Drop
'''Drop''' is an English noun and verb with multiple meanings. == Science and nature ==- [[Liquid drop]], a small quantity of liquid
- [[Drop (unit)]], a unit of measure
- Drop (graphical user interface), a user interface element
- Drop (database), a database operation to remove objects
- Drop (music), a section in electronic dance music tracks
- Drop D tuning, a guitar tuning
- ''Drop'' (album), various albums titled Drop
- "Drop" (song), various songs titled Drop
Science and nature
Liquid drop
A liquid drop is a small, discrete volume of liquid bounded completely or nearly completely by free surfaces, often adopting a nearly spherical shape due to the minimizing effect of surface tension on surface area.[1] This shape arises because surface tension acts to contract the liquid's surface, balancing the cohesive forces among molecules at the interface with the surrounding medium, such as air or another immiscible fluid.[2] In the absence of external forces, the equilibrium shape minimizes the surface energy, leading to a spherical form for isolated drops.[3] Liquid drops typically form through the accumulation of liquid at an orifice or nozzle, where the liquid builds up until gravity overcomes the retaining force of surface tension, causing detachment.[1] This process involves the thinning of a liquid neck, driven by surface tension, which pinches off the drop in a singularity where the neck radius approaches zero in finite time.[1] Capillary action can also contribute, particularly in narrower channels, by drawing liquid upward against gravity due to adhesive forces between the liquid and the solid surface./20%3A_Miscellaneous/20.02%3A_Surface_Tension) The key physics governing drop shape and pressure difference across the interface is described by the Young-Laplace equation: \Delta P = \frac{2\sigma}{r} where \Delta P is the pressure difference, \sigma is the surface tension, and r is the radius of curvature for a spherical drop. This equation quantifies how surface tension creates an internal overpressure in smaller drops, influencing their stability and behavior. Examples of liquid drops include raindrops, which maintain a roughly spherical shape during free fall due to surface tension until aerodynamic forces deform larger ones; dewdrops, which form spherical beads on surfaces; and oil drops in water, where immiscibility leads to stable spherical droplets suspended by buoyancy and tension.[3] These phenomena illustrate the interplay of surface tension with gravity and viscosity. In applications, controlled drop formation is essential for inkjet printing, where piezoelectric or thermal mechanisms eject uniform droplets for precise deposition; fuel injection systems in engines, which atomize liquid fuel into fine drops for efficient combustion; and medical nebulizers, which generate aerosolized drops for respiratory drug delivery.[4][5][6] Early observations of liquid drop shapes date back to Leonardo da Vinci, who noted the spherical form of water drops and soap bubbles, attributing their stability to cohesive forces akin to magnetic attraction and recognizing the role of surface elasticity in maintaining hemispheric domes for dew drops.[7]Units of measure
In scientific and medical contexts, the drop serves as a non-SI unit of volume, conventionally approximated at 0.05 milliliters (mL) for water dispensed from a standard dropper under typical conditions. This value represents a practical standardization rather than a precise physical constant, as the actual volume depends on factors such as the liquid's surface tension, density, and the dropper's orifice size.[8] Variations exist across systems: the metric drop is explicitly defined as 0.05 mL, aligning with the approximation for aqueous solutions, while the US drop also adopts this 0.05 mL standard in pharmaceutical contexts. In contrast, the minim—a unit from the historical apothecary system—equals approximately 0.0616 mL, derived as one-sixtieth of a US fluid dram (itself one-eighth of a fluid ounce). This minim was traditionally equated to a drop in early medical practice, though modern usage favors the smaller metric value.[9] The physiological drop, commonly used in pharmacology for dosing eye or ear preparations, approximates 0.05 mL but is regulated to range between 20 and 70 microliters (μL) in multidose containers to ensure safety and efficacy. Historical standards trace back to apothecary conversions, where one minim equated to about 1.23 metric drops, facilitating transitions from imperial to metric systems in the 19th and 20th centuries despite the drop's inherent imprecision.[10] In applications such as alternative medicine, homeopathic remedies are often dosed in drops, relying on the 0.05 mL approximation for dilution and administration. Similarly, in laboratory pipetting, drops provide a rough volumetric estimate for non-critical transfers, though calibrated pipettes are preferred for accuracy. However, limitations persist due to variability: drop volume can decrease with higher liquid viscosity or increase with narrower dropper designs, leading to inconsistencies of up to 20-50% in practice.[10]Computing and technology
User interface elements
Drag-and-drop is a user interface technique that allows users to move data or objects within or between applications by selecting an item with a pointing device, dragging it to a target location, and releasing it to perform the drop action.[11] This interaction simplifies tasks like file reorganization and data transfer by mimicking physical manipulation.[12] The concept originated in the 1970s at Xerox PARC, where researchers developed early graphical user interfaces incorporating drag-and-drop for object manipulation, such as in the Xerox Alto system.[13] It gained widespread adoption through Apple's Macintosh in 1984, which integrated drag-and-drop into the Finder for icon-based file management, making intuitive interactions accessible to non-expert users.[14] Microsoft followed suit with Windows 3.0 in 1990, introducing drag-and-drop support in the File Manager for moving files between folders and drives.[15] Common implementations include desktop file management, where users drag icons to copy, move, or delete files, and web applications via the HTML5 Drag and Drop API, which enables browser-based dragging of elements like images or text between HTML5-supported pages.[11] For instance, in modern operating systems, dragging a file onto an application icon opens it directly, streamlining workflows.[12] A drop-down list, also known as a drop-down menu or combo box, is an interactive UI element that displays a list of selectable options upon activation, typically via a clickable arrow or button, and collapses to show only the selected item.[16] This design conserves screen space while providing quick access to choices, such as in forms or navigation bars. The feature traces back to the Xerox Star workstation in 1981, which pioneered fixed drop-down menus in a menu bar for command selection.[17] Examples include context menus in operating systems, which appear on right-click to offer actions like copy or paste, and combo boxes in web forms that combine a text field with a selectable list for input validation.[16] Accessibility is crucial for both drag-and-drop and drop-down elements to ensure usability for all users, including those relying on keyboards or screen readers. For drag-and-drop, alternatives like keyboard shortcuts (e.g., arrow keys for movement) and visual feedback (e.g., cursors indicating drop validity) address motor and visual impairments, while ARIA live regions announce drag states to assistive technologies.[12][18] Drop-down menus require proper keyboard navigation (e.g., Enter to open, arrows to select) and ARIA attributes (e.g., aria-expanded) to convey open/closed states to screen readers, preventing entrapment in expanded lists.[16] These considerations align with WCAG guidelines to support diverse interaction methods without relying solely on mouse input.[18]Database operations
In relational database management systems, the DROP statement is a Data Definition Language (DDL) command used to delete entire database objects such as tables, indexes, views, or schemas, along with their associated data and metadata. For instance, the syntaxDROP [TABLE](/page/Table) employees; permanently removes the specified table and all its contents from the database. This operation is irreversible and cannot be rolled back in most systems unless executed within a transaction that supports DDL rollback, such as in some PostgreSQL configurations.[19][20][21]
The effects of a DROP operation extend beyond mere data removal; it eliminates the object's structure, dependencies, and any related privileges or triggers, potentially cascading to dependent objects if specified. Execution requires appropriate privileges, such as the DROP privilege for the target object in MySQL or ownership of the table in PostgreSQL, to prevent unauthorized deletions. In Oracle Database, the command can optionally move the table to a recycle bin for potential recovery rather than immediate permanent deletion, providing a safety net absent in standard SQL implementations. Failure to possess the necessary privileges results in an access denied error.[20][21][22]
The DROP statement was formalized as part of the ANSI SQL-92 standard, which introduced standardized syntax for dropping various database objects, including tables and assertions, to promote portability across compliant systems. This standard built on earlier SQL revisions by specifying behaviors like RESTRICT and CASCADE options for handling dependencies during drops. Prior to SQL-92, implementations varied widely, but adoption of the standard ensured broader consistency in DDL operations.[23][24]
Variations of DROP exist across database systems to accommodate different paradigms. In NoSQL databases like MongoDB, the db.dropDatabase() method removes the current database and its data files entirely, requiring execution on a mongos router in sharded clusters and preserving user accounts unless explicitly dropped separately. Oracle extends the standard with vendor-specific clauses, such as PURGE to bypass the recycle bin for immediate deletion, and supports dropping other objects like sequences or synonyms with tailored syntax. These adaptations maintain core SQL semantics while addressing system-specific needs, such as handling distributed data in NoSQL environments.[25][22]
Best practices for using DROP emphasize caution due to its destructive nature; always perform a full database backup beforehand to enable restoration if needed, and verify the object's dependencies using system catalogs or queries before execution. As an alternative for removing only data while preserving the table structure and indexes, the TRUNCATE TABLE statement is recommended, as it is faster and resets auto-increment counters without logging individual row deletions, though it still requires appropriate privileges and cannot be used on tables with foreign key references in some systems. Testing in a non-production environment and scripting drops with conditional checks (e.g., IF EXISTS) further mitigate risks.[22][19][26]
A common challenge with DROP operations involves foreign key constraints, which can prevent deletion if the target object is referenced by another table, triggering errors like "cannot drop table because it is referenced by a foreign key constraint" in MySQL or similar violations in PostgreSQL and SQL Server. To resolve this, constraints must first be dropped using ALTER TABLE ... DROP CONSTRAINT, or the CASCADE option can be used to automatically remove dependent objects, though this risks unintended data loss. In cases of complex schemas, querying the information schema for dependencies (e.g., via INFORMATION_SCHEMA.KEY_COLUMN_USAGE) helps identify and address issues systematically before attempting the DROP.[20][21][19]
Music
Drop in music production
In electronic dance music (EDM), the drop refers to the climactic moment in a track where built-up tension releases into an intense, rhythmic section, typically featuring a sudden influx of heavy bass and percussion.[27] This transition marks the song's energetic peak, often serving as the hook or main danceable portion that drives audience engagement on the floor.[28] The drop is characterized by a preceding buildup phase that heightens anticipation through elements like rising synths (risers), accelerating snares, vocal chops, and filtered effects, which strip away the full beat to create contrast.[29] Upon release, it shifts to a bass-heavy drop dominated by sub-bass layers, sidechained compression for punchy kicks, and minimal melodic leads to emphasize groove and intensity; this structure is prevalent in subgenres such as dubstep and house.[29] Production techniques often involve automating filters, distortion on bass synths, and dynamic EQ to ensure the drop feels "alive" and impactful, with sparse elements in the buildup amplifying the subsequent density.[28] The concept evolved from 1990s rave and club culture, drawing roots in 1980s Miami bass music's use of Roland TR-808 drum machine kicks for sudden bass emphasis, and UK garage tracks that switched abruptly from calm intros to full beats.[30] It gained prominence in the 2000s through house, techno, and trance, before exploding in the 2010s via dubstep producers like Skrillex, who refined aggressive, wobbling bass drops for mainstream appeal.[31] In DJ performance, the term "needle drop" describes a technique where the stylus is precisely cued and dropped onto a vinyl record to initiate playback instantly at a specific point, such as a breakbeat, enabling seamless transitions and rapid rhythm shifts akin to modern digital drops.[32] This hip-hop-originated method, developed in the 1970s, underscores the performative aspect of drops by allowing DJs to manipulate timing for surprise and energy.[32] Digital audio workstations like Ableton Live facilitate drop creation through tools for arrangement, such as automation clips for risers and reverb swells, sidechain compression via the Compressor device, and layering synths with plugins for bass design.[29] Producers use these features to craft builds and releases efficiently, often starting with drum patterns and iterating on contrast for genre-specific impact.[28] Culturally, the beat drop fosters communal euphoria at festivals, synchronizing crowd movements and releasing dopamine in listeners' brains during the anticipation-to-excitement transition, as shown in neuroimaging studies of EDM tracks.[33] This has spawned online memes celebrating exaggerated reactions to drops, amplifying EDM's role in youth culture and social media sharing.[31]Guitar tunings
Drop tuning refers to a family of alternate guitar tunings in which the lowest (sixth) string is lowered from its standard E pitch, while the other strings remain in standard tuning (EADGBE). This adjustment, often by a whole step or more, creates a deeper, more resonant low end and simplifies the formation of power chords across the lower strings.[34] The most prevalent form is Drop D tuning (DADGBE), where the low E string is detuned to D, aligning its open pitch with the fourth string (D) an octave lower. This configuration enables players to execute power chords using a single finger on the low three strings, facilitating faster riffing and barre shapes that incorporate the open low D for added bass depth. The resulting heavier tone has made Drop D a staple in rock and metal, allowing easier access to low notes without requiring a seven-string guitar. Artists such as Jimi Hendrix and Nirvana have utilized Drop D to enhance the aggressive, grounded sound in their recordings.[35][36][37] Variations extend the concept to even lower pitches for intensified heaviness, particularly in extreme metal subgenres. Drop C (CGCFAD) lowers the entire tuning by a whole step from Drop D, producing a thicker, more ominous timbre suited to down-tuned chugs and palm-muted rhythms. Drop B (BF♯BEG♯C♯), another whole step below, is common in nu-metal and further amplifies low-end aggression, though it demands adjustments to maintain playability. These tunings offer similar advantages to Drop D—simplified power chords and enhanced bass response—but require careful setup to preserve string tension and intonation.[38] To achieve Drop D, begin with standard tuning and loosen the sixth string by one whole step to match the pitch of the open fourth string or use an electronic tuner for precision; the other strings stay unchanged. After tuning, verify intonation by fretting the 12th fret on the low D string and comparing it to the open string's 12th-fret harmonic—if sharp, extend the string length by moving the bridge saddle rearward. For Drop D, standard 10-46 gauge strings suffice, but heavier sets like 10-52 provide better tension; lower variations such as Drop C or B benefit from 11-56 or 12-60 gauges to prevent slackness and buzzing, especially on shorter-scale guitars.[37][39] Historically, drop tunings trace back to Renaissance lute and classical guitar practices for richer harmonic intervals, later adopted in folk and blues for modal playing and drone effects. By the mid-20th century, they transitioned into rock via pioneers in heavy music, evolving into essential tools for modern genres like nu-metal where extreme low-end drive defines the sound.[36]Albums titled Drop
Several music albums have been released under the title Drop, often exploring experimental and genre-blending sounds across electronic, jazz-rock, and garage rock styles. These works highlight innovative production techniques and have garnered attention for their boundary-pushing approaches. Drop is the fourteenth solo studio album by English musician Brian Eno, released on July 7, 1997, by All Saints Records. The album features ambient and experimental electronic music, characterized by short, looping compositions that evoke a sense of improvisation and subtlety. Produced entirely by Eno, it draws from his interest in generative music systems, where minimal elements create evolving soundscapes. The tracklist includes:- Slip, Dip (2:18)
- But If (1:48)
- Belgian Drop (1:56)
- Cornered (2:02)
- Block Drop (2:50)
- Out/Out (1:51)
- Swanky (2:50)
- Coasters (2:55)
- Blissed (2:53)
- M.C. Organ (4:07)
- Boomcubist (2:07)
- Hazard (2:15)
- Rayonism (2:55)
- Dutch Blur (3:02)
- Back Clack (3:19)
- Dear World (3:16)
- Iced World (7:14)
- Neo Caliban Grides (6:23)
- All White (6:14)
- Slightly All The Time (13:16)
- Drop (7:40)
- M.C. (3:25)
- Out-Bloody-Rageous (11:30)
- As If (6:10)
- Dark Swing (1:55)
- Intropigling (0:53)
- Pigling Bland (4:44)
- Penetrating Eye (3:23)
- Encrypted Bounce (5:41)
- Savage Victory (4:07)
- Put Some Reverb on My Brother (2:37)
- Drop (2:30)
- Camera (Queer Sound) (2:00)
- King's Nose (3:08)
- Transparent World (4:21)
- The Lens (3:54)