Visible light Flashcards
Segment of the ElectroMagnetic Spectrum that the human eye can view
Visible light spectrum
Lies between the UV and Infrared Radiation
Visible light spectrum
Travels through a prism
Visible light spectrum
Which color has the longest wavelenth?
Red
Which color has the shortest wavelenth?
Violet
Red wavelength
620-750nm
Orange wavelength
590-620nm
Yellow wavelength
570-590nm
Green wavelength
495-570nm
Blue wavelength
450-495nm
Violet wavelength
380-450nm
Discovered Visible light
Lawrence Isaac Newton
How was Visible light discovered?
Newton took a glass prism and held it up to a beam of sunlight streaming through a window.
Where visible light was discovered
Cambridge University of England (1665)
As light passes through a ______ it is bent/refracted.
Prism
How do prisms work?
As light passes through a prism, it is bent/refracted
Dominant source for light waves our eyes recieve
Sun
Produces white light (formed by the core)
Sun
The yellow tint we see as the sun is because?
The other colors are absorbed by clouds in the atmosphere
Sun surface temperature
5,500°C
Produces the white light of the sun
The core
Outermost layer of the suns atmosphere
Corona
Can be seen in visible light, but usually only on total eclipses
Corona
Tapered patterns that are formed around the sun by the outward flow of the plasma that is shaped by magnetic field lines
Coronal Streamers
Provides important scientific clues that reveal hidden properties/elements
Absorption lines
Acts like fingerprints for atoms and molecules
Absorption lines
Close examination of the visible-light spectrum from our Sun and other stars reveal a pattern of dark lines
Absorption lines
Absorption lines occur when______
An electron jumps from a lower energy state to a; higher energy state –> Produces photons –> Light particles
What are light particles called?
Photons
Spectral Signatures
Graph of an objects reflectance across a spectrum
Obtains information about the spectral response of ground materials and land vegetation phenology, as reference for satellite measurements
Spectral signatures
Helps scientists determine the composition of the planets and other stars by identifying the specific wavelenths of light that they emit or absorb
Spectral signatures
The light that is emitted or absorbed by a planet or star can be separated into its various colors, which form a _____
Spectrum
Example of active remote sensing using visible light
Laser Altimetry
A device used aboard planet-orbitting satellites to map a planet’s terrain
Laser Altimetry
The elevations of surface features can be calculated by comparing how long it takes a laser pulse to echo back at different locations
Laser Altimetry
Spectroscopic techniques
Employ light to interact with matter and thus probe certain features of a sample to learn about its consistency or structure
Uses visible light to produce a spectrum or absorption lines
Spectroscopic Techniques
Different elements have different ____?
Spectra
When light passes through an atom, the atom can _______
Absorb certain colors and wavelenth
Doppler red-shift of light
Observed from distant stars and galaxies
When did Edwin Hubble measure the redshift and ground and found that the redahift of a galazy depends on its distance from Earth
1929
Measured the redshift
Edwin Hubble
What ore did Uranium, Polodium, and Radium come from?
Pitchblende
Marie found that the ore was ___ more radioactive than Uranium.
4x
Marie Curie broke the ore down and found ______ which had varrying radio activity.
Radium and Polonium
Produces electrical charges produced by the radioactive sample begits to move the small light along the ruler
The Curie’s Electrometer
Crystal used in Curie’s electrometer which emits an electric charge
Piezoelectric quartz
Marie Curie also used _____ to obtain the absorption lines of the newly found elements.
Spectroscopic techniques
What proved that Marie had really found two new elements?
Absorption lines
GLAS
( Geoscience Laser Altimeter System) NASA instrument
Onboard the Ice, Cloud, and land Elevation Satellite (ICE Sat)
Geoscience Laser Altimeter System
Enables scientists to calculate the elevation of Earth’s polar ice sheets
Geoscience Laser Altimeter System
Uses Laser and Ancillary data
Geoscience Laser Altimeter System
Can make unique measurements of the heights and characteristics of clouds
Geoscience Laser Altimeter System
Could end the need for travellers to switch to flight mode, Intrinsically safe
Visible light communication
What does LiFi stand for?
Light Fidelity
Can use existing power lines as LED Lighting so no new needed infrastructure is needed unlike with where you need to install new lines
LiFi
Range of wavelengths of visible light
380-700 nm
Nanometer
Metric unit of one billionth of a meter
Why is visible light important?
The human eye and brain work together to convert visible light energy into an electrical impulse that can be interpreted as an image.
Our eyes can detect electromagnetic radiation in the form of ________.
Visible light
The reason we can see things around us is because they ______.
Either emit, reflect, or absorb visible light.
Dispersion
The seperation of light into colors by refraction or diffraction with formation of a spectrum
Frequency of Red
400-484 THz
Frequency of Violet
668-789 THz
Why are some colors not in the visible light spectrum?
Because they can only be made from a mix of multiple wavelengths.
Colors containing only one wavelength are called ________.
Pure Colors or Spectral Colors
In the past, visible light resulted in industry-revolutionizing discoveries like _____________.
Light bulbs and fiber optics
Currently, visible light is necessary for medical imaging technologies such as ________.
CT, MRI, and X-rays for diagnosis.
How is visible light crucial in photosynthesis?
It utilizes pigments such as chlorophyll to absorb specific wavelengths of light.
The sky appears blue due to _______.
Rayleigh scattering
