Saturday, March 15, 2008

Big Bang in a Lab

Aeons before humans started to gaze into the star studded sky and tried to gauge the depths and mysteries hidden in the gigantic universe and reasoning the most basic philosophical questions of our existence. Who are we? Why are we on Earth? Is there more than one Earth? What are the basic laws governing the universe? What are we made of? And many more fascinating questions to ponder upon.

We have come a long way from that age, and as we make progress into the future, we still gaze with the same excitement and awe into the deep wells of the Universe, trying to unravel new worlds and knowledge. The naked eye has been substituted with the Hubble Telescope, taking us to the beautiful galleries of the Universe beaming back at earth, pictures of the new born Universe, star births and deaths, galaxies, and the wonderful workings of the universe. Moreover, as physicists and astronomers try to stitch a working model of universe with theories and experiments, they take humanity to a new level of comprehending our surroundings and our universe.

Hubble Telescope

It all started with the Big Bang theory. The term was framed by Sir Fred Hoyle on a 1950 BBC Radio Show, a British Astronomer, in derision of the theory, which he never acknowledged and rejected it completely. Big Bang Theory came into existence by the works of Georges Lemaitre, George Gamow, Ralph Alpher and Robert Herman. But, the most important consitituent of these works was Hubble’s law. Hubble’s law states that the recessional velocity of the galaxies and distance between galaxies are linearly related. He discovered the law observing the red shifts in the spectrum of the lights received from distant galaxies, meaning the light was shifting to longer wavelengths. Plainly speaking, it meant that either we are the center of the universe and everything is receding from us, or that the universe is expanding. But we cannot be at the centre of universe, since it violates the Copernican Principle. Big Bang theory worked upon this analysis that the universe started from a singular point of infinite mass and density and an explosion started the expansion of the universe, which explained the expansion of the universe. And as we gained further knowledge, we got many more clues that Big Bang might be the right explanation of the existence of the Universe. The accidental discovery of the Cosmic Microwave background noise in 1964 by Arno Penzias and Robert Wilson, while working on a new microwave receiver at Bell Laboratries, increased credibility to the Big Bang Theory. They both were awarded Nobel Prize for their discovery. Findings by Cosmic Background Explorer satellite(COBE) launched by NASA in 1989, also reported findings which were consistent with the Big Bang Theory.

The theory of Big Bang raised many more questions for humans to ponder upon, leading to more theories that tried to better define our fundamental understanding. Particle Physics is that field of physics that looks into the fundamental constitutents of matter and radiation and their interactions. Its like answering the question- if the Universe were indeed created by a huge explosion, were there particles formed in that explosion which were the fundamental ones which changed into us and everything around us. It‘s trying to go into the realm of sub-atomic particles which are the building blocks of protons, neutrons and electrons of which atoms are made of, the building block of everything in existence. It’s not easy to study these fundamental particles in nature as they do not exist in normal conditions, i.e. absence of astronomical pressures and temperatures. To create such conditions, in lab, we need to build a device which can somehow accelerate these particles to the velocities of light(3 × 108m/sec) and in temperatures near absolute zero(-273 ‰). When the atomic particles are accelerated at such high speeds and collide , they fragment into sub-atomic particles releasing huge levels of energy and a glimpse of their world. Particle Physicists try to capture such subatomic particles and study them in detail (if they can capture them) or confirm their presence (if they can’t capture the particles), thus validating or refuting the existing theories or try to modify them.

A paper published in 1905, On a Heuristic Viewpoint Concerning the Production and Transformation of Light, by a young physicist, Albert Einstein, changed the whole dynamics of our fundamental understanding of the world. He described a particle, namely photon, in this paper. This led to an important contribution to the evolution of quantum physics, winning him his Noble Prize for this discovery and not for General Relativity, as most people falsely associate him with. After decades of hard work and toil, physicists have found till date, 24 fundamental particles according to the Standard Model theory as the fundamental or elementary particles. The theory tries to create a model by merging three of the fundamental forces in nature, namely, Weak-Nuclear, Strong-Nuclear and Electromagnetic. There has been on going research for the last 30 years to include the last fundamental force of gravity to create a Grand Unified Theory, which will be able to provide answers to all the fundamental forces at work. All the fundamental particles can be classified into either fermions or bosons, depending on the spin. The particles associated with the matter are fermions and particles which generate forces are bosons. That means fermions’ interactions are mediated by bosons. All of the particles hypothesized in the Standard Model have been empirically observed in the laboratory conditions. However, one particle called the Higgs Boson has been providing researchers with difficulty to be studied in the lab conditions because the energy required to produce it is enormous, making it impossible for scientists. Why is the Higgs Boson, so important a cog in the wheel of the Standard Model? The answer to this question lies in the unique relation of the Higgs Boson with other elementary particles. Higgs Boson can explain the mass origins of the other fundamental particles, there by helping scientists to compare the masses of heavy bosons with photons and other elementary particles.

The search of this elusive particle, Higgs Boson, led one of the major research organizations, The European Organization for Nuclear Research, more commonly known as the CERN to come up with an innovative design experiment called as LHC1. This lab is a state of the art research lab located at CERN in Geneva, Switzerland. Currently, under final stages of construction, LHC is one of the most awaited ambition of man to quantify the inner most workings of the Universe, etched in tonnes of steel. This lab is in a 27 km, 1Large Hadron Collider circumferential length circle, ranging from 50m to 175m in depth, covering two nations, Switzerland and France, with the major part of tunnel being in France. Once it is commissioned, it will be the World‘s largest and highest energy particle accelerator. The lab consists of a plethora of equipments. But, the most critical ones are the Supermagnets and the pipe assembly in which the protons will finally travel before the small big bang in the lab. To allow for the Supermagnets to work and for simulating the right conditions before accelerating the protons, the whole assembly has to be chilled to a temperature of 1.9 K (-271 ‰) making it the coolest place in the whole universe. This cooling is achieved by first cooling with Nitrogen(-196 ‰Boiling Point) and then with special freezing units and pumps, liquid Helium is used to achieve the required temperature at a pressure of 15 millibar. At this temperature, the liquid Helium becomes superfluid, i.e. it has no viscosity, hence achieving high heat transfer rates. The gargantuan effort for realizing this dream can be gauged in the numbers, which say a story for themselves. The whole assembly contains 1700 Magnets with 40,000 leak-tight welds (if converted to length would amount to 10 km!) and 65,000 splices of superconducting cables. The lab is divided into eight sections, each of which were commissioned separately and will be cooled to the absolute zero. Once all the ingredients are put in place, the proton beams will be accelerated using powerful SuperMagnets to upto 7 Tev (each proton) resulting in total 14 Tev2. Also, special measures have been taken to make the generated data (it will produce roughly 15 petabytes (15 million gigabytes) of data annually enough to fill 100 000 DVDs a year! ) widely accessible for the scientists all over the world for analysis. For this, a powerful data streaming architecture has been put in place, namely GRID, which will be able to stream around 1800 Megabytes/sec. Around 7000 scientists from eighty countries will have access to the LHC, with the largest contingent of 700 scientists from US. The project of LHC was conceived in the early 1980’s and the project was approved in 1994. The total project cost has been estimated to be about 6 billion US dollars.

There has also been some speculations about the risk associated with the experiment. There can be a possibility of producing micro black holes inside the assembly, which some claim can lead to catastrophic results. But scientists at CERN have dismissed these fears, stating these fears are not genuine, 2Tev stands for Tera electron volts and very strict measures have been installed for the safety. LHC As May 2008 approaches, the whole scientific community and the world waits with bated breath for a spectacle which can lead us to a new future of understanding and a new level to man’s eternal quest for answers…

Vittoria Vetra:

Religion is like language or dress. We gravitate toward the practices with which we were raised. In the end, though we are all proclaiming the same thing. That life has meaning. That we are grateful for that created us.
Robert Langdon:
So you‘r saying that whether you are a Christian or a Muslim simply depends on where you were born?
Vittoria Vetra:
Isn‘t it obvious? Look at the diffusion of religion around the globe.
Robert Langdon:
So faith is random?

Vittoria Vetra:
Hardly. Faith is universal. Our specific methods for understanding it are arbitrary. Some of us pray to Jesus, some us go to Mecca, some of us study subatomic particles. In the end we are all just searching for truth, that which is greater than
ourselves. (Angels and Demons, Dan Brown)

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