I am an astronomer and so I put you
in front of a starry sky a sky that
of course you could see to curtain that
is famous for the excellent quality of the
his sky
if there were no clouds there
remember why the early evening serene
I invite you to stop for a moment to enjoy
of the beauty of the sky and leave it
some questions arise because of the
heaven raises questions also does
to dream but the questions can be
very tied to dreams and the question that
I want you to poniate now it is
to ask you what relationship we humans have
with the stars to put you on good
Street
v I invite you to watch this this
painting an American painter greg morgue
very close to astronomical themes of fa
see a beach of shells against
a starry sky what the painter
he wants to tell you that there is a relationship
the stars between the shells
because the material of which they are
made the shells ie the carbon the
calcium oxygen nitrogen was
synthesized from the stars not
it existed in the primordial universe
it exists because the stars are the year
then synthesized the stars release it
in the interstellar medium
there are many ways in which the stars
they donate material in the middle
interstellar equa you see a star that
it has swollen so much that it loses
its surface layers the matter
it will enrich the clouds
interstellar from which will be formed
new stars
and here you see, for example, the gods
images of star-shaped stars
just formed studied by the off hubble
space telescope
in these images they have one
characteristic discoid form because
the stars are formed inside
dust water gas discs from
which are the planets
we now know that almost all of them
stars have planets but we are
particularly fond of ours
planetary system what one is
formed about five billion years ago
around a normal star that
we call our sun system
planetarium is made from four planets
rocky near the sun and four
distant gaseous gaseous gas planets
from the sun
planetary formation
however it is not a one-way street
is it not an always quiet at times
rather tumultuous and leaves dead e
injured and therefore our solar system
it is actually full of leftovers
remnant that
soon late
come into contact with the planets and in
effects what you need to know that
all the planets in the solar system do not
they are isolated systems but they collect
material for example on the ground each
40,000 tons of years are falling
extraterrestrial material is not there
get scared
it is from the beginning of time that this
it happens is what we owe
ask what kind of material you see
in this
in this fantasy image these
celestial pebbles are a bit like le
T-shirt curtains are all
the sizes and goes from extrasmall to 3xl
and each of these interacts
differently with the atmosphere
the more normal ones we say those of gran
more numerous are the grains of
dust when they interact with
the atmosphere ignites and they make one
trail of light are the shooting stars
you saw a few days ago there was
the peak of the perseids
and if you are fond of the stars
Falling surely you have admired them
of the celestial stones a little bigger
they make the biggest ones
even bigger ones explode
in the atmosphere they make a big bang
if they explode in inhabited areas
we have beautiful videos of these
great barrels
this is
the video of the explosion that is
occurred in February 2013 in Siberia
above the city of celiabinsk the stone
heavenly when he entered
in the atmosphere it weighed about 10 thousand
tons and therefore it is a stone of
size about 15 meters bigger than
this room is as I said exploded
as always happens in these cases the
bigger piece went into
a frozen lake making a nice hole
it was then recovered when the ice
they are loose but the children of the
celiabinsk region and have played
for days and days looking for
cosmic bits that someone then has
sold on the internet this is the hole
left the crater left by a
meteorite decidedly larger than the
meteor crater in arizona
but the mother of all our fears for
regarding the impact of objects
celesti is certainly the event that i
66 million years ago he did
extinguish the dinosaurs
now we are right to be afraid of one
event of this kind
the answer is no and it’s no for two
reasons first because and the asteroids
so big at this point they are all
mapped in the solar system and none of
they are on a collision course with the
land
second reason for tranquility
you must think that if nobody had
we did not take the dinosaurs out of the way
we will be because the dinosaurs are mammals
they ate them so someone took it off
between lizards and mammals are
exploded so we do not have to follow
the example of asterix
no need to go around with
the menhir because asterix obelix had
afraid that the sky would fall on him
the concern of an impact of
asteroids is a concern
absolutely exaggerated and remember
that the probability of dying for
the impact of a meteorite is a lot
less than that of being devoured by
a shark none of you is afraid of
to be devoured by a shark
so please do not be afraid of
die from the impact of a meteorite
I wanted to finish by telling you about it
what happens to the celestial stones of
dimensions a little bigger than the
powder but definitely smaller than
those who do the cars are
lots of these little stones
celestial beings entering the atmosphere
remember that all your celestials
more or less go to speed
of 20 kilometers per second
so when they enter the atmosphere
they suffer a terrifying friction yes
they heat a lot and they evaporate
they vaporize instantly then
we have a cloud of vapors that
they may be ferrous vapors and vapors
acidic depending on what you did
the celestial stone and these vapors
condense because they are in an up
atmosphere is very cold minus 50 degrees
and form some microspheres of the
microspheres as large as ours
hair or even smaller
these microspheres act as centers
condensation for rain and for the
snow so when it rains when it snows
these microspheres fall to the ground
so let’s start with the curtain you’re used to
see the roofs covered with snow when
the snow melts
spring arrives the water evaporates and
dirt remains in the gutters
that maybe you have to clean up in this
soil there are certainly the
microsferules but they all always had
thought it was absolutely
impossible to extract the
celestial microspheres from all the dust
terrestrial instead a player of james
in oslo called john lance ha
decided he wanted to try it went
around to recover all the dirt
of the gutters of oslo that he found e
has put together three quintals of
dirt varies and eventual has
asked how he could recognize them
celestial ferule from the terrestrial ones
approved he was helped by magnets
from polarized light has passed hours and hours
under the microscope and he did it
found 500 microspheres for a large
total of one gram has started from three
quintals how big there are in three
quintals in a quintal there are 100 kg
in a kilo there are one thousand grams 300,000
g to get to have an ounce of
celestial spheres
but they are beautiful working at
microscope has them
photographed and then you see these are
the different colors he sees but then he is one
he’s a jazz player did this
filmed with all its beautiful
microsferules I invite you this movie in
network I invite you to watch it because it is
really very poetic and while it is
look you think you these
you definitely have microspheres
you have certainly eaten them
so these microspheres have you
made become and they made us
become all a little bit
extraterrestrials when you will succeed because
clouds will open to see the sky
so you think there is really a
direct relationship between the stars and e
humanity and when you are doing it yourself
take from the beauty of the del
show
you must always think that there is not one
inside and outside there is not one above it
an under when you look at the stars
but there is a whole because we are part
of a whole and the microspheres there
remember every moment thanks
[Applause]
”
Be First to Comment