1. The electromagnetic spectrum is the set of all the possible frequencies of an
electromagnetic wave.
So e.m. waves are classified by their frequency and wavelength and by their typical
use.
Radio waves have the shortest wavelength and they’re used to transmit information
in general.
Then we have microwaves which are used in microwave ovens to move hydrogen
atoms to heat food.
We’ve done an experiment about microwaves ovens to detect the wavelength by
observing melted spots on a piece of chocolate.
The infrared radiation is emitted by thermal agitation of bodies and it is visible by
special cameras. It is also used for remote controllers.
The visible light is the portion of the e.m. spectrum that we can see.
Ultraviolet light is close to the visible light and it absorbed by some materials which
emit another e.m. wave visible to us. Ultraviolet rays from the sun are responsible of
many types of tumors.
x-rays are used in many fields to see hidden objects with special machines.
Gamma rays have the shortest wavelength of the spectrum. We’ve done a group
research about gamma rays and the fermi telescope.
One hypothesis about dark matter is that it consist in hypothetical particles called
axions which are able to transform in photons when influenced by a magnetic field.
During the explosion of a supernova gamma rays’ photons are transformed in
axions, then they escape quickly the explosion and return to gamma rays form.
The Large Area Telescope is able to detect gamma rays but the problem is knowing
when and where to look for supernova explosions.
So new studies are focused on tracking and mapping supernova explosions with
common telescopes to predict when they’re going to happen in the future.
