So I will talk about Neutrinos. I will try to explain that
these are particles with really curious and different properties
compared to the other particles known so far.
Particle physics is able to answer to questions like:
what are we made of? what are animals made of?
So, these walls of this building, the stars, everything
is made up by a small quantity of few ingredients.
Only a few elements are needed in order to explain what everything is made of.
So, there are quarks, that exchange gluons among them.
Gluons are only exchanged among quarks.
There are electrons that exchange photons among them and with
the quarks because they are all charged.
So, what we may be asking ourselves is: Is that it?
Is this everything the Universe is made of?
Well, it is everything we can easily see but
there are more things in the Universe, particularly neutrinos.
And there are a lot of neutrinos in the universe:
ten billion for each quark or electron.
They are everywhere and have diverse origins.
For instance, in each cubic centimetre of the universe
(in a little cube with a side of 1cm) there are
300 neutrinos approximately.
Neutrinos were produced in the first stages of the Universe,
they are vestiges of the Big Bang that are still wandering arround:
300 in each cubic centimetre.
By its nature, our bodies produce hundreds of thousands of neutrinos each day.
Here we have an intern, that probably lives under poor conditions,
and that is continually producing neutrinos without noticing,
hundreds of thousands of neutrinos each day.
But actually, the Sun, is one of the most productive sources
of the neutrinos around us. The Sun produces considerably
more neutrinos than the unfortunate intern.
Specifically, 100 trillion neutrinos that
come from the sun go through us and through the
unfortunate intern each second without being noticed.
The question then is, if there are so much neutrinos everywhere
produced by the Sun and also by ourselves without realizing about it,
being these neutrinos in each cubic centimeter,
How is it possible that it took us so long to discover them? Why can't we feel them?
The fact is that, even though there are tons of them,
they behave as if they were ghosts, that is why they seem to be invisible.
They are able to go through matter without interacting with it,
without changing and without altering the matter they go through.
Ir order to have an idea, from all of these trillions of neutrinos that
come from the sun and that go through us each second,
only one out of every 100 quintillions (of
those who go through us) interacts with us,
and this few that achieve interaction with us
posses such a tiny mass and so low an energy
that it is impossible for us to perceive them.
Excerpt from the conference held
November, 14th, 2013, at the Residencia de Estudiantes,
during the sessions "La frontera de la Física Fundamental".
Full video available at: www.eddaddeplata.org