Theory of Light Flashcards
the electromagnetic radiation of any wavelength
Light
value of the speed of light
3.00x10^8 m/s
True or False: light travels faster through matter
False: light travels slower through matter
4 primary properties of light
- intensity
- propagation direction
- frequency/wavelength
- polarization
the branch of physics that deals with light
Optics
what theory states that light is composed of subatomic particles (quanta) called photons
Particle Theory
what theory states that light is a form of radiant energy that travels wave-like from one point to another
Wave Theory
this is an experiment that proved that light behaves as a wave and as a particle
Double-slit experiment
this is a subatomic particle known to be discrete pockets of energy and carry momentum. It has no mass and travels at the speed of light
Photons
The main source of natural light on earth
Sun
True or False: the cornea absorbs below 360nm
True
contains both electric and magnetic fields that oscillate
electromagnetic radiation
- perpendicular to magnetic field
- useful in optical mineralogy
- E
Electric field Vector
- perpendicular to the electric field
- small and can be ignored
- B
Magnetic Field
True or False: the electric field and magnetic field are perpendicular to the propagation direction of the wave
True
- the number of crests/ troughs that pass a given point within a second
- Hertz (Hz) ; F
Frequency
distance between two crests
Wavelength
amount of kinetic energy
Energy
important in understanding how light moves through samples and microscopes
Propagation Direction
- represents the direction of propagation of light energy
- not always parallel to wave normal
Light ray
what is the relationship of frequency and wavelength?
indirectly proportional
- light rays are parallel to wave normal
- same velocity of light in all directions
- bonds are the same in all directions
Isotropic materials
examples of isotropic materials
isometric minerals and mineraloids
- light rays are not parallel to wave normal
- different velocity of light in all directions
- bonds are not the same in all directions
Anisotropic materials
examples of anisotropic materials
- tetragonal
- hexagonal
- orthorhombic
- monoclinic
- triclinic
True or False: light rays travelling along the same path in the same direction will NOT interfere w/ each other
False: they will interfere with each other
distance that one wave lags behind the other
Retardation
an interference where two waves are said to be in-phase or in-sync
Constructive Interference
an interference where two waves are said to be out of phase or out of sync
Destructive Interference
visible light with one wavelength
Monochromatic light
visible light with several wavelengths perceived as one color
Polychromatic light
amount of light that can successfully PASS THROUGH a medium
Transmission
amount of LIGHT ENERGY that materials can absorb, reflect, and scatter
Transmittance
incident light hits an object and bounces off
Reflection
incident light causes atoms and molecules to vibrate
Absorption
bending and spreading of waves around an obstacle
Diffraction
light bounces off an object in a variety of directions
Scattering
light waves change direction as they pass from one medium to another
Refraction
limiting the direction of oscillation
Polarization
measures how effective a material is in bending light
Index of refraction
most minerals have indices of refraction that fall in the range of ____________.
1.4 to 2.0
this law states that light is refracted towards the normal upon a medium with higher index of refraction
Snell’s Law
ordinary light that vibrates in all directions
Unpolarized
True or False: All crystalline materials are birefringent
False: not all, isotropic materials are not birefringent
the difference of the indices of refraction that associated with different crystallographic directions
Birefringence
True or False: materials with high index of refraction accelerates the velocity of transmitted light
False: materials with high index of refraction slows the velocity of transmitted light
this visible light has the highest frequency
Violet
this visible light has the lowest frequency
Red