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Slide 1

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RED SHIFT ELECTROMAGNETIC RADIATION
Light is shifted towards the red end of Remember: RMIVUXG
the spectrum. It shows that the galaxies Radio-waves, microwaves, Infrared, Ultra-violet, X-ray, Gamma
are moving away from us, as galaxies
with a bigger red shift are further away.
The universe is expanding because of Frequency increases, wavelength decreases
Radio-waves: Used for communication, t/v & radio
`Big bang' theory: that the universe
Microwaves: Used for satellite communication-mobiles &
exploded from one point
cooking. Danger: overexposure=burning
Nuclear radiation
P1b Infrared: Remote controls ,optical fibres
Visible: We can see this
Alpha: helium nuclei, 2 protons & 2 X-rays: detect broken bones
neutrons Telescopes
Gamma: Can treat & cause cancer!!
Beta: electron Earths atmosphere
Gamma: electromagnetic waves Analogue & digital signals blocks most E.M.
Alpha: most penetrating, gamma: waves so telescopes
Digital signals carry more info, are
least penetrating are made above
securer & faster. They have only 2 ground/sea level
Gamma: most ionising, alpha: least
Alpha used 4 smoke detectors: alpha
values 1& 0. Space & mountains
causes ionisation in air=current. Analogue signals pick up interference & telescopes: Avoid
When smoke enters current stops= noise= no longer original signal. They're earths atmosphere
siren sounds put into repeater stations but the noise and get clearer
Beta: thickness of paper: If paper is is also amplified. picture but they're
too thick then less beta particles will more expensive to
go through launch & maintain!
Gamma: cancer, sterilising food…read more

Slide 2

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Electromagnetic spectrum
Want more info? http://www.bbc.co.uk/learningzone/clips/10677.flv
OPTICAL FIBRES
The infrared rays are totally
internally reflected (T.I.R) because
the reflection angle is above the
critical angle
HELP!! http://www.bbc.co.uk/learningzone/clips/12236.bb.rm
RED-SHIFT The opposite of red shift is blue shift when the colours are shifted
towards the red end of the spectrum/
Doppler effect: apparent increase in wavelength BUT decrease in
frequency for sound
NUCLEUR RADIATION Need more revision? http://www.bbc.co.uk/learningzone/clips/4561.bb.rm
<Penetration
Alpha & beta are deflected in
a magnetic field, gamma isn't…read more

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