Archeoastronomy, Planetary Models, and Atomic Physics

Flashcards covering historical astronomy, the Copernican revolution, scientific methodology, modern telescope design, non-photon astronomy, and quantum mechanics fundamentals.

What is archeoastronomy, and why did Neolithic societies develop it?

Archeoastronomy is the study of ancient structures designed to observe astronomical phenomena. Neolithic societies developed it after transitioning to settled farming to establish a calendar for planting and harvesting independent of weather variations.

How does the duration of a sidereal day compare to a standard solar day?

A solar day is $24\text{ hours}$, whereas a sidereal day is $23\text{h } 56\text{m } 04\text{s}$, making the solar day slightly longer.

What is the tilt of the Sun's ecliptic path relative to the celestial equator, and what is the resulting declination range?

The ecliptic is tilted $23.5^\bullet$ from the celestial equator, giving the Sun a declination range from $+23.5^\bullet$ to $-23.5^\bullet$.

What are the four key solar locations and their corresponding dates?

The four key solar locations are the summer solstice (June 21), autumnal equinox (September 23), winter solstice (December 21), and vernal equinox (March 21).

In pharaonic Egyptian beliefs, which deities represented the celestial sphere, Earth, Sun, Moon, Mercury, and Mars?

Nut represented the celestial sphere, Geb represented Earth, Ra represented the Sun, Isis represented the Moon, Thoth represented Mercury, and Horus represented Mars.

How many nesting spheres were used in Eudoxus's geocentric model and Callipus's refined model?

Eudoxus used 26 nesting spheres to account for planetary retrograde motions and misalignments, which Callipus refined to 33 spheres.

What additions did Ptolemy make to his geocentric model, and what was the name of his astronomical work?

Ptolemy introduced eccentrics and epicycles to improve planetary predictions. His work was published in the book The Almagest.

What were the main proposals of Nicolaus Copernicus's heliocentric cosmology, and in what year was it published?

Copernicus proposed that the Sun is at the center, Earth rotates daily and orbits the Sun annually as the third of 6 planets, and fixed stars are extremely distant. It was published in De Revolutionibus Orbium Coelestium in 1543.

What observatory did Tycho Brahe build, and into what publication were his 25 years of planetary observations gathered?

Tycho Brahe built the Uraniborg observatory, and his measurements were collected into the Rudolphine tables.

What key astronomical observations made by Galileo Galilei supported the Copernican model?

Galileo observed the Comet of 1577 crossing non-crystalline spheres, four moons orbiting Jupiter, spots on the Sun, mountains on the Moon, and the phases of Venus.

In what year did Isaac Newton publish Philosophiae Naturalis Principia Mathematica, and how did it unify physical motion?

Published in 1687, it unified terrestrial motion (falling objects) and celestial orbital motion under universal principles of gravity, calculus, and mechanics.

Who observed the planet Uranus in 1781, and what names were initially suggested for it?

William Herschel reported finding it in 1781 and named it 'Georgium Sidus' (after initially calling it a comet), while Johann Bode proposed the name 'Uranus'.

How was the existence of Neptune predicted and discovered in the 1840s?

English and French astronomers calculated that Uranus's orbit was being perturbed by an unseen planet, and Heinrich d'Arrest (a student in Germany) discovered Neptune where predicted.

What range of wavelengths in nanometers defines the visible light spectrum shown in this diagram?

The visible spectrum ranges from approximately $400\,\text{nm}$ to $700\,\text{nm}$.

Which wavebands of the electromagnetic spectrum are transmitted by Earth's atmospheric molecules?

Earth's atmosphere transmits only visible and radio wavelengths, requiring telescopes for other wavebands to be placed in space.

What are three examples of non-photon astronomy described in the lecture notes?

1. Cosmic rays (charged particles/protons discovered in the 1920s).
2. Neutrinos (massless, chargeless particles detected by the IceCube Observatory).
3. Gravitational waves (predicted by Einstein c. 1915 and detected in 2015).

According to the periodic table, which elements correspond to atomic numbers 1, 2, 6, 7, 8, and 26?

Atomic number 1 is Hydrogen ($\text{H}$), 2 is Helium ($\text{He}$), 6 is Carbon ($\text{C}$), 7 is Nitrogen ($\text{N}$), 8 is Oxygen ($\text{O}$), and 26 is Iron ($\text{Fe}$).

Based on this atomic model diagram of Carbon, what subatomic particles compose its nucleus and surrounding electron cloud?

The nucleus consists of 6 protons and 6 neutrons (giving an atomic weight of 12), surrounded by an electron cloud containing 6 electrons.

According to quantum mechanics, how does an atom absorb or emit photons during electron transitions?

An atom absorbs a photon of a specific wavelength when an electron transitions from a lower level to a higher level (e.g., $n=2$ to $n=3$), and emits a photon of that wavelength when transitioning from a higher level to a lower level.