Earth science Flashcards
(37 cards)
- Radio
: Longest; least energetic
- Gamma Rays
used in radiation for cancer treatments; most energetic
Spectrum of waves in order
- Radio: Longest; least energetic
- Microwaves
- Infrared: heat energy
- Visible Light: only type of energy perceived by humans
- Ultraviolet: from sunlight-humans make vitamin D from UV
- X-rays: used to see hard substances beneath skin surface
- Gamma Rays: used in radiation for cancer treatments; most energetic
Red
Red has the longest wavelength
Violet
Violet has the shortest wavelength
SPECTROSCOPY
The study of light
All elements have their own spectrum, like a fingerprint
- Continuous Spectrum
uninterrupted band of colors (ROYGBIV)
- Emission Spectrum
lines of emitted light appearing against a black background
- Absorption Spectrum
continuous spectrum where light is absorbed and seen as black lines (no light)
DOPPLER EFFECT
As an object moves, the wavelengths change. This is sometimes called RED SHIFT.
What color does a thing become when its coming to you
An object moving toward the observer would shift to the blue/purple end of the spectrum and have shorter wavelengths.
What color does a thing become when its going away
An object moving away from the observer would shift to the red end of the spectrum and have longer wavelengths
- Light year
: unit of distance; how far a photon (particle) of light travels in one year (used to measure outside of solar system)
- Astronomical Unit
average distance between the Earth and the Sun (used to measure within our solar system); Sun = 93 million miles
ASTRONOMY
The study of the universe (NOT ASTROLOGY
Geocentric
all planets and the sun orbits around the earth (incorrect); Ptolemy (geo-earth; centric-centered)
Heliocentric
:all planets orbit the sun (correct); Copernicus (helio-sun; centric-centered)
Religion in the 1500’s suppressed the heliocentric model because it went against their doctrines
ROTATION
The rotating of a planet/star on its axis
1 rotation = 1 day
Earth day = 24 hours
Only 50% of Earth is illuminated at any given time
REVOLUTION
The movement of a planet, star, or other celestial debris (ex. comet) around its main star
Also called orbit
1 revolution = 1 year
Earth year: 365.25 days
PERIHELION
The point in Earth’s orbit where it is closest to the Sun (Jan. 6)
APHELION
The point in Earth’s orbit where it is farthest from the Sun (July 6)
SEASONS
Caused by the tilt (23.5o) of Earth’s axis. Equinox: days and nights of equal length (equi-equal; nox-night)
When are the seasons solist (IK i spelled dat wrong)
Vernal: March 20-21, Autumnal: September 20-21 Solstice: days and nights of unequal length Summer: June 20-21, Winter: December 20-21.
NORTHERN HEMISPHERE
On Winter Solstice, December 20, shortest day of the year
**In polar regions, 24 hours of darkness (sun does not rise; dark 24 hours)
**North Pole tilted away from the Sun
The Southern Hemisphere experiences seasons opposite from the Northern Hemisphere
