Nothing That Matters

While the Standard Model goes overboard with quantum effects that prevail at less than Planck's length (10^-33 CM). Its almost a boiling cauldron with virtual particle and breaking of various conservations/symmetries. The String theory is rather mum about what is there besides strings at such scale of universe. How does it make or break the theories?

While its not so devastating for String Theory, since Strings are Planck-length sized and hence even if you do not look below that length, your theory works at Planck length - where the boiling cauldron effect of smaller lengths is not there.
But Standard Model - Hmm.... As German would have said "Ganz Schlim". Very Bad. The particle like neutrino, quarks and electrons as per this theory are point sized. That is they are singularity with no size at all. So you have to drill down to zero length to work the theory. It gets into problems. Its only by sleight of Renormalization that anomalies and infinities are kept away. Read my earlier post on Renormalizarion.
String or Standard, no theory can expect to be complete unless it can explain what is beyond their particles in the Vacuum. You cannot do just "Nothing" about "nothing". Nothing cannot be left alone.
Even String theory has to come about the vacuum states of universe.
In that sense both theories are inadequate. Standard Model by not being able to handle vacuum states till the point sized particles and String Theory by trying to avoid dealing with vacuum states at all.
This round goes Zero-Zero to Both. With score remaining 3-1/6 in favour of String Theory.

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Both String Theory and the Quantum Field Theories treat Time in a cavalier manner. It is taken as a given, evenly, continuosly flowing irreversibly.
Both do not explain the arrow of time. In fact the whole of Physics, except for perhaps indirectly Thermodynamic (2nd law: Entropy) can account for this arrow. String Theory does now talk of time being grainy.
But the treatment of time is inadequate in both the theories. An ideal theory should show that the theory is consistent only for forward moving time. It should show by its equations - whether time is continuous or grainy, not simply as an assumption.
Hence both theories score ZERO in this round. The score now is still (3-1)/5 in favour of String Theory.

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When in Euclidean Geometry we work with space we talk of three co-ordinates: x, y and z. Geometry is all built up from definition of a point, then leading to a straight line and then to an area and then to a volume. Thus whatever flavour of geometry (polar co-ordinates or Euclidean) is used, we have to use three numbers to define a position in space - and three co-ordinates. Since this very geometry is also used in Models of Space-Time in physics, we call space 3 dimensional. But does each co-ordinate of geometrical space qualifies as "DIMENSION" in the sense of String Theory. Do semantically and conceptually 3 dimensions of space stand on the same footing as other dimensional entities like 'Time' or other curled-up dimensions of String Theory? No! No! definitely NOT!!
The 3 dimensions used to describe space are an inadequacy of our mathematics. In vector representation of space there is no need for three dimensions. The three co-ordinates are isotropic, not a dimension in its own right.
Space should be seen as a single String Theory Dimension, just like Time or any other dimension.
So we should not talk of 10 dimensional String Models but only 8 dimensional ones!!!

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Quantum Field Theories (as epitomised by Standard Model), use 4-dimensional space-time, rather 3-D space and unidirectional Time. Number of dimensions in this theory are actually 'filled-in by pen' as the initial fact of universe. Ironically the 4-D space-time is an a-priory borrowed by Standard Model from Einstein's General Theory Of Gravity - a theory which Standard Model fails to encompass within its structure of other three Forces. Therefore space-time and its dimensions are external factors for such theories.

On the other hand the number of dimensions in string theory arise out of the formulation of string-theory itself. The 10 dimensions arise out of the fact that string theory mathematics show that its only with these many dimensions the theory would work. This is a more satisfying and complete situations as compared to assuming the dimensions a-priory as in Standard Model.
This round also therefore goes to String theory. The score-card thus far is 3-1 in favour of String Theory.
But I have a fundamental objection to space hogging 3 dimensions. I would therefore break from this String Theory vs Standard Model slug-fest and revert to this aspect in next post, with your indulgence please!!

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In many quizzes in the newspaper or the web, the answer is given somewhere partially hidden. You are not supposed to cheat and look at the answer before attempting the quiz. String Theory has done something like that. It started with the answer! Quantum Field Theories moved from known to unknown. The approach evolved like peeling the onion skin by skin. It started from electrons to protons, Neutrons and further down to Quark. On the way it took into its unifying fold the three fundamental forces - Electro-magnetism, Weak Force and Strong Force - failing only to grapple with gravity. It was an organic, natural step-by-step evolution. Finally it had still to peel the layer of skin that could explain what the quark is in-turn made of? And the skin to take gravity into its fold?
The string theory started off by first saying what the elementary constituent of all particles and Forces that we know? Simply because its a good mathematical framework and answers many questions - some which quantum Field theories cannot answer.
So this round 3 about starting from an uncertain fundamentals to build super-castles is against String theory. This round goes to Quantum Field Theory. The score so far is 2:1 in favour of string Theory.

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This is round 2 of our discussions about the differences and similarities between the String Theory and the Quantum Field Theories(as epitomised by Standard Model. Click Here For Round1
Elementary Particles emit or absorb other particles(e.g. Force Particles like Bosons) without themselves loosing identity. These may also split up into two or three different particles. In Quantum Field Theories (epitomised by Standard Model) this is intuitively difficult to understand within the scope of this theory. I had earlier pointed it out:-
There must be some type of "Conservation" for a process to be called a change/transmutation.
In fact science is about only those changes where conservation is observed - rest isn't science.
In disappearance of a neutron and in its place appearance of a proton + an electron and an anti-neutrino - the quarks(that make-up both neutron and proton) and leptons(electron and neutrino) are conserved, so is mass/energy. Scientist use a more rigorous approach to call it conservation of quantum numbers that they assign to properties of these fundamental particles.
But in appearance of neutrino just out of "nothing"(Space) there appears to be no conservation here. Perhaps our knowledge of that level of particle structure is incomplete. May be the sub-space entities out of which space is structured (as I propose in this blog), are conserved, in transmutation of space into a neutrino.

For details See my post The More It Changes The More It Stays The Same.
I had also argued on similar lines about a Muon (a fundamental lepton) decaying into a mu-neutrino + an electron and a positron - all three fundamental leptons of different families. Please see my post - Being Fundamental is No Fun' and also on more fundamental issues in my post - 'Elephant = Monkey X Chimpanzee Squared'. But String Theory Beautifully tackles these since it says that particles that we see are only different modes of vibration of strings. Thus a string can change the mode of vibration or split into two strings with different vibrations or else two strings may combine. Neat! I have no issues with it. In fact this is what I have all along been saying in my hypothesis.
This round again goes to String Theory!!! Its ahead of Standard Model by 2-0.

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What are the similarities and differences between String Theories and The Quantum Field Theories(epitomised by Standard Model) of the Particle Physics?. Which one is better in different aspects? Brace for a series of posts on this! Lets look at the procedure of Renormalization.

In Quantum Field Theories of which Standard Model is the epitome, behaviour of particles at very small distances of the order of particles it self - is not known. As I wrote earlier:-
"The equations Scientists write to describe the sub-atomic particles is in too dense a mathematics, even beyond a BS majoring in Mathematics. These equations in raw, strictly theoretical form, give infinite or nonsensical results or are unsolvable - capable of no result. Like too smart an Accountant fudging his books till clean looking figures are achieved, Scientists coax an answer out of these equations through largely empirical mathematical operations called renormalization.
For example the first theory that started the chain of Particle Physics, was Electro-Dynamics propounded by Dirac. While the equation was supposed to describe mechanics of electrons, one of the results showed the world to be filled with negative energy positrons. This is obviously not the thing we observe in reality.
One of the justification for re-normalization is that the measured parameters of sub-atomic particles are the net observable values and intrinsic values are much different."
For detailed justification, please see my earlier post on this - 'A Tycoon Surrounded By A Bevy OF Expensive Bunnies'.
This is highly unsatisfactory way. But the Standard Model did give verifiable answers. The fact remains that this model cannot deal with phenomenon at small distances of space-time.
String Theory is a theory of phenomena at sub-particle distances. Such Renormalization is therefore not needed. Thus the String Theory wins over the Standard Model in explaining phenomena at such distances!!
And The First Round Goes To STRING THEORY!!!

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How many dimensions of space-time a string theory predicts varies in different flavours of the theory. It started with a "Bosonic" model which explained only Boson Particles (Particles that explain the behaviour of Forces), no Fermions (Other particles that explain the material world). This theory was consistent only in 26 dimensions. (How cool!! These can be labelled from A to Z. Most scientist make their best contribution around this age. Einstein published his paper on General relativity at this age. My son was also born when I was 26 year old ;-)
Bosonic String Theory had some unacceptable predictions. Other theories followed to improve upon this, add Fermions and remove other inconsistencies. These are called by unimaginative names (quite rare in Physics) like I; IIA; IIB; HO & HE. These flavours agree on the number of dimensions - a perfect 10. (People of my age would recall Bo Derek!)
Efforts are on to integrate these flavours into a theory called M-Theory (Mother Of all Theories). Which requires an 11 Dimensional Space-Time. But to retain the advantages of earlier flavours, one of the dimension is assumed to be compacted (curled-up) into a small circle leaving only 10 significant dimensions.(Must have been invented by a Cricket-playing scientist : - where a team is complete if there are 11 players, but after 10 players are out, the 11th does not get to play.)
So how do we encounter only 4 dimensions, when the theory needs 10. The other 6 are compacted into a ball. Each point on our 4-dimensional space has a finite but minuscule 6 dimensional curled-up ball. These curled up dimensions would need very high energies (of the order available at the time of Big-Bang) to open-up, hence are beyond our perception.
What are differences and similarities between String Theory and Standard Model.
About that in subsequent posts.
Till Then. Enjoy the Ice-Cream!!

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So what are the strings attached to String Theory:

• Instead of building blocks of atomic and sub-atomic particles as per Standard Model, string theory says that these particles are only manifestations of string-like entities vibrating in different modes and different dimensions of space.


• The strings is only a conceptual crutch - these are not material. Strings do not have a structure of their own. Strings are one-dimensional instead of particles which are point entities. Length of string is of the order of Planck-length (10^-32Cm.). But longer strings are postulated when weak-interactions are dealt with.


• Some particles are manifestation of strings in loops, some of open-ended strings. Particle interactions are explained by cutting/combining and change in vibration modes of the strings.


• There are four forces of nature (Strong Force, Weak Force, Electro-magnetism and Gravity) which are mediated by Boson-particles as per Standard-Model. String Theory says even these Bosons are a manifestation of string vibrations in various dimensions. Hence even Forces are explained by Strings, Vibrations and Dimensions.


• The Time-space which is only 4 dimensional as per Relativity, but has many more dimensions in String Theory. These dimensions are dictated by the mathematics of the String Model to explain the behaviour of four forces etc. Number of dimensions are different in different flavours of String-Theories. Dimensions other than four seen by us are curled up into miniscule length. I would discuss this in next post.

C U Soon!!

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Now that I have started giving you videos, please checkout on this site full of videos on similar subjects: Videos on String Theory in more than 2 minutes

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There was a contest on youtube to explain string theory in 2 minutes. The duckie video is the best and simple. The pronunciation is a bit foreign:

Its really good - I also learnt a lot in two minutes. CU Soon!!

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We live in a four dimensional space-time. Three are spatial dimensions and the fourth one is Time. Have you seen time go by. The three spatial dimensions are quite accessible to our physical senses. Although we are sure that Time does exist, but we cannot physically connect with it. Its the unseen dimension.
String theory propounds a universe consisting of 10 or 11 dimensions. Are other 6-7 dimensions also as ephemeral as time. Once we accept that in our 4-dimensional universe one dimension is already ephemeral - its not difficult to come to terms with an idea of higher-dimensional universe. The additional dimensions can be curled up or extended finitely/infinitely.
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I have written about the enigma of time before. Suffice here to highlight that time as a dimension is substantially different from other three dimensions.
Time is always flowing - moving, but the spatial dimension are stationary. Time is only uni-directional, but other dimensions can freely be traversed in either direction.
Still time and spatial dimensions are considered to be an integral whole space-time. Its only we, who try to discern different dimensions to it. For example fixing three mutually perpendicular dimensional axis is just an arbitrary exercise. For space the three dimensions are not distinguishable from others - the three are integrated enough - that we cannot de-integrate or differentiate them. We can substitute one of the spatial dimensions by any one of the rest of two - without changing the equations etc. So should be time. It should not be differentiable from spatial dimensions - we should be able to substitute any spatial dimension for time and vice-versa. But that is not true.
What gives?

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Four forces of nature - Strong force; Electromagnetic force; Weak force and gravitation, have varying strengths. Strong force is strongest and gravitation is the weakest (billion on billion times weaker than others). This extreme weakness of gravitation makes it difficult to comeup with a unifying theory of all four forces together - although the standard model does cover rest of the three. Scientists call this a "hierarchy problem". Dr.Lisa Randall, string theorist, Harvard professor and a very graceful 43 year old, developed a model of universe based on string theory(alongwith Dr. Raman Sundram), which explains why the gravitation is so weakly felt in our universe though in the beginning of universe all the four forces were indistinguishable from each other.
String theory (M-Theory) says that all particles and forces are nothing but a different vibrational states of thin stringlike structures which exist in 11 dimensions.
Universe consists of 3-dimensional membrane (jargon="brane") surrounded by a higher dimensions.
In their model called RS-1 and RS-2(published in 1999), they propounded that while all other forces are on the same "brane" as our universe, gravity resides on another "brane" separated from our universe by a five dimensional space with extra fifth dimension (time being the fourth). Gravitons (a loop of string), the particle associated with force of gravity is free to travel from gravity-brane to ours. However the space is warped in a negative way by the gravity-brane (anti De Sitter space), due to which though there is a large cluster of gravitons near gravity-brane only a small number are able to make it to our universe-brane. This explains why is the gravity so weak compared to other three forces which are resident on home-brane. Is it not familiar - Dogs bark louder near home-turf.
The extra 5th dimension of the 5-dimensional space separating us from gravity-brane is large enough but appears to be only 10^-31cm wide to us because it is warped in negative fashion. Otherwise Newton law of gravitation would have been inverse cube law instead inverse square it actually is.
This theory and other competing ones (Arkani-Dvali-Dimopoulos= ADD) would be put to test in CERN's Large Hadron Collider (LHC) near Geneva, when it fires up in 2007.
Dr. Randall recently published "Warped Passages: Unraveling the Mysteries of the Universe's Hidden Dimensions" to convey to the lay readers the excitement of her work on RS-1 and RS-2.
Happy Reading!! Fources

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Analysis of past Telemetry data of Voyager I and II show that they are about 8000 miles short of their calculated positions. What gives? Who is shortchanging Voyager Scientists? Scientists say that there are many possibilities:
1. There is a theory that in far out spaces, speed of light has a miniscule acceleration. Therefore the Voyager is in fact at correct position as per calculations, but the radio signals are covering that distance at a faster than uniform speed of light would warrant.
2. Newton's laws of gravity, duly modified for relativity, still require further modification.
3. Something else like action of dark matter in intervening space or curvature in space-time.
Gotcha! What gives, is that we loose our certainty of knowing the laws of physics. There is lot to be still learnt when scale of distance and time is too large or too small.
Oh! I have a better exlanation: Please read my following post Square The Cube

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