second midterm notes

7 Pages

Astronomy & Astrophysics
Course Code
Clifford Orwin

This preview shows pages 1 and half of page 2. Sign up to view the full 7 pages of the document.
Ch.5 White light-mixture of basic colored light in equal proportions. Black=no light, no color Emission-eg.light bulb,energy of light comes fr electricity potential energy. Absorption-eg.cover light bulb w hand,hand absorbs some light&this energy makes hands warm.,air allows light to pass through. Reflectionscattering-light bounce off matter,reflection-same direction. Scattering-random direction wave-wavelength, frequency, period.c=f*wavelength, Particles-thing Wave-pattern revealed by p. Light-Electromagnetic waveconsists of individual photons characterized by wavelength,frequency& energy.Speed is constant.-both wave&particles. Electomagnetic spectrum-Gamma rays-Xrays-ultraviolet-visible-infrared-radio. Atoms-protons, neutrons,electrons,nucleus. Atom#=proton# Atomic mass#=#of protons=#neutrons Isotope-elements w different# of neutrons. Atoms-molecules-compounds Phases-solid,liquid,ice.-Chemical bonds stronger-tighter-sold , if weaker, then liquid, gas -eg. Water- Sublimation-escape solid Evaporation-escape liquid -Molecular dissociation-high temp->molecule collide->break bonds->lose electrons->ionized -Plasma-type of gas which atoms have become ionized. eg. Sun is made of plasmahot gas Pressure-force per unit area. Earth core is solid cuz of pressure, tho its temperature is high. Energy level transition-as electron rise fr low energy level to higher onefall fr high to low. Spectroscopy-obtain spectrum&read info.display graphs showing intensity at diff. Wavelengths. -Continuous spectrum-broad range of wavelengths wout interruption. -Emission line spectrum-low density clouds emits light only at specific wavelengths. Depends on composition&temperature. Emission lines against a black background. -atoms in cloud collide bump electrons to high energy level,then fall back &loses energy by emitting photon of light at specific wavelength. -Absorption line spectrum-cloud lies bw source&us, still see most continuous light,cloud absorbs some at specific wavelengths. Dark absorption lines over rainbow. -as atoms absorb light,electon fr high leve return to low level&emits a photon of same energy absorbed but goes to random directions. Chemical Fingerprint-elements emitsabsorb light at diff wavelength, by observing spectrum,unique patterns can determine wat element. Ions cud help determine temp.->high temp-more highly charged ions. Molecules-create spectral lines wen electron change energy levelvibrationrotation.Tightly brunched lines-molecular band Thermal Radiation-atoms&molecules in objects r not independent, have complex energy levels-> absorb light across broad range of absorb photons,photons try to escape, its quickly absorbed by atommolecule->reemits photon at diff wavelen. &direction->photons bounces randomly->constantly exchange energy->when it finally escapes,the radioactive energies spread over wide range of wavelengths ->produce continuous spectrum--Only depends on temperature->rep.avg.kinetic e. -Two laws-1.Each square metre of hotter objects surface emits more light at all wavelength. 2.Hotter objects emit photons w higher avg. energy (shorter avg. wavelengths) -estimate stars temp. by observing its color. Eg.ppl-infrared star-red-3000k. -reflected light gives color, absorbed light heat the surface &help determine temp. Doppler effect-Blue shift-Object move toward us,waves bunch up bw us&object,shorter wavelengh -Red shift-object move away fr us,light is shifted to longer wavelength. Only when object is moving directly away fr. Us we know full speed. Ch.7 Comparative planetology-compare to one another,find similaritiesdifferences. Sun-helium+hydrogen. Sun spots are cooler areas. Solar storms->send streamers of hot gas above surface. Loses 4 million tons of masssec,will shine for another 5 billion yrs. Mercury-Smallest among eight.-not active, no wind. Both hot and cold extremes. Heavily cratered.
More Less
Unlock Document

Only pages 1 and half of page 2 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.