The (in)visible Universe | Roberto Battiston | TEDxBergamo

This talk was held at a TEDx event using TED talks format, but organized indipendently by a local community. For additionl info, please see at http://ted.com/tedx

Roberto Battiston was born in 1956 in Trento-Italy. since 1993 he is professor of General Physics at Engineering Faculty of Perugia University and since 2012 professor of Experimental Physics at Physics Dept. in Trento.
For more than 30 yers active in international scientific collaborations about experimental physics on fundamantal particles interactions in accelerators or in space (Strong , Weak and Electromagnetic interaction Physics, Study of Space cosmic rays).

He was eputy spokesperson for AMS, the big experiment to search space antimatter, instalìed on ISS spacestation, on May 2011, during STS134 mission. He authored more than 400 papers published on international journals and 3 patents. In additon he organizes numerous congress on space sciences (Trento 1999, Elba 2002, Washington 2003, Beijing 2006, CERN 2012).

He also carries out activities for scientific publications, collaborating with newspapers (La Stampa, Il Corriere della Sera, Il Sole 24 Ore) and magazines (L'Indice, Le Scienze). For years In the latter he is writing a monthly column
and a blog "Stars and Particles".

Light, where does light come from?

All the light around us,

even the one coming from
these lit objects

comes from the sky.

One way or another it reached us,
maybe some time ago, from the sky.

Light comes from cosmos only.

From which cosmos? From the one around us.

From this sky, that we cannot see
in our city.

Bergamo cannot see this sky,
you can see this sky in Africa only.

You see it in the dark, when the city
doesn't illuminate night sky.

If you happen to go in southern world,
you can see this sky.

Well, let's imagine to be some time ago,

two and half million years ago.

There will even been a first hominid
in his evolution phase

who raised up from the ground

and he realized what he got
above his head.

Imagine that moment,
an important moment for our history

that comes from the remote ancient times.

From that moment onwards, man always had
with him in his culture

the awareness of universe
and of light coming from the sky.

Let's have a quantum leap.

You know this profile very well.

It's Stonehenge profile.
What Stonehenge is?

It is an achievement
of a primitive people.

About 4,500 years ago,

then practically before History begins.

It is an example on how the study,
the sky observation,

had shaped the human culture.

In order to make this particular
building system,

that ancient people did a huge effort,

they brought very heavy stones

from dozens, perhaps hundreds
kilometers far away,

to structure them
in a very large circular frame.

Why?

In order to watch stars.

To see planet motion,
to understand when it is sow time,

when to harvest.

In order to do rituals
related to mythologies,

just related to information
coming from the sky.

Sky always shaped our culture:

Mayan, Egyptian and
all the humanity history

and, according to this example,
using technology,

most advanced features at that age.

Let's have another jump,
about 2,300 years.

We are in the Mediterranean Sea,

a Greek-Roman ship
carries some goods

between Greece and Italy

and it sinks in front of Kythera Island,
a Peloponnese island.

In 1906, at previous century beginning,
this wreck was found

and while collecting the wreck stuff,

in the hold of a 2,200 years old ship

at that point,
apart from the usual amphorae,

structures like these were found,
some sort of small wheels

completely covered with limestone,
brought to Athens museum

and left there for 60 years long.
Nobody knows what they were.

60 years later, they make them
radio-graphs with x-ray

and discover within those wheels
some very thin gears

like clocks of 1600 century,
but we are in 200 b.C. century.

This was some sort of astrolabe,

a system which allowed
to powerful people of that time

to compute planet motion,
above all sun and moon eclipses.

Imagine what does it mean
for a General, or for a politician,

to know when the sun is going to hide,
when the moon is going to be overshadowed.

An incredibly sophisticated technology.

Marcus T. Cicero told us that
two of this machine type,

were available at that time,
in the Greek-Roman civilization.

We found one of them undersea,
an extraordinary good luck!

Another example of how technology,
the more advanced one,

had been made available,

but for what?

In order to study, to understand the sky.

Let's have another jump.

This is an Almagesto page.

Almagesto was a sort of encyclopedia,
like the Britannica one,

where all the information known
to mankind were collected

in one thousand years between
the end of Roman Empire

and half of first millennium.

As you can see from these images,
Earth is perfectly shaped.

It has all its continents: North and
South America, even Australia.

What's the problem?
It is at the center of the world.

All the celestial spheres surround it.

The one carrying the Sun,
the one carrying the Moon,

the various planets, gradually up to
the sphere that leads to the fixed stars.

Indeed, being in 1550, America
was discovered by Columbus in 1492,

but it is not yet a clear understanding
where this planet stands

within the Universe.

Indeed, we have to wait until 1609,
when Galileo,

using this small spyglass which
you can buy with 50€ in a general store,

understood that some satellites
were turning around a planet, Jupiter,

and that they were drilling, ruining,

they were destroying
celestial spheres harmony.

At the end Earth found
its position in the Universe.

The Sun was not turning around the Earth,

but Earth was turning around Sun.

Spyglass, the technology of that moment,

now, the technological development
leads to extraordinary progresses.

This is a previous century spyglass,

it is the spyglass through which Hubble
looked at our galaxy for a long time,

he took pictures of our set of Stars,

that then it was thought to be
the whole Universe

and while studying some small stars,
a bit blurry,

from night to night he understood
that other galaxies exist,

very, very far away.

From night to night
Universe expanded

by a factor of a thousand more

and from then on
we continued expanding it,

up to, pretty much, to its origins.

This by using a telescope clearly
very much powerful than Galileo's one.

Today we have in space
the telescope of telescopes:

Hubble telescope,
which looks at the Universe

using extraordinarily favorable conditions

being able to do observations
from the space

and this picture you can see
on the right side

is a Cosmos pinhead
on our head above

hugely magnified by Hubble

and we can see early galaxies,
early protostars,

we can see an Universe how it was
billions and billions of years ago.

I told you that technology is fundamental
to understand the Universe around us

but you'll see how amazing
is the pace

of technology evolution
in the last century.

Last century allowed us to do much greater
advancements

than in thousands and billions of years
before now.

You can see this picture,
we are in Scrovegni Chapel

and we see how in 1301 Giotto
painted a wonderful series of paintings

including the Nativity and you can value
this painting beauty

because we can see the shape,
the persons images,

animals, a hut perspective

but above the hut we see a ugly comet

some sort of reddish shapeless small ball

and we wonder why a so great painter
as Giotto was

had drawn a so ugly comet.

Because he had seen it in the sky,
because in that moment he saw

that star passing on his head.

It is Halley comet, which passes
each 76 years

and in 1301 it was passing
on this painter's head

who precisely copied it.

In fact, these photo in 1910,
first ones of this comet,

show us a structure totally similar

to the painted one by Giotto in 1300.

In 1986, 76 years later,

man was able to make
his artificial satellites

his remote-controlled robots

which literally went to pinch the tail
of Giotto comet

In order to see how it is made.

600 years to go from eye to photography,

76 years to pass from photography

to the ability to reach Halley comet.

Technology, technology.

These gentlemen are Penzias and Wilson,

two engineers who become famous

because substantially they authored
a paper which says:

we tried to build an electronic equipment

with a very low environmental noise

which had practically to measure
no one of any noise types

and we hear a continuous, deafening noise,

coming everywhere from the universe.

This equipment has its own ear,

which is an antenna, a sort of
a big radio antenna,

which allowed them to realize that
their noise comes from everywhere.

They don't know what they had found,
published this finding

and after a few later,
others understood

that they were listening to
the Big Bang echo

and they awarded Nobel prize for that.

A noise which is actually the echo
of the initial big explosion.

Today, we perform studies of the same kind
using more powerful equipments.

This stratospheric balloon studied
that Big Bang echo,

understanding that it has
a very particular structure.

If you wear glasses in order to see
the Big Bang

they are a sort of someway
special Goggle glasses,

made by scientists studying these things

and you get out to see the sky,
you'll see a pocked one,

as it had measles.

That measles is the detail
of Big Bang explosion,

as you can see it 300,000 years later.

Maybe you have seen
a picture like this

In the headlines of main newspapers:

a satellite named Plank

completed this picture of the sky
affected by measles,

Big Bang measles,

this is just a sky, which revealed
280,000 years,

300,000 years after Big Bang.

But recently you read on newspapers
this unbelievable thing,

an equipment located at South Pole
did much more.

It found in this picture
of 300,000 years ago

a mark of something that happened

1 billionth of second after
the initial explosion.

These polarized light circles in the sky

are telling us what happened
just at the beginning of time.

Technology. But what happened
over the past 50 years?

A very big revolution.

We learned how to see the Universe colours

which are not visible to human eyes

and above all not visible from the Earth.

The Universe seen by Galileo, Hubble,
using telescopes,

is sending us the light
which goes through atmosphere.

This light is a visible light which
goes fairly through the air.

Radio waves seen by Penzias and Wilson
are like the ones done by cellular phones,

they fairly go through the air.

But there are many other waves

that cannot go through the air,

and, in order to see them, we have
to go out, literally, from the atmosphere.

Over the past 50 years we were able
to do so systematically

and we were able to get all the colors
of an otherwise invisible Universe.

For instance this picture you can see
if we shift to visible light

is the Universe, Milky Way,

which dominates our viewpoint,
seen from the Earth,

by the first hominids' eyes,
by Galileo's eyes and Hubble's ones.

in the visible range.

It has some structure,

We cannot see it clearly as a whole,

but it has these features.

If we shift in the infrared range,

which is a frequency that doesn't go
through the atmosphere,

we can see a totally different shape.

In the microwaves range,

the ones of the microwaves oven
we have in our kitchen,

again it changes completely.

In the radiowaves range, the one
we can see from Earth, too,

where are Penzias and Wilson measures,
it changes again;

some set of cold gas

which appear and give out
that kind of radio light.

In the ultraviolet range,

which is a color not going easily
through atmosphere,

all a series of stars appear which are
otherwise invisible in the visible range.

In the x-rays range,
our Universe changes again,

it looks completely different
with very hot sources.

To finish in the gamma rays range,
which are those nuclear explosions,

where some objects are exploding
in a nuclear way

inexhaustibly, since millions
and millions years.

This is the Universe we have
in front of our eyes

a Universe full of colours,
that 50 years ago we don't know.

This is the part of an invisible Universe
which has become a visible one,

which has unveiled during
the last 50 years,

thanks to people work
like Riccardo Giacconi,

an Italian who awarded Nobel prize in 2002

because he found Universe
made of X-ray sources,

nobody believed it,
"He can't do this experiment."

He stubbornly insisted,
he went to America

and he made this satellite,
put into orbit

and he saw first X-rays sources.

Or this satellite called Fermi,

as a tribute to our great physicist
in 40-50 years,

which literally observes
the very hot Universe

along an endless nuclear explosion.

Or these even more modern equipments
called "Cherenkov-light" tools

which look at light
with a so ultimate color

that we aren't able even
to produce it in our labs

a terribly high energy

produced in some cases
by those sources, energy monsters,

which are somewhere In our Universe.

This partially explains because
we have so many satellites,

each is an eye looking at
different colours

looking at different distances,
looking at a short or long distance

reaching visible Universe borders,
unto Big Bang touching.

Then we now have these beautiful pictures

of the Milky Way, but of the Universe, too
in all the imaginable colours.

This is our Universe,
become visible over the past 60 years,

previously its 90%
was completely unreachable.

We finished, did we reach
science fulfillment?

Do we get visible limits?

No, we don't.

We indeed don't yet know what is
the true dark Universe.

There is a so dark Universe that
light cannot be released,

not only released light
doesn't go through atmosphere.

It is a Universe substantially invisible
for any light type.

Then we recently learned
over the past 50 years,

many things about the Universe.

We know it is flat, homogeneous,
isotropic, made of radiation,

matter, protons, neutrons,
as we are,

but we knows that is 4% only of the whole.

It exists a component, called dark matter,

that we know is about 23%,

six more times plenteous than usual matter

and it is in this room, it goes across us,
but we cannot see it.

Not only, we understood that there is
another 73%,

which is vacuum-hidden energy,
absolutely unknown

beside that it exists.

Among other things, primeval anti-matter

that symbolizes Big Bang

has gone away and we don't know
where it has been.

So we learned to look at
all the Universe colours

but while we are doing so,

we discovered that about 95%
of the Universe,

which is literally here, but invisible,

using all the techniques we invented

over the past 50 years,

So we know that we don't know,

we never have been
so consciously ignorant

about nature.

So, after a century
of extraordinary growth

after a literally exploding technology

that opened us all the Universe colours,

we reached a new board, a new border,

we know that 95% of what is around us
should still be discovered.

So we are on the new millennium
thresholds

when we have still to discover most things

which are around us.

So my meaning for this TEDx Talk is,

"AAA. We know that 95% of Universe
is invisible at all.

Looking for ideas to understand
what is made of."

Thank you.

(Applause)