Throwback 1900

Posted: August 15, 2013 in Uncategorized

Aristotle believed that everything in the world was composed of four basic elements – earth, water, fire and air. He also suggested the nature of forces that acted upon these elements, gravity – which caused earth and water to sink, and levity – which caused fire and air to rise. No matter how primitive and vague his concept was, it is still very consistent with our division of particles of the universe into matter particles and force particles. Aristotle believed that matter particles were continuous and there was no stopping point at which matter could be divided further. Democritus and Leucippus on the other hand, considered matter to be discrete and being composed of small units called atom (atom in greek means indivisible).

For centuries there was no real evidence to prove whether matter was continuous or discrete. In 1803 a British physicist, John Dalton, hinted the fact that chemical compounds always combined in certain proportions could be explained by grouping together of atoms to form units called molecules. In 1897, another British physicist, J. J. Thomson demonstrated the existence of negative charge in matter particles with his cathode ray tube experiment. Still, the structure of atom was quite vague as one couldn’t comprehend the origin of the negative charge. But it was clear at this point that atom was not in fact the smallest unit.

One of the important pieces of physical evidence was provided by Einstein. In a paper written in 1905, a few weeks before the famous paper on special relativity, Einstein pointed out that what was called Brownian motion – the irregular, random motion of small particles of dust suspended in a liquid could be explained as the effect of atoms of the liquid colliding with the dust particles. Later in 1911, another British physicist, Ernest Rutherford corroborated the existence of elementary particles within an atom. With his alpha-particle bombarding experiment, he proposed that atoms comprise of a very small and dense region composed of positive charge – the positive charge being proton and the dense region being the nucleus. He inspired the idea of the structure of atom. After James Chadwick, in 1932, discovered neutron, the structure of atom became explicit, with proton and neutron forming the nucleus and electron spinning around the nucleus – the solar system model.

One thing worth contemplating is that until 1930 physicist like Einstein and Schrodinger didn’t even know how an atom looked like, however they were able to formulate theories that had ground breaking implications and far reaching and elegant enough to be still consistent with the model of atom, the universe and other theories. Perhaps, you do not need to know many things to revolutionize the world.

Reference: A Brief History of Time – Stephen Hawking

Special theory of relativity is an extension of Galilean relativity. In simple, Galilean relativity states that if you are in an object that is moving at a constant speed, you won’t be able to tell whether you’re at rest or motion. For instance, we don’t feel any motion sitting in a planet that is rotating around the sun at a speed of 30km/sec. Einstein special theory of relativity takes the relativity perspective to a different dimension by incorporating the speed of light and its effect on time and object. Some famous corollaries of this theory include the feasibility of time machine and time travel, a yard stick that would contract and expand depending on its velocity etc. This is the best video explanation of Einstein Theory of Relativity I’ve found in the web. Enjoy the video, it is worth the time:


PS: Feel free to can leave questions in the comment section.

Video  —  Posted: June 10, 2013 in Science
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Do you ever ponder upon dreams? And how it gets so fascinating and surreal? Real, scary, living up some fantasies and sometimes quite mysterious than your day to day experience. That’s dream. One of the other thing that bewilders me is the time we travel. There are so many incidents happening, your brain goes through so many ideas and processes it in a relatively short time. Literally, your brain is working many times faster than when you are conscious.

The aspect I really like about dreams is the fact that I can do multiple things in a small time period. Last week when I was traveling with two of my friends from Boca Raton to Miami, I felt asleep on the way in the backseat of the car. While sleeping I had this crazy dream of winning the lottery of 350 million, which I saw in an advertising board on the way, but wasn’t able to enjoy the money for some god forbidden reasons. After waking up, I asked my friends to go to a nearby store and purchase the lottery ticket.

Well, I did not win the lottery, but that is not what’s it’s about. I slept for 7 minutes, from 9:35 to 9:42, and in this 7 minutes – I bought the lottery, won it, got the money, tried to use the money, but no one allowed me to spend the money, and there was so many drama, which is not worth mentioning here.

It makes me feel that one’s brain is a highly powerful machine that can operate much faster that the real world clock. And it is this world that is confining one’s brain and limiting it’s performance. Will we be able to think much faster if we were in a different world driven by different physical parameters, different gravitation force, different speed, different constraints? Well may be! I feel that when we fall asleep here, our another side becomes active in a parallel world. The parallel world operates much faster, and is similar to the real world, and populated by people we know here, except the fact that the physical limitation has already been defied by technology and evolution. The another side of you doesn’t need much time to carry out its daily routine, as the difference in time is huge. Say, a 5 second in earth is like a 5 hour in the parallel world. Sleeping here for those 7 minutes, I practically lived for 7 hours or 7 days or even 7 years in the parallel world. And we always do that as we sleep – live up our inner desires and ambitions or encounter some noble incidents that we have not yet experienced, all in the parallel world. We call them DREAMS.

PS: Everyone must have experienced free falls while dreaming – falling off a cliff or a building and never reaching the bottom. You never reach the ground! It gets so real, yet mystic because our brain cannot process things in other dimension greater than 3D. String theory asserts that there are 11 dimension, 8 of which we don’t know. The parallel world probably operates in a higher dimension, say 5D or even 11D.

The Scripted World

Posted: March 25, 2013 in Science

Do you believe that your actions have already been fixed? In fact whatever you do in future is bound to happen irrespective of your will. For instance you are reading this article because you were destined to read it, and I wrote it because that was my destiny as well. The idea seems quite bizarre, but there’s a majority of physicists that believe it’s true. Since everything is made up of the same elementary particles just with different composition and concentration, the behavior of every matter and the way in which everything occurs must be explicable and defined. Therefore what you do, in fact whatever happens in this world – the atomic bomb, the world war, advent of computers, airplanes etc. has already been scripted 13 billion years ago, right at the time of the big bang.

Well if this happens to be true, things and cases it ensues can get quite complicated. One cannot be blamed (or accredited) for his actions, as he was destined to do it. For instance, a murderer or criminal should not be held responsible for the tragedy and must be exonerated from his crimes if this is true. Now the world can be a real disturbing place to live in. This created a huge contention among scientists of the 19th century. Einstein opined that a person should be no matter held responsible for his/her actions no matter bad or good, and a criminal should be punished accordingly. He said it was necessary to do so in order to maintain stability in the world. Otherwise, the world would run into riots.

This entails an interesting relation between religion and science. Now as religion, indeed every religion, believe in destiny and fate, and god deciding all the events and happenings that take place in this world – science seems to be justifying it. But with scientific reasoning, of course. Well I’m not an advocate of religion trying to impress or urge you to believe in it with my hypothesis. Personally, I won’t reject nor believe in the possibility of existence of god. If you ask me, throw me into the agnostic category.

So was Einstein a genius, or just an extremely lucky man to have been chosen to formulate those equations?

Perplexed I am. Constantly. Eternally.
Absurd obsessions profoundly grounded.
Mystic is this star dancing around. Mystic is this world.
Only if you look closely, you’ll see.
Take my eyes, take my mind.
Comprehensible enigma toys me throughout,
Incessant thoughts turn into crazy dreams,
Seeking unobvious answers;
Willing to solve the missing elusiveness;
Willing to elucidate the prevalent ignorance,
Blinded by orthodoxy, blinded by lack of imagination.
Futile venture you may call,
Trivial you may call.
Trivial I am.

Trash talk:

On contrary to the title, that is pressing you to skip this article RIGHT AWAY, you might well give a second thought to actually go through the context that has been described further, simple enough to be understood, even by a layman. For the love of science, I hope this article serves as a wonderful experience to your learning process.

Background:

The advent of satellite-fiber network dates back to 1965 when Intelsat launched the first commercial satellite. They proudly paraphrase this as ” Nasa put a man on the moon, and the world watched it happen via Intelsat”. It can be regarded as a breakthrough in the field of modern satellite-fiber communication system. Although optical fibers only came into extensive use since the early 90’s, the need for a cheaper and efficient system became prevalent, as neither satellite nor copper cables could suffice the need for the growing bandwidth. Cost of service being the other instigator.

Introduction:

Satellite-Fiber hybrid network is a seamless integration of satellite and fiber network that offers enhanced data rate, dynamism, robustness, flexibility and many more features that can’t be achieved by either of the network individually. A satellite-fiber network works in coordination with each other, such that, information sent through one of the network can be easily transferred to other for convenience. The transmission of information may take multiple interplay between them before being broadcasted. Information received over fibers may be transferred to satellite through antennas and then back to fibers, and vice-versa.

Satellite communication is a highly expensive form of communication system that offers much less bandwidth compared to Fiber networks. However in regard to reliability, security, mobility and availability of service, satellite communication holds its eminence aloft. Therefore, satellite communication is extensively used in military and scientific purpose. Fibers, on the other hand, offer higher bandwidth and transmission rate at a much, much cheaper rate compared to satellites. Data being transmitted in the form of light, invulnerability to external noise and interference is another advantage that fiber edges over satellite. However, one must have to endure network-complexity and the constant maintenance issue entailed by fibers.

Optical Fiber Network:

An optical fiber is a transmission medium that enables information to be sent through it in the form of light. It is made up of silica or polymer. Polymer fibers are generally used because of the durability and flexibility.  An optical fiber is composed of three layers –

  • Core
  • Cladding
  • Buffer Coating

The core is the inner-most part of the fiber. It is the very medium through which information is transmitted. The diameter of the core varies on the nature of fiber. It ranges from 8 micro meter to 100 micro meters (or more). The core material is made up of silica or polymer. The refractive index of the core and cladding determines the angle of incidence at which the light signal must strike the fiber core.

Optical Fiber Layers

Cladding is a protective layer that encloses the core to maximize fiber strength and microbend resistance. It also prevents the light signal from straying away from the core. The material used for cladding should always have a refractive index lower than that of the core in order to attain total internal reflection. Also, the absorption coefficient of the cladding material must be low to prevent diffraction. The buffer coating offers enhanced durability to the fiber. It, along with the cladding, protects the core from physical and environmental damage.

On the basis of their working methodology, optical fibers can be broadly classified into two types:

  • Single-mode fiber.
  • Multi-mode fiber.

The classification is merely based on the nature of transmission of light inside the fiber. In the single-mode fiber, a highly directed light wave is sent through the fiber, perpendicular to the fiber surface to prevent the light from dissipating. Hence, the light travels along a straight path. The source is usually a laser device or an ultra-high frequency LED. Single-mode  fibers are used in cases where high transmission rate and low interference is expected.

As the name suggests, multiple signals i.e. a beam of light is sent through the core in case of multi-mode fibers. Consequently, multi-mode fibers offer higher bandwidth. Thus is used in general purposes.  However, multi-mode fibers are affected by ISI (Inter Symbol Interference) and Diffraction that deteriorates the system due to noise, signal overlapping and transmission delay. Graded index multi-mode fiber is a solution and a better form of multi-mode fibers.

Satellite Network:

A satellite is a geo-stationary object that revolves around the earth in a fixed orbit. It constantly exchanges information with the ground station in the form of RF signal. Satellite communication was primarily used for telecommunications and scientific purpose because of their expensive rate of service. Gradually they became more commercialized as the need for exchange of information in geographically remote couldn’t be accomplished by cable networks. The cost required to install a satellite in outer space and the need for a highly powerful transmission system in order to send information over such a long distance, imposes expensive service rate for satellite communications. A satellite communication system comprises of two terminals:

  • Earth terminal (also known as ground station or earth station).
  • Satellite terminal.

Satellite network

The earth terminal acts as a hub for data exchange between the satellite and the other communication channels. An antenna, maintained at line-of-sight with the satellite, is used to interact with the satellite. The signal received by the antenna is sent to the processing unit that processes and records information constantly. If the information needs to be sent over optical fiber, it is first converted into respective form and then transmitted. This forms a satellite-fiber network.

The link between the earth station and the satellite is called an uplink. An uplink is a channel that serves as a medium when an earth station transmits data to the satellite. Similarly the link between the satellite and the earth station is called a downlink. A downlink is a channel that serves as a medium when a satellite sends data to the earth station.

Implementation:

Satellite is effective in delivering point-to-multipoint coverage i.e. broadcasting, while fiber is more efficient to route point-to-point traffic. A satellite-fiber network is used in conjunction with each other to deliver information. However due to the difference in the nature of transmission one must always take in consideration – the data conversion process.

Satellite-Fiber Network

Information is sent in the form of RF signal in case of satellite. While in fiber communication, data is transmitted in the form of light. Hence, it must be converted to respective form before transmission. Also it must be noted that fibers offer much higher bandwidth compared to satellite. Therefore, the amount of information sent through fiber cannot be handled by satellite simultaneously. Hence, proper data scaling must be done before transmission i.e. before forwarding the data from fiber to satellite, it must be converted to a lower rate and vice-versa, expecting transmission delay.

The four fundamental forceUntil the 19th century, it was believed that there was only two force that defined the mechanism behind everything: the gravitational force and the electromagnetic force. The Gravitational force is defined as the force that acts between two bodies with mass, and is defined by Newton’s famous equation: F = k*G1*G2/D^2. It is the force that keeps two things together and explains the movement and positions of heavenly bodies, and most importantly keeps us attached to the ground surface.

The Electromagnetic force is the one that explains almost all phenomena in the world, except gravity. It was discovered by Michael Faraday, and later on revised by James C. Maxwell. The electromagnetic force is comprised of the Electrostatic force and the Magnetic Force. Atoms are electrically neutral, but when two materials are bought in contact, electrons from one body is transferred to other developing an Electrostatic force between them. For instance a balloon clings to our sweater if we rub it. In this process, the sweater (made of wool) is likely to lose electron while the balloon (made of rubber) is likely to accept electron. Magnetic force is similar to electrostatic force. Like in case of charge, opposite pole attract each other while similar pole repel. Electrostatic and Magnetic force are interrelated phenomena that cannot be addressed separately, as changing one of them causes change to the other. Taking both of this inseparable phenomena into account, Faraday postulated his laws of electromagnetism. In simple terms, it said that a change in electric field, develops a magnetic field and vice-versa. Here’s a short video demonstration: https://www.youtube.com/watch?feature=player_detailpage&v=cy6kba3A8vY#t=75s

From propagation of electromagnetic wave such as light, RF, microwave etc to the binding of electrons in the nucleus, and simply, the working of my laptop that I’m currently using to upload this post, which uses electricity generated by rotating that turbine by those water molecules, by causing a change in the magnetic field in that hydroelectric cell – the laws of electromagnetism governs almost everything.

“Einstein regarded Maxwell as the most profound contributor in physics since Newton.”

According to Electromagnetism, like charges repel while unlike charges attract. This, however, contradicted with the structure of atom, as in atoms positively charged protons stay together inside the nucleus. To explain this phenomena, scientists discovered a force called the Strong force that kept the proton and neutron in the nucleus from busting apart. As the name suggests, the Strong force is so strong, it undermines the electrostatic force between the protons and holds them inside the nucleus. The Strong force is extremely complicated, and one must have the knowledge of fundamental particles such as hadrons, quarks, gluons etc to understand the process. Briefly explaining, Proton and Neutrons are called Hadrons and are composed of 3 Quarks. Proton is composed of 2 Up quarks (+ve) and 1 Down quark (-ve), while neutron is composed of 2 Down and 1 Up quark. Gluons are Strong-Force charge carriers that interact with the quarks and makes them change their Color. Gluons are extremely powerful particles, that prevent the quarks from straying away, thereby stabilizing the nucleus.

The Weak force, as the name implies, is the weakest of all fundamental forces and acts over a very tiny range. The weak force explains why some atoms undergo radioactive decay, the process that fuels every star in the universe, and indeed keeps the sun shining. Just like the strong force that changes the color of the quark, weak force changes the Flavor of the quark, by the impact of force carriers. The force carriers in weak force are called Bosons that interact with the quarks. Briefly explaining, Bosons are of two types – W boson that is either +ve or -ve, or Z boson that is electrically neutral. When a -ve W boson comes in contact with a Proton (you know what quarks Protons are made up of right? If not, see paragraph above), the proton changes to a neutron, as the -ve W boson changes the quark flavor of the proton from 2 Up and 1 Down to 1 Up and 2 Down quark. With change in the number of protons and neutrons, the atom as a whole changes i.e. decays to a more stable form.

I hope you understand the 4 fundamental forces of physics now, if not, at least the top two. The strong and weak force is fairly complicated to comprehend without knowledge of quantum particles. However, to simplify the matter, I’ll write about the fundamental particles, explaining its characteristic and behavior in detail in my next blog.