From being India’s largest international carrier to near bankruptcy
Naresh Goyal founded Jet Airways in 1993 with a fleet of four leased Boeing 737 aircraft. At a time when private airlines had just started coming up in India, Jet Airways, a full-service airline, grew fast to become India’s largest international carrier.
However, with budget airlines such as SpiceJet and Indigo entering the broil, the aviation industry became a highly competitive one. Calling themselves ‘budget’, SpiceJet and Indigo started offering low airfare, forcing Jet also to lower fares. But it continued to offer full services, increasing operational costs and forcing it to keep borrowing from banks to stay afloat. Macro-economic changes such as a weakening rupee and rising fuel costs only hurt it further. It all led to unpaid dues and grounded flights which put JetAirways into the fray.
Back in 2013, when Jet had a debt of over $2 billion, it struck a deal with UAE-based airline Etihad, taking advantage of new policy changed that allowed foreign airlines to invest in domestic airlines. The agreement, which almost went through, would have seen Etihad bringing in a new investor who would invest around Rs 1,900 crore for a 20% stake. This would mean that Goyal and promoter group stake would fall. Goyal, however, didn’t want promoter shareholder capping to be a part of the deal, following which the deal fell through.
Again in November 2018, Tatas offered to invest in Jet. However the deal didnt go through for the same reason since Tatas wanted full control, which would mean Goyal stepping down. Goyal wouldn't just give up.
As of March 25th, Naresh Goyal and his wife Anita Goyal has finally stepped down from the board of the company. This step brings some hope on the revival of Jet airways. What is the next move is not determined. This all depends on the steps taken by interested investors like Etihad and Tatas. It is to be seen whether or not the Jet aiways will be able to come back from the dead, and if it does, how it shall flare.
Yogendra Rijal
See the trailer of the previous Jurassic Park movies here below.
Jurassic Park released in the summer of 1993 is an adaptation film of the book by the same name by Michael Crichton. In essence, Jurassic Park was a test for Spielberg, as is the same test for all competent filmmakers, to make a film translation of the book. What we got was (what some considered) a better version of the book.
Jurassic Park tells the story of Dr. Alan Grant, a modern day rendition of Indiana Jones and his adventures on a fictional island called Isla Nublar. Grant has been invited by John Hammon, the CEO of InGen, to study the dinosaurs on the island and to validate if it’s ultimately safe for civilians to visit the island as a vacation resort. Alan initially disagrees with the concept altogether before he’s star stricken at the landscape of a vast selection of dinosaurs on a plain.
After learning how these dinosaurs are created, Alan also begins to wonder about the ethics of recreating a species that died out “for a reason.” His gripes aren’t necessarily with the fact that this particular species of animal was created. Instead, Alan continuously retorts that dinosaurs were never meant to be kept in cages.
From here, we saw the true ethics of the movie; as the 20 minute segments rolled by, we understood what Alan meant in his theory. The moral of the movie was mankind’s human conditioning for control of other species through uncontrollable means. Effectively, Spielberg showed us what could happen when we try to play God with an entire species.
Aside from metaphors and two-bit analogies, Jurassic Park reached into the special effects library and pulled an early Avatar marvel of the 90s. Jurassic Park would go on to be talked about for the next 20 years with still no let up in the amazement that its graphics designers managed to squeeze out of the film.
In the time that we must wait for Jurassic Park 4, Spielberg has gone to say that a 3D re-release of the original film will be put into theaters, while a 3D release is also planned for Jurassic Park 4.
1. If the sun were to "turn off", the Earth would completely freeze within a week with a temperature of 0 degrees Fahrenheit even in the equator. In a year's time it would dip to -100 degree Fahrenheit, and millions of years later it would be a stable -400 degrees Fahrenheit.
2.The sun is getting hotter, becomming 10% more luminous around every billion years. This could mean that in a billion years, there will be no liquid water on Earth.
3. The sun is comprised of 72% hydrogen, 26% helium and other trace elements. These dense mass of gases makes up 99% of all the mass in our solar system.
4. The sun puts out a huge amount of energy to heat the solar system. Every second around 700 million tons of hydrogen are converted into helium ashes by the sun's fusion process.
5. The sun's surface is comparatively colder than its atmosphere, at around 6000 Kelvin. The atmosphere can reach 10,000K while the core is about 1 million Kelvin.
6. The sun is around 25,000 light years away from the center of the Milky way galaxy. It takes about 240 millions years to orbit once around the galactic center.
7. Different sections of the sun rotate at varied speeds, as it is made of gas. The equator regions rotate around every 25 days, whereas the poles take about 36 days to complete one rotation around the sun.
8. On some planetary bodies and moons, there exists a "peak of eternal light" where the sun never sets. This is due to the angle of rotational axis on relation to the sun.
9. The sun is middle aged. Astronomers believe it formed around 4.59 billions years ago. In 5 billion years time, it will enter the red giant phase of its life time.
10. 100,000,000,000 tons of dynamite would have to be detonated every single second to match the energy that the sun produces.
Source: universitytoday.com
The celestial mechanics or the orbital mechanics is the study of dynamics of satellites and planets in their orbit around bigger masses. For example, the moon and artificial satellites such as GPS, International Space station, etc. revolve around the earth in their orbit while the planets revolve around the sun in their orbit. The orbit around the sun is called helical orbit while the orbit around the earth is named as geo-orbit.
Nomenclature: It is important to understand the terminologies used to define the characteristics of orbit. In the demonstration figure below a mass is revolving around a bigger mass in its orbit. When the smaller body is at the closest distance with the bigger body (at position 2), its position is called as the periapsis. On the other hand, when the body approaches the farthest point (at position 1), its position is called as the apoapsis.
If the center body is sun, the closest and farthest positions are called perihelion and apohelion position respectively. Similarly, if the center body is earth, the closest and farthest position are called apogee and perigee respectively.See table below for more terms of apogee and perigee.
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| Body | Farthest approach | Closest approach |
|---|---|---|
| General | Apogee | Perigee |
| Sun | Apihelion | Perihelion |
| Earth | Apogee | Perigee |
| Mercury | Apohemion | Perihermion |
| Venus | Apocyterian | Pericytherian |
| Mars | Apoareion | Periareion |
| Jupiter | Apozene | Perizene |
| Saturn | Aposaturnium | Perisaturnium |
| Uranus | Apouranion | Periuranion |
| Neptune | Apoposeidion | Periposeidion |
| Pluto | Apohadion | Perihadion |
| Star | Apoastron | Periastron |
| Galaxy | Apogalacticon | Perigalacticon |
| Black Hole | Apobothra | Peribothra |
Obviously, you must have noted that the periapsis is equal to the apoapsis for a circular orbit. The circular orbits can be seen in case of artificial satellites only. By nature, each and every cellestial body revolves in an elliptical path. The Keplers law define these kind of properties of properties of planets around the sun.
Kepler's law:
1. The orbit of each planet is an ellipse with the sun occupying the focus (center object).
2. The line joining the sun to a planet sweeps out equal areas in equal intervals of time
3. A planets orbital period is proportional to the mean distance between the Sun and the planet raised to the power 3/2.
| First law |
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| Second law |  |
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| Third law |
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Helical Orbits:
- Energy is not continuous, but comes in small but discrete units.
- The elementary particles behave both like particles and like waves.
- The movement of these particles is inherently random.
- It is physically impossible to know both the position and the momentum of a particle at the same time. The more precisely one is known, the less precise the measurement of the other is.
- The atomic world is nothing like the world we live in.
Scientists are always in search of reality, how did it all began? So far, they have been able to explain the evolution and the birth of our universe as a result of big bang theory. They eventually want to know more. Descrbing the universe from this point haven't satisfied the scientists and they are starting to look even backwards. What was it that caused the big bang? What was there beyong the bigbang and the spacetime? To answer this mystery, scientists are in search of a theory- THeory of Everything! The concept of parallel universes yielded the M-theory (membrane theory / mad-theory / made-up theory / meaningful theory / meaningless theory - there are many opinions about this theory among the physicists of today). The parallel universe and the M-theory is explained in the documentary below. The theory further discusses about the 11-dimensions.
Fantasy has long borrowed the idea of "another world" from myth, legend and religion. Heaven, Hell, Olympus, Valhalla are all "alternative universes" different from the familiar material realm. Modern fantasy often presents the concept as a series of planes of existence where the laws of nature differ, allowing magical phenomena of some sort on some planes. This concept was also found in ancient Hindu mythology, in texts such as the Puranas, which expressed an infinite number of universes, each with its own gods. While technically incorrect, and looked down upon by hard science-fiction fans and authors, the idea of another "dimension" has become synonymous with the term "parallel universe". The usage is particularly common in movies, television and comic books and much less so in modern prose science fiction. Source: http://en.wikipedia.org/wiki/Parallel_universe_(fiction)"Our universe (that we feel to exist) is a collection of selected events from these multiverses based upon the probabilties and the actions/decisions that we take/make." [my understanding]
And hereby, I present the summary of my understanding of the M-theory:
- Every matter in this universe is composed of vibrating strings which are about 10^(35) of a mm.
- Our universe is a bubble floating in a membrane.
- There are many such bubbles floating around.
Australian transport investigators have announced they have identified a "critical safety issue" with engines fitted to the world's largest passenger airliner. Some Rolls-Royce Trent 900 engines, which power some Airbus A380 "superjumbos", may be prone to "fatigue cracking", which could lead to oil leakage and a fire.
There was an age when communication and transportation was limited which kept us to persue a limited ammount of space on earth. With each slight progress in communication and transportation, our community suddenly elaborated. We started from streeet to street and then town to town and eventually from country to country. With this rapid development in science and technology, we might eventually talk about planet to planet. For example, in the past people used to represent themself saying "I am from blah blah town". Thereafer "I am from that province" and now we talk about I am from this country. It might be such that in the future that we represent our planet and we introduce ourself in other planets/galaxies by saying "I am from earth".
One of the recent progress in technology is the flying bird. It is of no amaze that humans can fly today in the sky like birds with the development in aeronautics. But this recent development is the flying car which is hybrid and is infact a car that can fly in sky.
The concept of flying cars is not a new one. It was preliminarily designed before but the practical one which could be used in real life was not achieved before. Terrafugia company in Oskkosh, USA have designed the rodable aircraft which can roll on the road as well lift on the air. The design is both a rear-wheel drive road vehicle and a light sport aircraft that can cruise at 170 kph (105 mph). Although this technology is still limited to certain class of people, it can be common to ordinary people once the commercialization takes on and production becomes efficient. Besides that, the air certification plays a role in bringing these cars to public as well.
This newly designed flying car may pave the way for future personal transportation. This development will certainly defy the constraints in living. No landscapes can block the cars, no roads need to be paved, no any terrains will resist to move. The range for transportation will increase and the life on earth will be different once these flying cars will start to be on garages of personals.
Let us see what progress and success will this technology achieve in the future.
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"We are on the verge of the perpetual flight," he said.It is certain that there won’t be any life on earth once the sun gets burnt out and it starts expanding to form a red giant which will end the earth and solar system. This is estimated to happen in five billion years from now on. But that time is very far from us, so we don’t need to panic right now. Besides, the search for another shelter planet is going on with the rapid development in science and technology. The other thing that we should fear is about the changing climate and unpredictable weathers that we have been facing currently. It has certainly been a time to be serious about the preservation of earth and its atmosphere to keep our human kind alive.
People might have misunderstood the definition of climate change when they see some extreme winters and get confused that there is no such thing like global warming. It is well to be taken into account that the extreme winters and extreme summers are a part of climate change.
Now let us see how the water has escaped into the atmosphere which will be interesting for us in Earth. As ultraviolet radiation from the Sun streams into Venus' atmosphere, it breaks up the water molecules into atoms: two hydrogens and one oxygen atom. Such continuous reaction transformed water to oxygen and hydrogen. These gases could easily escape to the atmosphere. This shows us that ultraviolet rays from the sun are the main reason for the loss of water on Venus. As a reason of ozone depletion, the water on the earth could face the same attack. The current surface of Venus is like a hot oven. It could be such that the surface was similar to ours in the past over there. I hope and wish that our earth will never be an hot oven. Let us preserve our earth and let preserve ourselves.
South Korea has lost contact with its Naro-1 rocket, just 137 seconds after take-off. Officials believe the rocket exploded.
Korea Aerospace Research Institute (KARI) and Khrunichev State Research and Production Space Center had hoped to use a Naro-1, South Korea's first carrier rocket, to launch a STSAT-2B satellite.
South Korea had postponed the launch on Wednesday due to problems with the rocket's fire extinguisher system. Science Ministry spokesman Pyun Kyung-bum said, "We expect that it will be difficult to launch today".
The rocket lifted off from Goheung's Naro Space Centre at 1701 (0801 GMT) today. The rocket apparently exploded 137 seconds after launch, when a flash was seen from an on-board camera and communication was lost. The loss of communication occurred when the rocket had achieved an altitude of around 70 kilometers (43 mi). Television cameras captured a white speck, presumably part of the rocket, falling into the sea.
Analysts say the failure is a setback for South Korea. If it had been successful, it would have been the first Naro-1 launch to reach orbit. The launch cost South Korea an estimated US$400 million, and if successful, would have launched a satellite called the STSAT-2B into orbit. The satellite was designed to examine climate change and its effects.
The incident is seen as a major setback for South Korea's space program, which had been aiming to become the 10th country to achieve the capability to launch satellites, and the fourth Asian country, after China, Japan, and India. A successful launch would have helped South Korea to become a player in commercial space launches, an industry valued at around US$250 billion. Since 1992, South Korea has launched 11 satellites from overseas sites with foreign-made rockets.
Lead researcher Michelle Simmons said the technology has major implications for code-breaking, financial transactions and weather forecasting, which involve testing enormous numbers of possible scenarios.
Fishtail Air has with the help of Air Zermatt, a Swiss helicopter company, introduced an advance "Alpine Rescue System" in the Himalayan region of Nepal.
Air Zermatt has also introduced ambulance facilities in the rescue helicopter to make rescue operations effective.
It had organized a week-long training programme on how to conduct high-altitude rescue operations for Fishtail Air pilots on March this year, said Suman Pandey, chief executive officer of Fishtail Air.
The pilot and rescue specialist of Fishtail Air will be leaving for Switzerland for additional training in Alpine in the near future, he added. Fishtail Air also believes that after the additional training by the pilot and rescue specialist, it will have the best rescue team in the whole of Asia.
It has also plans to expand its service to the neighboring counties like India, Bhutan and Tibet.
Are eco-friendly airplanes possible?
The ecology is finally getting more attention, and eco-friendly products are becoming increasingly popular. Hybrid cars are one of the best examples how eco-friendly vehicles are becoming more and more popular as their sales have experienced significant growth in the last few years.
And now it looks like air traffic might also have its green representative in form of eco-friendly plane after MIT-led team designed an eco-friendly airplane that is estimated to use 70 percent less fuel than current planes while also reducing noise and emission of harmful nitrogen oxides.
Current estimates say that air traffic will double by 2035 so it is of vital importance to develop eco-friendly planes that would be far more efficient than current planes in order to tackle climate change problem.
THE MIT scientists have designed two series of eco-friendly planes: the 180-passenger D "double bubble" series to replace the Boeing 737 class aircraft, currently used for domestic flights, and the 350 passenger H "hybrid wing body" series to replace the 777 class aircraft now used for international flights.
D series was constructed by reconfiguring the tube-and-wing structure. Instead of using a single fuselage cylinder, scientists used two partial cylinders placed side by side to create a wider structure whose cross-section resembles two soap bubbles joined together. They also moved the engines from the usual wing-mounted locations to the rear of the fuselage. Unlike the engines on most transport aircraft that take in the high-speed, undisturbed air flow, the D-series engines take in slower moving air that is present in the wake of the fuselage. This techniques is knows as the Boundary Layer Ingestion (BLI), and it allows the engines to use less fuel for the same amount of thrust, although the design has several practical drawbacks, such as creating more engine stress.
H series utilizes much of the same technology as the D series, including BLI, a larger design is needed for this plane to carry more passengers over longer distances. The MIT team designed a triangular-shaped hybrid wing body aircraft that blends a wider fuselage with the wings for improved aerodyamics. The large center body creates a forward lift that eliminates the need for a tail to balance the aircraft.
Eco-friendly air traffic certainly sounds very good, especially after construction of eco-friendly airplanes look possible. Let us hope that such aircraft will be flying sooner in our sky and thus protecting our environment.
Conceptual Design of eco-friendly aircraft as designed by MIT-Cambridge research team
1. The Earth spins at 1,000 mph (1,610 kph) but it travels through space at an incredible 67,000 mph (107,826 kph).
2. Every year, over one million earthquakes shake the Earth.
3. The Earth is 4.56 billion years old…the same age as the Moon and the Sun.
4. In 5 billion years the Sun will run out of fuel and turn into a Red Giant.
5. It would take over an hour for a heavy object to sink 6.7 miles (10.8 kilometres) down to the deepest part of the ocean.
6. Around a million, billion neutrinos from the Sun will pass through your body while you read this sentence.
7. Every hour the Universe expands by a billion miles in all directions.
8. Venus is the hottest planet in our solar system with surface temperature above 450 C.
9. If we are to believe scientists there are approximately 50,000,000,000 galaxies "out there". there might be even more than that however
10. Our moon is extremely dry, it is for instance one million times drier than a earth desert.
11. The highest recorded temperature on Earth was measured in Libya in 1922, and it was 58°C.
12. The lowest recorded temperature on our planet was -89.6°C. This was measured in Antarctica in 1983.
13. Not all animals on our planet have brains, for instance starfish do not have brains.
14. Our brain isn't much different than the rest of our body in terms of water since 80 % of our brain is water.
15. Our brain for proper functioning needs about quarter of total oxygen used by our body.
16. Ants are so hardworking that they even do not sleep.
17. Our fingernails are growing much faster than our toenails, about 4 times faster.
18. Talking about the hot stuff - The highest temperature produced in a laboratory was 920,000,000 F (511,000,000 C) at the Tokamak Fusion Test Reactor in Princeton, NJ, USA.
19. Hurricanes cause havoc which is really no surprise since a typical hurricane produces the energy equivalent to 8,000 one megaton bombs.
20. In case you have ever wondered why giraffes are such a quiet animals it is because they have no vocal chords to make any noise.
21. In Mercury, a day is longer than a year. Note that the rotation in its axis makes a day while the revolution around the sun makes a year.
22. Sun loses 360 million tonnes of material each day as its fuel burns.
23. Astronauts can become upto 2 inches taller returning from space.This happens because the cartilage disks in the spine expand in the absence of gravity.
24. Methane is extremely potent greenhouse gas and cows are among the largest methane emitters with each domestic cow emitting about 105 pounds of methane a year.
25. The fastest spacecraft till the date can cruise at 40,000 mph (67,374 kph).
26. Fetuses react to rock music by responsing with a continous kick inside mother's belly.
27. Average male brain is larger than average female brain (1,4 kg to 1,25 kg).
28. Polar bears would make perfect thieves since they cannot be detected by infrared cameras because of their transparent fur.
29. Average person breathes about 10 million times a year.
30. It snows in the upper atmosphere of Mars but vaporizes before reaching the ground.
31. There was a time when Mars had large amounts of surface water. Proof of this facts have been fund on certain valleys and canyons.
32. Saturn's rings are about 500,000 miles in circumference but only about a foot thick.
33. December 21st 1968, was the first time that humans actually left the Earth, when Apollo 8 became the first manned space vehicle to leave Earth orbit and to orbit the Moon.
34. A satellite launched by Britain was called Black Arrow.
35. Our moon is in fact moving away from Earth at a rate of about 2.5 cm per year. There are different statistics for the moon's rate of moving way from the Earth, some claim the rate of moon's moving away from the Earth is up to 34 cm per year but according to the most credible sources it moves 2.5 cm away from Earth each year.
36. Buzz Aldrin's(second man on the moon) mother's maiden name was "Moon".
37. Did you know that astronauts cannot burp in space?
38. It is said that just 20 seconds worth of fuel remained when Apollo 11's lunar module landed on the moon.
39. A comet's tail always points from the sun.
40. Every day, Earth accumulate 10 to 100 tons of material.
41. The largest found meteorite was found in Hoba, Namibia. It weighed 60 tons.
42. Did you know that the heart of an astronaut actually gets smaller when in outer space?
43. The earth is .02 degrees hotter during a full moon.
44. Some large asteroids even have their own moon.
45. On average, Saturn is 886 million miles away from the Sun.
46. Saturn's density is less than water on average, although this fact is a bit misleading. As one looks deeper into the planets gas surface, density rises well above water.
47. Jupiter has 60 known moons, but some of them are quite small and look fainter.
48. A 100 pound object on Earth would weight 116 pounds on Saturn.
49. Mars is red because it is rusty. There is a lot of iron in the soil, and the air on Mars has made it turn red-just like rusty iron on Earth.
50. It takes about 29.46 Earth years for Saturn to complete its orbit around the sun.
51. Mars complete its orbit around the Sun in 687 days.
52. The atmosphere of Saturn comprises mostly of Hydrogen and Helium.
53. At its brightest, Mars outshines every other planet apart from Venus.
54. Only moon of Saturn to have an atmosphere out of its thirty satellites is Titan.
55. Jupiter has a mass 318 times greater than the Earth's and a diameter that is 11 times larger.
American biologist Craig Venter has announced that he has created the first ever "artificial life form" on Earth at the J. Craig Venter Institute, a U.S. laboratory and research center.
The breakthrough is the culmination of fifteen years of research and builds upon earlier work, research which saw the creation of a synthetic bacterial genome and the transplant of a genome from one species of bacteria into a second. "Synthia", a nickname derived from synthetic lifeform, combines these two techniques to create a "new lifeform".
A genome was created using synthetic chromosomes made from bottles of chemicals, the chromosomes sequenced to create a genome using as a template an existing bacterium. A bacterium from different species then had its own genome removed and the synthetic one transplanted in its place. Venter's achievement is that the new genome switched on and the new cell was able to replicate. A process likened to the booting of a computer with a new operating system.
Venter's achievement has been dismissed by some as falling short of a true technological breakthrough, claiming that rather than creating a new genome, that he has merely recreated the genome of an existing bacterium: "a technical tour de force" but not breakthrough science, according to Caltech geneticist David Baltimore.
Amongst the possibilities of artificial bacteria talked about are bacteria tailored to solve climate change by taking CO2 out of the atmosphere and to develop new vaccines. More complex organisms could include algae which would both be a source of biofuels and a CO2 remover. This is not, however, the instant solution to the Earth's major problems. Although enough is now known to duplicate a genome, there is insufficient knowledge as to what the role of individual chromosomes within the genome do. Any advances in synthetic biology to design life forms would require a much greater understanding of how the creation of proteins are coded in a genome's chromosomes.
Without no doubt, everyone knows that Jupiter is the fifth member of our solar system and it is the largest planet in our solar family. Here below can you find some more interesting facts about Jupiter.
Equatorial Radius: ~71500 kms [11.21 times that of earth]
Surface Area: 6.21796×1010 km² [122 times that of earth]
Volume: 1.43128×1015 km³ [1321.3 times that of earth]
Mass: 1.8986×1027 kg [318 times that of earth ; 1/1047 solar mass]
Equatorial layer gravity: 24.8 m/s² [2.5 times that of earth]
Escape velocity: 59.5 km/s [that of earth is 11.186 km/s]
Atm. surface Pressure: 200 kPa [twice as that of earth surface ]
Atmospheric Contents: 89% Hydrogen, 10% Helium, 1% of rest including Methane, ethane ammonia, water, etc.
Some Interesting facts about Jupiter:-
- Jupiter technically has no surface as it is entirely made out of gas.
| What is a black hole ? In simple words, a black hole is a strange astronomical body which is formed when a massive star dies. As the star dies, the nuclear fusion reactions stop because the fuel for these reactions gets burned up. At the same time, the star's gravity pulls material inward and compresses the core. As the core compresses, it heats up and eventually creates a supernova explosion in which the material and radiation blasts out into space. What remains is the highly compressed and extremely massive core. According to the general theory of relativity, a black hole is a region of space from which nothing, including light, can escape. It is the result of the deformation of space-time caused by a very compact mass. In other words, a black hole is a region of space that has so much mass concentrated in it that there is no way for a nearby object to escape its gravitational pull. Black hole is something which has immense gravity and thus nothing can pass through it. |
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| Why not even light can pass through a black hole? Suppose that you are standing on the surface of the earth. You throw a rock straight up into the air. Assuming you don't throw it too hard, it will rise for a while, but eventually the acceleration due to the planet's gravity will make it start to fall down again. If you threw the rock hard enough, though, you could make it escape the planet's gravity entirely. It would keep on rising forever. The speed with which you need to throw the rock in order that it just barely escapes the planet's gravity is called the "escape velocity". As one would expect, the escape velocity depends on the mass of the planet: if the planet is extremely massive, then its gravity is very strong, and the escape velocity is high. A lighter planet would have a smaller escape velocity. The Earth's escape velocity is 11.2 km per second (about 25000 mph), while the Moon's is only 2.4 km per second (about 5300 mph). Now imagine an object with such an enormous concentration of mass in such a small radius that its escape velocity was greater than the velocity of light. Then, since nothing can go faster than light, nothing can escape the object's gravitational field. Even a beam of light would be pulled back by gravity and would be unable to escape. | |
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Even Horizon and the Singularity of a black hole In general relativity, gravity is a manifestation of the curvature of space-time. Massive objects distort space and time, so that the usual rules of geometry don't apply anymore. Near a black hole, this distortion of space is extremely severe and causes black holes to have some very strange properties. In particular, a black hole has something called an 'event horizon'. This is a spherical surface that marks the boundary of the black hole. You can pass in through the horizon, but you can't get back out. In fact, once you've crossed the horizon, you're doomed to move inexorably closer and closer to the 'singularity' at the centre of the black hole.  You can think of the horizon as the place where the escape velocity equals the velocity of light. Outside of the horizon, the escape velocity is less than the speed of light, so if you fire your rockets hard enough, you can give yourself enough energy to get away. But if you find yourself inside the horizon, then no matter how powerful your rockets are, you can't escape.The horizon has some very strange geometrical properties. Far away from the black hole, the horizon seems to be a static, unmoving spherical surface. But once you get close to the horizon, you realize that it has a very large velocity. In fact, it is moving outward at the speed of light. That explains why it is easy to cross the horizon in the inward direction, but impossible to get back out. Since the horizon is moving out at the speed of light, in order to escape back across it, you would have to travel faster than light which is impossibly practically as well as theoretically. | |
Gravity is a well-known term and everyone in general knows that it is a pulling force. It is such a force which keeps everything in contact and everything thus constrained to something. Gravity of earth keeps the moon where it is supposed to be and gravity keeps you where you are now. If you weren’t under gravity of earth, you would be floating in space. This understanding of gravity is not really limited to the force of attraction between two masses or let’s says a pulling force. It is something more mysterious.
Newton’s Gravity:
Gravitational force = (G * m1 * m2) / (d2)
where G is the gravitational constant, m1 and m2 are the masses of the two objects, and d is the distance between the centres of gravity of the two masses.
Einstein’s Gravity:
Thus, space-time is a common quantity and as time and space are bonded together.
Space is a fibre where our universe exists. This can be seen on the picture below.
Thus, when an object is placed on this fabric space, it distorts the space-time and created a curve on the space-time. This is what we experience: gravity. Big masses create big distortion (big curvatures) while small objects create, small distortion. This is because of this face that the smaller objects are pulled towards bigger objects. Consider this with earth and moon.
Our earth being a big mass has created distortion in space-time and thus a curvature is created on the fabric of space. The moon is thus constrained to move in its orbit and hence attracted towards the earth and so are we all.