The Superforce
 

Even stronger! this "theory of Everything" unifies gravitation and the electronuclear interaction from the GUT theory. The 4 original interactions would be nothing but 4 facets of the same interaction, nicknamed the Superforce, which ruled at the ultimate origin of time at a titanic energy of 10¹⁹ GeV. This energy was only possible in a hyperdense Universe of a diameter equivalent to 10^-33 m (For comparison, a proton measures 10^-15 m)! see big bang....
 

This extremely hypothetical Superforce would unify all known particles (and other unknown ones) by calling upon two other super-theories:

• supersymmetry
• superstrings

Supersymmetry
 

In fact there exist multiple supersymmetry theories grouped together by the acronym SuSY.

We have already seen that each interaction can be mathematically modelled by force fields possessing a certain symmetry. Physicists dream of unifying all of the existing interactions in a single Superforce, which should have as a property a supersymmetry which would unite fermions (particles of matter) with bosons (particles of force).

Supersymmetry transforms the wave function (mathematical representation of the quantic state) of an ordinary particle into that of a hypothetical superparticle (called sparticle) by modifying by a half-unit the value of its spin (rotation of the particle around itself). With SuSY, the total number of particles would thus double!

Each particle will then be associated with a corresponding sparticle:
 
 

These sparticles would also be particles super...heavy: For the moment, no collider is capable of detecting them and this theory has never been confirmed by experiment.
 
 

Superstrings
 

According to this revolutionary theory, elementary particles are no longer considered as points, but as little strings.
We speak of superstrings because this theory obeys the laws of supersymmetry. Certains strings would be closed in loops, others  se refermeraient en boucles, others would be open and would therefore possess two extremities. But their total length would be millions of millions of times less than that of an atomic nucleus. At a larger scale, they would appear as simple points and one would again find the characteristics of our "habituel" particles.
The dimensional scale of superstrings approaches then 10^-33 cm, that is to say the length limit of Planck.

What is the interest in imagining a string?

It's very simple: a string can vibrate.
Indeed in the theory of superstrings, all existing particles would in fact be nothing but different modes of vibration (or harmonics) of a single and unique superstring!
A string can vibrate following more and more complex harmonics which would correspond with particles which are more and more massive...

Whereas Science-Fiction writers make us dream about the 4^th dimension (which is in fact nothing but time itself), superstring theoritians do better: they explain to us that matter is finaly constituted of nothing but strings of 10 dimensions!
Don't try to think of something to represent such a space-time: it's impossible for us who live trapped in 3 spatial dimensions.

But then, where are these 6 hidden dimensions which  add themselves to our 4 usual spacial-temporal dimensions?
 
 

Imagine first that our Universe of 3 spatial dimensions is reduced into a single dimension... You would henceforth be a modest point unable to move except in a straight line.
Next imagine (still more effort!) that now we introduce a new dimension wound round on itself with a very small diameter...so small that this hidden dimension is imperceptible at our normal scale. You could theoretically, like all the other points, take a trip around this "spaghetti-dimension" if it wasn't so small.
It is necessary then to imagine these 6 mysterious dimensions wrapped around on themselves with a diameter of 10^-33 cm, the famous and mysterious Planck constant beyound which our human physics seems incapable of describing the world.

The interaction of two superstrings is by contrast easy to imagine. Wherever two superstrings interact, they melt into each other, and they can subsequently divide anew into several superstrings of different harmonics.
 

It is necessary to realise that there exist, not one,but five famillies of superstring theory which radically oppose each other.
Nonetheless, recent progress leads us to believe that these different theories are nothing but limited cases of a single theory called theory M, which describes interactions of small strings and membranes...
Alas, the dimensions of superstrings are beyond the reach of the current colliders and no experimental results have been obtained to confirm the existance of superstrings.
 

crazyflash: May the Superforce be with you

The gallant physicists armed with colliders have a sacred destiny: The quest for the Superforce.  To attain this blessed concept, they must first unite, one by one, the 4 forces of mother nature and discover these new interactions :  electromagnetism + weak force = new force: it is very weak, but for its discovery it necessitates the creation of the Higgs field! weak electric force + strong force = new force: very nuclear. This magic force permits the transmutation of quarks into leptons... The alchemists exult. electronuclear force + gravitation = the Superforce : the Grail of physicists on their quest for the Theory of Everything. This ultimate force will be protected by a guardian with more than one superstring to its quantic bow, which can teleport you into the 10th dimension at the least false step.

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