--%>

What is Hubble constant

Hubble constant: H0 (E.P. Hubble; 1925): The constant that determines the relationship among the distance to a galaxy and its velocity of recession due to the growth of the Universe. As the Universe is self-gravitating, it is not truthfully constant. In cosmology, it is stated as

H = (da/dt)/a,

Here a is the 4-radius of the Universe. Whenever computed for the present, it is written as:

H0 == H (t = now)

The Hubble constant is not acknowledged to great accuracy (only in about a factor of 2), however is believed to lie someplace between 50 and 100 km/s/Mpc.

   Related Questions in Physics

  • Q : What is Reflection law Reflection law :

    Reflection law: For a wave-front intersecting a reflecting surface, the angle of incidence is equivalent to the angle of reflection, in the similar plane stated by the ray of incidence and the normal.

  • Q : Define Olbers paradox Olbers' paradox

    Olbers' paradox (H. Olbers; 1826): If the Universe is infinite, consistent, and unchanging then the whole sky at night would be bright -- concerning as bright as the Sun. The further you stared out into space, the more stars there would be, and theref

  • Q : What is Hooke law Hooke's law (R.

    Hooke's law (R. Hooke): The stress exerted to any solid is proportional to the strain it generates within the elastic limit for that solid. The constant of that proportionality is the Young modulus of elasticity for that material.

  • Q : Explain Poisson equation and Poisson

    Explain Poisson equation and Poisson spot: Poisson equation (S.D. Poisson): The differential form of Gauss' law, that is, div E = rho, Pois

  • Q : Report on Radiobiology for Travel Space

    I have a problem in wirting a report on Radiobiology for Travel Space.  Can someone provide me a complete report on the above topic.

  • Q : Define Grandfather paradox Grandfather

    Grandfather paradox: The paradox proposed to discount time travel and exhibit why it violates causality. State that your grand-father makes a time machine. In the current time, you employ his time machine to go back in time a few decades to a point be

  • Q : Define Rydberg constant Rydberg

    Rydberg constant (Rydberg): The constant that governs the relationship of the spectral line features of an atom via the Rydberg formula. For hydrogen, it is around 1.097 x 107 m-1.

  • Q : Define Siemens or SI unit of an

    Siemens: S (after E.W. von Siemens, 1816-1892): The derived SI unit of an electrical conductance equivalent to the conductance of an element which has a resistance of 1 O [ohm]; this has units of O-1.

  • Q : Explain Coulombs law Coulomb's law (C.

    Coulomb's law (C. de Coulomb): The basic law for electrostatics, equivalent to Newton's law of universal gravitation. It defines that the force between two point charges is proportional to the arithmetical product of their respective

  • Q : Why the length of a standard meter

    Describe the reason in short why the length of a standard meter re-defined in the year of 1983?