--%>

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 Weiss constant Weiss constant :

    Weiss constant: The characteristic constant dependent on the substance, employed in computing the susceptibility of the paramagnetic materials.

  • Q : Problem on waveforms The voltage v mV

    The voltage v mV in a circuit is given by: v = 20 sin (200 Πt - 0.7854)           where t is the time in seconds (a) State the amplitude, frequency, period and phase angle of v.(b) Determine the initial voltage.(c) Determin

  • Q : How energy transformed in windmills

    Explain how is energy transformed in the windmills?

  • Q : Define Planck equation Planck equation:

    Planck equation: The quantum mechanical equation associating to the energy of a photon E to its frequency nu: E = h nu.

  • Q : Explain Drake equation Drake equation

    Drake equation (F. Drake; 1961): The method of estimating the number of intelligent, scientific species (that is, able to communicate with other species) in subsistence in our space. N

  • Q : Nuclear Physics Homework Help NUCLEAR

    NUCLEAR PHYSICS (PHY555) HOMEWORK #1 1. Calculate the luminosity for a beam of protons of 1 µA colliding with a stationary liquid hydrogen target 30 cm long. Compare this to a typical colliding beam luminosity of ∼1034 cm-2

  • Q : Problem on spacecraft Assuming that

    Assuming that ground stations are equally distributed on the Earth, how many ground stations are required to maintain constant contact with a spacecraft at 750 km altitude, and 72 degrees inclination?

  • Q : Define Hertz or SI unit of frequency

    Define Hertz or SI unit of frequency: Hertz: Hz (after H. Hertz, 1857-1894): The derived SI unit of frequency, stated as a frequency of 1 cycle per s; it therefore has units of s-1.

  • Q : Conservation laws and illustrations of

    Explain Conservation laws and illustrations of conservation laws (Conservation of mass-energy, electric charge, linear momentum and angular momentum) ? Conservation laws: The law which states that,

  • Q : Define Lux or SI unit of the illuminance

    Lux: lx: The derived SI unit of the illuminance equivalent to the illuminance generated by a luminous flux of 1 lm distributed consistently over a region of 1 m2; it therefore has units of lm/m2.