Study Guide Test #2 (Spectroscopy) Definitions Flashcards
Definition of Gravity?
The force that attracts a body toward the center of the earth, or toward any other physical body having mass.
Definition of microwave?
Part of the electromagnetic spectrum, with large infared waves and short radio waves. Which is a version of a small ove, used to heat up food quickly.
Definition of reflection?
The return of light or sound waves from a surface.
Definition of dispersion?
the action or process of distributing things or people over a wide area.
Definition of Cepheid Variable?
A variable star having a cycle of brightness and luminosity, allowing the estimation of its distance towards earth.
Definition of Big Bang Theory?
The scientific explanation of how the Universe began.
Definition of white light?
Light like sunlight that contains all the colors in the visible spectrum in ‘‘roughly’’ equal ammounts.
Definition of gamma rays?
Electromagnetic radiation of the shortest wavelength and highest energy.
Definition of radio waves?
A type of electromagnetic radiation that are longer than infared light, generated by trasnmitters and recieved by anttenas.
Definition of refraction?
Basically when light bends.
Definition of index of refraction?
Measure of the bending of a ray of light when passing from one medium into another.
Definition of emission spectrum?
A spectrum of the electromagnetic radiation emitted by a source.
Definition of Hubble constant?
The unit of measure used to to describe the expansion of the universe?
Definition of cataracts?
A medical condition in the eye in which the lens of the eye is progressing into more and more blurred vision.
Definition of x-rays?
An electromagnetic wave of high energy and very short wavelength, which is able to pass through many materials opaque to light.
Definition of crest?
A point on a wave with the maximum value of upward displacement within a cycle
Definition of absorption?
The process or action by which one thing absorbs or is absorbed by another.
Definition of medium?
A substance that makes possible the transfer of energy from one location to another, especially through waves.
Definition of star?
A natural luminous body visible in the sky especially at night.
Definition of Hubble’s Law?
The statement in astronomy that galaxies move away from each other, and that the velocity with which they recede is proportional to their distance.
Definition of ultra violet?
Being energy that is like light but has a slightly shorter wavelength and lies beyond the violet end of the spectrum.
Definition of trough?
A crest point on a wave with the maximum value of upward displacement within a cycle.
Definition of trough?
A trough is the opposite of a crest, so the minimum or lowest point in a cycle.
Definition of prism?
A transparent solid body, often having triangular bases, used for dispersing light into a spectrum or for reflecting rays of light.
Definition of binary star?
A system of two stars in which one star revolves around the other or both revolve around a common center.
Definition of doppler effect?
Doppler Effect refers to the change in wave frequency during the relative motion between a wave source and its observer.
Definition of luminosity?
The brightness of a star.
Definition of visible light?
The visible light spectrum is the segment of the electromagnetic spectrum that the human eye can view
Definition of wavelength?
The distance between successive crests of a wave, especially points in a sound wave or electromagnetic wave.
Definition of absorption spectrum?
A spectrum of electromagnetic radiation transmitted through a substance, showing dark lines or bands due to absorption of specific wavelengths.
Definition of blueshift?
The displacement of the spectrum to shorter wavelengths in the light coming from distant celestial objects moving toward the observer.
Definition of absolute brightness?
The apparent brightness a star would have if it were placed at a standard distance of 10 parsecs from Earth.
Definition of spectrograph?
A spectrograph is an instrument that separates incoming light by its wavelength or frequency and records the resulting spectrum, like a photographic plate.
Definition of infared light?
A type of radiant energy that’s invisible to human eyes but that we can feel as heat.
Definition of frequency?
The rate at which a vibration occurs that constitutes a wave, usually measured per second.
Definition of visible light spectrum?
The visible light spectrum is the segment of the electromagnetic spectrum that the human eye can view.
Definition of redshift?
The wavelength of the light is stretched, so the light is seen as ‘shifted’ towards the red part of the spectrum.
Definition of apparent brightness?
How bright the star appears from Earth.
Definition of electromagnetic radiation?
Electromagnetic radiation is energy that is transmitted at the speed of light through oscillating electric and magnetic fields.
