Let’s hear the Universe

Date: 14-09-2015

Location: Bangalore

Monsoon at its peak. Rain bearing clouds showering and thundering across the landscape.  I was getting started at my new office. A space research institute. Fascinating work. A thunderous afternoon with the sound reverberating in the corridors of a dead quiet office. I was chatting with my colleague who was working on the brand new gravitational wave detector. Just discussing the possibility of detecting a gravitational wave and the possibility of listening to the universe talks. This is a brave move by the scientific community to understand the universe and our place in it.

The news was covering this historical event.

At 6’o clock in the morning on September 14 2015, the scientists and engineers witnessed something no human had ever seen, two black holes colliding 1.3 Billion years ago in a galaxy far, far away as they violently spiraled into each other. Both about 30 times as massive as our own Sun. They had been orbiting each other for millions of years. As they got closer together, they circled each other faster and faster. Finally, they collided and merged into a single, super massive black hole. A fraction of second before their crash, they sent a vibration across the universe at the speed of light. They created travelling distortions in the fabric of space-time; Gravitational waves. The energy released in these waves was 50 times greater than the energy being released by everything else in the entire observable universe combined. I was flipped by the amount of energy released. It’s an awe inspiring kind of energy.

After about a billion years, here on earth these waves were picked up by a detector called Laser Interferometer Gravitational Wave Observatory or LIGO. The signal lasted only for 200 milliseconds.

What are these ripples in space ?

The answer starts with gravity. The force that pulls any 2 objects together. That’s the case for everything in the observable universe. The more mass something has, more the gravitational pull. The farther away the object, the lower is the pull. If every mass has an effect on every other mass in the universe, then changes in gravity can tell us about what those objects are doing. Fluctuations in the gravity coming from the universe are called gravitational waves. They move out like ripples in a pond, getting smaller as they travel farther from the center.

Like water has water ripples. What do gravitational waves ripple on ?

Let’s  go to 1916. Best time of scientific inventions and discovery. When Einstein devised his theory of relativity, he imagined gravity as a curve in a surface called Space-time.  A mass in space creates a depression in space-time just like a ball on a cloth creates a depression. All the planets, stars and the moons are sitting on this space-time. No one knows what space-time is made off. The bigger the mass, deeper the depression and stronger the gravity. When the mass moves in space-time it creates gravitational waves.

What would a gravitational wave feel like ?

If our bodies were sensitive enough to detect them, we would feel like we were stretched sideways while being compressed vertically and vice versa. This happens on a very minute scale that we can’t feel any of it. So, we built the detectors to feel it for us.

When the gravitational waves passed through the earth, everything and everyone on it, including you are stretched and pulled at the same time.

LIGO – An L shaped detector.

Gravitational waves are like radio waves, they are all around you but you cannot feel them.

After spreading throughout the Universe at the speed of light for over a billion years, the waves reached earth, where they stretched and squeezed space such that 2 light beams travelling in perpendicular pipes were put slightly out of step allowing humans to detect the existence of gravitational waves for the first time.

That is a simple enough story to tell. This story hides the absurdity to what was required to make that detection.

So, what is the absurdity  in detecting them ?

Firstly, the main problem with detecting gravitational waves is that they are tiny. They stretch and squeeze space by 1 in 10^21 meters. To detect such tiny wiggles, the scientists and engineers had to measure over a large distance as possible, which is why the arms of the interferometers are 4 km long. Even with arms this long, gravitational waves vary the length of the arms by at most 10^-18 meters. So the detector has to be able to reliably measure the distance just 1/10000 the width of a proton. It is the tiniest measurement ever made. Imagine a hydrogen atom, take the proton of that atom and then measure only a fraction of it’s movement. That is the level of measurement that we are talking about.

So, with the measurement that small. how is it possible to precisely measure considering all the other sources of vibration and noise in the environment such as earthquakes, traffic, storms. etc ?

The mirrors are the smoothest ever created. They weigh 40 kg. These mirrors are suspended by a silica wire just twice the thickness of the human hair to isolate them for their environment. The only way to be certain not to be tricked by environmental noise was to build 2 detectors far apart from each other in quiet locations in which gravitational waves pass simultaneously.

The next challenge is the laser. The laser needs to provide one and exactly one wavelength. Massive machinery in bone cold chilled rooms make the light wave to be almost exactly one wavelength. The light stability is precisely calculated to be 10^-6 meters.

The wavelength is exactly 1064 nano meters – infrared light which has the wavelength of 10^-6 meters.

But wait, how can you measure 10^-18 meters with 10^-6 meters ?

It is like measuring your height with a single 15 cm scale.

If your scale size is changing all the time, how do you expect to make a measurement. Here light is our scale. So, the scientists measured the interference with slightly darker and slightly brighter sections when the light wave interferes with the gravitational wave. This measurement is possible because the light is discrete in the packets called photons.

Thirdly, the length of the arm is 4 km long and the light may die out due to quantum uncertainty principle. So higher number of photons means lower the uncertainty. This is why the laser power in the arm is 1 megawatt. That is enough energy to power a thousand homes, in light beam. If you would come in the way of the laser, then you would be vaporized. Even with a perfect laser and the power, the light can interfere with the air molecules in the arm. So all the air in the arms of the detectors had to be eliminated and it took 40 days to pump down to just a trillionth of atmospheric pressure and arms had to be heated to the temperature of a oven to expel any residual gases.

Since gravitational waves stretches space-time, the light travelling through should be stretched as well. If everything is stretching, how do you know anything is stretching ?

That is the conundrum. This doesn’t make any sense.

This is a bogus thing, shut it down !!

The amount of time it takes for the light to go down the tube and come back is very short. When the gravitational wave comes through, the light gets stretched. So, the scientists are sending a continuous pulse of light beams, the light goes down and comes back, this is the older light and then the newer light and so on. During the gravitational wave, the light requires a longer time to go and come back as the space is stretched out. Doing this over and over again computes the interference pattern to detect the gravitational wave.

One of things that limit the sensitivity of the detector is quantum mechanics. It’s a whole new topic to talk about. Let’s not kill my neighbor’s Schrodinger cat.

Scientists and Engineers are using their ingenuity to figure our quantum noise and eliminate it. I am with them in this journey.

The information from the device is then analyzed and the scientists derive the information like mass, shape of the orbit, etc. We can also hear the gravitational waves by playing the signal through the speakers. Other astronomical events such as a supernova, neutron stars colliding create a gravitational wave too which spread across the space time fabric. Every time we create a new tool to look at space, we discover something we didn’t expect, something that might revolutionize our understanding of the universe.

https://www.ligo.org/detections/ringtones/gw150914.mp3

You can hear the sound of the black holes colliding in this audio. The graph plots the interference pattern with the laser beam.

Who knows what revelations may be now propagating across space towards our tiny blue planet and its new way of perceiving the universe.

When the black holes collided, the energy was brighter than all the stars in all the galaxies in the entire universe.

1.3 billion years ago, earth had just started to evolve multi cellular life. Yes, the event took place when earth was an infant. Corals, fish, plants, dinosaurs, people and the internet. This is brilliant nuts.

Detectors like these are popping all around the planet. INDIGO or IndIGO (Indian Initiative in Gravitational-wave Observations) is a consortium of Indian gravitational-wave physicists. A site in the Hingoli district in Maharashtra is to be commissioned in 2025. I am proud that I have personal connections to the people who work there.

LIGO is a way to hear the universe. A new way to look at the universe. We can study the core of the stars. Normal telescopes cannot peak through the kilometers of silicon and carbon and hydrogen, but LIGO can pass through it like a light through glass.

What is more audacious than to listen to the universe, to listen to the big bang. Our job now is to dream big. The frontier is everywhere. Dream with me.

To Gravity,

Vishal

Just a normal guy.

The Machine Era – Part 1

Date: 25^th May 2017

Location: Bangalore

A warm summer night, clear skies, twinkling stars, buzzing mosquitoes and loud crickets disturbing me. I was up all night watching the infamous “Alpha Go vs Lee Seedol” match of GO (An ancient Chinese game, which is considered one of the toughest in the world) that was live telecast all over the world. Watching closely as the match progressed. Every passing minute, every move on the board raised my heart beat, clouded my thinking, sweaty palms. I was thinking that Humans that made this machine can triumph over it. Sadly, round after round Lee Seedol  was defeated by a software that has no tangible existence. The clock turned 3 am. I was in a deep thought. Thinking of the humiliation faced by a machine.  On that day, the world’s best Go player flummoxed by Google’s godlike AlphaGo AI.  The machine has outsmarted the best human brain. The following day, some showed concerns over it, while others gave the possibilities of a super level intelligence. The machines can learn on their own.  A grand master humbled by a machine. The engineers and scientists thought that such an event was at least a decade away, but they were in utter shock. The event soon died out in all the other nonsensical news.

Six months later, Bangalore was bracing for a cold winter. One Saturday afternoon, I was chatting up a Scientist. My gang of childhood buddies had gathered over to discuss the possibilities of machines taking over. Yes, we brain storm about everything that we can think of. During the discussion, the Scientist told us a view point. This is a real story – “A young man in his early thirties had been diagnosed with brain tumor. The doctor had taken a CT scan of his brain to locate the tumor. After precisely pin pointing the location of the tumor within an estimation error of millimeters, the neurosurgeon then decided to operate on the patient which was going to be a marathon 8 hour complicated brain surgery. You must know that the fact that brain is encased in a skull. So, anything which is enclosed with the fluid surrounding it has a pressure. So whenever the surgeon breaks open the skull the brain gets sloshed around and becomes depressurized. It is analogous to the pressure difference in your coca cola bottles. So, as soon as the surgeon opened his skull, the brain got depressurized and the surgeon lost the position of the tumor in the patient’s brain. Since the CT scan was taken when the brain was inside the skull, the surgeon cannot take the risk of cutting the wrong portion of the brain which corresponds to the measurements taken before hacking open the skull. The surgeon cannot risk the patient’s life as cutting the wrong portion causes paralysis, blindness, loss of movements, loss of speech, the possibilities are endless. So, without knowing the precise location, the surgeon had to take another CT scan to pin point the new location of the tumor and continue to operate on him. By that time, it was too late. The soul had drifted into the other corner of the universe far away from his loved ones. A sad demise.”

Imagine that if the CT scan machine could think as the Alpha GO and could have pin pointed the location before and after pressurization using complex fluid dynamics, then the man could have been happily playing with his children. Just think of the possibilities.

Technology is a double edged sword. The onus lies on the person’s view.

The rise of AI’s is here.

So, with so much hype about the AI’s that is circulating in your news feeds. Let us learn about the nuances that goes with it.

Artificial Intelligence(AI) is easily one of the most prevalent themes in all of science fiction. The idea that the machine could exhibit the same level of intelligence and sentience as a human being has captivated writers and audiences alike for decades.

AI is not a new concept, but a concept of the 1950’s. Without the advent of computers, data or the processing capabilities the idea was put in the back seat for a considerable amount of time. Now, with the processing capabilities sky rocketed and with the advent of smartphones and social media which churn out trillions of data points without your knowledge has given a much needed boost in the field of AI.

Over the past few years AI has exploded, and especially since 2015. Much of that has to do with the wide availability of GPUs that make parallel processing ever faster, cheaper, and more powerful. It also has to do with the simultaneous flood of data of every stripe (that whole Big Data movement) – images, text, transactions, mapping data, you name it.

This is the first of a multi-part series explaining the fundamentals of AI.

Artificial intelligence is the future. Artificial intelligence is science fiction. Artificial intelligence is already part of our everyday lives. All those statements are true, it just depends on what flavor of AI you are referring to.

The terms AI, machine learning, and deep learning were used in the media to describe how Google won against Lee Seedol. And all three are part of the reason why AlphaGo trounced Lee Seedol. But they are not the same things.

The easiest way to think of their relationship is to visualize them as concentric circles with AI the largest, then machine learning, and finally deep learning fitting inside both.

Artificial Intelligence  is loosely defined as Human Intelligence Exhibited by Machines.

Back in that summer of 1956, the dream of those AI pioneers was to construct complex machines that possessed the same characteristics of human intelligence. This is the concept we think of as “General AI” —  fabulous machines that have all our senses (maybe even more), all our reason, and think just like we do. You’ve seen these machines endlessly in movies as friend —  TARS from Interstellar —  and foe —  The Terminator. General AI machines have remained in the movies and science fiction novels for good reason; we can’t pull it off, at least not yet.

What we can do falls into the concept of “Narrow AI.” Technologies that are able to perform specific tasks as well as, or better than, we humans can. Examples of narrow AI are things such as image classification on a service like Instagram and face recognition on Facebook.

But how? Where does that intelligence come from? That get us to the next circle, Machine Learning.

Machine Learning is loosely defined as an approach to achieve Artificial Intelligence.

Machine Learning at its most basic is the practice of using algorithms to parse data, learn from it, and then make a determination or prediction about something in the world. So rather than hand-coding software routines with a specific set of instructions to accomplish a particular task, the machine is “trained” using large amounts of data and algorithms that give it the ability to learn how to perform the task.

As it turned out, one of the very best application areas for machine learning for many years was computer vision. For example, you want to detect a STOP sign on the road, the people would write edge detection filters to detect the STOP sign object, then check the color, if it is red then continue and then check for the characters “STOP” to make sure that it is a stop sign.

Good, but not mind-bendingly great. Especially on a foggy day when the sign isn’t perfectly visible, or a tree obscures a part of it. The continuation of improvements in machine learning can be used in deep learning.

Deep Learning is loosely defined as a technique for implementing Machine Learning.

Artificial Neural Networks comes into picture. Neural Networks are inspired by our understanding of the biology of our brains – all those interconnections between the neurons. Hence, the name Neural networks. But, unlike a biological brain where any neuron can connect to any other neuron within a certain physical distance, these artificial neural networks have discrete layers, connections, and directions of data propagation.

You might, for example, take an image, chop it up into a bunch of tiles that are inputted into the first layer of the neural network. In the first layer individual neurons, then passes the data to a second layer. The second layer of neurons does its task, and so on, until the final layer and the final output is produced. Here, each neuron is a node in the graph shown in the image above.

Each neuron assigns a weight to its input which determines how correct or incorrect it is relative to the task being performed. The final output is then determined by the total of those weightings.

So think of our stop sign example. Attributes of a stop sign image are chopped up and examined by the neurons —  its shape, its red color, its distinctive letters, its traffic-sign size. The neural network’s task is to conclude whether this is a stop sign or not. It comes up with a “probability” which is really a highly educated guess, based on the weights. In our example the system might be 86% confident the image is a stop sign, 7% confident it’s a speed limit sign, and 5% it’s a kite stuck in a tree ,and so on.

So, how to increase the probability percentage ?

It needs is training. It needs to see hundreds of thousands, even millions of images, until the weightings of the neuron inputs are tuned so precisely that it gets the answer right practically every time. It’s at that point that the neural network has taught itself what a stop sign looks like; or your mother’s face in the case of Facebook; or a cat.

Deep Learning has enabled many practical applications of Machine Learning and by extension the overall field of AI. Driver less cars, better preventive healthcare, even better movie recommendations, are all here today or on the horizon. AI is the present and the future. With Deep Learning’s help, AI may even get to that science fiction state we’ve so long imagined.

You have a TARS, I’ll take it. You can keep your Terminator.

So, What is the difference between Machine Learning Programs and Normal programs ?

So, whenever we write a traditional program, we build the logic (decision making) directly into the program. So, if I wanted to write a program to recognize my face. We would write, look at the glasses, look at the eyes, look at the black hair, look at the lips.

With machine learning, we would not write any of that. We build an agent which would look at a bunch of images and over time, figure of to recognize the face. That agent would be many of the machine learning algorithms.

Regular program:

You have some input X and you want your output to be Y. You accomplish this by writing a program(code) that performs a function f. This way f(X) gives you your desired output Y.

AI program:

You have some input X and you want your output to be Y (you somewhat know what this should be like) but you don’t know how Y can be generated from X i.e. the function f is unknown. So you write a program(code) that approximates this function f  and this process is known as learning.

So,

Regular program: take input and function to produce output.

AI program: take input and output to produce the generating function.

Summary:

AI is a broad area that allows computers to think.

Machine Learning is a part/subset of AI which is a bunch of statistical tools to learn from the data

Deep Learning is a part/subset of Machine Learning which uses multi layer neural network.

Data science overlaps with AI and ML but not with DL. Data Science is understanding or making sense of data. Visualizing data is the core aspect of data science.

Tools in probability, statistics, linear algebra, numerical optimization and computer programming  are used in various applications of AI.

I haven’t covered the concept of neural networks, perceptions, reinforced learning, supervised learning, unsupervised learning, getting started in any of AI, ML or DL ?

blah blah blah.

So much more to learn. I will write these in the upcoming posts. Hope you stay tuned to my frequency.

AI has been heralded as the key to our civilization’s brightest future.

To AI,

Vishal

Just a normal guy.

How to color only with light ?

Cold bone chilling winds, blinding blizzards and a vast open expanse of ice cover. Antarctica. A researchers paradise. The rising and setting of the sun controls many of our daily rituals, from when we eat breakfast in the morning to when we wind down at night. But what happens to us if the sun never rises? Or if it never sets? It’s an annual occurrence for residents who live in Antarctica, when summer can bring months of almost constant sun and winter can blend into one long period of darkness. Absolute bliss.

Let’s go 8400 Km north from the cold bitterly environment to the sun kissed beach paradise of the Rio de Janeiro, sun bathing and listening to “Copacabana” on the beach with the warm waters washing beneath the feet. A fun paradise.

Think Jungle. Another paradise in South America is the great Amazon rain forest. Residents of which include the tiny insects to the apex predators. But one captured my attention – “The Blue Morpho Butterfly”, nature’s mind blowing spectacle.

Wait, enough about nature and forests and butterflies. Aren’t we supposed to talk about how to color with light?

So, let’s begin this incredible story about light.

Yes, I love to study light.

Take any ordinary piece of clear transparent plastic found in your homes. I know that every home has a plastic bag filled with a lot of plastic bags. So, you took your plastic, let’s continue.

😀

I want to show you how to add color to a transparent piece of plastic without adding anything to it, no dyes, paint, nothing except holes.

Shocked!!! Me too.

But first, Let’s  discuss about light.

Light – It is a form of electromagnetic radiation. It is a combination of electric and magnetic fields perpendicular to each other where the fields are continuously changing. The light, as every wave has a wavelength. The wavelength of visible light varies from 400 to 800 nano-meters.

 

To imagine a nano meter – take a millimeter of a millimeter and divide that in half. That is about 500 nano meters, the wavelength of green light.

It is tiny but it not that tiny. And nature has actually figured out a way to take advantage of the size of light. Remember the butterfly from Amazon forest. It has a blue iridescent shiny wings. Nobody actually knows why it adapted to such a color. That beautiful iridescent blue color isn’t created by a pigment but it is created by the structure of its scales.

What!

If you were to zoom in on this butterfly we would see all these little sort of gratings and holes within these gratings that trap the light and reflect out the blue light.

If you take the butterfly and expose it to the path of direct light then you see only the brown grating structures because the wings are transparent.

The light is not able to reflect of the wings, it is not blue anymore.

Fascinating, right!

:-O

So, what are the implications of coloring transparent plastic using light ?

Scientists are secretly working with the government to create similar hole structures to be used in security devices on bank notes, credit cards, identity cards and tickets. The holes are about 100 nano meters deep and 100 nano meters in diameter.

Each of the image in this contains about 500 million holes. These holes create a 3D grading that allow for light to reflect and refract to create those brilliant colors.

Don’t confuse with holograms. Again, lot to explain in holograms. That’s a story for another day. Let’s not kill the cat.

But, how do they creates such small holes ?

You must be thinking that the nano pin used to punch nano holes must break off. No, it does not, because it has low aspect ratio, i.e. the ratio of height to width is low. And these nano pins have a low aspect ratio of 200 nano meters to 400 nano meters, essentially the ratio of 1:2, which is incredibly strong.

This is the same principle that you have definitely seen. Remember the bubbles formed by soap. Don’t you see a rainbow color on the soap film.

Holes of different thickness creates different colors.

Simple concepts, but the applications are creative. Imagine one day your notes and tickets are embedded with this simple image by the help of a special 3D printer. These applications can stop counterfeiters. So, clean money.

So many applications of light.

Light is the connection between us and the universe. Through light we can look at the stars and the existence of the universe itself. The age and the size of the cosmos are written in light. The story of light has many beginnings and no ending, its heroes come from many times and places.

A simple butterfly, light and some plastic has the power to change the world.

To light,

Vishal

Just a normal guy obsessed with light.

 

The Current War

Every spring India slowly heats up. By late May, the country is burning with over 40 Degrees, by June the monsoon season is about to begin. Beneath the clouds lie the towns and cities of India. Over the next 4 months the forces of rain, thunder and lightning will collide which is essential to India’s survival. Let’s go back 3 centuries to Boston, USA 1750. Young Benjamin Franklin had ventured outside to fly a kite in the thunderous monsoon only to be exhibited by a crack of lightening. He discovered the secrets of the energy governing above us. From Ben Franklin to Michael Faraday to Thomas Alva Edison to Nikola Tesla, the genius minds have made our world light up literally.

This is the story of Electricity. The screen you are looking at, the light in your house is all possible because of this. An enormous contribution made by a handful of brilliant minds who unlocked the key to the power itself.

Electricity – the power to turn night into day. Imagine a world without light. How did we learn to produce it, control it and consume it. Until a few centuries ago, we had to rely on wind, water and muscle for power then we learnt to make our own, from the steam engine to the electrical generator. This is our pivotal love affair with power. From replacing machines drawn by 6 horses to power stations working at 6 Million horses.

Let’s start this electrifying story.

So, What is Electricity ?

Electricity is all around us–powering technology like our cell phones, computers, lights, soldering irons, and air conditioners. It’s tough to escape it in our modern world. Even when you try to escape electricity, it’s still at work throughout nature, from the lightning in a thunderstorm to the synapses inside our body. But what exactly is electricity? This is a very complicated question, and as you dig deeper and ask more questions, there really is not a definitive answer, only abstract representations of how electricity interacts with our surroundings.

Electricity is briefly defined as the flow of electric charge, but there’s so much behind that simple statement. Where do the charges come from? How do we move them? Where do they move to? How does an electric charge cause mechanical motion or make things light up? So many questions! To begin to explain what electricity is we need to zoom way in, beyond the matter and molecules, to the atoms that make up everything we interact with in life.

Let’s go Atomic.

An atom is built with a combination of three distinct particles: electrons, protons, and neutrons. Each atom has a center nucleus, where the protons and neutrons are densely packed together. Surrounding the nucleus are a group of orbiting electrons.

Just like this picture.

The atom’s electrons aren’t all forever bound to the atom. The electrons on the outer orbit of the atom are called valence electrons. With enough outside force, a valence electron can escape orbit of the atom and become free. Free electrons allow us to move charge, which is what electricity is all about. Electrons in atoms can act as our charge carrier, because every electron carries a negative charge. If we can free an electron from an atom and force it to move, we can create electricity.

Now consider a copper wire: matter filled with countless copper atoms. As our free electron is floating in a space between atoms, it’s pulled and prodded by surrounding charges in that space. In this chaos the free electron eventually finds a new atom to latch on to; in doing so, the negative charge of that electron ejects another valence electron from the atom. Now a new electron is drifting through free space looking to do the same thing. This chain effect can continue on and on to create a flow of electrons called electric current.

Now we know what exactly electric current is. Let’s go a little far in knowing the types of Electric Current.

Electric current comes in two varieties: alternating current and direct current, abbreviated as AC and DC.

Pufft!! So Simple. Eye roll inwards.

So, where do we use AC and DC ?

You might be thinking that AC is used in homes and DC is used in batteries, mobile phones and torches. Hold on to your hats, seats or anything or anyone that you are sitting on.

Look around your homes, offices and in your pockets. The devices that you are using are all DC powered. What !?

Yes, all the devices you use in your everyday life like TV, Laptop, Computer, Lights, Mobiles are all DC powered with the exceptions of some AC devices like your Motor Water Pump. If majority of your devices are running DC then why is AC transmitted ?

Yes, the lines outside your homes carry AC and not DC. But this does not make any sense. We are all using DC devices but transmitting AC. This is stupid, right ?

Have you thought about it ?

It’s alright if you didn’t. I will teach you. Let’s continue.

Let’s time travel to 1905. Imagine, use your brains.

Location: Lower Manhattan, USA.

Thomas Alva Edison – an inventor, business man and more over the patent of Direct Current. Edison’s electric system is cheaper than gas and is an instant hit among the general populace. Stoves, washing machines, electric carriages were all running on DC power. He was in a hurry of electrify the entire world.

Enters a man with the knowledge of electricity unlike anyone, ladies and gentlemen, the legendary Nikola Tesla, the inventor of Alternating Current with over 2000 patents, the current he produced was much better and cheaper than Edison’s Direct Current. The war has begun. The war of currents. Which was better ? Which was safer ? Which was efficient ?

Story on Nikola Tesla on some other day. Let’s not kill the cat.

Okay, stop day dreaming in 1900’s and come back to the present.

Modern devices contain semi conductors, which run only on DC power, then why is AC power transmitted ?

Let’s find out.

To find the answer you need to know the basic electron flow in both the DC and AC power.

Alternating current describes the flow of charge that changes direction periodically. As a result, the voltage level also reverses along with the current.

Direct current is a bit easier to understand than alternating current. Rather than oscillating back and forth, DC provides a constant voltage or current.

This is the definition of AC and DC. Let’s see what this means.

In DC transmission, there is a continuous and direct flow of electron along the wire from negative to positive. So, in essence the electrons move from the negative end of the DC source, goes through the wire and into the device and then goes back into the positive end of the DC source. The problem with this setup is the electrons encounter resistance along the wires. It’s difficult for the electrons to travel great distances, so most of the energy is lost in the wire.  So, transformers were required at regular distances. Edison would have to put a power plant or a DC transformer every mile to counteract the drop in the current through the loss of resistance to keep the voltage constant across the power grid.

In AC transmission, Tesla discovered that the electrons need not necessarily travel the entire distance but he alternated the current back and forth along the wire between the negative and positive poles at 60 cycles per second with absolutely no power loss, a transformer can be used to step up the voltage and lower the current which then, can be transmitted over a large distance without the need for a transformer at regular distances. So, AC could be transmitted hundreds of kilometers further than DC.

So, does the current actually flow back in an AC transmission ?

Yes, it actually goes back and forth. It goes front on the upper cycle of the Sine wave and goes back on the lower cycle of the Sine wave. There you have it, electricity. The very definition of electricity defines the movement of electrons in a conductor. It does not specify that the electrons has to travel the entire distance, the electrons can travel a millimeter or the length of the entire wire. Ingenious thinking.

So when you want to transmit huge amounts of power over a large distance, AC power transmission is the key.

If you would transmit the same power in DC then it would be a nightmare of cables and wiring’s over head, as a matter of fact some streets would be block out the sun because the DC cables are so thick.

Street in Manhattan during the DC era.

 

Left one is the DC cable and the right one is the AC cable used in transmission.

Both the cables are used to carry the same amount of power. Both carry a million volts of electricity but see the size of both these wires. The cost of cabling, transformers is extremely high in the case of DC.

A simple act of controlling how the movement of electrons behaved had a profound impact of the nature of the current itself.

So, this is the reason why AC is transmitted instead of DC.

Simple, right ?

The man who controls the current, controls the future. History has neglected the genius Tesla but today he is being discovered. Electricity is one of the greatest technological innovations of mankind.

So, every time you turn on the light on a flick of a switch, or to respite yourself from the searing heat of the Indian summer in front of your air conditioner, remember the contributions of the genius minds that went into powering them. The electricity has to travel a large distance to get into your bedroom. So, it is your responsibility to use it wisely.

Conserve electricity for the your children and your children’s children.

To Electricity,

Vishal

Just a normal guy.

Are Physics laws always true ?

Date: September 2017

Overcast skies, rough winds, dark clouds, lush greenery and a quiet office. Window seat at the Office, just peering out to take in most of the great Indian monsoon. Soon, it was raining cats and dogs in Bangalore. I was taken aback by nature at its best. I soon turned in to see that I was sitting on a computer with code running on a “Black and Green” screen.

I was working on the image processing pipeline software of ASTROSAT. The software is a brilliant piece of architecture and coding, brains of many Scientists and Engineers have been sourced to build a masterpiece of Science, Space and Computing. The pipeline software is used to generate a image based on the input stream of bytes that we get from the satellite. It is an extremely complex software that accounts for many Mathematical models along with the physics of the satellite considering that the satellite is moving around the Earth in space at 7 km/s or 25920 km/h. Yes, it is extremely fast. The software needs to consider the drift, roll, pitch and yaw of the satellite. Taking an image with so much dynamics is lot harder. Imagine you are moving in a car at 150 km/h and you want to take a picture of your girlfriend standing on a side walk. Yes, I feel the pain of a blurry image on your shitty smartphone. Magnify this problem by a factor of 1000X for a satellite. Many more factors like cosmic rays, bright rays from sun and moon, etc. All these corrections has to be coded in the software. It’s like writing a software for the most expensive, fragile and a very big camera. The satellite is capable of taking images beyond 20 Million Light Years away. Far, far beyond.

Bored already huh. Let’s change the topic.

That afternoon, I was chatting up a Scientist, topics ranged from Indian monsoon to politics. Not much interesting though. I caught a process running in the software called “Red Shift Correction”. Inquiring about it with the professor was the one of the most profound moments that ever happened to me. Let’s begin in understanding the process of Red Shift Correction.

In 1929, Astronomer Edwin Hubble made an unusual discovery that most the galaxies in the universe are moving away from us, which led him to realize that the universe is expanding and that expansion has strange implications. It means that everything in the universe, even light, gets stretched out.

Didn’t understand ! Let me explain.

Light as we know consists of the 7 colors of the rainbow – VIBGYOR. Where the color RED has a longer wavelength than the color VIOLET. Easy right!.

So, when light gets red shifted – that is its wavelength becomes more stretched and the light becomes redder in color. So, when a star or galaxy 10 Million light years away is actually emitting blue color, the light after travelling for 10 Million years gets stretched due to the universe expansion and the light we see in the present day is the color red.

Shocked, Me too, on hearing it for the very first time.

So, the space-time fabric is literally expanding along with all the contents inside it. So, as space-time gets stretched out, so do any of the light waves that travel through it. This is known as “Cosmological Redshift”. Note that, the Cosmological Redshift is different from Doppler Redshift of BlueShift which is caused by things moving towards or away from us through space.  I won’t take up this topic today and kill the cat. We’ll discuss this some other day.

Now to the extremely interesting part of the story. Buckle up people.

Now, longer wavelengths of light has less energy, this can be derived from Planck’s Equation. Max Planck is a Nobel Prize winning Physicist. Genius German Guy.

You should note that in the above equation, the only variables are E (Energy) and Lambda (Wavelength), others are all constants like c (speed of light)  and h (Planck constant).

So, as the wavelength gets longer, the energy of the light decreases. Inverse Proportion. But wait, you learned in 1st standard physics that “Energy can neither be created nor destroyed, it’s just transferred from one form to another” – Law of conservation of Energy. So, where did the redshifted photon’s energy go ?

Maybe one would say that light waves die out the same way a ripple in water or sound wave dissipates, but these waves are mechanical waves and they die out due to friction between air or water molecules. The total energy in these types of waves is conserved. In contrast, light from the galaxy is not travelling through any medium, it is travelling through pure space. Most of space is pure vacuum. There is no air resistance or friction, so there is no where to pass the energy. So, where is the lost energy going ?

What!!? How!!? Why!!? All these questions were in my head. I was dumb founded by this simple correlation.

Oh my universe, What is this happening to light !?

Is Energy not conserved !?

Can the laws of Physics be broken ?

Seams freaky, right ?

Some say that the symmetries law of the universe applies and always the energy is conserved or some point to quantum physics to prove their mettle in understanding the universe or point out that relativity does not apply to light, time invariance, …….Blah, Blah.

I don’t know why.

So it turns out something we usually talk about as universal truth has cosmological exceptions. What do those exceptions mean ?

For me, they are a reminder that everything we know and intuitively understand is far from universal.

My fellow scientist told me a story which I will never forget – “There is an old folk tale about a frog that lives his entire life down a well, and everything there made sense to him. He knew where the bugs hid, he knew where the comfortable rocks were, until one day a turtle showed up and told him about the outside world, about mountains, trees and oceans. And the frog just couldn’t warp his head around it. He couldn’t imagine anything bigger or better or different from his own well. The law of conservation of Energy applies down our own well. For almost everything we experience as Humans on a daily basis, sure, it’s accurate enough to say that the law of Physics don’t change over time. But when you zoom out, the Physics starts to look foreign. There is more to the story.”

:-O = Yes, this was my reaction that time.

In the mean time, the software had spit out an image of a beautiful galaxy. I will never look at the universe and the laws the same way again.

So, whenever you are driving and taking a moving shot of your girlfriend or boyfriend, just think about this.

To Light,

Vishal

Just a normal guy.

 

Why are plants not black ?

Date: 5 Jan 2017

Time: 11:30 AM

It was a cold day of the January month in Bangalore. I was working in my office, doing some data analytics work. The data was a solar data which is obtained from NOAA (National Oceanic and Atmospheric Administration). In the process of data analytics, I needed to plot the Sun spectrum to find out more about our host star.

The Sun, a star just 8 light minutes away from Earth is white in color. Yes, it is a white star. When we see the Sun at sunrise or sunset, when it is low in the sky, it may appear yellow, orange, or red. But that is only because its short-wavelength colors (green, blue, violet) are scattered out by the Earth’s atmosphere, much like small waves are dispersed by big rocks along the shore. Hence only the reds, yellows, and oranges get through the thick atmosphere to our eyes. It is a common misconception that the Sun is yellow, or orange or even red. However, the Sun is essentially all colors mixed together, which appear to our eyes as white. This is easy to see in pictures taken from space.

You know that white color contains all the colors of the visible electromagnetic spectrum – VIBGYOR.

NOAA has launched a satellite called GOES (Geo Stationary Satellite) in 2011 at a height of 36,000 km from Earth in outer space. It is mainly used for meteorological services as well as continuously monitoring the Sun, 24/7/365.

After plotting the data on a rather slow server, I got the result. I took some time to interpret the results. The result was that Sun emits Green color most apart from other colors in the VIBGYOR electromagnetic spectrum. You must remember that the green color is the most prominent color emitted by the Sun in outer space as well as inside our atmosphere.

I thought it was just a normal result and went out to take a break post completing my work. I just stepped out of my office into the garden. I was shell shocked and just stood there for a few minutes. My brain stopped working. I saw that the plants are green. This made absolutely no sense to me whatsoever.

Let me walk you through this, So why are plants green ?

Leaves are green because chlorophyll is green and chlorophyll is the molecule that takes light from the Sun and converts it into useful energy for the plant – Photosynthesis.

I hope you all are with me. Let’s continue the journey.

Now, let me walk you through the process of color perception of an object. If a ball is red, then it absorbs all the colors of the electromagnetic spectrum but reflects the red light. True, right.

Now, if a leaf is green then it absorbs all the colors expect green. Now, this made me go crazy. It makes absolutely no sense evolutionarily. Plants and trees are shooing away the most common color emitted by our Sun.

WHAT?! WHY?!

If plants wanted to absorb the most energy then wouldn’t they absorb all the colors, wouldn’t they be black ????

 

 

 

 

 

 

(Black pigmented plants exists, but they are extremely rare)

Trees are green all around the planet Earth. It is a global thing. So, why are the plants green ?

Now trees with green leaves have been traced back to 385 Million years ago and older.  No one knows why plants are evolved to be green.

There are many theories but no conclusive evidence.

May be evolution is not a perfect engineering process. Is evolution an accident ?

I don’t know any of its answers. Life’s most simplest questions like why is the grass green has no answer ?

So when my children (“future”) ask me, why is the grass green?, it would be a profound moment for them to know that I don’t know the answer to it. Hopefully we would have found out the answer by then.

The winter sun was a powerful awakening tool for me that aroused an seemingly obvious question in me. I will never look at plants the same way again. So, step outside and take a deep breath of fresh air created by the plants around you.

To answers,

Vishal

Just a normal guy.

Cheers.

You are Insignificant

Date: 27-02-2018
Time: 17:15:00

Past my usual working hours, but I can’t help.

I just constructed an image of NGC 1512 galaxy. It is a galaxy 13 Million Light years away from the Earth and saw something pro-founding to digest.

What you are seeing at the center (White surrounded by Red) is the Ultra Violet radiation emitted by the Accretion Disk (cloud of gas and dust) that surrounds the black hole. There is a super massive black hole at the center of that white blob. The mass of the black hole is under study by my team using Spectra Analysis. The picture is of a merging galaxy with NGC 1510 (left smaller) and it started when “The atmosphere stabilized and glaciers melted because Earth was warmer and sea level rose and the first jawed fish evolved”, this event started 400 Million years ago and will continue for yet many millions of years to come by. The two galaxies are separated by a distance of 45000 light years. There are fusions of stars creating Gold, Uranium and other heavy metals at their cores so that some Alien civilization in that galaxy could be a part of their journey in understanding the Universe. The Gold and other heavy elements on our planet Earth has been forged at temperatures and pressures unimaginable to the Human scale. The Calcium in your bones, Iron in your blood, Phosphorous in your teeth, all the elements in your body has been cast in the core of gigantic stars and spreading through the universe through exploding Supernovas. We are star stuff. We are the universe.

This dance is just a lonely speck in the vast cosmic arena. In this scale, Earth is not even a pixel on the device that you are viewing this. Humans are such fervent to fight the inhabitants from one corner of the pixel to another corner of the same pixel. How much do we know the universe, Who answers all these questions, Do Humans live long enough to find out. I don’t know.

“Twinkle Twinkle great big star.
Astronomers know just what you are.
Shining big and shining bright.
To show us that inspirations are born tonight.

Twinkle Twinkle great big star.
Universe has placed you where you are.”

The observable universe of around 95 billion light years is something beyond imagination. Truly, The universe is beyond your imagination. I have had a profound experience in studying the Universe at its grandest scale. This insignificance should be an absolute inspiration to bring in peace among-st the Earthly beings and to bring us closer rather than farther apart.

We are just a lonely speck of rock, mud, and water suspended in the sunbeam.

To Humility,

Vishal

Just a normal guy with excruciating curiosity about everything.

How to Reduce Data Usage When Browsing the Web on a Smartphone ?

When you don’t have unlimited mobile data on your Android or iPhone, every Megabyte counts. Mobile browsers like Google Chrome and Opera offer a built in data compression feature, allowing you to browse with less data.

There are only a few small trade-offs here. If you want to use less data, enabling this feature will allow you to browse all the same websites with little noticeable difference.

How Does This Work?

When you load a web page on your phone, your browser connects directly to the website’s web server, which sends you the web page you asked for just as if you were browsing on Wi-Fi. Your cellular provider just sits in the middle, passing traffic back and forth and charging you for it.

Enable the Data Compression feature in Chrome or Off-Road mode feature in Opera — this was formerly known as the Opera Turbo feature, and things will happen differently. When your browser loads a website, it will first send a request to Google or Opera’s servers. Their servers then download the page you wanted to view as well as all its images and other assets. They compress the web page on their servers, making it take up less space, and then send it to your phone.  In other words, these services function as compressing proxies. This is just one good way to reduce your phone’s data usage.

Images are also transcoded so they’re smaller and only as detailed as they need to be — your phone probably doesn’t need the same high-resolution web images you would need on a full PC if you’re hurting for bandwidth.

What About Performance and Privacy?

If you have a fast data connection, web pages may take a tiny bit longer to load because the connection isn’t direct and you’re waiting for the proxy. By the same token, since your phone will have less data to download, the web page may download even faster if you have a slower data connection.

There are also potential privacy concerns here, as Google or Opera will be able to see the web pages you’re accessing. Realistically, that’s not not unusual — your cellular carrier, Internet service provider, and various state security agencies around the world are all able to see what web pages you’re visiting, anyway. If you use Chrome or Opera browser sync, your history will synchronize through their servers, so they’re not getting any new data. And Google Analytics is on so many pages that Google can see many of the web pages you visit. In other words, we’re already in deep here — and since we’re already giving away our browsing history, we might as well take advantage of this convenience feature in return.

Both Chrome and Opera also do not use the compressing proxy for encrypted HTTPS pages. If you access a secure website, like your bank, you’ll connect directly to the secure site. This means you don’t get the benefits of less data usage, but your sensitive data isn’t routed through the proxies, so you can stay secure. Google says using Chrome’s incognito mode also bypasses the proxy.

Enable Data Compression in Chrome or Opera

To enable Data Compression in the Chrome app for Android, iPhone, or iPad, tap Chrome’s menu button and select Settings. Tap Bandwidth management under Advanced, tap Reduce data usage, and set the slider to On.

To enable Off-Road mode in the Opera browser for Android or iOS, tap the O menu button and set the Off-Road mode slider to On. This feature is conveniently located so you can easily disable and enable it whenever you like — perhaps you want it disabled on Wi-Fi, but enabled when using mobile data. You can also open Opera’s Settings screen and lower the quality setting for Off-Road images — this will allow you to save bandwidth on images, but they won’t look as nice.

The Opera web browser for Windows, Mac, and Linux also offers this feature, so you can use Opera on your laptop to reduce bandwidth consumption while you’re tethered to your smartphone’s data connection.

See How Much Data You’ve Saved

After you’ve used this feature for a bit, you can head to the same Reduce data usage settings page in Chrome and see exactly how much data you’ve saved by having it enabled. This can give you an idea of how worthwhile the feature actually is.

When every megabyte counts, this feature is very worthwhile. On the other hand, if you have a fast LTE connection with unlimited data, browsing may be a bit faster without Data Compression enabled.

For Secure connections don’t enable Data Compression.

So, You want to save Your Data Usage?

Fun Time

This one’s awesome.

Google: “I have everything!”

Facebook: “I know everybody!”

Internet:”Without me, you all are nothing.”

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Electricity: “Keep talking, bitches!!!!”

A Quote for all…

A Quote for all my fellow users.

“I do not fear computers. I fear the lack of them.”