Gamma rays:)

external image gamma_ray_sky.gif

What are they?

-Gamma rays (γ-rays) are electromagnetic waves with the smallest wavelengths in the electromagnetic spectrum They were discovered in 1900 by Paul Villard and named in 1903 by Ernest Rutherford.
-Gamma rays are ionizing radiation, and are thus biologically hazardous.

Are they dangerous?external image angercamera.gif%3Fw%3D342%26h%3D323

-Gamma rays are very harmful to living creatures.

Where do they come from?

-Gamma-rays are produced by radioactive atoms and in nuclear explosions.
-Gamma rays are a form of radiation.

How do we detect them?

-Gamma-ray detectors typically contain densely packed crystal blocks. As gamma rays pass through, they collide with electrons in the crystal.

What can they be used for?

-Doctors use gamma-ray imaging to see inside your body. The biggest gamma-ray generator of all is the Universe.
-In interactions with matter, gamma rays are ionizing radiation and produce physiological effects which are not observed with any
exposure of non-ionizing radiation, such as the risk of mutations or cancer in
tissue.
-Gamma rays provide information about some of the most energetic phenomena in the universe; however, they are largely absorbed by the Earth's atmosphere. Instruments aboard high-altitude balloons and satellites missions such as the Fermi Gamma-ray Space Telescope provide our only view of the universe in gamma rays.

Anything else interesting?

-Gamma rays have the smallest wavelengths and the most energy of any wave in the electromagnetic spectrum. They are produced by the hottest and most energetic objects in the universe, such as neutron stars and pulsars, supernova explosions, and regions around black holes. On Earth, gamma waves are generated by nuclear explosions, lightning, and the less dramatic activity of radioactive decay.
-If we could see gamma rays, the night sky would look strange and unfamiliar. The
familiar view of constantly shining constellations would be replaced by
ever-changing bursts of high-energy gamma radiation that last fractions of a
second to minutes, popping like cosmic flashbulbs, momentarily dominating the
gamma-ray sky and then fading.

how do mobile phones work?

As you talk on your phone, your phone converts yourexternal image how-mobile-networks-work.jpeg
voice into an electrical signal, which is then transmitted
as radio waves and converted back into sound by
your friend’s phone. A basic mobile phone is therefore
little more than a combined radio transmitter and a
radio receiver, quite similar to a walkie-talkie or CB
radio. In order to remain portable, mobile phones
need to have relatively compact antennas and
use a small amount of power. This means that mobile
phones can send a signal over only a very short range,
just like a walkie-talkie.Many people use phones now,
therefore the waves that send the texts will be quite
cluttered. In reality we can't see these waves but if
we could we wouldnt see past them.





In the table below, fill the cells with very brief notes. Use the other pages to gather the information from, and you may want to go outside of this wiki if you really can't find the information here (though I'd be surprised!).



Gamma
X-rays
UV
visible
IR
microwaves
radio
How are they generated?
Gamma-rays are produced by
radioactive atoms and in nuclear
explosions.
X-rays are generated by an X-ray tube,
a vacuum tube that uses a high
voltage to accelerate the electrons
released by a hot cathode to a
high speed, they can be produced
many different ways to produce
different frequencies of wave that
can be used to see through different
objects. They are produced in parcels
of energy called photons.
They can come from the sun,
but you can get man made
lamps for experimental perposes,
tanning ect... they produce
ultra violet rays, just as the
sun does.
hot thingslumenecnt things
stars
photons
NOT THE MOON.



How are they detected?
Gamma-ray detectors typically
contain densely packed crystal blocks.
As gamma rays pass through, they
collide with electrons in the crystal.
In hospitals the pictures were
captured using image receptors
such as thin films and photographic
plates.
To detect them you can simply
use a filtrate this is the cheepest
option and used frequently.
with our eyes.



How might they be dangerous?
Gamma are dangerous as they are
radioactive.
X- rays can damage cells and
cause cause cell mutation
which can cause cancer or cell death
Tthey can be dangerous as they
damage and kill cells.
Seeing
displaying info
lighting areas.



Infrared waves are heat waves.
If the cells absorb too much
infrared radiation the
heating will damage or kill the cells.


What are the main or most significant uses?
Doctors use gamma-ray imaging
to see inside your body.
X- rays can be used to look atthe internal structure of objects.
Ultra violet rays can be used
for tanning, in a tanning bed or
by the sun.
entertainment




The section on Gamma rays is done well, though the table still needs some work, after a good start.
Well done.
B+


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