Translator: Roberto Minelli Reviewer: Ivana Korom
Technology.
We are surrounded by technology.
The computer has become our travel companion,
the smartphone our appendix,
we use hyper-technological cars.
If we have to go somewhere,
we type the address on our smartphone or satnav
because we know that the GPS will take us wherever we want.
If we have to do a check-up at the hospital,
we do not worry if they lie us down on a bed
and slide us into a tunnel for a CT scan,
or an MRI scan, or a nuclear medicine exam.
Technology.
How did we get there?
Technology submerges us with images.
We live with images, we are bombarded with images,
we remember things through images,
we develop concepts with images.
2016 is the year of gravitational waves.
The infinitely large.
Who has never seen
the beautiful images, the pictures, of the Hubble telescope,
which shows us the depth of the universe?
Those images fascinate us because they talk about who we are,
where we come from, where we go.
The infinitely large.
In 2012 we all learned about the Higgs boson
and we saw the images of the infinitely small,
of particle accelerators like the LHC,
where they shoot 40 million photographs per second
with tens of billions of pixels,
to show us what happens when two protons collide
originating a Higgs boson.
The infinitely small.
And then mankind.
On December 23, 1895 the rector of a German university
publishes the first X-ray in history,
an X-ray of his wife's hand.
On December 23, 1895 modern medicine was born.
Until then, to look inside your belly, they opened it with a scalpel;
from that date, they make you an X-ray.
In 70 years we have been able to turn an X-ray tube
all around the patient
to cut her in many slices,
that combined together make us see the inside of her body
as if it were open in front of us.
The CT scan.
Between the 30s and the 40s, more or less,
another branch of diagnostic medicine was born:
nuclear medicine.
That branch of diagnostics
that wants to see how your body works
and not how it is done.
We have turned patients into radioactive sources
to discover their hotspots,
that is, those areas that are particularly active
that may signal that something is wrong.
The image you see behind me it is not made up,
it is a CT scan of a patient
together with a nuclear medicine exam:
a positron emission tomography.
Technology and images.
How did we get there?
How did we get to this level?
We have observed nature,
we have understood how it works and we have used it.
What glasses did we have to build
to be able to observe the infinitely large,
the infinitely small, all that surrounds us,
and also what is inside us?
The glasses we have built, and we will continue to build,
to observe nature are called
"particle detectors."
I did not mispronounce the word.
A "detector" is the person who calls you
to know how many times you drink milk in a week.
The English word "detector"
derives from the Latin "detegere":
remove the cover, uncover, remove the blanket, remove the bed sheet.
Detectors make us remove the veil from nature to understand how it works.
I am a physicist who develops particle detectors.
The funny thing is that to observe
the infinitely large, the infinitely small
and all that surrounds us,
we use the same detectors, based on the same principles.
There are incredibly different ones.
Some are as small as the nail of my little finger,
like those that are in your smartphones when you take a picture
or those who went on Mars with the robots
to understand the composition of the rocks on Mars.
There are also bigger ones,
like the ones I put on the AGILE satellite,
which is orbiting at 500 km above the ground.
Tiles of ten by ten centimeters that filled a cube of one meter per side.
There are huge ones,
such as those for studying the infinitely small,
such as the ones of the LHC.
CMS weighs 7.000 tons,
ATLAS is 20 x 20 x 30 cubic meters.
It is incredible,
but to study the infinitely small,
we build things that are larger and more complex.
Some of them are extra large.
The ones used to study rare particles
that come from the depth of the universe
or those that are particularly elusive.
Every second, each of us is crossed by several billion neutrinos
without realizing it.
One who studies neutrinos needs large quantities of materials.
Afterwards,
she uses the Earth's inter-atmosphere, or fills a mine with water,
or uses the light that neutrinos emit when they interact with sea water.
Particle detectors: our glasses.
But that's not enough,
because, if you think about it, detectors do not make us see a phenomenon,
they show us a product.
You do not see my vocal cords,
you hear the sound they emit.
We do not see the nuclei of the sun that merge,
we see the light that comes from that fusion.
We do not see two protons colliding at the LHC,
we see the tens of millions of electronic channels that light up
and tell us what happened when the two protons collided.
Particle detectors show us a product,
we have to deduce the phenomenon from the product.
We must frame it in a theory and make predictions,
because if a theory cannot predict, it is only a sandcastle in our mind.
Verify the predictions,
if they work, good; otherwise we start from scratch.
This was our winning recipe.
Putting together the observations done with the detectors
with a theory
which we devise with our intuition and our creativity.
In this way, we tell the story of Nature.
Do you want some examples?
We all know the Big Bang.
We all know that 13.7 billion years ago there was an "explosion,"
in which an immense amount of energy --
at a very high temperature of 10 to the 32 degrees Kelvin --
was transformed into matter.
First the constituents of elementary particles,
then the elementary particles themselves.
Protons were born a microsecond after the Big Bang, 10 to the -6 seconds.
We, and everything around us, are made of those protons.
We are made of the protons of the Big Bang.
Then all the other elementary particles: atoms, molecules, and the elements;
gradually up to 13.7 billion years later.
The universe -- as we have seen it through the Hubble telescope --
definitely colder than when it was born.
This is a beautiful theory, but theories need confirmations.
This theory has had many proofs;
I'll tell you one that I find terrific.
In the 50s in New Jersey, USA -- as part of a telecommunication project --
someone build an antenna, known as Holmdel Antenna.
We are talking about telecommunications, radio waves, we all know them.
We all know what a radio antenna is.
The name of the project was Echo, there were satellites communicating.
When the project was over,
the Bell Telephone Labs and two physicists,
Robert Wilson and Arno Penzias,
decided to modify the antenna to pick up radio waves
from the depths of the Milky Way.
In 1964 they switch it on, they turn it in all directions
and they keep hearing an annoying ticking.
So, they pick up the phone and call Princeton,
where there was Robert Dickie,
one of the major theorists of the Big Bang theory.
He answers, puts down the phone, turns to his employees and says,
"They beat us on time,"
takes his car and sets off towards them.
Robert Wilson and Arno Penzias discovered
the "cosmic background radiation."
When the universe celebrated its 380th thousand birthday, more or less,
it has become transparent.
At that point, the light was able to pass through.
The cosmic background radiation is the candle
that the universe has blown when it turned 380 thousand years,
13.7 billion years ago.
The cosmic background radiation is isotropic, uniform in all directions.
Think of it as a stretched cloth.
In reality it has very small fluctuations.
The image you see behind me,
is the image collected by NASA's WMAP satellite.
The yellow and red dots are the fluctuations
of the cosmic background radiation.
The yellow and red dots are the seeds of today's stars and galaxies.
We are talking about radio waves, it is not rocket science.
The glasses we have built to measure them
allow us to read a book that is 13.7 billion year-old.
Unbelievable!
At the beginning of the 1900s, physicists started to panic,
because they could not understand how light and matter talk to each other.
Light is a wave that infinitely pervades space.
Matter is made of atoms which are infinitely small particles.
How does this wave instantly interact with the electrons
that are in the atoms of my retina so that I am able to see?
Among other things, the eyes are the oldest example of particle detectors,
made in billions of pairs more or less working.
So what do they understand?
The observations were correct, but the interpretation was not.
The combination is the victory, the winning recipe.
They understand that the observations are correct and they say,
"It means that when we move towards the microworld,
the infinitely small,
the laws we have written
to frame what we observe in our surroundings
do not work so well, we have to change them."
Because in the microworld
the waves are particles and the particles are waves.
Think how hard having this intuition is --
before formalizing it.
Waves are particles and particles are waves.
This is where our technology comes from.
Having this intuition, formalizing it,
and understanding that nature really works like that
has led us to develop more powerful glasses.
Do you want an example?
You have all used an optical microscope:
a light source, the sample, and a lens.
And you look at your sample in two dimensions.
But, if I replace the light source with electrons,
I tear them apart from atoms like marbles -- because marbles are;
I accelerate them with a potential difference -- because marbles are;
and finally I send them to collide against the sample.
When they arrive, they get there with some energy
so they behave like a beam of light
with a much smaller wavelength than visible light.
This means that I see smaller samples.
But they still remain marbles charged with energy.
And that means that I can easily scan
and get the third dimension.
This is the principle behind the scanning electron microscope.
The images it produces are like the one you see behind me,
which is the image of a larva's mouth.
Glasses.
Particle detectors.
But what's even more fascinating is that the detectors
we use to see the electrons interacting with the mouth of the larva
are the same ones that are in smartphones to take pictures,
they are the same ones that went to Mars,
they are the same ones we use to see the protons collide
to reconstruct their traces,
they are the same ones that I installed on the AGILE satellite
that is traveling at 500 km of altitude in equatorial orbit
observing the depth of the universe.
As WMAP of NASA,
but with a different wavelength:
gamma rays.
Think about it, it's like reading the book of the universe
written in another language.
They are part of the same family as those we use to make you a CT scan.
They are detectors that allow us to study and preserve the past.
In 1970, they discovered the En-Gedi Scroll.
More than a parchment it is a small pile of ash
slightly bigger than a coin.
Absolutely unusable.
It could not be manipulated, it would have crumbled,
and it would have been lost.
A few weeks ago,
a group of US and Israeli researchers
made a preclinical micro CT scan, such as those used in hospital:
an X-ray tube running around the pile of ash
to dissect it in many slices.
The same thing is being done in Italy for the scroll of Herculaneum.
They applied a 3D virtual unwrapping algorithm
and they managed to read it,
finding out that it is a copy of the Book of Leviticus.
It seems to be the oldest copy of a book of the Pentateuch
ever found in a sacred ark.
Carbon-14 dating says that it dates back to the third-fourth century.
Detectors, glasses, and our own interpretation
have enabled us to understand that nature is a very complicated puzzle
with many pieces.
Someone has guessed the design,
someone has placed some pieces,
someone has discovered new ones.
What is certain is that
the ultimate goal for those like me who develop particle detectors,
and for all who analyze the incredible amount of data
that these detectors collect, is still the same:
to improve the life of mankind at 360 degrees.
Paraphrasing Einstein,
between your diagrams, your experiments, and research labs
remember mankind, and forget the rest.
What we do, we do it for our and your future.
What we do, we do it for the future of mankind.
Thank you.
(Applause)