Quantum Computers - Taking Human civilization to a whole new lavel

Need to move on from classical computers

 We know that our computers perform the daily life calculations and solve our engineering problems. We do our office work on these computers and We can also watch videos, listen to music, surf the internet and play games. All of these computers including personal computers, workstations and super computers are conventional computers. Because all of these use binary to do everything they do. They use the combinations of 1s and 0s. Everything including sounds, videos and images are represented using binary in these computers. Computers make their decisions in 1s and 0s using logic circuits using some basic logic gates which work on high and low voltage and computers recognize the high voltage as a 1 and low voltage as a 0. We call these 1s and 0s as bits. A bit can either be 0 or 1. 

The problem with our current computers is that we're close to hitting the limit for how advanced they can get, Plus, classical computer cannot solve some complex problems; those involving very large number of variables or some complex optimization problems.

The strange & fascinating world of Quantum mechanics

 Our perception of reality has completely changed over the past seventy-five years, because of the new revolutionary set of laws; the laws of quantum mechanics. These laws govern every atom in every piece of matter in stars and galaxies, rocks and oceans, and in you & me. And for decades now, scientists have been trying to use these strange laws in order to devise a whole new generation of computers; Quantum computers.

Quantum computer uses sequence of quantum bits or simply; Qubits, not the conventional or classical bits. The difference between a conventional bit and quantum bit is that a bit can either be 0 or 1 at a time where as a Qubit can be both 1 and zero at the same time which makes the quantum computers very powerful.  This is hard to understand because these concepts are from physics. Precisely, quantum mechanics. And the roots of quantum computing lie deep down in the strange and mysterious laws of quantum mechanics. And the bizarre predictions made by them; Phenomenon’s like Quantum superposition, Quantum entanglement etc. I strongly recommend you to read my previous post in order to understand these things, which is in turn, important to have a better understanding of the working of quantum computers.

Working of Quantum computers

 Quantum computers are fundamentally different from the classical computers. Due to the fact that a classical bit can either be 0 or be 1 at a time. Whereas, a Qubit can be 0,1 or both at the same time. Precisely, superposition state of 0 and 1, in case of quantum computers, a bit (Qubit) is not in the form of voltage, rather a Qubit can be anything which behaves quantum mechanically; atom, electron, photon. Take electron for example; according to the laws of quantum mechanics; the spin motion of electron can either be clockwise, anticlockwise or superposition of both. It means that an electron can spin in a lot more ways than clockwise and anticlockwise. Unless you measure the spin state of the electron, it is in the superposition. The act of measurement forces it to acquire one of the states, we can say clockwise to 1 and anticlockwise to 0 or vice versa.  This spin motion of electron serves as a qubit. But there's a catch; when we measure a Qubit, it transforms and collapses itself into a simple classical bit. That’s why quantum computers are not very good alternative for small daily life calculations involving some amount of steps. However, quantum computers are indeed exponentially faster in case of calculations involving a lot of variables. Checking a lot of possible combinations to find one right answer, hit and trial kind of operations. Like those involved in cryptosystems. Or calculations involving trillions of variables, for example; to determine what happened at the instant of big bang. Because of the reason that we don’t need any intermediate results in these long calculations, instead we only need to arrive at the final answer, we don’t disturb the qubits by measuring them halfway through the calculations. We don’t need to, which allows them to work efficiently. To understand how qubits work, consider 2 bits and 2 qubits. The state of a 2-bit classical computer will be one of these four possible states, whereas, a two Qubit quantum computer will be in superposition state of all these our states, like being in all the states at a time.

Furthermore, for two bits there are four possible states; 00, 01,10,11. Now in case of classical bits, in order to determine the state of computer we only need to have two pieces of information. In which state both bits are, so they will be two pieces of information. However, in the case of quantum bits, quantum mechanics allows us to create the superposition state of the four states which will be some coefficient say A times 00, B times 01, C times 10 and D times 11. And all of these coefficients are complex. So basically now we need 4 pieces of information. That’s how 2 qubits have 4 classical bits. When we’ll have 3 qubits, we’ll need to have 8 pieces or 8 bits of classical bits in order to determine the state of computer. This makes the quantum computers exponentially powerful than classical computers. And the power of exponentials means that when we’ll reach 300 qubits which are fully entangled with each other we’ll have more classical bits then there are total atoms in the observable universe.

 It is again, worth mentioning that Qubits can be anything. Spin motion of electron in the presence of magnetic field, motion of nucleus, photons. Everything which behaves quantum mechanically can be used as a Qubit.  For these new kind of Qubits, new gates are to be developed depending on what is being used as a Qubit. For example, if photon is being used as Qubit; such gate should be developed which could control the photon. Possibly optical materials be used in that gate. If spin motion of electron is to be used as Qubit, some magnetic kind of materials will be used to develop gates, there is no hard and fast rule for now, as this field is in its infancy, different experiments are being made and different kinds of Qubits and different approaches are being used.

In addition to this, it is necessary that all the Qubits involved in a quantum computer must be entangled with each other; in order to achieve maximum potential of the computer.

Plus, in order to make use of all the fascinating quantum properties of quantum particles, they are needed to be calmed down; cooled down to the very low temperatures; to fractions of degree kelvins above absolute zero. Furthermore, in order to reduce quantum noise they are needed to be kept in highly maintained conditions where even the sound of a car passing through the road outside your home cannot reach, because that will disturb the behavior of quantum particles.
That's why there's a low chance that you'll ever use a quantum computer in your home.

Approaches to Quantum computing

There are two general approaches to quantum computing; quantum gate model computing and quantum annealing approach.

Gate model quantum computing involves the controlling of quantum state of the qubit/particle involved, and as quantum particles are highly delicate and very difficult to control, so this is model of quantum computing is very slow in its progress. However, more control means that this gate model quantum computer can solve higher class of problems. Specially Shore’s algorithms for factorizing numbers and Grover’s algorithms for searching in the large 

whereas, Quantum annealing does not require the control over quantum state of particles, rather it just determines the best and most suitable answer by using energy levels. The lowest energy corresponds to the best answer. 

It is Used by the D-wave systems; first quantum computing company. So far, quantum computer of 1097 Qubits has been developed using this approach.

Commercially available Quantum computers

‘D-wave systems’ is the first and the only recognized quantum computing company. Till now, they’ve released 2 quantum computers. D wave one and D wave 2x.

D-wave one

D-wave one was released in 2011, it was the first ever commercially available quantum computer. It is a 128 qubit processor based on quantum annealing. It was followed by collaboration b/w google Inc., NASA and USRA. It solved optimization problems and its price is US$ 10,000,00.
Later is found proven that this quantum computer was no better than the classical computers in terms of speed.

                                                                                     

D-wave 2X

D-WAVE 2x was a giant leap forward in the field of quantum computing. It is based on 1097 qubit quantum annealing processor. It is not a general purpose computer, but rather it solved only a specific class of problems called optimization problems. It was placed in Google headquarters and google claims that it solved a problem in seconds which a classical computer would have taken 10,000 years to solve.
In D-wave 2x, a particle is said to be entangled with 6 other particles at the same time. D wave 2x is said to be 100 million times faster than classical computers in terms of solving these optimization problems.

                                                                                           

It must be mentioned here that these are not Gate model quantum computers on which Grover’s algorithm or Shore’s algorithm. And these are rather quantum chips which can solve certain limited problems. 

Conclusion

Although quantum computers don’t seem to be a perfect replacement for classical computers. However, they can solve the problems which classical computers can never solve and are immensely powerful; to the scale of being regarded as a threat to human civilization.  Looking at the current situation, Quantum computers seem to be the future of mankind. If used positively, they have huge potential to make human civilization enter into a new era, an era where there will be no more scientific problems left. Time travel, Human teleportation and all the science fictions we see in the movies today would take the colors of reality. Although It seems to be a far fetching Idea today but for those who allow their imaginations to roll, Even the sky is not the limit.

The Bizzare world of Quantum mechanics

Lying just beneath everyday reality, is a breath taking world, where much of what we perceive about the Universe is wrong. In the world smaller than the size of atom, the laws of physics as we know them, completely break down. If we, humans had been living in that world, we'd have been able to do the things which may sound completely insane. For example, you being in the school and sleeping in your home at the same time, Travelling from one place to another without covering the distance between them, Walk through the walls, or make your twin brother do what you want without any kind of communication between you two, even if he is millions of light years away from you. Sounds absurd right? really isn't in the world of atoms, electron and photons.

Our perception of reality has completely changed over the past seventy five years, because we've discovered new revolutionary set of laws; the laws of quantum mechanics. These laws govern every atom in every piece of matter in stars and galaxies, rocks and oceans, and in you & me. Therefore, the nature of reality lies deep down to the smallest scale; the scale of quantum particles, where these strange and crazy laws rule.

Something unknown is doing we don't know what—that is what our theory amounts to.[Expressing the quantum theory description of an electron has no familiar conception of a real form.]

— Sir Arthur Stanley Eddington

There is a sense in quantum mechanics that particles don't like to be in one place at a time. They can be in many places at the same time. And according to quantum physicists, these particles continue to be at more than one places and do more than one things until you observe them, the act of observation forces them to choose one place to be in and do one thing  out of all the places where they could've been and all what they could've been doing. This all goes back to the double slit experiment, when there was no observing the photons they formed the pattern of waves, actually behaving like waves, interfering, cancelling each others effects and all that stuff. But when no one was observing the process, they behaved as particles; forming the pattern of particles on the screen behind the double slit metal plates.  

Photons behaving as particles when being observed and as waves when not being observed

Plus, the M theory predicts 11 dimensions, 10 of them in space and one dimension of time. As we live in 3 dimensional world, we are not able to observe or even imagine these dimensions but that's the way it is. Some of these dimensions are smaller than the size of photons. And the nature of reality in each point of  space is determined by the behavior of the strings in these hidden dimensions.

Perhaps the most puzzling, the most bizarre, the most absurd, and the most craziest thing which quantum physics predicts is entanglement. Two particles when come closer to each other, they become entangled. If one particle spins in clockwise direction, the other entangled particle must spin in anti-clockwise direction. And when the spin of any of those two particles is changed, the other one automatically changes its spin in the direction opposite  to that of the entangled particle. Sounds perfectly alright. But now comes the crazy part; if you separate those particles they still remain entangled, even when  one particle is millions of light years away from the other. How could this be? How can two things remain connected without any kind of  communication or connection between them. Einstein called it 'spooky action at a distance'.

Two entangled particles

So why do we believe in all this? that's because these laws of quantum mechanics describe everything and every experiment made in  the history of science perfectly, and not a single exception or disagreement has been found yet. Although people may found this stuff hard to believe. There was one person In the 1930s who found these things very hard to believe; Einstein . Because Einstein believed in certainty, not probability. 'particles being in more than one places at one time until someone looks towards them' wasn't Einstein's cup of tea. As he said: "I'd like to think that the moon is still there even when I'm not looking at it"

Einstein believed that there was something missing in the laws of quantum mechanics. Some kind of missing piece which will describe everything completely with certainty, and not just with probabilities. There was a whole kind of rivalry between Einstein and quantum physicists like Bohr, Heisenberg and de Broglie etc.

Einstein claimed that God doesn't play Dice with the Universe, and Bohr Answered him : "Stop telling God what to do."

The Secret of this Universe- Law of attraction

If you  know this secret, it'll give everything you want; happiness, health & wealth.

You can have, do or be anything you want, whatever you choose, no matter how big it may be.

what kind of house you want to live in? do you want to be a millionaire? what kind of business do you want? do you want more success? What do you really want? Haven't you seen miracles taking place in peoples' lives, of physical healing, mental healing & financial growth? Are they mere coincidences? Why do 2% of population is wealthier than the rest of 98%? why do some people bring negativity and why do some people bring positivity with themselves wherever they go? Why are some people always lucky?

All of this happens because of applying 'The secret', either consciously or unconsciously.

"The secret is the answer to all that has been, all that is, and all that will ever be"

-Ralph Waldo Emerson-

You'll probably be sitting there wondering what is the secret. I'll tell you how I've come to understand it. I don't care if you are sitting in Dubai, Australia, England or Belgium. We all work with one power, one Law; and its 'Attraction'. All the things and people that have been coming to your life, you've attracted them. Do you believe in Karma? What goes around comes around? Do you think it just happens? No! You attract everything in your life by the virtue of your thoughts, feelings and emotions. This law only has three words; "Thoughts become things". Whatever is going through your mind, you are attracting it to you. You not only get what you think about the most, you often become what you think about the most.

What most people don't understand that every thought has a frequency, You are a vibrational being. You are so much more than a mere human body. You have an immensely powerful mind, and if you know how to use it, you can pick up a glass without any physical action. You are made of atoms, electrons and strings of energy, and so are the starts galaxies & everything in this Universe. Everything is energy. And your thoughts have energy, negative energy attracts the negative energy and positive energy attracts positive energy. And that energy might be attracted towards you in any form, negative or positive people, excess of wealth or lack of wealth, good luck or bad luck. Anything! Why do you think the wise people advise you to be positive? What is the logic behind that? How can being positive change the circumstances for you? The answer to this question is the secret I'm talking about right here and right now, In this very moment, you are being introduced to what all the successful People have been using it, from the very start.   The Law of attraction is always working, and for everyone. No exceptions. Whether you believe it or not. Whether you understand it or not. You don't understand the lighting of a bulb either, I don't understand how electricity works. So what? Does it stop working? You and I still take benefit of it without caring about how it works.

"Everything is energy and that's all there is to it, Match the frequency of the reality you want and you cannot help but get that reality. It can be no other way. This is not philosophy, this is physics."

-Albert Einstein-

You might be thinking about the past, present or future. Or anything that you want or you don't want. No matter what, you are activating a thought and The Universe is responding to it with a 'Yes'.  When you think about having something, you are still activating a thought. When you think that "Oh! I don't want this, I don't want that!" but still it comes to you again and again, why? Because the Law of attraction Doesn't care whether you perceive something to be good or bad, It just responds to your thoughts. And your thoughts have a frequency of that very thing, And it will come to you whether you want it or not, as long as your are thinking about it.  You might be thinking that you never get something you want, instead you get something which you never want, or you're afraid of. That's because you are always thinking of what you don't want, or what you're afraid of. You never focus on the thing which you want. Even if you do, You still think of that in a negative way. like: " Oh, I want that car, but I can't buy it because I don't have the resources."  You are saying that You can't have it, and The Law of attraction, which is the most powerful Law of this Universe says Yes, like always. It says 'Yes' to you when you say "Oh I can't have that thing": " Yes(You can't)".

"What we think, we become"

-Buddha-

The Law of attraction is every where, if you understand what it is, when you notice that those who talk the most about illness have it, those who talk the most about prosperity have it. All the 'anti' walks , protests or actions; anti-war, anti-hunger things add to wars and hunger in this world. Because the people are activating the thoughts of that very thing and they are adding energy to that very thing, which they may perceive to be good or bad. It doesn't matter. You might be thinking : " should I stop working for peace instead?" No! Anti is itself a negative word, Go for "pro"; Pro-peace walk, 'Pro-excess of food for everyone' walk. That is why Mother Teresa used to say; " Don't ever invite me to an Anti walk or protest, Invite me to the pro ones" Because she understood this very thing.

"You create your own Universe as you go along"

-Winston Churchill-

When we are positive in our orientation, we tend to attract positive events, people and things in our lives and when we are negative in our orientation, we attract negative events, people and things.

Me.

Mostly people don't know what they want. They have no single goal. Their thoughts keep on changing all the time. For two weeks, they'll think about being popular, then for a week they'll think about having someone they love with them. What people don't understand is that its not like a wish. It's more than that. There are some steps to it. The first step is to know what you really want. One goal at a time would be best because you'll generate more thoughts about it, you'll be more focused towards it. Tell your self that this is what you want. Maybe write it on the wall of your room so that every time you'll see it, you'll get focused towards it. I must say that there are no hard and fast rules, you just have to be focused on what you want.

"Imagination is everything. It is the preview of life's coming attractions."

-Albert Einstein-

 The second step is believing that you already have it, Imagine! Visualize! When you Visualize, you materialize. And then feel it. Say if you want a car; everyday for ten to twenty minutes, sit back, close your eyes and visualize you driving that car, feel the steering wheel in your hands, feel the gear in your hand. Take turns, apply brake. Feel the feeling of having that car. Believe that you are actually driving it. You'll automatically go into the state of having that car. And you'll generate thoughts, feelings and emotions of that frequency and the Universe will align itself in your orientation and give you back the energy of that same frequency. The last and the most important step is 'gratitude'. Be Thankful for everything you have, no matter how small the things maybe. Be thankful that you have eyes to see, ears to hear, a house to live in. Be thankful and stay positive always, in every situation. Because positive thought  have frequency much higher than negative thoughts.

Mostly people think how long will it take to manifest a car, wealth, health or whatever it happens to be. It totally depends on you. I ask from you, how bad do you want it? and how much you are ready to give your energy, focus and everything into it? That's where passion comes in. Those who are more passionate, achieve milestones more quickly. You don't need to look at the whole staircase, just have faith in one step at a time.

Another question that people ask is that how are they going to have that thing, This is certainly not your problem. "How" is just not your domain. Leave this part to the Universe. We have examples of people who Believed that they'll to do a certain thing, but never knew how. Later, they found the ways of doing that. It could be in anyway, a dream, an idea coming to your mind, an inspired thought, or you may meet a person accidentally who'll help you to accomplish your goal. You'll be made to see the ways, you just have to follow your instinct and work for it. Remember that there are no coincidences. Things don't just happen. Luck just doesn't play dice. It favors those who believe. In other words, those who apply this law, either consciously or unconsciously.

The people have to understand that their thoughts and feelings not only effect themselves but the other too, When you see someone having too much health, beauty or anything that you aren't happy about, and you think negatively about them, the negative energy of your thoughts and emotions do effect you but it also  affects the other person negatively. And your positive thoughts about someone affects them positively. That's why the wise people advice others to surround themselves with positive people.

Some people complain that they are stuck in their past, or they feel like stuck at a point. And no matter how hard they try, life keeps on repeating the things of their past for them. The reason behind this is that they keep thinking about the past. And their thoughts have the frequency of the events or the people of their past, and they are attracting the same energy to themselves. So in spite of having the desire to move forward, they never can.

According to Quantum physicists, we can have a universe entering a mind into it. The Mind has the capacity to change things, change the results of an experiment, change the behavior of particles. This all goes back to the famous experiment, known as the double slit experiment. What the scientists discovered was something amazing; when an observer was observing the experiment, photons behaved as particles. And when no one was looking, they behaved as waves.  This is called mind over matter; the behavior of matter is determined by the mind of the observer. Plus, the Process of Quantum entanglement confirms that two particles when placed very close to each other become quantumly entangled and if one spins clockwise, other should spin in the counter clockwise orientation. They remain entangled even if you move one particle millions of light years away. This has been proven through experiments. Maybe you have the particles in yourself which are entangled with the particles in others or particles in stars, galaxies millions of light years away. Who knows.

Karma is nothing but the Law of attraction. You think bad for others, do wrong to them, your thoughts vibrate at that frequency and you attract the same towards you. If you think or do good to others, you attract the energy of same frequency towards you.

Most people define themselves with this finite body, however, it is not they case. You are much more than you think.  Your body has the potential energy to light the whole city.

"Follow you bliss, and the Universe will open doors for you where there were only walls"

-joseph Campbell-

                                                            

The M theory and Parallel realities

Imagine that You could explain everything in this Universe, from the behavior of sub-atomic particles to the functioning of giant structures like starts, galaxies & black holes, everything with one theory, with one equation. This is the dream which has captivated the most brilliant & intelligent minds since Einstein. But it is as old saying that be careful what you wish for, because you  might get it. And it fits in the scenario of scientists finding a single explanation of everything, because In the quest of finding one theory; the theory of everything,  physicists found something amazing &  astonishing, something mind-blogging; they found that there might be other universes out there and some of them may exactly be like ours.

 Almost around one and a half decade ago, String theory emerged, which had a perception that it might be the theory of everything. According to this theory,  everything is made up of tiny strings of energy, much smaller than quarks. and these strings exists in 9 spatial dimensions and 1 dimension of time, they vibrate at different frequencies and move in different ways which determine the form of matter they'd generate. It should be noted that we live in 3 spatial dimensions, So 6 extra spatial dimensions were described by the string theory. It was tested  again and again and it explained everything perfectly which gave the scientists an impression that the string theory might really be the theory of everything. But for a theory to be a theory of everything, it should explain the singularity or what happened just before big bang. Amazingly, string theory explained formation of matter, atoms and nuclei and events that happened something like 0.35 seconds after the big bang, it was a great achievement. But the problem was that five different string theories emerged. Each one claiming to be the right one. This made the string theory to lose its grip and physicists started to believe that the string theory couldn't be the theory of everything.  This was a disaster because physicists spent decades working on the string theory. However, some out casts and out laws didn't give up. They were in a very small number and spent years trying to figure out the solution. And finally Michael Duff, presently a professor in the University of Michigan, who worked alone for ten years, came up with a solution. When he added one more dimension in the math of all the five string theories, they merged to give a one single theory, which was later named as  'M theory'. This was a giant leap forward in the quest of finding the theory of everything. But adding one dimension in string theory, changed the string itself. The strings were no more strings anymore, they stretched and made the strings more like a membrane. This 11th dimension  is said be  smaller than 10 to the power -20 millimeters. And on the basis of M theory, Physicists claim that there are membranes  in the hyperspace and when some part of one membrane collide with some part of other membrane, a giant explosion occurs, just like the big bang and a Universe is born.

Membranes in hyperspace

The M theory not only  revived the idea of Multiverse, it also explained how a universe is born. Furthermore, the extra  dimensions brought to light; an astonishing and amazing possibility and it was one step forward in the idea of Multiverse; the idea of parallel existence. Physicists claim that the particles exist in more than one places at a single point of time. It has been tested experimentally in case of electrons. As everything is made up of these particles, everything which exists in this universe exists in probably infinite number of other universes too. I'm using the term infinite because strings can acquire infinite orientations in the hidden dimensions. And for each orientation, its another universe. (read the previous post on Multiverse)
Physicists claim that everything that can happen, will happen. But in a parallel universe, a parallel reality. But we live through only one reality at a time. To understand what I mean, Imagine that a man had a job interview but he woke up late and missed the interview. It is possible that he might've gotten the job which could've changed his entire career and lifestyle but he missed that opportunity. He is now having a moderate job with a moderate salary but in a parallel universe, he acted more responsibly and reached for the interview in time and got the job. And he is enjoying a great life in that parallel reality. It was upon him to wake up late or early that morning, it was his own decision. The reality for him in both cases was decided but he only lives through one, depending on the choice he made at that point.  Similarly, there are infinite number of parallel realities for us at each point of time, depending on the choices we make. But we only live through one at one time. Or one set of realities throughout our life. Its not that they do not exist. They do exist somewhere out there but we just cannot observe or interact with them.  So anything that can happen will happen in a parallel universe. Out of infinite amount of parallel universes out there, In one of them, Einstein may still be alive. Or  U.S.A may be a colony of British Empire. In one, you might be rock star. In one, you were never born.
Although, the idea that there are infinite number of parallel realties for each of us at each point of time is very hard to put up with. But for those who allow their imaginations to roll, it is a very fascinating idea. When we think of the size of a grain of sand at  one end and imagine infinite number of stars in one galaxy and then infinite number of galaxies in the Universe at the other end, it is not very hard to believe that there might be infinite number of universes too, and then infinite number of realities for each of us. Nothing is wrong with that. We always thought how destiny works and if it has already been decided, what is in our hands to do with our lives? At least science has given us the answer to this question.

The Multiverse

Someone who hasn't been living under the rock for the past ten years must've heard the term 'Multiverse'. In the beginning, we thought that our Earth is the center of everything and the Sun rotates around the Earth. Then came Galileo, who told us that  our earth is not the center of everything. Instead, It is the Sun which is at the center and our earth and other planets rotate around it collectively forming the solar system. Later, it was found that our solar system is not the only one, and there are other stars too, much bigger than the sun an that there are an infinite number of stars & galaxies adding up to make everything that was there; "The Universe".
In the 1980s, Stephen hawking claimed that physics is entering into a new realm, and soon we'll be able to read the mind of God and understand why everything is the way it is. But the nature had different ideas. Just when the physicists though that they were about to find the theory of everything, something incredible, something astonishing was brought to light during the quest; the idea of more than one universes or the Multiverse. The basic questions which may arise in someone's mind at this point  might be: "What is Multiverse?", "Why do we believe in something which cannot be seen or observed?"

Let's discuss three different theories, from different fields, all of them pinpointing towards the idea that our universe may not be the only one.

1. The Theory of Inflation:

It all started with the quest of explaining The Big Bang. According to the big bang theory, our universe was formed as a result of an intensely violent explosion; The Big bang. But one thing which it doesn't really explains is the bang itself; "what bang?" , "why bang?", and "what caused the bang?". So basically it was like saying that everything just came out of nothing. In the beginning there was nothing and suddenly that 'nothing' exploded and the stars and galaxies came into existence.
In 1979, Alan Guth, currently a professor in the MIT, got interested in explaining the formation of particles at the time of big bang. And after years of research, he found something amazing; the math that could explain the formation of particles at the time of big bang suggested that at the very beginning, gravity would've acted in reverse. Instead of pulling things together, it would've repelled everything around it. Its consequence was the big bang. Described mathematically, this force was so powerful that it could blow a molecule to the size of the milky way galaxy in a billionth of a billionth of a nanosecond. And these equations explained the formation of stars and galaxies just as the big bang theory. The powerful repulsive force of gravity was what which caused the big bang. Guth called this burst as inflation. The reason why inflation theory gained so much popularity was that it could be tested through observations. According to physicists,  If this theory were right, there should be some heat and radiation due to the  inflation, left in the space, in the form of cosmic background radiation. So in 2001, NASA cosmic background radiation explorer was launched which measured the amount of heat and radiation very precisely. And surprisingly, It was exactly in accordance with the values predicted by the inflation theory. Guth had no idea what could be the implications of his theory. He said:

"I had no idea what could be the implications of my work, I was more, looking for a permanent job."

At that time, there were two scientists; Andre Lindae, and Alex Vilinken who believed in the idea that our universe may not be the only one. Alex Vilinken discovered form the equations of inflation theory that; inflation never occurs every where at the same time. Instead, there is always a series of inflations. According to him, there could be a space out there in which  energy is distributed in an irregular manner, when the concentration of energy at a point increases immensely, inflation occurs an a new universe is born,  Which means that there were more inflations before the inflation which made our universe and there were probably many more after that, forming other universes.

the phenomenon of universes being born in the model of inflation theory according to Alex Vilinken

Alex Vilinken  wrote more than a dozen of research papers explaining this Idea. But at that time, the scientists were least interested in a hypothesis which could never be tested.

 

     2. The Dark Energy:

In 1990s, the astronomers discovered the most disturbing, perplexing and bizarre fact of the decade; that the expansion rate of our universe is continuously increasing. This was a disaster for the physicists at that time. To understand how confusing this is, imagine that you throw a baseball in the air, common sense says that as it will move forward, it will gradually slow down because the gravity will pull it back. Or if somehow, it leaves the gravitational field, it will move at the same speed. How bizarre it would be, if the ball itself continues to speed up for ever? 

Thus, the astronomers discovered that there was some kind of force or energy, which was present in the space throughout the Universe which was acting as the driving force, they called it as the dark energy. The 'dark' itself explains why it is named as dark energy. Because we cannot observe it, we have no idea what kind of force it is and why it is there. Only one thing which the scientists discovered by the math, was that it is really in a very small quantity. something like to the trillions of the trillions of  the trillions decimal points. Such a small amount of energy is making the entire universe to accelerate at a grater and greater rate. Plus, if this energy had been a just a little bit more than it is, the stars and planets could not have been formed because of the immense acceleration provided by this energy. And for a little smaller amount, the universe would've collapsed within itself. This perfectly right amount of dark energy allowing every thing to exist and function elegantly and smoothly was quiet amazing. But its occurrence cannot be explained if our universe is considered to be the only universe. This amount of dark energy and its existence perfectly fits if we consider that there are more Universes present other than our universe. And it all goes down to the probability, in some universes, due to a different amount of dark energy, the laws of physics would probably be completely different. And in the others, matter as we know it, probably doesn't even exists.

This made the scientists to reconsider the idea of Multiverse. And after 10 years of darkness for Alex Vilinken, the discovery of Dark energy wasn't less than a bright sunshine.

       3. The string theory:

String theory was a giant leap forward in the process of understanding and explaining the Universe. Some of the quantum physicists claim that, in the future, the theory of everything will be the modified form of string theory. According to this theory, deep inside the sub-atomic world, in the world smaller than the quarks, there are strings which make up everything. Strings vibrate and move in different dimensions in a manner which  determines what sort of particle or matter it would from.

 strings vibrating at different frequencies

Surprisingly, the math of string theory suggests that strings can move in  six more spatial dimensions in addition to our common three spatial dimensions; the height, width and depth. These extra or hidden dimensions are very small and curled up within the strings and are present at every single point in space and act as the DNA of the universe, determining its behavior. Which means that the behavior of the Universe is determined by how these strings move in extra dimensions.

Strings jumbled up , acquiring different shapes at each point in the space

But the problem was that the more the scientists looked deeper into it, the more ways they found for the strings to move  in these extra dimensions. More than 500 research papers were published, each one giving a right solution, and each one explaining different ways for the strings to move in the extra dimensions.  But what kind of theory suggests more than 500 different  correct solutions for a single problem. This made the string theorists somewhat unhappy, somewhat depressed. However, some string theorists found it amazing, they looked the other way around. They looked into it as an enormous amount of probabilities and found that this theory fits extremely well into the ideas of cosmology and physics related to Multiverse. With each probability corresponding to another universe.
String theory without even trying, solved the problem of Multiverse. Explaining how could they be formed by the particles at the tiniest level.

However, some physicists argue that science is about the evidence. And no such experiment has been carried out, or even an observation which has been made that would make them to believe in the idea of Multiverse. But during the last few centuries, mathematics had predicted the presence of things like black holes etc. well before the experimental evidences were provided. There was a time when people didn't believe that the earth is spherical or there are other planets too. Furthermore, three different lines of reasoning point towards the same idea. And just as it takes three legs to support a stool. Three different theories form different fields make this idea very convincing that our universe is not the only universe, and there may be infinite number of universes out there making up 'The Multiverse'. If you consider this mind-blowing, reconsider your thought because there is a next step to it; the parallel universes having parallel realities. What I mean is, in one of the universe out of infinite universes out there, there might be one exactly like ours, having a galaxy like the milky way and a nice planet just like the earth rotating around a sun alike star. Except for small differences like; in one of them, Einstein may still be alive. Or  U.S.A may be a colony of British Empire. In one, you might be rock star. In one, you were never born.

The mysterious force of Gravity

We deal with the gravity in our every day lives, and we know gravity as a force that makes an apple to fall down on the earth, a force which keeps us and everything on the surface of earth. It makes the moon to rotate around the earth and the earth to rotate around the sun. But the question is, what actually it is, and how does it really works?

Hundreds of years ago, Newton gave us the simple equations to calculate the gravitational force exerted by the objects on each other and we still teach those equations in high schools. We know that we only need two things  to calculate that force; the mass of those two objects and the distance b/w them. But how it is even possible that an object affects another abject thousands of miles away through an empty space and without anything happening b/w them?
Newton gave us the equations to deal with the gravity, to calculate the gravity but surprisingly, he himself didn't know how the gravity worked.

This caught the attention of The great Albert Einstein, he read the book of Newton containing all of his work, equations & experiments written by himself. He straightaway went to the section of gravity. And To the very surprise of Einstein, Newton said that I don't know how it works, what he himself had written was: "I leave it to the understanding of the reader". Most of the people including scientists who read that book, went through that section, ignoring that part, but Einstein had different ideas. He took upon himself; the task to describe the nature, working and origin of gravity. And after a long research of 10 years, he came up with the 'general theory of relativity'. In which, Einstein showed that our space wasn't actually an 'empty space', but it had its physical component too. He called it as 'the  fabric of space-time'. Before Einstein , it was thought that space was the stage set where all the drama happens, but Einstein showed that space too, was an actor in the drama. In order to understand this, lets make this 3-D concept it simple. Consider the fabric of space as two dimensional:

You can think of the fabric of space as a thin plastic sheet, because it actually behaves that way in 2D. Imagine that we place the bigger orange ball on this fabric; due to its mass, it will bend the fabric  over some area or cause it to warp the fabric around it in the way shown in the figure below: ( neglect the presence of smaller ball for a while)

Now, The taking the smaller ball into account, we can tell that that smaller ball has lower mass as compared to the bigger one, so common sense says that it will bend the fabric over a smaller area around it, as compared to the bigger ball. There is a certain area around each ball in which, when  another ball comes, it moves towards the first ball because the sheet around it is bent. And we can intuitively say that the larger ball will attract the smaller ball towards itself because it bends the sheet more than the smaller ball.

Imagine that you push  the smaller ball towards the larger ball until it enters into the area bent by the larger ball, we know that it would fall into the larger ball, but instead of falling straight into it, it curls around it in circular paths and the radius of its circular path gets smaller and smaller until it finally falls into the bigger ball. Until or unless the smaller ball has a considerable mass too in addition to velocity, so it could also bent some fabric of space around it in order to cope with the bigger ball. So that it could rotate around the bigger ball. It is very important to note that it will acquire a curved path not because it do so, but because the space in which it was moving got curved.

 Now consider the example again by thinking of the bigger ball as the Earth, and smaller ball as the moon. This is how the gravity works.

The gravity is actually caused by the curvature of space which is caused by the mass of the bodies. Or It would be better to say that when matter interacts with space, it causes the space around it to warp, and its effect on another body within that warped space is what we call gravity.  And more mass, means more area (In 2D) of curvature, which means the motion of some other body can get affected at a larger distance. We simply say that a certain body has more gravity. 

We know that it warps the space around it, and as space and time are dependent on each other, (we've already discussed this in previous posts) It directly effects the time around it. The three dimensional demonstration is given below in the figure and  I suppose you can understand it in 3-D now with great ease.

One of the implications of the gravity is that it slows down the time which directly means  that for a person living on the ground floor of a building on earth, time will pass more slowly as compared to a person living on the top floor of the building because there is more gravity on the ground floor. But the difference will be so much smaller that we'll not be able to experience it, probably billionth of a billionth of a billionth second.  And for a person living on Jupiter, time will pass more slowly, as compared to the one living on the earth, because Jupiter has a higher gravity as compared to that of the earth. But a giant body with super gravity, like the black hole, a minute in its gravitational field would probably be equivalent to a year or more on the earth.

Some physicists claim that gravity is not only attractive, it can be repulsive too. They argue that gravity behaves in a different way in the presence of immense amount of radiation or heat. Because by making this assumption, We can give a better explanation of the Big bang. In addition to this, If it's not this way, we cannot explain the fact that the distances b/w galaxies in this Universe are continuously increasing. Because intuition says that Gravity should at least maintain the distances b/w the bodies, if not bring the bodies closer.    

This was the model presented by Einstein and I don't want to give an impression  that newton's equations got ruled out, we still use them in our daily lives, as well as when we have to land our spacecraft on the moon, or when we want to accelerate the rocket within the gravitational field of the earth. Newton told that gravity is 'something' and it works this way, but he didn't tell us how. Einstein told us  how it works and what are its implications. But the basic and most fundamental question is that why it works this way? The answer to this "why?" is still unknown. It took us almost 100 years to provide an answer to "how?", so it'll probably take a lot of time to have an answer of "why?".

Furthermore, there's a drawback in Einstein's model; it fails to explain the attraction b/w particles at the quantum level. We use Quantum theory for that purpose. Presently, physicists are trying to  find a theory of something which they call as "Quantum gravity", which will probably explain the attraction b/w particles in quantum world plus the attraction b/w giant bodies like stars, planets and galaxies using the same set of equations. One thing is for sure, there's still a long way to go in our journey of understanding the universe.

The mystery of Time Travel

In the beginning, it was all darkness. And then, Bang! Giving birth to an endless ocean of Time, Space and Matter. 

Every day, physicists are discovering the mysterious, mind blogging and deadly secrets of the Universe. One of the most fascinating mysteries of the Universe is Time Travel.

This all goes back to Einstein's theory of relativity, when he showed that Time is experienced individually and it depends on the position and velocity of a certain individual. According to Einstein's theory of relativity, the faster you move through space, the slower you move through time. If you travel at the 99.9% of the speed of light for 7 years, that would be equivalent to 500 years for the people on earth. And if somehow, you travel faster than the speed of light, you'll move backwards in time. (read the last post to have a better understanding of what we're talking about)

 But traveling into the past has been the most controversial topic among the physicists  during the past few decades. There are some paradoxes we face when consider time travelling into the past; one of them is the grand father's Paradox:
Suppose you some how travel into the past to the time of your grand father, just  when your grand father is about to meet your grand mother, and somehow, you convince him not to meet her,
In that case, your father never meets your grand mother so how could you be born in the first place to be able to travel back into the past in order to stop him from meeting your grand mother?

However, some physicists argue that the nature will somehow prevent you to stop your grand father from meeting your grand mother,  That's because universe prevents every inconsistency in its way of doing things. We may not be sure about that but one  thing is for sure, and it is the fundamental property of Universe too, that it ultimately makes sense. So you'll not be able to do that anyway. But the question here is that when you'll born in the world where you time travelled to the past, what will be the significance of your existence in the first place? will you be real you or that baby-you who'll born? Plus, apart from this, when that baby-you will grow up and travel back into the time, it will start a never ending loop and this is again an inconsistency. Well, this is pretty bizarre.

A stronger theory against the grand father paradox is the idea of parallel realities, or parallel Universe. According to this theory, when you'll travel back into the time, you'll enter a parallel universe and nothing will change in the universe where you came from. This may sound strange to you but this theory is widely accepted by the physicists. We'll go through this idea in future but for the time being, you need to know that the existence of parallel universes have been proven  theoretically using the laws of quantum mechanics. According to quantum mechanics, a particle can exist at multiple place in a single point of time. This has been proven experimentally in case of electrons. In addition to this, the murphy's law states that what ever can happen will happen ( but in a parallel reality). But we only live through one group of realities depending on the choices we make throughout our lives.

Anyhow, time travelling into the past or even to the future is still a pretty far-fetching idea.

Because for higher velocities we need a really large amount of fuel which would obviously add to the mass of the spacecraft and consequently we'll need even more and more energy to accelerate it. for speed of light, we'll need infinite amount of energy, according to the theory of relativity.

The good news is that , for travelling into the future, higher velocity isn't the only way.

Because Einstein showed that space bends due to gravity and as the space and time are dependent on each other, when space bends, so does time. And nothing bends time more than the super gravity of  a Black Hole. To understand what I mean is, suppose you are in a spaceship travelling near the black hole i.e. in its gravitational field. Time will pass more slowly for you as compared to your friend who's on earth. Your some hours will mean years to him and by the time you'll reach the earth, you'll probably meet your friend's grand grand grand children.

The methods we discussed  are  the slow kinds  of time travelling, or its like cheating, this is surely not in the way which we've been watching in the movies since our childhood, where one person enters into a time machine and the machine takes him to the future or to the past in an instant.

Actually that idea was taken from wormholes, a wormhole is kind of a shortcut in time, it is actually a distortion in space and time. both ends of the worm hole have same date and time no matter what happens, what I mean is, when you'll enter into the worm hole from one end, you'll appear trough the next end in an instant, while hundreds of years would've been passed for some one who's on earth, it depends on the size of wormhole. The worm hole also works in reverse i.e. travelling into the past, from where you started. The good news here is that nothing in the laws of physics forbids the wormholes, they are theoretically possible. But if theory says that wormhole is the secret to time travel, then what does it takes to make one?

In order to make a worm hole, we need to manipulate the fluctuations &  distortions in space-time found in the sub atomic particles and expand them, this would require very high energies; possibly, the energy released by a dying star when it explodes. So hopes shattered once again. 

However, there is just a slight possibility that nature has already made them for us somewhere in the universe, like it has created black holes. We don't see it coming in near future though.

To conclude, I'd say that time travelling seems to be a far-fetching idea today, but those who allow their imaginations to roll, there is a bright glimpse of hope for them. There was a time when the airplanes and modern vehicles seemed to be impossible for the mankind, and we already know that where we are today with them, so maybe one day, hopefully in near future we'll be able to discover the missing laws of physics that would enable us to accomplish wonders, and that day might not be very far. We must keep in mind that all of the above concepts & methods were from the modern physics, but today, the Quantum physics has radically challenged the way we perceive things. Teleportation; for example, enables us to transfer a body from one place to another, which could be thousands of miles away, in just an instant. Although Human teleportation has don't been done yet, but  Physicists have already teleported  photons, which means transfer of information at the speed of light.

Furthermore, the phenomenon of quantum entanglement, The String theory, Law of attraction, murphy's law and the existence of parallel realities has opened new doors for the mankind through which we'll be able to achieve the things which appear to be impossible today.