Light and Optics (full)

4 basic properties of light

1. Travels in straight lines

2. Can be reflected

3. Can bend

4. Is a form of energy

What is the law of reflection?

angle of incidence = angle of reflection

What is the normal?

An imaginary line that's perpendicular to the surface at the point of incidence

What are reflections?

Form of energy made of protons

What is refraction?

Bending of light when it passes through a diff. substance with a different density causing a change of speed

Frequency (Hz)

the number of complete wavelengths that pass a point in a given time

What happens when light passes through a small opening?

The waves spread out

which color has the most visible light?

Red

What is the incident ray?

a light ray that strikes a surface/ incoming ray

How does the reflection appear clearer?

With shinier/smoother surfaces

What does a concave mirror do?

Reflects light and focuses it to one point

What does a concave lens do?

bends towards normal and diverges light, appears virtual, upright and smaller (focal point in front of lens)

What are oscillations in light?

Back and forth motions of the electromagnetic fields

Which color has the shortest visible length?

Violet

What happens to the frequency if the wavelength is longer?

The frequency lowers

Gamma rays are?

high energy electromagnetic waves

primary colors of light

red, green, blue

What do the primary colors of light make?

White

secondary colors of light

yellow, magenta, cyan

Different wavelength of light have?

Different amounts of energy

Why is the sky blue?

The air molecules scatter blue light better than red light, so more blue light reaches our eyes.

Why is the sunset red?

the majority of the blue light has already been scattered away

What do convex mirrors do?

Reflects light outward, appears virtual, upright and smaller, wide view

What do convex lenses do?

bends light towards normal and converges (magnifies) focal point behind lens (virtual)

What do and red and blue light make?

magenta

Which part of EMR sterilizes metal?

Ultraviolet

How can hyperopia be corrected?

convex lens

incadescent light

Electricity running through wires causing it to glow

What is in the EMR that is felt with heat and thermograms?

Infrared

How do our eyes adjust to darkness?

The iris/pupil dilated/gets bigger

How can myopia be fixed?

concave lens

Which has the shorter wavelengths, ultraviolet or infrared? Which has the higher frequencies?

Ultraviolet has shorter wavelengths and higher frequencies.

Is this right or wrong? Lower frequency = high energy

Wrong

How does the image form with hyperopia?

Forms behind the retina

What is specular reflection?

Reflection when parallel rays hit a smooth surface; all ray reflect at the same angle

What is diffuse reflection?

Reflection when parallel rays hit a rough surface; rays reflect at diff. angles

What is intensity?

Brightness of light; a light meter a measures the intensity of light

What is non-luminous?

Objects that don't produce light but may reflect it

What is luminous?

Objects that produce light

What is the reflected ray and point of incidence?

Point of incidence is where the incident eay strikes and the reflected ray leaves the point of incidence

What is the angle of incidence and reflection?

Angle of Incidence - angle between incident ray and normal

Angle of reflection - angle between reflected ray and normal

What is refractive index? (Index of Refraction)

Measurement of light bending in diff mediums- refractive index of air is 1.0

What happens as the medium gets denser?

Light moves slower

Refractive index increases

What is Plano concave and convex?

Flat on one side and curved on the other

What is bi concave and convex?

Curved on both sides

What is the universal wave equation?

v = f × λ

v = wave speed

f = frequency

λ (lambda) = wavelength

What is frequency?

number of cycles completed by a vibrating object in a unit of time- measured in hertz (per second)

What is the EMS?

Radio - microwave - infrared - visible - ultraviolet - X-ray - gamma ray

What is the highest and lowest of the EMS?

Radio - lowest

Gamma rays - highest (radioactive materials)

What part of the eye is the shutter of the camera?

Eyelid- opens and closes to let light in or out, gives moisture to cornea

What are the cornea & lens function and in the camera?

Helps focus image to the retina- lens of a camera

What does the cornea do how does the lens help?

Cornea- front surface of the eye, does most of the focusing on the eye

Lens- finetunes the focus

What does the iris do in a camera?

Camera diaphragm- open and close to let light in

What does the pupil do in the camera?

Aperture- black dot in the centre of the iris, hole that lets light in the eye

What does the retina do in the camera?

acts like the film- detects light and contains photoreceptors, converts image into a form for the brain

What is the ciliary body and function in the camera?

Focusing ring- Muscle structure controlling lens for focus

What does the aqueous humor do?

keeps your eye inflated and provides nourishment

What is the sclera?

White outer layer providing eye structure and protection

What are photoreceptors?

Rods: sensitive to light- cones: detect color- about 107 million

What is the blind spot?

Where the retina and optic nerve connect- place with no photoreceptors

What is young’s double slit experiment?

Experiment where light passes through two slits- creates a interference pattern, proving light acts like a wave

What does the choroid do?

delivers oxygen and nutrients to outer retina

What is the vitreous humor?

A gel-like substance filling the eye’s interior

What is the optic nerve and it camera function?

Wires- Transmits visual information from retina to brain

What is light adjustment?

Process of iris and pupil regulating light intake