Are we Alone in the Universe?

We exist as a beat in the complex cosmic fugue. We are the product of primordial fiat lux of life. We exist as a dot in the canvas of the universe. We exist as a frame in the grand spectacle of life. We exist as a surge on the cosmic cavalcade. We are but a pageant of evolution, the poltergeist of life that creep the silences of the far away universe. There is more life on our planet then ever expressed in the fiction. Life is slithering and sprawling in every nook and corner of our planet, beings die and new generations and species take their place. There are more things in heaven and earth than dreamt of in the philosophy. There are things at our exposal in the vast contemptuous ocean of the cosmos all we need is a telescope but are there beings too?

Are we alone in the universe? Our planet is teeming with life but is the life as we know of unique with our planet? All my life I have wondered of the life beyond the earth. All the countless 400 billion galaxies, planets, the exo-planets, the comets, the asteroids and the stars burgeoning in the universe, are there also life? Will the beings of other worlds resemble us? Or will they be astonishingly different? What is life in the shores of cosmos? Is our understanding of life complete or are there discoveries yet to be made which will entirely reform the way we contemplate of life and universe. The nature of life on earth and the quest of life elsewhere are the two sides of the same question: Who we are and are we alone in the universe?

542 Million Years ago the foundation of life was set on earth in a Cambrian explosion that saw the sudden burst of evolution of complex animal life on our planet. All living things on earth are made of organic molecules, a complex microscopic architecture around atoms of carbon, in the great space and dark between the stars there are also organic molecules in the immense clouds of gas and dust. The surface of the newly form planets and other celestial bodies in the universe is shrouded by these organic molecules. These organic molecules are not life but they are the stuff of life.

The first revolution in our quest to find life beyond earth was ushered in by the introduction of the telescopes in the 1600s. With the help of the incredible invention of the changing world, the astronomers namely Galileo Galilei standing on the shoulders of the great astronomers Nicolaus Copernicus and Johannes Kepler, opened up the mysterious heavens for the first time to serious scientific scrutiny. Building upon the works of Galileo, Sir Isaac Newton laid down the laws governing the motion of celestial bodies and for the first time cosmos was put forth people beyond the prejudice of dogma and mysticism. The second revolution is cosmology was initiated by the inventions of twentieth century modern telescopes.

Astronomer Edwin Hubble further revolutionized the way we gloated upon the stretched heavens. The third revolution is now underway with the surge of modern high-tech instruments, such as space satellites, lasers, gravity wave detectors, X-ray telescopes, and high speed supercomputers. We now have the most authoritative data on the nature of the universe and what it is made up. We have the best tools needed to analyze this data.

We are here, made of stardust. The first living microbial cell is believed to be brought to earth by a comet. Life cells are the product of years of grinding and baking inside the core of the stars. It gives us a clear indication that life as we know of exists beyond the stretch of our solar system; all that is lacking is the evidence. Today scientists hope to obtain more statistics to find something more substantial and more edifying. The most recent discoveries made today vehemently point to the optimistic view that extraterrestrial life does exist.

Astrobiologists are excited by the modern explosion of new planets discovered outside our solar system. Since the last decade of the previous century when the first planet was discovered orbiting around another normal star, now the number of Exo-planets has swelled to 200 and more are being discovered. Some of these exo-planets are incredibly earth like and lie within the habitable zone of their stars. 

The recently spotted Earth 2.0 is found to be only 20.5 light-years away in the habitable zone of its star and considered to be highly probable of supporting life as we know of.

Recent discoveries suggest that the solar system and broader Milky Way galaxy bourgeon with climate that could support life. Oceans of liquid water slosh beneath the icy shells of the Jupiter moons Europa and Ganymede, as well as that of the Saturn satellite Enceladus. NASA’s curiosity rover has found carbon-containing organic molecules and fixed nitrogen, basic ingredients necessary for Earth-like life, on the Martian surface. Kepler space telescope suggests that nearly every star is in the sky hosts planets-and many of these worlds may be habitable. It has also shown that rocky worlds like earth and Mars are more common throughout the Milky Way galaxy than the gas giants such as Saturn and Jupiter.  

Though still the evidence for life on planets and galaxies far away from our solar system or Milky Way galaxy is inconclusive. Researchers are working toward more intensive goals of realizing the first contact with the extraterrestrial life. NASA’s Mars rovers scheduled to launch in 2020 will search for signs of past life and cache the samples back to the earth; it also plans to land astronauts on Mars in the 2030s, which is supposed to be a key step in this regard.

Astronomers are to embark on the most intensive search for alien life by listening out for potential radio signals coming from advanced civilizations far beyond the solar system. Our universe is beaming with electromagnetic radiations and within spectrum outside the one of our planet we will be able to detect the signs of intelligent civilization far away. The world most powerful telescope, 50 times more sensitive than any other previous telescope which will also cover 10 times more sky,  in US and Australia launched in compliance with the leading physicists Stephen Hawkins will solely look for radio emissions to hunt the signature of intelligent civilization.  

Finally we may not be very far from our first contact with the alien beings in the outer space as predicted by NASA’s chief scientist Ellen Stofan who says, “I think we’re going to have indications of life beyond Earth within a decade and I think we’re going to have definitive evidence within 20 to 30 years”. What we need to think about is: Are we ready for such an excursion? Are we advanced enough to resist the contact with a hostile outer intelligence? Should we stop being a threat to each other and work out the greater possibility of our survival if and when we meet a civilization brewing inside the human tendency of awe and destruction?

                                                              

Refs: Space.org, Parallel Words by Machio Kaku, Cosmos by Carl Sagan

Why is there Something rather than nothing?

                                                  Lawrence M. Krauss
                           A Universe from Nothing, Why is there something rather than nothing?

The deepest, most far reaching and sublime question “Why is there something rather than nothing?” has always been a cosmological mystery ever since it was first posed in the intellectual history in 17^th century. From theology to philosophy, ontology to teleology to epistemology there have been enumerate answers given for this ultimate question but as far as scientific rationality and empirical studies are concerned, we have reached nowhere. Standing amidst the vastness of ever expanding universe, sometimes with huge telescopes, sometimes with mathematical models, sometimes with melancholy and sometimes with faith, men stood and wondered “Why is there something rather than nothing?”


Why does this question matter so much? Ludwig Wittgenstein, the greatest philosopher of 20^th century says “It is not how things are in the world that is mystical; it’s that the world exists.” And Arthur Schopenhauer, another great philosopher went on to say as much that those who don’t wonder about the contingency of their existence and the contingency of world’s existence are mentally deficient.  

Since about 1960s and 1970 physicists, with the development of quantum mechanics, started to purport the idea that a universe could actually come from sheer nothingness or out of a void. Among great physicists of today who support the spontaneous origin of universe from nothing, Stephen Hawkins and Alex Vilenkin are the prominent ones, but never was this bright and breath-taking idea more popularized than it was by Lawrence M. Krauss. 

In classical physics (applicable to macroscopic phenomena), empty space-time is called the vacuum. The classical vacuum is utterly featureless. However, in quantum mechanics (applicable to microscopic phenomena), the vacuum is a much more complex entity. It is far from featureless and far from empty. The quantum vacuum is just one particular state of a quantum field (corresponding to some particles). It is the quantum mechanical state in which no field quanta are excited, that is, no particles are present. Hence, it is the "ground state" of the quantum field, the state of minimum energy. The picture on the left illustrates the kind of activities going on in a quantum vacuum. It shows particle pairs appear, lead a brief existence, and then annihilate one another in accordance with the Uncertainty Principle.

The Uncertainty Principle states that for a pair of conjugate variables such as position/momentum and energy/time, it is impossible to have a precisely determined value of each member of the pair at the same time. For example, a particle pair can pop out of the vacuum during a very short time interval.

These are few questions which been raised with the advent of quantum mechanics. We may not know for sure why is there something rather than nothing. If we wish to draw philosophical conclusions about our own existence, our significance, and the significance of the universe itself, our conclusions should be based on empirical knowledge. A truly open mind means forcing our imaginations to conform to the evidence of reality, and not vice versa, whether or not we like the implications.     

Lawrence M. Krauss is a theoretical physicists, cosmologist, professor of the School of Earth and Space Exploration and director of its Origins Project at Arizona State University, America. He is the bestselling Arthur of “The physics of Star Trek”, “The fears of physics” and “A universe from nothing” among other great books. He, by this day has published more than 300 scientific peer reviewed journals and is hailed as a formal public intellectual.

Science is the best guide to the nature of reality. The epistemology of our universe, with the lambda-cold dark matter (_CDM) model and all available observations (cosmic microwave background, abundance of light elements), is usually explained as an event of big bang aided by inflation, where a singularity underwent exponential expansion which is still going on. Big bang, inflation and expansion may well be considered as facts in scientific community but where did singularity come from, or how did it form still remains a mystery. This is a scientific question, not a theological one and science must answer it, but can it?

Aristotle defined “nothing” as “What rocks dream of” while others define nothing as “Absence of something”. But nothing in science is different from that of philosophy. Nothing is though absence of something or in scientific terms can be defined as absence of space, time and matter or absence of space, time and energy.Something that has zero energy is actually nothing and can come out of nothing,  with the development of flat model of our universe it has been proved that the total energy of our universe is zero. There is repelling gravity in outer space that plays the part of nagitive enery so the rotal energy of universe comes out to be precisely zero. Lawrence Krauss, supporting his insight with quantum mechanics says that nothing is actually something and it is unstable. If you take everything out of this universe, what you are left with is nothing or vacuum. Our vacuum is the fabric of cosmos and it is a bubbling, boiling gas of virtual particles which emerge and emerge out in it due to quantum fluctuations. 

Quantum fluctuation is the temporary appearance of energetic particles out of nothing, as allowed by the Uncertainty Principle, in the temporary change in the amount of energy in a point space, That means that conservation of energy can appear to be violated, but only for small values of t (time). This allows the creation of particle-antiparticle pairs of virtual particles. The effects of these particles are measurable.

We have to keep in mind that universe was created as a singularity underwent exponential expansion, where singularity itself was so small that not even quark could exist in it. Here Lawrence Krauss (in his book Universe from nothing) emphasized that a little quantum fluctuation could have formed the singularity which underwent expansion.   A vigorous mathematical proof of the idea has also been given.

If particals like virtual particals can come out of nothing, spontaneously then why can't our universe? Or if there can be a slight chsnge in quantum enery due to uncertainity, why can't singularity be formed spontaneously some 13.7 billion years ago? A vigorous mathematical proof of the idea has also been given.

We have to keep exploring asking 'Why' and ''How'' instead of ''Who?'' We may try and fail or we may succeed but the final arbiter of this question will not come from hope, desire, revelation, or pure thought. It will come, if it ever does, from an exploration of nature. 

Multi Layer PCB Designing and Assembly

Printed Circuit boards (PCBs) are the core building blocks of most of the electronic items today and the drive for innovation and improvement in the operation and reliability of the modern electronic circuits is more powerful today than ever before. PCBs are used in all major applications from simple to highly complex integrated circuitry. Looking at this large range of application and dependence of the electronic devices of the Printed circuit boards, it wouldn’t be wrong to say that they PCBs drive the world of today.

PCBs have reduced the size and weight of the conventional circuits while they have increased the design capabilities of the circuits manifold. They have paved the way for faster and more efficient processors to be built which require billions of transistors to be integrated on the board and work in unison. The high precision applications in aerospace technology and computer servers require the operation of integrated circuit of high density which has only been made possible through the advent of printed circuit boards.

Multi layer Printed Circuit Boards (PCB) has greatest and complex functional capability of all types of PCBs available today as they are used in wide range of consumer electronics i.e. smart phones and microwaves. Such devices tend to use Multi layer Printed Circuit Boards (PCB) for attaining less weight and small size. The multi layer PCBs are used in telecommunication devices such as transmission systems, GPS and satellite transmission systems. The reason behind using multi layer Printed Circuit Boards (PCB) in the telecommunication industry is the durability and high functionality provided by the multi layer Printed Circuit Boards (PCB).  Multi layer PCBs are also widely used in the medical industry due to the high density design capability made possible by them. In medical industry they are mostly used in x-ray machines, CAT scan, heat monitor devices and numerous other electronic devices used in the medical industry. Military and defense applications also widely use the multi layer Printed Circuit Boards (PCB) mostly in air traffic control systems, high power computers and servers operated in these environments, monitoring of sensors and wide range of military electronic devices.

The major reasons behind the wide use of Multi layer Printed Circuit Boards (PCB) is the high assembly density made available to the manufacturer. In Printed circuit board assembly it is given priority to choose the design such as to minimize the size and weight of the device, hence the multi layer Printed Circuit Boards (PCB) comes into play.  The multi layer Printed Circuit Boards (PCB) also allow for controlled impedance features, greater EMI shielding and overall design quality which makes them most suitable for applications where smart designs are required.

Multi layer Printed Circuit Boards (PCB) are like single or double layer Printed Circuit Boards (PCB) but in multi layer Printed Circuit Boards (PCB), the layers are substrate and copper coating exceed from two layers. The substrate of the multi layer Printed Circuit Boards (PCB) also range from glass epoxy resins to Teflon while the copper coating on the layers serves the purpose for drawing the conducting paths though the thickness of the copper coating can vary depending on the design and requirement of the application.

In Multi layer PCBs, the top and bottom layer contain the core between them which contain the inner layers stacked together. The different layers of the PCB are connected through via of various types depending upon the requirement. Some of the main types of via used in multi layer Printed Circuit Boards (PCB) are Plated through via, buried via hole and blind via hole.

    Plated through Via

Plated through via connects the top and the bottom layer of the multi layer Printed Circuit Boards (PCB). In order to spot a plated through hole, you can see if the light passes through it or it is possible to see through it. Plated through holes are the simplest kind of holes and they only need drilling or laser light to be drawn. Drilling of plated through holes is relatively cheap but they may take up more space as compared with the other types of via or the micro via.

    Blind via hole (BVH)

Blind via hole connects the outer layer of the PCB with the inner layers and it is not possible to see through the Blind via Hole (BVH) which is the reason why it derives its name. Blind via Hole is mostly used where the size and space utilization of the Printed Circuit Boards (PCB) is of importance. Blind via Hole are difficult to deal in as they require special attention to the depth of the hole to be made as anything imprecision in this regards can lead to severe design and operation complications. Due to the difficulty in handling them, the blind via Holes are not frequently used in the Printed Circuit Boards (PCB) assembly.

     Buried Via Hole

The buried via Hole connects the inner layers of the Printed Circuit Boards (PCB) while it does not pass through the outer layer. The buried via holes are made use of where space utilization is important and high density applications are to be supported. The buried via holes are commonly used in HDI technology. Buried via holes are extremely difficult to work with as they require more time as compared with the blind via hole and the plated through hole technology while special care is required in working with them.

    Micro Via

Micro via are another type of via used in the Printed Circuit Boards (PCB). They are via of very small size less than few micro meters and are used in highly sophisticated application. Micro-via are commonly used in flexible Printed Circuit Boards (PCB) or rigid flex Printed Circuit Boards (PCB).

Multi layer PCBs can be slightly costly as compared with the single layer PCBs which is only fair considering the high level design capabilities they are capable of supporting. They are also more complicated as compared with single layer PCB and skilled designers are required to work with them. 

Quality tests for Printed Circuits Boards

Quality tests for Printed Circuits Boards

The Printed Circuit Boards (PCBs) are very sophisticated and complicated items which are of utmost importance in the smooth operation and sustainability of the electronic machinery and it would not be an overstatement to say that even the slightest of faults in a PCB can bring the working of fundamental machinery to a standstill. In this scenario, it is of vital to have approved standards of quality control for the manufacturing, development and operation of the Printed Circuit Boards (PCBs). Some of the standard tests performed in order to ensure the quality of the Printed Circuit Boards (PCBs) are as follows,

    1)      100% Electrical Test

    2)      100% Visual Inspection

    3)      Dimensional Inspection

    4)      Micro Section

    5)      Solder Ability Test (245+-5C) , 10 sec

    6)      Thermal Test (288+-5C)

    7)      Tape Test

    8)      Peel Test

    9)      Impedance Test

    10)  Ionic Contamination Test

     1)    100% Electrical Test

Electrical testing is of utmost importance for a PCB which involves the electrical testing of various aspects of the Printed Circuit Boards (PCBs). In electrical testing every “Node” on the PCB board is tested. Short circuit tests are performed to be if any part of the PCB is short circuited. Clam shell tests are performed to obtain the simultaneous testing of both sides of the PCB in case of double sided Printed Circuit Boards (PCBs). Continuity tests are performed to check if the resistance between the tests points is within specified limit.  Some of the other tests performed in Electrical testing of the Printed Circuit Boards (PCBs) are flip test, high pot test, impedance control test, leakage test, opens test and optimized net list tests.

     2)    100% Visual Inspection

Visual tests are performed using AOI machines to check if all the components after the Printed Circuit Boards (PCBs) assembly process are there where they are supposed to be. The AOI machines use high resolution cameras aided with software Gerber and drill files to make the comparison on the Printed Circuit Boards (PCBs).

3)    Dimensional Inspection

Dimensional inspection is necessary because the size and dimension of the Printed Circuit Boards (PCBs) is specified as per the design of the device in which the PCB has to be used in. The dimensional test compares the physical dimensions of the PCB against the software provided design of the PCB.

    4)    Micro Section Testing

The micro testing of the Printed Circuit Boards (PCBs) is performed in order to check the drill via on the PCB. Via are micro sized in PCB and have to be carved with greatest care as slight offset in via can be of serious design and operation faults. 

    5)    Solder Ability Test

It is our understanding that components are soldered on the PCB during the Printed Circuit Boards (PCBs) assembly process therefore it is necessary to check the durability of the solder through the solder ability test. The solder has to withstand high temperatures and extreme working conditions without showing any signs of deterioration. The solder tests are performed up to 245C for 3 seconds to check the response of the solder. If the able to withstand such conditions, only then it passes the solder ability test.

     6)    Thermal Ability Test

During the working of Printed Circuit Boards (PCBs), extreme conditions can arise which can lead to heating of the inner core. In such cases, the Printed Circuit Boards (PCBs) should be able to withstand the extreme heating. Thermal ability tests are performed by subjecting it to temperatures up to 288 for about 10 seconds to check its performance.

7)    Tape Test (adhesion test)

Tape tests are performed to check the adherence of the copper foil on the PCB. The tape is applied to the Printed Circuit Boards (PCBs) and peeled off in order to check if any copper foil residue adhered to the tape. The Printed Circuit Boards (PCBs) is only passed for further processing if no copper residue adheres to the tape.

     8)    Impedance Test

Impedance testing is done in order to check the impedance between different nodes and the components of the Printed Circuit Boards (PCBs). The impedance should not be offset to the specified limits.

     9)    Ionic Contamination Test

The Printed Circuit Boards (PCBs) during manufacturing and developing process can be contaminated with ionic impurities which can lead to the decrease in the impedance of the Printed Circuit Boards (PCBs) which can cause operational ambiguities. In order to avoid any unforeseen circumstances, the ionic contamination tests are performed.

Metal Core Printed Circuit Boards

Metal Core Printed Circuit Boards

Printed Circuit Board (PCB) can be classified into three categories if the criteria of classification were to be made the core material of the PCB. The Printed Circuit Board (PCB) are available in ceramic based core material, FR-series or fire retardant series of the core material and the Metal core Printed Circuit Board (PCB) or most commonly known as MCPCB. The most commonly used Printed Circuit Board (PCB) is standard FR4 boards which have various fire retardant material as their core. FR4 or FR-4 is a NEMA used for the glass reinforced epoxy laminate material which is commonly used in standard Printed Circuit Board (PCB) used in the PCB industry.

Ceramic Printed Circuit Board (PCB) or CPCBs

The second type of PCB is the ceramic Printed Circuit Board (PCB) or the ceramic core PCBs. The ceramic PCBs are used for high temperature, pressure, frequency operations. They provide greater insulation and are highly reliable as compared with other type of the PCBs. The ceramic Printed Circuit Board (PCB) are mostly used for minor volume production of the electronic devices as for high volume production it is more economical to use the standard FR-4 type PCBs. The composition of ceramic Printed Circuit Board (PCB) is usually alumina aluminum nitride and beryllium oxide. The conducting material used in ceramic Printed Circuit Board (PCB) is either copper or silver palladium. 

Metal Core Printed Circuit Board (PCB) or MCPCBs

The third type of the Printed Circuit Board (PCB) is the Metal Core Printed Circuit Board (PCB) or MCPCB. The metal core PCBs have some metal as their core which mostly range from Aluminum, Copper and steel alloy. All three metal cores have either own advantages and are used for their specialized purposes. The aluminum core has greater heat transferring and dissipating capabilities and it is also relatively cheaper as compared with copper and silver. Copper has better overall properties as compared with aluminum but it is more expensive. Steel is more rigid and provides greater stability to the core as compared with aluminum and copper but its conducting properties are inferior as compared with copper and aluminum. Making the comparison, it can be analyzed that aluminum is more suitable and economical to be used as compared with silver and copper, so most of the Metal Core Printed circuit boards make use of the aluminum core.

The metal core PCBs are also referred to as the metal backed PCBs, metal base or metal clad PCBs.

Advantages of Metal core Printed Circuit Board (PCB)

The main advantage of Metal core Printed Circuit Board (PCB) over ceramic and FR-4 type of Printed Circuit Board (PCB) is their ability to dissipate heat more efficiently away from the components on the circuit board, hence in turn saving the components from overheating and damage. In most LED applications, metal core Printed Circuit Board (PCB) is used because of its ability to dissipate heat generated in the LED circuitry. In this case if the heat were not properly dissipated, it would cause severe damage and output inefficiency for the system. In this case, the main purpose of the metal core is to dissipate the heat away from the board so as to protect the system.

The second advantage of the metal core Printed Circuit Board (PCB) over the other kind is their better coefficient of thermal expansion. Thermal expansion and contraction is the inherent nature of the material and most material suffer from it. The aluminum core Printed Circuit Board (PCB) on the other hand has greater ability to without such changes under severe circumstances.

The third bigger advantage of the metal core Printed Circuit Board (PCB) is their dimensional stability. Even at high temperatures and severe conditions, the size change of the metal core PCB is minimal as compared with the other type of the PCBs.

Applications of Metal Core Printed Circuit Board (PCB)

The metal core Printed Circuit Board (PCB) are used in major applications such as LED lights, cars, amplifier and audio systems, printers, switching electronic devices.

The metal core Printed Circuit Board (PCB) is also further divided into five categories depending on the location of the metallic core and the layers of the Printed Circuit Board (PCB). The five categories are named as single layer, chip on board, double layer, double sided and multi layer metallic core Printed Circuit Board (PCB).