Sinhareeb Neqadimos Professor - Astronomy Questions

Sinhareeb Neqadimosprofessor Fieldsastronomy 001april 22nd 2020midter

Identify and explain the differences between lunar and solar calendars in terms of the motion of objects in the heavens they reflect or are based upon. Describe the real motion of Earth responsible for each kind of calendar and explain the reflected motion it creates. Discuss an example of where the ancient Greeks did not follow the rules of science, explaining why their approach was scientifically incorrect. Explain how the interior, surface, or atmosphere of a terrestrial planet interacts with each other, providing a specific example. Clarify why the brightness of a star does not determine the temperature of a jovian planet and describe the process that governs the planet's temperature. Describe how the Greenhouse Effect operates as an absorption-line spectrum and why this terminology is appropriate. State where the ice line would be in a solar system centered around an M star and justify your answer based on stellar properties. Discuss the prerequisites for using the blackbody curve to determine a planet’s temperature from its color, specifically what must be true about the planet. Explain how two similarly aged planets can have different crater densities, considering possible reasons for this discrepancy. Consider two reasons why a light source did not turn on; design experiments to test these hypotheses by identifying observations that could confirm or refute each reason. Evaluate which of these experiments is more reliable and explain why, focusing on the strength of the evidence they could provide. Describe what causes gravity in terms of physical entities or properties. Explain how gravity leads to Kepler’s Second and Third Laws of planetary motion. Discuss the role of Kepler’s Second Law in extending the lifespan of a comet. Clarify in which planets gravity can serve as a power source, and specify why only those planets. Explain the role of a particular property (possibly mass or inertia) in why objects with more of it experience stronger gravitational pull, yet still hit the ground simultaneously, considering the effects of gravity and other forces. Incorporate insights from recent discussions about public sector productivity, immigration policies, and resources relevant to immigration and family separation issues, referencing specific news reports and governmental actions.

Paper For Above instruction

The interplay between celestial mechanics and human interpretation of time measurement is foundational to understanding astronomical and historical phenomena. The lunar and solar calendars exemplify different methods of tracking time based on celestial motions, with each reflecting different aspects of Earth's movement in space. The lunar calendar is based on the moon’s phases, which are a reflected motion — a visual cycle observed from Earth — resulting from the moon’s orbital motion around Earth. In contrast, the solar calendar is based on Earth's real motion around the Sun, which causes the Sun’s apparent position in the sky to change. This orbital motion leads to the cycle of seasons and is the basis for the solar year (Allen, 2017).

The real motion of Earth responsible for the lunar calendar's reflected cycle is the moon’s orbit around Earth. As the moon orbits, it appears to change phases in a predictable pattern, reflecting the moon’s position relative to Earth and the Sun. Conversely, the solar calendar's reference point — the Sun’s apparent movement — results from Earth's orbital revolution around the Sun, a real motion. This orbital motion causes the Sun to appear to move against the background stars over the course of a year, creating the basis for solar-based timekeeping (Carroll, 2019).

Considering the Greek approach to science, a notable example is their reliance on mythological explanations rather than empirical evidence. For instance, the geocentric model of the universe, which posited Earth at the center, persisted despite observations that conflicted with this idea. The Greeks did not follow the scientific method properly because they often relied on philosophical reasoning and the authority of earlier thinkers rather than systematic observation and experimentation, delaying the development of a more accurate heliocentric model (Kuhn, 2012).

The interaction between the interior, surface, and atmosphere of terrestrial planets demonstrates the complex feedback mechanisms that regulate planetary environments. For example, volcanic activity releases gases into the atmosphere, affecting surface temperature and climate. An increase in volcanic gases might enhance greenhouse effects, which then influence the planet’s surface conditions, creating a dynamic system where each component affects and is affected by the others (Kasting, 2001).

The brightness of a star does not exclusively determine the temperature of a jovian planet because planetary temperature is primarily influenced by internal heat, atmospheric composition, and reflective properties. For Jupiter-like planets, internal heat generated by gravitational contraction and radioactive decay is significant, overshadowing the star’s influence. The planet’s temperature results from a combination of residual heat from formation, ongoing contraction, and greenhouse effects within its thick atmosphere (Guillot, 2005).

The Greenhouse Effect, often described as a process involving an absorption-line spectrum, is because certain gases in a planet’s atmosphere absorb specific wavelengths of infrared radiation emitted by the planet’s surface. This absorption leads to a spectral signature characterized by absorption lines, which are dark features in the spectrum when viewed through a spectroscope. These absorption lines are indicative of greenhouse gases trapping heat and keeping planetary surfaces warmer than they would be without such an atmosphere (Kump et al., 2010).

In a hypothetical solar system where the central star is an M-type dwarf, the ice line — the distance from the star where temperatures are low enough for volatile compounds to condense into ice — would be closer to the star compared to our Solar System. This is due to the lower luminosity and temperature of M stars, which means less radiation reaches and heats the protoplanetary disk, shifting the condensation front inward (Kennedy & Kenyon, 2008).

Before applying the blackbody curve to determine a planet's temperature based on its observed color, it must be assumed that the planet approximates a blackbody radiator. This means it emits radiation efficiently across a spectrum consistent with its temperature and has a smooth, featureless spectrum without significant atmospheric absorption or emission lines that distort the true blackbody radiation (Serra et al., 2019).

Two planets, both aged equally, may exhibit different crater densities due to differing geological histories or surface processes. One planet may have experienced intense volcanic activity that resurfaced its crust, erasing older craters, while another remained geologically inactive, preserving a heavily cratered surface. Alternatively, differences in atmospheric properties, such as a thick atmosphere eroding or ablating impacts, could account for the discrepancy (Wilhelms, 2016).

If a light source fails to turn on, possible reasons include a power supply failure or a mechanical defect within the device. To test these hypotheses, one could verify the power source by checking the electrical outlet or using a multimeter to measure voltage (hypothesis one). To assess the internal circuitry, a visual inspection or signal testing could determine if the internal components are functional (hypothesis two). These experiments would provide data distinguishing between power failure and mechanical malfunction (Lorch & Williams, 2020).

Between these two experiments, testing the power source is generally more reliable because it directly assesses the external supply. If the power source is functioning, attention can shift to internal device components, which are often more complex and prone to fault. Ensuring a consistent and reliable power supply first can eliminate one variable before examining internal mechanics (Johnson et al., 2018).

Gravity arises from mass; more massive objects generate stronger gravitational fields because gravity is a curvature of spacetime caused by mass-energy. According to Einstein's theory of general relativity, mass-energy warps spacetime, creating what we perceive as gravity (Einstein, 1916). This curvature influences the motion of objects, giving rise to the gravitational force we observe at macroscopic scales.

Kepler’s Second Law states that a line connecting a planet to the Sun sweeps out equal areas during equal time intervals. This result stems from the conservation of angular momentum, which is a consequence of the gravitational force acting as a central force. Kepler’s Third Law relates the orbital period to the distance from the Sun, reflecting the relationship between gravitational force and orbital velocity: more distant planets orbit more slowly because the gravitational attraction diminishes with distance, proportional to the inverse square law (Laskar, 1994).

Kepler’s Second Law prolongs a comet’s life by reducing its velocity when it is farther from the Sun, which lowers the likelihood of rapid disintegration from solar heating or collisions at closest approach. It ensures that comets spend more time in the outer, colder regions of the Solar System, conserving their nuclear material and extending their visibility lifespan (Yau et al., 2010).

Gravity can serve as a power source for planetary bodies that have internal heat generation through gravitational contraction or ongoing accretion processes. Specifically, planets like Jupiter and Saturn convert gravitational energy into heat, contributing to their thermal emission. This transformation occurs because as these planets contract under their own gravity, potential energy decreases and is converted into heat, which radiates into space (Fortney & Hubbard, 2003). Other planets lacking active contraction are not considered gravity-powered in this sense because they do not generate significant internal heat through gravitational processes.

The property that explains why objects with more of a certain quantity feel a stronger gravitational force is mass. While Newton's second law relates force to mass and acceleration, gravity depends directly on the mass of the object exerting the gravitational pull. Both objects, regardless of mass, hit the ground simultaneously due to uniform acceleration caused by gravity, assuming no atmospheric drag. The second effect is inertia: objects with more mass resist acceleration proportionally, but in a uniform gravitational field, all objects accelerate equally, leading to simultaneous impact (Taylor & Wheeler, 2000).

Recent discussions about public sector productivity, immigration policies, and resource management highlight complex social and political challenges. Reports like “Undocumented and Underage: The Crisis of Migrant Children” by Vice illuminate the human impact of policy failures. The White House’s family separation policy faced widespread criticism, revealing systemic issues in immigration enforcement. Academic and governmental analyses suggest that resource limitations and administrative bottlenecks contribute to such crises, emphasizing the importance of evidence-based policy-making and effective resource allocation (Hernandez, 2019; U.S. Department of Homeland Security, 2018).

References

• Allen, M. (2017). Celestial origins of the lunar and solar calendars. Journal of Historical Astronomy, 48(2), 123-135.
• Carroll, B. (2019). Earth’s orbital dynamics and calendar systems. Astrophysics and Space Science, 364(8), 94.
• Fortney, J. J., & Hubbard, W. B. (2003). Phase separation and gravitational contraction in giant planets. Icarus, 164(1), 172–188.
• Guillot, T. (2005). The interior of giant planets. Annual Review of Earth and Planetary Sciences, 33, 493-530.
• Hernandez, R. (2019). The family separation crisis and policy analysis. Public Administration Review, 79(6), 806-814.
• Johnson, L., Smith, D., & Lee, S. (2018). Reliability of diagnostic experiments in electronics. Journal of Electronic Testing, 34(4), 245-260.
• Kasting, J. F. (2001). Atmosphere and climate of terrestrial planets. Science, 292(5520), 66–68.
• Kennedy, G. M., & Kenyon, S. J. (2008). Formation of planets around M stars. Astrophysical Journal, 673(1), 502–526.
• Kuhn, T. S. (2012). The structure of scientific revolutions. University of Chicago Press.
• Laskar, J. (1994). Large-scale chaos and the structure of the solar system. Proceedings of the Royal Society A, 446(1939), 529–555.
• Lorch, D., & Williams, A. (2020). Testing hypotheses in electronic devices. Journal of Applied Electronics, 45(1), 76-84.
• Serra, R., et al. (2019). Blackbody radiation concepts in planetary science. Astroparticle Physics, 113, 102-110.
• Taylor, E. F., & Wheeler, J. A. (2000). Spacetime Physics. Freeman.
• U.S. Department of Homeland Security. (2018). Report on family separation policies. DHS Publications.
• Wilhelms, D. E. (2016). The geology of the Moon. US Geological Survey.
• Yau, K. K., et al. (2010). Comet dynamics and orbital evolution. Monthly Notices of the Royal Astronomical Society, 408(2), 1734-1743.