Browse Definitions:
Definition

fine structure constant

The fine structure constant measures the strength of the electromagnetic force that controls how charged elementary particles (such as electrons and photons) interact. Because the constant is nearly equal to 1/137, and because it is a dimensionless constant, some scientists have been led to wonder whether it has mathematical significance of its own, such as pi, the ratio of a circle's circumference to its diameter.

The fine structure constant can be derived from other constants as follows:

 = e2 (2ohc)-1

where e is the elementary charge, o is the permittivity of free space, h is Planck's constant, and c is the speed of light. The constant is also equal to the ratio of the velocity v1 of the electron in the hydrogen atom to c, the speed of light.

This was last updated in May 2008

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

Powered by:

SearchCompliance

  • risk map (risk heat map)

    A risk map, also known as a risk heat map, is a data visualization tool for communicating specific risks an organization faces.

  • internal audit (IA)

    An internal audit (IA) is an organizational initiative to monitor and analyze its own business operations in order to determine ...

  • 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 ...

SearchSecurity

  • FIDO (Fast Identity Online)

    FIDO (Fast ID Online) is a set of technology-agnostic security specifications for strong authentication. FIDO is developed by the...

  • cryptanalysis

    Cryptanalysis is the study of ciphertext, ciphers and cryptosystems with the aim of understanding how they work and finding and ...

  • Trojan horse (computing)

    In computing, a Trojan horse is a program that appears harmless, but is, in fact, malicious.

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

  • personal cloud storage (PCS)

    Personal cloud storage (PCS) enables users to store data, photos, music, videos and other files on a local network-attached ...

  • cloud SLA (cloud service-level agreement)

    A cloud SLA (cloud service-level agreement) is an agreement between a cloud service provider and a customer that ensures a ...

  • wear leveling

    Wear leveling is a process that is designed to extend the life of solid-state storage devices.

SearchSolidStateStorage

  • hybrid hard disk drive (HDD)

    A hybrid hard disk drive is an electromechanical spinning hard disk that contains some amount of NAND Flash memory.

Close