Browse Definitions:
Definition

black hole

1) The term "black hole" is sometimes used to refer to an imaginary place where objects, files, or funds go when they get lost for no apparent reason.

2) In physics and astronomy, a black hole is a region in time and space within which gravity is so strong that nothing can escape, not even electromagnetic radiation such as visible light. Black holes are thought to surround certain celestial objects.

The idea of a black hole (if not the term itself) is not new. As the intensity of the gravitational field around an object increases, so does the escape velocity. The escape velocity for a celestial mass (such as a star, planet, or moon) is the vertical speed with which an object must be hurled from the surface in order to fly forever beyond the gravitational influence of the mass. If a substantial celestial body such as a star becomes small enough in diameter, the escape velocity at the surface can theoretically exceed the velocity of light. This idea occurred to astronomers even in Isaac Newton's time. Modern astronomers believe they have observed black holes, consisting of stars that have collapsed under their own gravitation after spending their nuclear fuel. Black holes are also believed to exist at the centers of galaxies, including our own.

A black hole produces bizarre effects on time and space. As seen from outside, an object falling into a black hole would approach the so-called event horizon, which is a spherical "one-way membrane" or "Rubicon" surrounding the black hole itself. If the object were a clock, it would seem to run more and more slowly as it approached the event horizon, and would never quite make it inside the black hole. From the reference frame of the falling object, nothing out of the ordinary would take place in the rate at which time passed, and the entry to the black hole would proceed apace, although the gravitational force near the event horizon might tear the falling object apart.

Black holes have been fodder for wild ideas and science-fiction stories since the concept became well known in the mid-1900s. Some scenarios are sensational to the point of madness. For example, suppose a tiny black hole, manufactured for use as a doomsday weapon, were dropped onto the surface of the earth? It would, as the story goes, proceed to devour the planet with unstoppable and phenomenal violence.

Also see a spam-related term, blackhole list.

This was last updated in September 2005

Continue Reading About black hole

Start the conversation

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

SearchCompliance

SearchSecurity

  • Advanced Encryption Standard (AES)

    The Advanced Encryption Standard, or AES, is a symmetric block cipher used by the U.S. government to protect classified ...

  • identity theft

    Identity theft, also known as identity fraud, is a crime in which an imposter obtains key pieces of personally identifiable ...

  • spear phishing

    Spear phishing is an email-spoofing attack that targets a specific organization or individual, seeking unauthorized access to ...

SearchHealthIT

SearchDisasterRecovery

  • call tree

    A call tree -- sometimes referred to as a phone tree -- is a telecommunications chain for notifying specific individuals of an ...

  • mass notification system (MNS)

    A mass notification system is a platform that sends one-way messages to inform employees and the public of an emergency.

  • disaster recovery as a service (DRaaS)

    One approach to a strong disaster recovery plan is DRaaS, where companies offload data replication and restoration ...

SearchStorage

  • ZFS

    ZFS is a local file system and logical volume manager created by Sun Microsystems to control the placement, storage and retrieval...

  • CIFS (Common Internet File System)

    CIFS (Common Internet File System) is a protocol that gained popularity around the year 2000, as vendors worked to establish an ...

  • GlusterFS (Gluster File System)

    GlusterFS (Gluster File System) is an open source distributed file system that can scale out in building-block fashion to store ...

SearchSolidStateStorage

  • Tier 0

    Tier 0 (tier zero) is a level of data storage that is faster, and perhaps more expensive, than any other level in the storage ...

  • PCIe SSD (PCIe solid-state drive)

    A PCIe SSD (PCIe solid-state drive) is a high-speed expansion card that attaches a computer to its peripherals.

  • SSD caching

    SSD caching, also known as flash caching, is the temporary storage of data on NAND flash memory chips in a solid-state drive so ...

SearchCloudStorage

  • RESTful API

    A RESTful application program interface breaks down a transaction to create a series of small modules, each of which addresses an...

  • cloud storage infrastructure

    Cloud storage infrastructure is the hardware and software framework that supports the computing requirements of a private or ...

  • Zadara VPSA and ZIOS

    Zadara Storage provides block, file or object storage with varying levels of compute and capacity through its ZIOS and VPSA ...

Close