Flashcards in Lecture 4 Deck (31):
WHat is the closest star to the sun?
What binary star is Proxima Cen associated with?
Could the new planet Proxima b have life?
Potentially, it could support liquid water and has an 11.2 day orbit; it is within the habitable zone but almost too close in
What is FAP?
False Alarm Probability -- below 1% is considered probable
How did they discover Prox b?
They took data for 16 years, measured the signature of the planet using a spectrograph
What does a spectrograph do?
It shows that stars move due to planets, causing a slight red or blue shift
Who proposed the idea of atoms?
Who contributed to the atomic model?
Democritus, Dalton, Brown, Einstein, Perrin
Who proposed the plum pudding model?
What was Rutherford's experiment and what did it prove?
Gold foil, proved that there are nuclei
What did Bohr add to the electron theory?
That they were quantized
What did de Broglie and Schrodinger discover?
That electrons were both particles and waves
What are the three types of spectra?
Emission, Continuous, Absorption
What is a continuous spectrum?
Object emits all wavelengths
What is an emission spectrum?
Object emits only certain wavelengths (e.g. a thin gas with a temperature)
What is an absorption spectrum?
Object absorbs only certain wavelengths (e.g. a thick gas
Which part of the spectrum did Herschel discover?
Which part of the spectrum did Ritter discover?
Where is energy stored in atoms?
In the energy levels of the electrons
What two types of energy do molecules have?
Rotational and Vibrational
Why does thermal radiation occur?
Photos are emitted and absorbed and re-emitted many times over, and distorted by other collisions, thus light of all wavelengths ends up being emitted
What is an ideal blackbody?
absorbs all radiation, emits thermal radiation
What does the thermal radiation spectrum depend on?
A body's temperature
What is Boltzmann's law of thermal radiation?
A hotter object emits more light at ALL wavelengths
What is Wien's law of thermal radiation?
A hotter object emits photos of HIGHER average energy
What is the ecliptic?
THe path the sun appears to follow across the sky
What are the two components of locating a star?
Direction (azimuth) and altitude
How does the altitude of the celestial pole relate to your latitude?
They are equivalent
What is precession?
The wobble the earth's axis undergoes due to gravity
What is synchronous rotation?
Experienced by the moon due to Earth's gravity, the reason why we see the same face of the moon