The document summarizes the electromagnetic spectrum, which consists of different types of electromagnetic radiation ordered by wavelength. It describes radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays. For each type of radiation, it provides details on wavelength ranges, how they are produced and used, and examples of applications. It also briefly describes the Fermi Space Telescope and its use in gamma-ray astronomy observations to study astrophysical phenomena such as active galactic nuclei and dark matter.

1. ELECTROMAGNETIC
SPECTRUM
SARA DI LUZIO 5 E

2. TABLE
OF
CONTENTS
01. ELECTROMAGNETIC
SPECTRUM
02. FERMI SPACE
TELESCOPE

3. The electromagnetic wave is a
disturbance of a simultaneously electric
and magnetic nature that propagates in
space and can transport energy from
one point to another.

4. The electromagnetic spectrum
is the set of all possible
frequencies of electromagnetic
radiation.

5. The electromagnetic spectrum is
continuous. The names used to
differentiate its portions indicate
waves that have in common the
type of source and use.

6. BANDS ELECTRIC LINES
RADIO WAVES
INFRARED
VISIBLE LIGHT
ULTRAVIOLET
X - RAYS
GAMMA RAYS
MICROWAVES

7. RADIO WAVES
They are electromagnetic
radiations belonging to the
frequency band between 0 and
300 GHz, with a wavelength
greater than 1 mm. They are
used for the transmission of
sounds and images from a
distance.
They are produced by
accelerated electric charges in
a metal poles (antennas).
The amount of information that
can be carried by a radio signal
is proportional to its frequency.

8. RADIO WAVES
They are used for radio and TV
transmission.

9. MICROWAVES
Microwaves are electromagnetic radiations that
have a frequency between 1 GHz, corresponding
to the wavelength of 30 cm, and 300 GHz.
Microwaves are widely used in data
transmission or point-to-point television
transmissions between a mobile shooting site
and the main station.
They have been used since the
Second World War in radar systems
to determine the presence, position,
shape, size and speed of aircraft and
ships.

10. MICROWAVES
LABORATORY

11. How do you estimate the
speed of light?
LABORATORY
If you insert a chocolate bar in the
microwave for 15/20 seconds, you can
observe the half wavelengths
generated by the electromagnetic
waves emitted by the oven.
To estimate the speed of light, simply
measure the distance between the
crest and the trough with a ruler,
convert it into meters, multiply by 2
and then multiply by the oven
frequency in Hz. C ≈ frequenza * lunghezza d’onda
C ≈ 2,45 GHz * (2 * 0,06 m)

12. INFRARED RADIATION
Infrared radiation is electromagnetic radiation with
a wavelength between 700 nm and 1 mm. The term
means "under the red", because red is the visible
color with the lowest frequency.
It is mainly produced by thermal emissions. All
bodies emit infrared electromagnetic radiation, due
to the molecular thermal agitation. Molecules also
easily absorb these radiations, causing an increase
of vibration motion.
For this reason the bodies exposed to infrared
rays heat up.

13. elephant observed with
infrared rays
The infrared band
portion hepls us
give a temperature
map of the
surrounding world.
Infrared rays also
detect the traces left
by the paws .

14. VISIBLE LIGHT
The visible spectrum is the part of
the electromagnetic spectrum
between red and violet that includes
all the colors perceivable by the
human eye. The wavelength of
visible light in the air ranges
approximately from 390 to 700 nm .

15. ULTRAVIOLET RADIATION
A PARTICULAR
ECLIPSE
The colors that can be
admired therefore
correspond to the different
wavelengths in the
ultraviolet bands.

16. ULTRAVIOLET RADIATION
UV radiation covers that
portion of the
electromagnetic spectrum
with a wavelength between
100 and 400 nanometers and
is divided into three main
categories:
-UVA (315-400 nm)
-UVB (280-315 nm)
-UVC (100-280 nm).
Some substances can absorb UV
radiation and reemit radiation at a
different wavelenght, usually in the
visible spectrum: this phenomenon
is called phosphorescence.

17. Upon exposure to UV
rays, melanin
production increases
causing the skin to
tan, but a prolonged
exposure increases
the risk of certain
types of tomours.

18. X-RAYS
X-rays have a wavelength between 10 nanometers and 1/1000 of a
nanometer (1 picometer), classified as ionizing radiation, having a very high
penetration power: only thicknesses of the order of centimeters of lead or
decimeters of concrete can stop them.

19. X-rays
were
discovered
by Wilhelm
Conrad
Rontgen in
1895.
They are generated every time high-energy
electron beams are stopped by matter. The
electrons cause the ionisation of the gases they
pass through, moreover they cause
phosphorescence in some substances; these
properties allow us to build devices and screens
to detect this type of radiation.
Although they are very useful for therapeutic purposes, they are
very dangerous, so they should be used with caution!

20. In 1953, Watson e
Crick discovered the
double-helix structure
of DNA molecules
thanks to their
analysis of X-rays
diffraction patterns.

21. GAMMA RAYS
The frequency of this radiation is
greater than 1020 Hz and the
wavelength is less than 3x10−13
m, much less than the diameter
of an atom. This radiation is
spontaneously emitted by the
nuclei of radioactive atoms.
Gamma rays were initially thought of as particles, but various
observations, such as reflection on the surface of a crystal, showed
that it was electromagnetic radiation.

22. THE FERMI SPACE
TELESCOPE AND
GAMMA RAYS
Team work

23. The Fermi Gamma-ray Space Telescope is a space
observatory being used to perform gamma-ray astronomy
observations from low Earth orbit. It’s main instrument for
studying astrophysical and cosmological phenomena such as
active galactic nuclei, pulsars, other high-energy sources and
dark matter.

24. Mario Nicola Mazziotta and Francesco Loparco have been
analyzing the Moon’s gamma-ray glow to understand the
fast-moving particles called cosmic rays.
«Seen at these
energies, the
Moon would
never go through
its monthly cycle
of phases and
would always
look full»
Loparco
Although the gamma-ray Moon doesn’t show a
monthly cycle of phases, its brightness varies by
about 20% over the Sun’s 11-years activity cycle.

26. THE END
SARA DI LUZIO 5 E