Topic 2: What is the Universe? Flashcards
Earth Science focuses on how the world around us works, but we also need to understand how Earth fits into its surroundings of Space. Since the days of early astronomers, scientists have been observing Space and deducing how it works. As technology has developed, we have found more ways to observe and understand the physics and chemistry of our Universe. As we also gain this observational understanding, we can begin to interpret images and readings of what occurs outside our Earth.
Matter
Anything that has mass and takes up space
Atom
The smallest unit of an element that retains its properties
Nucleus
The center of an atom, which contains the protons and neutrons
Electron
A negatively charged particle, located in the space surrounding the nucleus
Element
A pure substance that consists entirely of one type of atom and cannot be chemically broken into simpler substances
Electromagnetic spectrum
All the frequencies or wavelengths of electromagnetic radiation
Frequency
The number of cycles, waves or vibrations per unit of time
Wavelength
The distance from any point on a wave to the same point on the next wave
Doppler effect
An observed change in the frequency of a wave when the source or observer is moving
Spectrum
A pattern of radiation observed when the components of light are separated in order of frequency
Parallax
An apparent shift in the position of an object when viewed from different locations
Nuclear fusion
The process by which nuclei of small atoms combine to form a new, more massive nucleus
Magnetic field
A region where a magnetic force can be detected
Sunspot
A dark area of the photosphere of the sun that is cooler than the surrounding areas and has a strong magnetic field
Solar activity
Variations in the energy output of the Sun
Visible light
The spectrum of electromagnetic radiations which the human eye can view
Ultraviolet radiation
A wavelength range of the Sun’s radiation that provides humans with vitamin D and sun tans
Infrared radiation
A wavelength range of the Sun’s radiation that is absorbed by matter to generate heat
Wind
The movement of an atmosphere due to the heating and cooling of the object it surrounds
Interstellar medium
Material, mostly hydrogen gas, other gases, and dust, occupying the space between stars
Nebula
A large cloud of gas and dust in interstellar space where stars form
Light-year
The distance that light travels in a vacuum in one year (~9.46 trillion km)
Big Bang Theory
The theory that all matter and energy in the universe was compressed into an extremely dense volume that 13.7 billion years ago suddenly expanded in all directions
Plasma
A state of matter that consists of free-moving ions and electrons
Cosmic wave background
(CMB) Radiation detected from every direction in space almost uniformly
