Given the question: Information:  - Chronology (from Latin "chronologia", from Ancient Greek , "chrónos", "time"; and , "-logia") is the science of arranging events in their order of occurrence in time. Consider, for example, the use of a timeline or sequence of events. It is also "the determination of the actual temporal sequence of past events".  - Diffuse reflection is the reflection of light from a surface such that an incident ray is reflected at many angles rather than at just one angle as in the case of specular reflection. An illuminated "ideal" diffuse reflecting surface will have equal luminance from all directions which lie in the half-space adjacent to the surface (Lambertian reflectance).  - Latin (Latin: ) is a classical language belonging to the Italic branch of the Indo-European languages. The Latin alphabet is derived from the Etruscan and Greek alphabets.  - Ice is water frozen into a solid state. Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaque bluish-white color.  - Snow pertains to frozen crystalline water throughout its life cycle, starting when it precipitates from clouds and accumulates on surfaces, then metamorphoses in place, and ultimately melts, slides or sublimates away. Snowstorms organize and develop by feeding on sources of atmospheric moisture and cold air. Snowflakes nucleate around particles in the atmosphere by attracting supercooled water droplets, which freeze in hexagonal-shaped crystals. Snowflakes take on a variety of shapes, basic among these are platelets, needles, columns and rime. As snow accumulates into a snowpack, it may blow into drifts. Over time, accumulated snow metamorphoses, by sintering, sublimation and freeze-thaw. Where the climate is cold enough for year-to-year accumulation, a glacier may form. Otherwise, snow typically melts, seasonally, and causes runoff into streams and rivers and recharging groundwater.  - Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum. The word usually refers to visible light, which is visible to the human eye and is responsible for the sense of sight. Visible light is usually defined as having wavelengths in the range of 400700 nanometres (nm), or 4.00 × 10 to 7.00 × 10 m, between the infrared (with longer wavelengths) and the ultraviolet (with shorter wavelengths). This wavelength means a frequency range of roughly 430750 terahertz (THz).  - The hexagonal snowflake , a crystalline formation of ice , has intrigued people throughout history . This is a chronology of interest and research into snowflakes . Artists , philosophers , and scientists have wondered at their shape , recorded them by hand or in photographs , and attempted to recreate hexagonal snowflakes .  - A spectrum (plural "spectra" or "spectrums") is a condition that is not limited to a specific set of values but can vary, without steps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors in visible light after passing through a prism. As scientific understanding of light advanced, it came to apply to the entire electromagnetic spectrum.  - A snowflake is either a single ice crystal or an aggregation of ice crystals which falls through the Earth's atmosphere as snow. Each flake nucleates around a dust particle in supersaturated air masses by attracting supercooled cloud water droplets, which freeze and accrete in crystal form. Complex shapes emerge as the flake moves through differing temperature and humidity zones in the atmosphere, such that individual snowflakes differ in detail from one another, but may be categorized in eight broad classifications and at least 80 individual variants. The main constituent shapes for ice crystals, from which combinations may occur, are needle, column, plate and rime. Snowflakes appear white in color despite being made of clear ice. This is due to diffuse reflection of the whole spectrum of light by the small crystal facets.   - Time is the indefinite continued progress of existence and events that occur in apparently irreversible succession from the past through the present to the future. Time is a component quantity of various measurements used to sequence events, to compare the duration of events or the intervals between them, and to quantify rates of change of quantities in material reality or in the conscious experience. Time is often referred to as the fourth dimension, along with the three spatial dimensions.  - Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe.  - Water is a transparent and nearly colorless chemical substance that is the main constituent of Earth's streams, lakes, and oceans, and the fluids of most living organisms. Its chemical formula is HO, meaning that its molecule contains one oxygen and two hydrogen atoms, that are connected by covalent bonds. Water strictly refers to the liquid state of that substance, that prevails at standard ambient temperature and pressure; but it often refers also to its solid state (ice) or its gaseous state (steam or water vapor). It also occurs in nature as snow, glaciers, ice packs and icebergs, clouds, fog, dew, aquifers, and atmospheric humidity.  - A timeline is a way of displaying a list of events in chronological order, sometimes described as a project artifact. It is typically a graphic design showing a long bar labelled with dates alongside itself and usually events  - Ancient Greek includes the forms of Greek used in ancient Greece and the ancient world from around the 9th century BC to the 6th century AD. It is often roughly divided into the Archaic period (9th to 6th centuries BC), Classical period (5th and 4th centuries BC), and Hellenistic period (3rd century BC to the 6th century AD). It is antedated in the second millennium BC by Mycenaean Greek.    What object entity has the relation of 'instance of' with the subject 'timeline of snowflake research'?   Choices: - alphabet  - bar  - branch  - case  - century  - change  - chemical  - chemical substance  - chronology  - color  - column  - complex  - component  - condition  - electromagnetic radiation  - enterprise  - formula  - glacier  - hydrogen  - incident  - language  - limited  - liquid  - material  - may  - molecule  - particle  - quantity  - range  - science  - sense  - set  - single  - snow  - soil  - space  - state  - surface  - temperature  - three  - time  - timeline  - understanding  - vapor  - variety  - water  - word
The answer is:
timeline