Lists of minor planets by number refer to an organized collection or catalog of minor planets (also known as asteroids) that have been assigned a numerical designation based on their order of discovery. The Minor Planet Center (MPC), which is affiliated with the International Astronomical Union (IAU), is responsible for tracking and cataloging these objects.

Lists of unnumbered minor planets refer to catalogues or compilations of minor planets (also known as asteroids) that have been officially discovered and observed but have not yet been assigned a permanent number by the International Astronomical Union (IAU). In the context of celestial objects, minor planets are typically those that are smaller than planets and don't dominate their orbital zones.

A list of Earth-crossing asteroids refers to a collection of asteroids whose orbits bring them into close proximity to Earth's orbit. These asteroids are classified as "near-Earth objects" (NEOs), and more specifically, some of them are categorized as "Atira" (no close approaches to Earth) or "Apollo" and "Aten" asteroids, which do cross Earth's orbit.

A list of Uranus-crossing minor planets includes those asteroids and other small celestial bodies that have orbits that cross the orbit of Uranus. These objects are a subset of the broader group of near-Earth objects and can include centaurs, trans-Neptunian objects, and asteroids.

The list of Venus-crossing minor planets includes a group of small celestial bodies whose orbits bring them close to the orbit of Venus. These minor planets are typically asteroids, and their classifications are based on the paths they take around the Sun, specifically those that intersect with Venus's orbital path. A minor planet is considered a "Venus-crossing" object if it has a semimajor axis and eccentricity that allows its orbit to intersect with that of Venus.

Pluto has five known moons. The most notable of these are: 1. **Charon**: This is the largest moon of Pluto and is almost half the size of Pluto itself, making it the largest moon in relation to its parent planet in the Solar System. Charon and Pluto are sometimes considered a double dwarf planet system due to their size and the way they orbit each other.

Loop quantum gravity (LQG) is a theoretical framework that aims to reconcile general relativity and quantum mechanics, primarily focused on the quantization of spacetime itself. The field has attracted a number of researchers over the years. Here’s a list of some prominent figures associated with loop quantum gravity: 1. **Carlo Rovelli** - One of the founding figures of loop quantum gravity, he has made significant contributions to the theory and its interpretation.

A direct proof is a method of demonstrating the truth of a mathematical statement by straightforward logical deductions from accepted axioms, definitions, and previously established results. In a direct proof, you begin with known facts and apply logical reasoning to arrive directly at the conclusion you are trying to prove. Here are some key characteristics of direct proofs: 1. **Logical Sequence**: Direct proofs rely on a clear sequence of logical steps, where each step follows directly from the previous one or from an established theorem or definition.

A "truth-bearer" is a philosophical term that refers to entities that can be said to be true or false. In essence, truth-bearers are statements, propositions, beliefs, or sentences that possess a truth value. The concept is important in discussions of truth in philosophy, particularly in debates about the nature of truth, the conditions under which a belief or statement is true, and how truth relates to reality.

"Four Epigraphs after Escher" is a composition for solo piano by the American composer and pianist *Ned Rorem*. Written in 1998, the piece is inspired by the works of the Dutch graphic artist M.C. Escher, known for his mathematically inspired artwork that explores patterns, symmetry, and impossible constructions.

In materials science, **polymorphism** refers to the ability of a material to exist in two or more different forms or crystal structures. These different forms can have distinct physical and chemical properties, which can affect the material's behavior in applications. Polymorphism is especially significant in the context of materials like metals, minerals, and polymers. For example: 1. **Metals**: Some metals can adopt different crystal structures depending on temperature or other conditions.

"Mott the Hoople" is the self-titled debut album by the British rock band Mott the Hoople, released in 1969. The band, formed in 1969 in Herefordshire, England, was known for its eclectic style and became an influential group in the glam rock movement. The album features a blend of rock, pop, and other musical influences, showcasing the band's early sound.

"Clocks" can refer to different concepts depending on the context. Here are a few possibilities: 1. **Timekeeping Devices**: Clocks are instruments used to measure and indicate time. They can be mechanical, electronic, or digital, and are found in various forms, including wall clocks, wristwatches, alarm clocks, and more.

Cutting machines are devices designed to cut various materials into specific shapes, sizes, or profiles. They are used in a variety of industries, including manufacturing, construction, textiles, and more. The types of cutting machines can vary widely depending on the materials they are intended to cut and the complexity of the cutting process. Here are some common types of cutting machines: 1. **Laser Cutting Machines**: Utilize a high-powered laser to cut through materials like metal, wood, plastic, and fabric.

Machinery refers to a system of machines, or components that work together to perform a specific function or achieve a desired outcome. It typically encompasses various mechanical devices that can include things like engines, tools, equipment, and other instruments. Machinery can be powered manually, electrically, or through other energy sources such as hydraulics or pneumatics.

Positive vorticity advection refers to the process in meteorology where air with higher vorticity (a measure of the local rotation in the flow of air) is transported into a region with lower vorticity. Vorticity is associated with the circulation of air, and positive vorticity is when there is a counterclockwise rotation in the Northern Hemisphere (and clockwise in the Southern Hemisphere, due to the Coriolis effect).

Simple machines are basic mechanical devices that change the direction or magnitude of a force. They are foundational components in the study of mechanics and physics. There are six classical types of simple machines, each with its specific function: 1. **Lever**: A rigid bar that rotates around a fixed point called the fulcrum. Levers can amplify force or change the direction of the force, making it easier to lift or move objects.

"Graphotype" typically refers to a type of machine used for creating typesetting and printing. Originally developed in the late 19th century, Graphotype machines were used for composing and casting types for printing presses. They allowed for the rapid production of metal type characters that could be used to print text and images, significantly streamlining the typesetting process in the printing industry.

In physics, collisions are typically classified into two main types: elastic and inelastic collisions. The primary difference between the two lies in the conservation of kinetic energy during the collision process. ### Elastic Collisions In an elastic collision: 1. **Conservation of Momentum**: The total momentum of the system is conserved before and after the collision. 2. **Conservation of Kinetic Energy**: The total kinetic energy of the system is also conserved before and after the collision.

A roof seamer is a specialized tool or machine used in the roofing industry, primarily for metal roofing applications. Its main function is to create seams between metal panels, ensuring that they are tightly sealed and securely connected. This helps in preventing leaks and enhancing the durability and longevity of the roof. There are different types of roof seamers: 1. **Manual Roof Seamers**: These are handheld tools that allow roofing professionals to crimp and seal seams manually. They typically require physical effort to operate.