--%>

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 : Define Kelvin or basic SI unit of

    Define Kelvin or basic SI unit of thermodynamic temperature: Kelvin: K (after Lord Kelvin, 1824-1907): The basic SI unit of thermodynamic temperature stated as 1/273.16 of the thermodynamic temperature of triple point of the water.

  • Q : Calculate time needed for thermocouple

    A thermocouple of K type is suddenly exposed to air with temperature of 1273K, Initial temperature was 293 K. Calculate the time needed for the thermocouple read the temperature with accuracy of better that 99%. Ignore radiation and conduction. The measuring element has a ball shape of diameter o

  • Q : Kirchhoffs rules or Loop rule or Point

    Explain Kirchhoff's rules or Kirchhoff's Loop rule and Point rule? Kirchhoff's rules (G.R. Kirchhoff) <

  • Q : What is Refraction law Refraction law:

    Refraction law: For a wave-front travelling via a boundary among two media, the first with a refractive index of n1, and the other with one of n2, the angle of incidence theta is associated to the angle of refraction phi by:

  • Q : Explain Youngs experiment or

    Young's experiment: double-slit experiment (T. Young; 1801): A well-known experiment that exhibits the wave nature of light (and certainly of other particles). The light is passed from a small source into an opaque screen with the two thin slits. The

  • Q : Why sun emerge flat throughout sunrise

    Briefly explain the reason why does sun emerge flat throughout sunrise and sunset?

  • Q : Define Radian or SI unit of the angular

    Radian: rad: The supplementary SI unit of the angular measure stated as the central angle of a circle whose subtended arc is equivalent to the radius of the circle.

  • Q : Define Zeeman Effect or Zeeman line

    Zeeman Effect: Zeeman line splitting (P. Zeeman; 1896): Zeeman Effect is the splitting of lines in a spectrum whenever the source is exposed to the magnetic field.

  • Q : Define Newton meter What do you mean by

    What do you mean by the term Newton meter? Explain briefly?

  • Q : Define Pseudoforce Pseudoforce : The

    Pseudoforce: The "force" that arises as an observer is plainly treating an accelerating frame as an inertial one.