good evening
what is history, history and history?
reconstruction of our past but it is
also a form of collective memory e
today we talk about memory and memory
we heard it right in this room
until now it is the base on which we build
our identity is as individuals
that as a society now as in a map
geographic I do not think we can not
find the names of all the locations of
that region so too is history
a kind of map in which not all
events are recorded for the
following maybe at regular intervals of
time but only those that memory
collective of a large human group or
little that is has internalized has
grouped structured has selected
according to the relevance criteria of
importance that naturally vary from
community to community
so I asked myself what are the
oldest historical documents in the world
or those that somehow like
it often happens in the story of the story
they force us to modify the map
of the history our vision of the
past
well the 5000 cuneiform tablets
found in the royal palace of the city
Syrian of ebla
dating back to around 2003
Christ are certainly documents
significant significant are above all
administrative documents then
they record entrances into the building
real but they are also treated
international the first dictionaries but
let’s say without to make it short in some
manner allowed the
detailed complete reconstruction of the
economic social policy life is lacking
of everyday life of this
city that was not known before the
excavation campaign done by archaeologists
of wisdom led by paolo mattia
that is, before the discovery of this
city was believed to be the only two
important poles of civilization a
that era were mesopotamia e
egypt
instead the Syria was considered one
species of land of shepherds and then
we say you will ask but why a
physical one who does physics
astroparticle tells us
things above notes on the ebla tablets
and see why the physicists by hand
overdo it and then consider it to be
always better than others in some
case they are also very arrogant and
surely I assure you that sheldon
cooper and an excellent representation of
certain environments of physicists
I believe that nobody has ever asked
sheldon in your opinion what is the document
oldest historical never found
from man and I’m sure that
would answer the historical document
older than man, he certainly does not have them
5000 years of the ebla tablets but
almost 13.8 billion years
now as we know this is
the age of the universe is therefore a
old historical document like
towards and what is this document
historical and this is the radiation
cosmic microwave
background discovered almost by chance from
two astronomers think wilson in 1965
you can have made this discovery is
like having found in an old man
memory drawer or physical
an image a self i as we would say today
of the universe but not as now but as
it was just 380 thousand years from the big bang
therefore 300,000 years against 14 billion
of years and how everything was possible
this as it was possible to shoot
this photograph
what we know about the universe we know
today that the universe is a space
homogeneous under expansion
indeed the latest discoveries tell us
that this expansion is accelerating
more and more that was born of big bang
that’s the big bang us physicists for maybe
to hide our ignorance
let’s say that a singularity one
quantum fluctuation of a point
ideal of high energy enel
obviously I can not retrace all of them
the stages of these 14 billion years
but some things I want to say
see in the first ten at least 43
seconds is an extremely number
not even space and time
could be defined what
call the era of planck and then there is
another very important stage that
it takes place around ten at least 35
seconds between ten and under 35 minus 32
how to have numbers are incredibly
small happens that the universe
suddenly it explodes
the mind lies in a vertiginous way like
we say exponential if you want
this is the real big bang
and then the universe passes from
size of less than one atom to that
of a balloon of a I do not know a little
beautiful that already contains all the energy
all that will be the universe afterwards
14 billion years
here and then let’s go in a moment
this inflation happens of things
important for example the matter yes
separates from antimatter and why
the universe has now become only of
matter is another mystery the forces
they begin to differentiate now
let’s go on when this ends
very little period that really lasts
less than a blink of an eye
the universe is still very hot, that is 10
at 27 degrees kelvin finished this
period of the so-called inflation
but the universe continues to expand
not so dizzying as before but
continue expanding, expanding itself
cools and then we get to this
fundamental stage of the cosmit of al
cmb point that when the temperature
of the universe has finally subsided
enough because the electrons are created
first they can permanently aggregate themselves
they are slowed down to be able to aggregate
with the nuclei of the first atoms that yes
they were created in the first three minutes
of the universe and then form i
first atoms and start a thing
fundamental that the radiation and the
matter that were previously in continuous
interaction the universe was yes
this primordial soup is very hot
opaque with the creation of atoms la
radiation the matter separate the
electromagnetic radiation and free of
move around the universe to permeate
the universe then the yes and bio
cosmic background radiation
another that this first light that has
shone in the universe 380,000 years
just after the big bang his
importance lies not only in the fact that there
shows that the big bang theory is
true but it is a real archive
historical because you have cosmologists says
will continue to say more and more of the
birth and evolution of the universe
now the map I showed you
first after the casual discovery made
in the sixties in fact many
other increasingly sensitive instruments
more accurately they have
rebuilt this map which is the map
in the whole universe accessible to us
actually tells us that this
electromagnetic and uniform radiation
in any direction we look at it
of the universe and uniform except for
of the very small points you see that the
color varies because there are some
small fluctuations of small areas
where this radiation and denser
the universe was denser and warmer
around these points they have been created
after about a billion years
the stars, the galaxies and so on
now I said the importance of this truth
historical archive and that is one
information mine on the universe
well, the importance is this document
so we are authorized
actually how could you say
sheldon cooper is the oldest
historical document never found by
man has entered the memory
collective of humanity and I would like to
to emphasize a difference
the historical documents that come
find again may have relevance for
a community for a human group but
they can have it and much less maybe
for another social group and well
instead, this historical document
this discovery of cosmic radiation
background has global universal value
it is valid for all humanity because
because the result of the sensible ones
experiences of which Galilean Galileans used to say
there is a scientific truth is one
scientific truth is not a truth
absolute but it is a shareable truth
I can share it with all of humanity
sorry for this physical interference
in the world of historians and I stop here
thank you
[Applause]
[Music]
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