Superstrings connect : What Happened Before The Big Bang

What is the fundamental thing that makes up matter? Do extra dimensions exist? If they do, where are they? Do parallel universes exist? How our visible universe was created?

Imagine you could find an explanation for everything in the universe, from the smallest events possible to the biggest. This is the dream which has captivated the most brilliant scientists since Einstein. But to make the dream true they needed “The theory of everything” which will unitie all the four fundamental forces into a single equation. The four forces (gravity, electromagnetism and the strong and weak nuclear forces) would be unified by an equation perhaps one inch long. During the last thirty years of his life Albert Eienstein sought, relentlessly for this theory and he came up empty handed and once said “Nature shows us only the tail of the lion”. But now scientists says that they have got that theory and that is the super string theory.

In the heart of string theory:

Think of a guitar that has been tuned by stretching the string under tension across the guitar. Depending on how the musical notes will be created by the string. These musical notes could be said to be excitation modes of that guitar string under tension.In similar manner, in string theory the elementary particles could be thought of as the musical note or excitation modes of elementary strings.So, roughly speaking everything in the universe in made of tiny strings, because the sub-atomic particles are really just resonance or vibrations of a tiny string.In string theory as in guitar playing, the string must be stretched under tension in order to become excited. The strings are floating at space time.If string theory is a quantum theory of gravity(it’s a theory which can unifie General Reletivity & Quantum mechanics, where general reletvity explains the largest events & quantum mechanics the smallest thing in the universe) then the average size of a string is about 10*-33 centimeters, or about a millionth of a billionth of a billionth of a billionth of a centimeter. Unfortunately, this means that the strings are too small to see by current or expected particle physics technology.There are both open & closed looped strings.

Extra dimensions:

We live in a universe of three dimensional space (3D), or can say four dimensional space-time. It means we can move back-front, up-down & left-right in these three ways. With these three dimensions adding time we get four dimensional (4D) space-time. But string theory says something different, strange and amazing.If a string has to oscillate properly if needs ten dimensions! Yes ten dimensions. But where are the extra six dimensions? Super string theory gives the answer. The extra six dimensions are compactified. The best way to draw this is to use complicated 6D geometry called Calabi-You manifold, in which all the intrinsic properties of elementary particles are hidden.There are infinite number of ways to wind a string around and extra dimension. Each way in topologically described by an integer called winding number, which can be positive or negative depending on the orientation of the string.
Five theories of everything!At first of early nineties there was total five distinct string theories in 10D space.The theories are So (32), Type I ,IIA,IIB & E8 X E8 heterotic.In that time string theory was said as “The theory of everything”. But it has five types. So it there are five theories of everything! and it is really impossible because we need only one. Besides Michel Duff (University of Michigan) and his team combined gravity and super symmetry which is called supergravity. Their equation said that totally there will be .11 dimensions where string theory said 10. So with everything string theory was in an embarrassing position. They were trying to add the eleventh dimension. It might rescue them.
Brane world:In 1995 Joe Polchinski of the University of California in Santa Barbara electrified the string-theory community with a major discovery that has subsequently impacted every field of physics. He discovered D-branes.D-branes are surfaces where the free ends of open strings are fixed. They come in various dimensions. 0.2-branes for example are two dimensional and can also be called D2-membranes, or super membranes. D0-branee are like particle like and D1-branes are string like. Higher dimensional objects can exist as well. D-branes are essential for making string-theory mathematically consistent, and have far-reaching implications for a theory of quantum gravity.

M-theory:

At last scientist’s were able to add the last one dimension, the eleventh dimension and something happened remarkable — the five theories turned out to be simply different manifestations of a more fundamental theory. It means in 11 dimensions looking from the mountain-top, looking down you could see string theory as being part of a much larger reality, reality of eleventh dimension.So with the addition of one extra dimension string theory made sense again, but it had become a very different kind of theory.Here the tiny invisible strings of string theory stretched and they combined. The astonishing conclusion was that all matter in the universe was connected to one vast structure: a membrane. In effect our entire universe is a membrane. The quest to explain everything in universe could begin again and at its heart would be this new theory. It was dubbed membrane theory or M-theory, but so enigmatic and profound did the idea seem that some thought ‘M’ should stand for other things as — magic, mystery, majesty, madness or mother theory. This is the mother of all superstring theories.

The 11th dimension:

With M theory it seemed at least there was a theory which might explain everything in the universe, but before they could decide if this was true the scientists needed to know more about this new eleventh dimension. It quickly became clear it was a place where all the normal rules of commonsense have been abandoned. For one thing it is both infinitely long but only a very small distance across.Scientists like Paul Steinhard (Princeton University) and Burt Or rut (University of Pennsylvania) tell that this 11th dimension exists only one trillionth of a millimetre away from every point in our three dimensional world. So it’s closer than your clothes to your body and yet we can not sense it. In this mysterious space our membrane universe is floating. At first no one could imagine how that worked. Then some suggested it might float like a thin rubber sheet. Others that it might be more like a bubble which vibrated as it was blown aimlessly across space. But is our universe alone or there are parallel universes? Let’s explore it. The journey began with Lisa Randall.

Parallel Universes:
Lisa Randall (Harvard University) had been fascinated by an apparently inexplicable phenomenon: the weakness of gravity.We know there are four fundamental force in our universes. If we assume the intensity of gravity ‘1′, then the intensity of weak Nuclear Force-10*30, strong Nuclear force- 10*40 and strong Nuclear force-10*42 (42 zero after 1). So gravity is extremely weaker than the other three forces. Now you might look around and say gravity does not seem weak, but if you think about if you have the entire earth pulling on you and yet can manage to pick things up.When M Theory emerged, Randall and Sundrum (John Hopkins University) wondered if it might be provide and explanation. Could gravity be leaking from our universe into empty space of the eleventh dimension?Randall tried to calculate how gravity could leak from our membrane universe into empty space, but she couldn’t make it work. Then she hard a theory that there might be another membrane in eleventh dimension. Now he had really strange thought. What if gravity was not leaking from our universe but to it? What if it came from that other universe? On that membrane or brain, gravity, would be as the other forces, but by the time it reached us it would only be a faint signal. Now when she reworked her calculations everything fitted exactly. So our gravity is just a weak signal leaking out of another universe into ours which spends most of the time near the other brane. We only feel the tail end of gravity.The weakness of gravity could at last be explained, but only by introducing the idea of parallel universe. Randall’s idea opened a pandora’s Box. Now suddenly physicists all over the world piled into the eleventh dimension trying to solve age-old problem and every time it seemed the perfect explanation was another parallel universe. Everywhere they looked it seemed they began to find more and more of them.within no time at all eleventh dimension seemed to be jam packed full of membranes. These membranes were possible other parallel universes. In those universes there may be people like us or not, may be different kinds of laws of physics.So M-theory was getting more and more stranger. But could it really be a theory which explained everything in our universe? Did it answered what caused the Bigbang, it mean the explosion from which our universe was created?

Before the Big bang:
Imagine there is an enormous ship standing at harbour which is 150 or 200ft high. This giant wave suddenly jumped from sea surface to air & crushed its windows. It means from 2d to 3d. Burt ovrut suggested our universe is moving through the eleventh dimension like giant, turbulent waves.Burt’s idea caught attention of the physicists and cosmologists. After a conference in Cambridge in which he explained this idea first time, Neil Turok (Cambridge University), Paul Steinhurdt and Burt decided to discuss about bigbang. Started to throw ideas. Suddenly they knocked at the right door and the mystery of bigbang opened.The idea was——-If two brains collide each other then it produces all the effects of early universe. It means Bigbang is the result of the collision of two brains or parallel universes. But the problem was things are not smooth out in our universe. In fact we have little clamps, we have galaxies & lumps of matter. Now they had to explain how the collision of two parallel universe could go on create these lumps of matter. Could they solve it?Yes, they solved it. They answer was — people tended to think of brains as being flat perfect sheets, geometrical plains, but the picture could not be correct. It cannot be perfectly flat. It has to ripple. When the rippling brains approach to each other and collide they don’t hit at exactly the same time, same place, but in fact they hit at different points and at different times. This rippling collision produces lumps of matter.So they finally had their complete explanation of the birth of our universe and the latest understanding of the universe is that there could be infinite number of universes each with a different laws of physics. Bigbangs probably take place all the time. Our universe co-exists with other universes which are also in process of expansion. Our universe could be just one bubble floating in an ocean of other bubbles. Perhaps out there in space there is another universe heading directly towards as — it may only be a matter of time before we collide.

Referance:

Elegent Universe-Brayan Greene

Superstrings-Leonerd Susskind http://www.physicsweb.com/

BBC science & nature

Image courtesy :

Google image

The Sun

Courtesy: Google images

Large Hadron Collider

At last after 20 years of preperation the mysterious ring is almost ready with its 1232 superconducting magnets to
guide the protons at almost the speed of light. Yes I am talking about theworld’s most powerful particle accilerator,LHC-
THE LARGE HADRON COLLIDER., which is scheduled to switch on in the November at CERN(EUROPEAN CENTRE
FOR NEUCLER RESEARCH) near Geneva, Switzerland. Physicists will then combine results from the LHC experiments
with insights from their theoretical investigations to explore phenomena whose effects are only detectable at small distances
and high energies. The theory known as the Standard Model of particle physics describes all known matter and the forces through
which it interacts. Experiments have thoroughly tested the Standard Model, and its basic ingredients are almost certainly
correct. But the Standard Model cannot be the final word: it leaves open important questions about the origin of elementary
particlemasses and puzzles such as the relative weakness of gravity. The LHC will help to resolve these mysteries, and
scientists all over the globe are busily preparing experiments they hope will provide answers to these questions. Perhaps
the most exciting proposal for extending and completing the Standard Model involves additional hidden dimensions of
space beyond the three dimensions with which we are all familiar: up-down, left-right, and forward-backward. The premise underlying particle physics is that elementary particles constitute the building blocks of matter.
Peel away the layers, and inside you will always ultimately find elementary particles. Because of Einstein's E=mc2 equation,
which states that energy (E) is equal to mass (m) multiplied by the square of the speed of light (c), we need high energies to create
particles with big masses. The LHC will produce enormous amounts of energy that can then be converted into particles
we would never find in any other way.

THE LHC:

The collider is contained in a 27 km circumference tunnel located underground at a depth ranging from 50 to 150 metres The tunnel was formerly used to house the LEP an electron-positron collider. The 3 metre diameter, concrete-lined tunnel actually crosses the border between Switzerland and France at four points, although the majority of its length is inside France. The collider itself is located underground, with many surface buildings holding ancillary equipment such as compressors, ventilation equipment, control electronics and refrigeration plants.
The collider tunnel contains two pipes enclosed within superconducting magnets cooled by liquid helium, each pipe containing a proton beam. The two beams travel in opposite directions around the ring. Additional magnets are used to direct the beams to four intersection points where interactions between them will take place.
The protons will each have an energy of 7 TeV, giving a total collision energy of 14 TeV. It will take around 89 microseconds for an individual proton to travel once around the collider. Rather than continuous beams, the protons will be "bunched" together into approximately 2800 bunches, so that interactions between the two beams will take place at discrete intervals never shorter than 25 nanoseconds apart. When the collider is first commissioned, it will be operated with fewer bunches, to give a bunch crossing interval of 75 nanoseconds. The number of bunches will later be increased give the final bunch crossing interval of 25 nanoseconds.
Six detectors are being constructed at the LHC. They are located underground, in large caverns excavated at the LHC's intersection points. Two of them, ATLAS and CMS are large, "general purpose" particle detectors. The other four (LHCb, ALICE, TOTEM, and LHCf) are smaller and more specialized.
The LHC can also be used to collide heavy ions such as Lead (Pb) with a collision energy of 1150
LHC experiments

OUR ACHIEVEMENTS:

Physicists hope to use the collider to enhance their ability to answer the following questions:
Is the popular Higgs mechanism for generating elementary particle masses in the Standard Model violated? If not, how many Higgs bosons are there, and what are their masses? The Higgs boson is a hypothetical massive scalar elementary particle predicted to exist by the Standard Model of particle physics. It is the only Standard Model particle not yet observed, but plays a key role in explaining the origins of the mass of other elementary particles, in particular the difference between the massless photon and the very heavy W and Z bosons So it a particle of great importance.
Will the more precise measurements of the masses of baryons (In particle physics, the baryons are the family of subatomic particles which are made of three quarks. The family notably includes the proton and neutron, which make up the atomic nucleus, but many other unstable baryons exist as well.) continue to be mutually consistent within the Standard Model?
Do particles have supersymmetric ("SUSY") partners? Supersymmetry means every boson has a fermionic super partner Bosons are particles those transmit forces(photon,W,Z & graviton) & fermions makes up matter(electron,quark etc)
Why are there violations of the symmetry between matter and antimatter?
Are there extra dimensions, as predicted by various models inspired by string theory, and can we "see" them?
What is the nature of the 96% of the universe's mass which is unaccounted for by current astronomical observations which is called dark energy and dark matter and dark energy?
Why is gravity so many orders of magnitude weaker than the other three fundamental forces?

IS IT DISASTEROUS FOR EARTH & UNIVERSE?:

People both inside and outside of the physics community have voiced concern that the LHC might trigger one of several theoretical disasters capable of destroying the Earth or even the entire universe. These include:
Creation of a stable black hole(a place of high gravitational intensity from where nothing can scape.)
Creation of strange matter that is more stable than ordinary matter
Creation of magnetic monopoles that could catalyze proton decay In physics , a magnetic monopole is a hypothetical particle that may be loosely described as "a magnet with only one pole". In more accurate terms, it would have net magnetic charge. Interest in the concept stems from particle theories , notably Grand Unified Theories and superstring theories that predict either the existence or the possibility of magnetic monopoles.
CERN performed a study to investigate whether such dangerous events as micro black holes, magnetic monopoles could occur The report concluded, "We find no basis for any conceivable threat." For instance, it is not possible to produce microscopic black holes unless certain untested theories are correct. Even if they are produced, they are expected to be harmless due to the Hawking radiation process(particle-antiparticle pair to appear close to the event horizon of a black hole. One of the pair falls into the black hole whilst the other escapes. In order to fill the energy 'hole' left by the pair's spontaneous creation, energy tunnels out of the black hole and across the event horizon. By this process the black hole loses mass, and to an outside observer it would appear that the black hole has just emitted a particle.). Perhaps the strongest argument for the safety of colliders such as the LHC comes from the simple fact that cosmic rays of much higher energies than the LHC can produce have been bombarding the Earth, Moon and other objects in the solar system for billions of years with no such effects.
However, some people remain concerned about the safety of the LHC. As with any new and untested experiment, it is not possible to say with utter certainty what will happen. In academia there is some question of whether Hawking radiation is correct.

So the LHC is on its way.Its costing not too much,only US$ 8billion.We hope it will not be diasterous & will make mankind the lord of the mysterious ring by smashing open the mysteries.

Referance:

Wikipedia

Cern

BBC science and nature

Interstellar Travel

In 1960 Bussard proposed an interstellar vehicle that would collect its fuel from interstellar medium. A large scoop would pick up protons present in space, and the protons would be fed into a fusion reactor where part of their mass would be converted into kinetic energy. How big would the scoop have to be in order to produce a constant 1g acceleration for a 3500-ton vehicle?

Walking on water

What is the minimal speed with which a person can run on the surface of the water.

(Please, no remarks about the gentelman who walked on the water (lake of Galilee) two thousand years ago.)

This question appears in the "Problems in Physics" by P.L. Kapitza

BIRD ON A TREE

How big does a seed on the ground have to be to justify a bird in flying off a tree branch to eat it?

This problem appeared among the London Physics Olympics questions

Halley's Planet

Not so many years ago there was no order of magnitude estimate of the age of the planet Earth. Edmund Halley (yes, that's the "comet guy") wrote an article in Philosophical Transactions of the Royal Society of London, 29, 296 (1714), where he observed that lakes that emit no rivers (such as Dead Sea, or Caspian Sea) are very salty, and thus it is reasonable to assume that rivers bring salt into the lakes. He further claimed that "'tis not improbable that the ocean it self is become salt from the same cause." Consequently, by measuring the salinity of the oceans and by determining the amount of salt brought by rivers every year, one could estimate the age of the Earth. Halley lacked the data to actually perform an estimate of the age of the Earth using his method. Halley's assumptions are wrong, but nevertheless it was a nice try for his time. What would be the age of Earth according to Halley's method?