The Big Bang 1 and
THE ORIGIN OF MATTER
or
Let there be light!
or
Let there be light!
First
of all, congratulations for having had the courage to read this site up
to this point!
It would seem that more than 95% of the netsurfers connecting to my
first page get lost on route... Certainly, the subject can seem fairly
dry, but what profound bliss to have a sharper consciousness of the Universe
around us, no?
Therefore, just for you, dear courageous reader, I have saved the best
till last...
The
Big Bang, is it an explosion ?
The origin of
matter is found in the fantastic story of the Big Bang and started
about 15 milliards years ago: This term "Big Bang" will always be
highly celebrated, but it's somewhat improper as it makes one think of
a gigantic deflagration which one could have visualised "from the outside".
Now, that would have been impossible because we form an integrated part
of the Universe: If we could have lived (and survived!) at this epoque,
we would have "witnessed" an explosion everywhere around us with an ultrarapid
dilatation even of the very structure of space and time themselves.
In the same manner that we are constituted of space and matter, the hypothetical observer of the Big Bang would himself have been subjected to this spatial dilation. Even more incredible, the 4th dimension, time itself, would have been born and would have expanded at the same time as space: The origin of the Universe has been unravelling since then at a speed which has been decreasing exponentially:
The
Big Bang is it a certitude?
It is important to point out that the big bang (as moreover the standard model of particles) is no more that a theory, nonetheless accepted by the largest part of the scientific community. This theory changes and is frequently refined. As do notions such as the exact age of the Universe, or even its future (evolution towards a dilution ora a recontraction), which is still the subject of controversy.
Before
10-43 seconds...The
Superforce
We'll say this clearly: Everything than happened
before this incredibly brief chronological date is a total mystery. Why?
Because 10-43
seconds corresponds with what we call Plancks Constant, a sort of
incompressible quantum time. This interval of time seems to be the shortest
possible according to quantum physics, in the same way that Plancks length
( 10-35 m ) seems to be the shortest distance accessible to
our physics.
Nothing
very much more is known about what our Universe could resemble at such
a scale as that of Plancks length. The difficulty appears when one associates
a time as miniscule as 10-43 seconds with
the colossal energy of the Universe, concentrated, at that epoque, in a
volume so minuscule. The value of this energy is very poorly defined. Now,
it is this energy, along with the matter, which imprinted its form upon
space and determined how time unfolds. With distances and durations of
the order of those at the scale of Planck, space and time become notions
very difficult to characterise. The notion of distance between two points,
did it still have a meaning when the Universe was so small? Did time already
roll forward from the past towards the future?
How should we imagine this original stage of the Universe?
This primordial phase primordial phase of the Universe is the domain
of the Superforce (also called
quantum
gravity) which then unified the 4 known interactions.
As in a black hole, time can become space and space can become time.
Maybe there exist numerous other dimensions, as the superstring
theory seems to indicate these dimensions would then be "coiled up" upon
themselves to leave the Universe to evolve following the 4 dimensions of
space-time which we now know.
At this stage of evolution, matter had still not come into existance, only the "void" prevailed, but attention! The void of the Universe was not empty: it comprised numerous virtual particles of matter and of antimatter which appeared and disappeared like soap bubbles. Our Universe now was maybe stems from one of these quantic fluctuations of the void !
 And
before the big bang ?
(extract from Science & Life Junior Series N° 30 special "Time") |
| If you can't help thinking about just what
there could have been before the big bang, even though you are continually
told that there was nothing there, not even time, there exists a good means
of rediscovering this state ie sleep.
Consider first that the manner in which we measure time is nothing more than a question of convention. Next follow the elegant suggestion of physicist Jean Marc Lévy-Leblond : decide, for example, that each time that the distance in space between two points doubles as a result of the expansion, the hands of the clock will have gone round once. If now you turn yourself towards the past, this is what will happen: following the chosen convention, one turn of the clock ago, the Universe was half the size of today; two turns of the clock ago, it was four times smaller, etc. We could then make as many turns of the clock as we want. Each time the Universe will be smaller, but we never arrive at anything which marks the beginning of time. « With this perspective, Jean-Marc Lévy-Leblond explains in effect, that the more we return into the past, the more the Universe retracts, but its size never becomes nothing, because it is not until at least infinity in time that the extent of the Universe tends to zero. » The instant zero is thus as inaccessible as infinity : there never was an instant zero! |
From
10-43 to
10-35 seconds...The Grand Unification of
forces
At the Planck time, that which would become our
Universe had but a diameter of about 10-33
cm, that is to say 10 million billions of times smaller than a hydrogen
atom!
Its temperature was around 1032
degree
Kelvin (0°K = -273°C).
 |
|
Nature here offers us the most astounding of spectacles: It is here that the infinitely large meets the infinitessimaly small during a laps of time infinitely short. If you can imagine all matter-energy contained in the billions of milliards of galaxies, each containing hundreds of milliards of stars, concentrated within a space very much smaller than the smallest elementary particle now ! I think that it is impossible for the human spirit to have a vision more grandiose than that! |
In this Universe, the fact is that the quantic void still boils with an unimaginable energy. This sporadically materialises ( don't forget E=mc² ! ) in fleeting phantom particles and antiparticles.
The superforce is divided into two forces: la gravitation, and the electronuclear force.
From
10-35 to 10-32
seconds... the inflation of the Universe
The cosmic thermometer "descends" to around 1028 degrees Kelvin.
At this precise moment of universal evolution, there is a secession of the electronuclear force into the strong interaction and the weak electric interaction. Along with gravitation, there then existed, from then on, three distinct forces in the Universe.
At
this temperature of 1028
°K,
the enormous energy of the void is liberated and imprints on the Universe
a lightning expansion which the physicist Alan Guth named inflation.
Between 10-35 and 10-32
seconds, its volume augmented by a factor of 1027
(or 1050 according to other sources ?)
whereas throughout the 15 milliards following years following, its volume
would only augment by a factor of 109.
|
And all that in 10-32 seconds... |
After the birth of space and time, matter would give rise to the quantic
void!