Browse Definitions:
Definition

gravity (or gravitation)

Gravity, also called gravitation, is a force that exists among all material objects in the universe. For any two objects or particles having nonzero mass, the force of gravity tends to attract them toward each other. Gravity operates on objects of all sizes, from subatomic particles to clusters of galaxies. It also operates over all distances, no matter how small or great.

Gravitation is one of the most studied phenomena in physics. Isaac Newton defined its behavior with his famous Law of Universal Gravitation. Newton hypothesized that the force of gravity between any two spherical objects of uniform density is directly proportional to the product of their masses, and inversely proportional to the square of the distance between their centers. According to this law, if m1 and m2 are the masses of two objects, and if their centers are separated by a distance d, then the gravitational force (f) between them is given is given by the following formula:

f = km1m2/d2

where k is a constant that depends on the units specified for m1, m2, d, and f.

Newton's theories about gravitation were modified in the 20th century when Albert Einstein developed the general theory of relativity. Einstein saw that the nature of the force of gravity is the same as the nature of the force exerted on any object that undergoes acceleration. This is known as the Principle of Equivalence. He also demonstrated mathematically that gravitational fields cause distortion in space and time. These hypotheses have been validated by experimentation.

Every object in the universe is surrounded by a gravitational field. The strength of the field is directly proportional to the mass of the object, and inversely proportional to the square of the distance from its center (for any point outside the object itself). Thus, the gravitational field of the sun is stronger overall than that of the earth, and the gravitational field of the earth is stronger in the vicinity of a person standing on the surface than it is at the altitude of a satellite in orbit. Nevertheless, the gravitational field surrounding any object extends indefinitely in all directions. Every particle in the entire universe is gravitationally attracted to every other particle. This is an important consideration in the development of theories concerning how the universe formed, how it is evolving, and what fate ultimately awaits it.

Long thought to exist before they were detected, gravity waves were first hypothesized in Einstein's general theory of relativity, which predicted that an accelerating mass would radiate gravitational waves as it lost energy. On February 11, 2016, David Reitze, executive director of LIGO (Laser Interferometer Gravitational-Wave Observatory) reported that researchers had detected gravitational waves. Reitze said the waves were created by the merging of two black holes, one of which had the mass of 29 suns and the other 36. The discovery is expected to yield a vast amount of information about the universe and the matter and energy within it and to also lead to a great number of practical applications.

Minute Physics explains gravity quickly and simply:

This was last updated in February 2016

Continue Reading About gravity (or gravitation)

Join the conversation

1 comment

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.

wow great site to bookmark and very useful information I would like to add some more points
about gravity: http://slcguru.com/gravity/
about gravitation: http://slcguru.com/gravitation/
Cancel

-ADS BY GOOGLE

File Extensions and File Formats

Powered by:

SearchCompliance

  • pure risk (absolute risk)

    Pure risk, also called absolute risk, is a category of threat that is beyond human control and has only one possible outcome if ...

  • risk assessment

    Risk assessment is the identification of hazards that could negatively impact an organization's ability to conduct business.

  • audit program (audit plan)

    An audit program, also called an audit plan, is an action plan that documents what procedures an auditor will follow to validate ...

SearchSecurity

  • insider threat

    Insider threat is a generic term for a threat to an organization's security or data that comes from within.

  • ransomware

    Ransomware is a subset of malware in which the data on a victim's computer is locked, typically by encryption, and payment is ...

  • hacker

    A hacker is an individual who uses computer, networking or other skills to overcome a technical problem.

SearchHealthIT

SearchDisasterRecovery

  • business continuity and disaster recovery (BCDR)

    Business continuity and disaster recovery (BCDR) are closely related practices that describe an organization's preparation for ...

  • business continuity plan (BCP)

    A business continuity plan (BCP) is a document that consists of the critical information an organization needs to continue ...

  • call tree

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

SearchStorage

SearchSolidStateStorage

  • 3D XPoint

    3D XPoint is memory storage technology jointly developed by Intel and Micron Technology Inc.

  • RRAM or ReRAM (resistive RAM)

    RRAM or ReRAM (resistive random access memory) is a form of nonvolatile storage that operates by changing the resistance of a ...

  • JEDEC

    JEDEC is a global industry group that develops open standards for microelectronics.

SearchCloudStorage

  • Google Cloud Storage

    Google Cloud Storage is an enterprise public cloud storage platform that can house large unstructured data sets.

  • 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 ...

Close