c'est quoi la lumiere?
une forme d'energie - lumineuse
types de lumiere
phosphorescence
fluorescence
bioluminescence
chimioluminescence
incandescence
fluorescnece
absorbe les particules uv et emet sous forme de lumiere
bioluminescence
light that comes from living things
chimioluminescence
lumiere emi a cause d'une reaction chimique
incandescence
light emitted because of heat
phosphorescence
absorbs the light and then emits it later (like the paint on car buttons)
sources de lumiere
chimique
naturel
artificiel
things that use light
microscope
loupes
lentilles portatifs
proprietes de lumiere
light travels in a straight line
light travels in waves
light refracts
light reflects
electromagnetic spectrum
gamma rays
x rays
uv rays
visible light
infrared
microwaves
radio waves
what happens to light when it hits something opaque
the rays bounce off (some get absorbed)
what happens to light when it hits something translucid
some go through, some bounce off
what happens when light hits something transparent
the rays go directly through it
parts of a reflection
normale, angle d'incidence, angle de reflexion, rayon d'incidence, rayon de reflexion
concave mirror
curved inwards, makes the light rays converge
convex mirror
curved outwards, makes the light rays diverge
refraction
the bending of light due to change in density
more dense substance to less dense substance
light refracts away from the normale
less dense substance to more dense substance
light refracts towards the normal
mirages
since light refracts, changes in density can make the light bend so you think something is closer
concave lens
curved inwards, makes the rays diverge
convex lens
curved outwards, makes the rays converge
nearsightedness / myopia
concave LENS
farsightedness / hypermyopia
convex LENS
lens/mirrors: microscopes
lenses
lens/mirror: binoculars
prisms/lenses
lens/mirror: refracting telescopes
lenses
lens/mirror: reflecting telescopes
mirrors
how the eye works
light enters the eye through the cornea and pupil, reaching the lens which is bent by the muscle ciliaire. the light is then refracted to converge at the retina, where batonnets and cones respond to the light level and colours. the invformation then travels to the brain by the optic nerve. the brain flips the image it receives, as when the light converges at the retina it also flips the image.
circular pupil eyes
depth perception, but less field of vision - predator
horizontal pupil eyes
this prioritizes vertical field of vision - predator
vertical pupil eyes
prioritizes depth perception close to the ground - predator
horizontal pupil eyes (not curtain like)
prioritizes a large field of vision
why can birds see tiny things far away?
their muscle ciliaire can bend their lens so much to focus on things very far away
how does a laser work?
rays of light reflect inside the laser to give it more energy, and then exit through one side that is very slightly translucid (2%) to make a concentrated beam of light
laser eye surgery steps
1 - peel off the top part of your eye
2 - shave off a small piece of your cornea ( changes the shape )
3 - changes the focus of your eye
nocturnal imagery
intensifies the light that it absorbs
infrared imagery
detects heat, and then makes an image out of information they get from each point of the area