turning point of science in the field of Quantum Physics and Chemistry. 

Bohr's Theory ( Old Quantum Theory )

Niels Bohr

Niels Bohr used Newton's Mechanisms to show that electrons orbited around a nucleus. This nucleus has some protons attached to them. The electron's positive force and proton's negative force cause the electron to orbit in fixed orbits around the nucleus. He also added that atoms contained only fixed amount of energy in the form of quanta and released or absorbed them also in the form of quanta. This gave the perfect theory about atomic structure.

Max Planck's Theory ( New Quantum Theory )

Max Planck

Max Planck gave the idea that the hot or black body radiations (radiations emitted by hot bodies) could be explained if they came in packets or Quanta (now known as photons). When there is a group of quanta is emitted, they appear like waves and exhibit properties of waves. Even Albert Einstein showed the photo-electric effect by the principle of quanta. His famous equation, E = hv, where E is the energy absorbed, h is Planck's Constant and v is the frequency or energy contained in a photon. In photo-electric effect, as described by Einstein, objects gain energy from the calculation of this equation. This same object emits energy in the form of photons, again calculated from this equation.  

Radiation

Radiations are emitted from electrons. Quantum Physics shows and describes an electron as a wave and a particle emitted by an atom. But this electron works for four fundamental forces' law except gravity. These forces are weak nuclear forces, strong nuclear forces and electro-magnetic forces. Most of these radiations are keep travelling in space and mostly emitted from nuclear fission, when one atom splits into two and produces gamma radiations. These radiations can also be emitted from radioactive wastes, which are dangerous to humans. 

Black Body

Any body that can absorb or emit complete energy in the form of photons are called black bodies, which are calculated by using Planck's formula. These bodies emit generally radiations hazardous and dangerous to humans. Black Body Radiations are electro-magnetic radiations emitted by black bodies which are non-reflective and black color at room temperature.

Wave-Particle Duality 

After Max Planck's idea of radiations, these elementary particles were been called electro-magnetic radiations, which are emitted by a hot body in the form of quanta. This duality was a unique fact in the quantum theory and quantum theory of light(see light) describes it and black body radiations as electro-magnetic radiations.  

Photo-Electric Effect

                                          Photo Electric Effect                                          Albert Einstein


Photo-Electric Effect shows that whenever a matter absorbs energy from light, electrons of that particular matter and substance is emitted. This principle can be seen in plants, in their process of photo-synthesis. Albert Einstein used the laws and principles of Quanta to explain this effect and showed that energy absorbed from light is same as energy absorbed from quanta. If quanta was not proved, Einstein would not have known from where energy is absorbed from light and photo-electric effect would not have been proved. 

                                                                                                                           Article by - M. Santosh
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Time Travel - Possible or Not?

                                                    

Time travel has been common and most interesting topic in many science fiction stories. As many science fiction stories have been converted into truth and can be converted, time travel has been an interesting idea in the history of science fiction stories. 

History of time travel

                                                       

                                                                       A 1960 Film

The first time travel was observed in the Hindu Epic, The Mahabharata, where Revaita travels to heaven to meet Lord Brahma, and on his return, he observes that he came to the future and many years have passed.

Theory of General Relativity

                                         

Albert Einstein

Albert Einstein has given theories and principles of light and time. He proved that light bends where there is a strong magnetic field and time runs slower at strong gravity fields. His theory of general relativity proves that if we keep on approaching the speed of light, the time's speed keeps on decreasing only for us. If a man builds a special machine that can achieve 99% of light's speed or even 99.99999%, only his time will be slow and the surroundings will experience 2 centuries when that person will experience one year. Einstein's theory of relativity ends here as Albert Einstein died before he would give ideas of going into past. Many scientists believe that when we approach light's speed, the time is running slower and when we touch light's speed, the time would stop and when we travel faster than light, we would automatically go to past. 

                                       

General Relativity also proves that where light travels faster, time also runs faster. So, time runs faster in vacuum (space) than on Earth (a gravitational force exerting mass). That's why when astronauts go in space, they experience less time than on earth. If he or she takes a clock and goes into space, and returns after a period of time, the clock gone to space would show less time than the clock on earth.

Paradox

                                   

It is something that has logic, but is an argument that will have no result. It is logic but there is no reason for it. Time Travel is also considered to be a paradox. For example, there is a thing called Grandfather Paradox or Ancestral Paradox. It means that when Mr. X travel into past and kills his own ancestor or Grandfather, he would also vanish that second as his grandfather will die at young age and he won't have a son (who is Mr. X's father) and not having son means not having grandson. And who is the grandson? Well, Mr. X is the grandson and he won't even exist. And this will cause a great damage to the future as all the descendants of Mr. X will not exist and their memory and family will also not exist.

Well, there can also be time travels that cannot cause a damage to the future. For example, when a thief travels to the future and steals a diamond. Then, he again travels to present and gives that to his son. When his son becomes old, he will actually be the person, from whom the thief stole the diamond. From this, we can conclude that there is a cycle that he will steal it, it goes to past. When the son grows old, that diamond again travels to the future, then again gets stolen. This won't cause any damage, just the money decreases from the old age, and it increases in the young age! That's all.

Time Travel in the Future

                                               

Time travel is not properly researched and developed. So, today time travel is not possible, but tomorrow? Many scientists believe that in the future, history will be strong as when time travel is possible, we can travel into past and experience the ancient life and learn about our ancestors.

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See the following video from National Geographic how time travel can be possible:

                                                                                                                         Article By - M. Santosh

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External Combustion Engine

External combustion engine is an engine almost similar to internal combustion engine. The only difference is the ignition of the fuel occurs external to the engine. Ignited fuel come into the combustion chamber on the both sides alternately, so that they push both sides of the piston up and down.

Some examples of the external combustion engines are the steam engines. Water is heated in the boiler, that uses a fuel (wood). This heated water will be steam and will push the piston up and down.

Industrial Revolution

                      

Industrial Revolution  during 1760 - 1820, got its strength from steam engines. It was used in railways, for transporting goods. Many automobiles were built using these type of engines. The European Industrial Revolution transported mined metals and raw materials using railways, that used steam engines, an external combustion engine. Modern steam engine was invented by James Watt, who used many scientific properties to build a steam engine, called Watt Steam Engine. 

Mechanism

                             

It is a simple mechanism. To push the piston up and down, pressure is needed. Here, one stroke can be possible as a single piston goes up and down on its own(in internal combustion engine, one piston goes down, and the other up) producing a 360 degree rotation. For this, a sliding valve, that can slide up and down is used. The steam will go in the upper direction, if the sliding valve goes down and blocks the way down. The steam goes in the downward direction, if the valve goes up and blocks the way up. When the valve is down, the piston moves down, and the steam will go inside a pipe in the valve. This pipe will direct the steam to the next combustion chamber, and then the next. The final steam will go to a condenser, when it will again become water, then to the boiler where it will become steam. 

An animation from Wikipedia shows the movement of steam engine

Sliding Valve

Sliding valve is a special valve that goes up and down, directing the steam down and up respectively. This is done to get the piston moving up and down to get rotatory motion. 

Boiler

                             

Boiler is a special compartment, where a fuel (wood) is burnt to heat water to steam. This steam will then pass on to the combustion chamber, where it is used to push the piston up ans down. Water must also be passed to boiler at a fixed amount because we would now want the whole amount of water to convert into steam and causing the boiler to explode. So a special device called Injector, is used to get water at fixed rate into the Boiler.

Injector

                               

An injector is a special machinery used to inject a low pressure substance, to a high pressurized, so that it just shoots out where we want. It is used in steam engines as it gives water high pressurized and periodically so that equal amount of water gets to boil. It has two entry tubes. One for the steam and one for water. These two meet at the middle path, where the steam becomes water and the whole water becomes a little heated. This will pass through a middle path, where the path is thin, to get high pressures. This high pressurized water goes into the boiler, periodically and we get equal amounts of water to boil. It works on a principle, called Venturi Effect that explains that pressure is inversely proportional to the cross sectional area. It means that pressure increases when the cross sectional area decreases. That's why, injectors have a thin path in the middle, so that the water becomes pressurized.  

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See the following video from You tube, how an injector works:

                                    

                                                                                                                               Article by M. Santosh

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