Gamma Raysexternal image gamma_ray_sky.gif


What are they?

They are electromagnetic waves with the smallest wavelengths in the electromagnetic spectrum.

They also have the most amount of energy. They were descovered by Paul Villard in 1900 and

named by Ernest Rutherford in 1903.

external image addgateway_cancertreatment.gif

Are they dangerous?

They are extremely harmful to living creatures, which is why they're used to destroy cancerous cells.

Where do they come from?

They are generated by radioactive atoms and in nuclear explosions. They also come from

stars, black holes and pulsars.

How do we detect them?

We detect gamma rays by using telescopes, but they don't look like normal telescopes.

They observe gamma rays indirectly, by monitoring flashes of visible light. Gamma rays

are a form of radiation.


What can they be used for?

They can kill living cells, they can even kill cancerous cells. Doctors also use gamma rays to find disease.

In hospitals, doctors can give patients radioactive medicine which emits gamma rays. You can also use

gamma rays to sterilise hospital materials. They can also detect brain and cardiovascular abnormoralities.


Anything else interesting?

They can go through a brick wall, gamma rays can travel through thicker materials than x-rays.


The History of the Radio

Who invented the radio?
There are several people that have been credited for inventing the radio. The first was Tesla and
Guglielmo Marconi, who sent the first radio signal in the year 1895.

Where does the name 'Radio' come from?
The device we call a radio took its name from radio telegraphy. It was commonly referred to as
“wireless” up until World War II when the military preference for radio caused that name to catch on
to describe the revolutionary receptacle of sound. The word radio is derived from radius, Latin for
“spoke of a wheel” or “ray of light,”because transmitted sounds travel out in all directions from a center
hub like the spokes of a wheel.

When was it invented?
In 1855 provided the first demonstration of wireless communication, and then in 1895 Guglielmo Marconi
sent the first radio signal. shhh
external image roberts-radio-rosa.jpeg















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?

They are generated by radioactive

atoms and in nuclear explosions.

They also come from

stars, black holes and pulsars.

An X-Ray tube or objects in space
They can come from the sun, but you can get man made lamps for experimental perposes,
like for tanning for example.

William Herschel conducted an
experiment measuring the difference
in temperature between the colours in the
visible spectrum. He placed thermometers
within each color of the visible spectrum.
The results showed an increase in temperature
from blue to red. When he noticed an even
warmer temperature measurement just beyond
the red end of the visible spectrum, Herschel had discovered infrared light.
Microwaves are essentially high
frequency radio waves, which are
made by different types of transmitter.
For example, in a phone, they are
generated by a transmitter chip and an antenna, while in a microwave oven they are generated by a 'magnetron'.
Radio waves are energy waves that are generated by a transmitter. Radio waves are also known as electromagnetic radiation and the typical shape of the wave produced by a transmitter is that of a sine wave.
How are they detected?
We detect gamma rays by using
telescopes, but they don't look like
normal telescopes.They observe gamma
rays indirectly, by monitoring flashes
of visible light. Gamma rays
are a form of radiation.
Satellites or image receptors such as thin films or
photographic plates
To detect them you can simply use a filtrate this
is the cheapest option and used frequently.

Humans can't see infra-red rays, but instruments that can sense infrared energy, such as night-vision goggles or infrared cameras allow us to "see" the infrared waves emitting from warm objects such as humans and animals.
Because humans cannot detect electromagnetic radiation we need special tools to detect them. If the waves are used for communications we use a reciver to detect them. If we are checking for contamination we can use a gieger tube to test for them.
Radio waves are detected by the use of radio telescopes.
How might they be dangerous?
They are extremely harmful to living creatures,
which is why they're used to destroy cancerous cells
The radiation can cause cell mutilation whichis often a cause of cancer
They can cause sunburn, and for the minority of
people this could result in skin cancer.

Infrared waves are heat waves. If the cells absorb too
much infrared radiation the heating will damage or kill the cells.
Infrared from the sun causes sunburn.
Prolonged exposure to microwaves is known to cause cataracts, which is a clouding of the lens, in your eyes preventing you from seeing clearly. Recent research indicates that microwaves from mobile phones can affect parts of your brain
It is believed that exposure to large doses of radio waves can result in disorders such as cancer.
What are the main or most significant uses?
They can kill living cells, they can even kill cancerous cells.
To detect bone breakage or they're used in dentists
For tanning, and killing bacteria.

Night vision goggles pick up the infrared light emitted by our skin and objects with heat. A remote control uses light waves just beyond the visible spectrum
of light—to change channels on your TV. Infrared is also used for cooking in grills and toasters.
Therefore we can use microwaves to cook many types of food. Mobile phones use microwaves too.
They can be used for transmitting sound and television signals, radio is used for the transmission of data in coded form. In the form of radar it is used also for sending out signals and picking up their reflections from objects in their path

Good work. The Gamma ray section has good information, and you have done well with the table.
Next time, either use images that fit with the text, or include cations that explain the images.
Good work. A-

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