--%>

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 Maxwells demon Maxwell's demon

    Maxwell's demon (J.C. Maxwell): A contemplation experiment describing the concepts of entropy. We contain a container of gas that is partitioned into two equivalent sides; each side is in thermal equilibrium with the other. The walls and the separatio

  • Q : Define Brackett series Brackett series

    Brackett series (Brackett) - The series (or sequence) that explains the emission spectrum of hydrogen whenever the electron is jumping to fourth orbital. All of the lines are in the infrared segment of the spectrum.

  • Q : Newtons laws of motion Briefly

    Briefly illustrate all the Newton s laws of motion?

  • Q : What is Cosmic censorship conjecture

    Cosmic censorship conjecture (R. Penrose, 1979): The conjecture, so far wholly undemonstrated in the context of general relativity, that all singularities (that is with the possible exception of the big bang singularity) are attended

  • Q : What is curvilinear motion What do you

    What do you mean by the term curvilinear motion? State in brief?

  • Q : Explain Bohr magneton and Bohr radius

    Bohr magneton (N. Bohr) - This is the quantum of magnetic moment. Bohr radius (N. Bohr) - The distance equivalent to the mean distance of an electron from the nucleus in the ground state of hydroge

  • Q : How elevation and air pressure affects

    Briefly state how does the elevation and air pressure affects the boiling point of water?

  • Q : What is No-hair conjecture No-hair

    No-hair conjecture (1960s): The conjecture (confirmed in the 1970s and 1980s) in general relativity that a black hole has merely three salient external characteristics: angular momentum, mass, and electric charge. All the other proper

  • Q : How radiation emitted from the body

    Describe the procedure how radiation emitted from the body? Illustrate 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