Diapositiva 1 - Dipartimento di Fisica e Astronomia



Diapositiva 1 - Dipartimento di Fisica e Astronomia
The Physics of MAGIC - INTRO
Elisa Prandini for the MAGIC-D Team
Padova, 2 November 2010
For your students
light is…
…what we observe with our eyes…
…and our telescopes…
Optical Observation: the “old” technique
The oldest technique… why?
Telescopes: lenses or mirrors?
Telescopes from Earth or Satellites
Very good angular resolution!
In physics, light
is a wave…
and a particle: the photon!
Collisions with
Molecules, Atoms and Nuclei have
something in common
“discrete” structure  discrete emission!
Nella transizione da una shell all’altra, l’elettrone emette pacchetti
discreti di energia e.m.
And is part of the electromagnetic spectrum
1 Km
700 nm
1 cm
1 mm
100 nm
1 nm
0,1 nm
400 nm
The Electromagnetic Spectrum
Now, let’s enter in the electromagnetic
spectrum starting from the so-called
The Radio Waves World
~10-8 eV
the signal is emitted and observed by antennas (oscillating dipoles)
It is the world of distant communications
Even if it is not visible with our eyes, it is an “everyday world”:
- mobile phone
- radio
- television
- microwave owen
The IR World
~1 eV
Before the RED in the e.m. spectrum
It is the world of HEAT
It is light typically emitted by warm
~3 eV
The Optical World… Our World!
It is the world of objects emitting and absorbing
visible light
The X and g World
keV – MeV – GeV - TeV
The X and g World
keV – MeV – GeV - TeV
The X-rays world is not very bright: high
energies! Man can produce artificially X-rays
(atom and nucleus).
The human body doesn’t emit X-rays, the
bones simply stop them!
What we call “light” is part of the electromagnetic spectrum: it
has the same origin and properties of radio, microwave, X-rays
and gamma-rays. What is different is their ENERGY.
An object can emit one ore more different waves
When we study astrophysical objects we have to consider ALL
the physical phenomena that happen -> that’s why we observe (or
we try to observe) the same target in different wavelenghts
The Milky Way emission
The atmospheric extinction
• Passaggio dalla fisica classica alla fisica moderna
• Misure sperimentali e discussione teorica
• L’evoluzione dell’effetto fotoelettrico: il Fotomoltiplicatore
SEDE DI LAVORO: Polo Didattico (Via Loredan)