--%>

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 : 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?

  • Q : What is Wave-particle duality

    Wave-particle duality: The principle of quantum mechanics that entails that light (and, certainly, all other subatomic particles) at times act similar to a wave, and sometime act similar to a particle, based on the experiment you are executing. For ex

  • Q : Define Hoop conjecture Hoop conjecture

    Hoop conjecture (K.S. Thorne, 1972): The conjecture (as so far unproven, although there is substantial proof to support it) that a non-spherical object, non-spherically compressed, will only form a black hole whenever all parts of the

  • Q : Explain Stefan-Boltzmann law

    Stefan-Boltzmann law (Stefan, L. Boltzmann): The radiated power P (that is the rate of emission of electromagnetic energy) of a hot body is proportional to the radiating surface area, A, and the 4th power of the thermodynamic temperature, T. The const

  • Q : Define Mach number Mach number (E.

    Mach number (E. Mach): It is the ratio of the speed of an object in a specified medium to the speed of sound in that medium.

  • Q : Brief note on the classification of

    Write down a brief note on the classification of Alloys?

  • Q : What is balmer series Balmer series (J.

    Balmer series (J. Balmer; 1885): An equation that explains the emission spectrum of hydrogen whenever an electron is jumping to the next orbital; four of the lines are in visible spectrum, and the remainder (residue) are in the ultraviolet.

  • Q : Balanced field takeoff Describe the

    Describe the process of balanced field takeoff in brief?

  • Q : Collision & Transition State Theory

    Assuming ideal gas: a)  Calculate the average velocity of a nitrogen molecule at 298K and compare to the velocity of a helium molecule at the same conditions. b)      Calculate the temperature wh

  • Q : Blackbody radiation What is Blackbody

    What is Blackbody radiation - The radiation - that is the radiance at specific frequencies all across the spectrum -- generated by a blackbody -- which is, a perfect radiator and absorber of the heat. Physicists had complexity exp