Speed of galaxy from distance to galaxy
=======================================

Hubble's Law is a cosmological law describing the expansion of the universe, according
to which the recessional speed of a galaxy is proportional to the distance to it from
the observer.

**Notation:**

#. :math:`H` (:code:`H`) is :attr:`~symplyphysics.quantities.hubble_constant`.

**Links:**

#. `Wikipedia <https://en.wikipedia.org/wiki/Hubble%27s_law#>`__.

.. py:currentmodule:: symplyphysics.laws.astronomy.speed_of_galaxy_from_distance_to_galaxy

.. py:data:: recessional_speed

    Recessional :attr:`~symplyphysics.symbols.classical_mechanics.speed` of the galaxy, i.e. the speed at which it moves away from the observer.

Symbol:
    :code:`v`

Latex:
    :math:`v`

Dimension:
    :code:`velocity`


.. py:data:: distance

    Proper :attr:`~symplyphysics.symbols.classical_mechanics.euclidean_distance` between the observer and the galaxy.

Symbol:
    :code:`d`

Latex:
    :math:`d`

Dimension:
    :code:`length`


.. py:data:: law

    :code:`v = H * d`


    Latex:
        .. math::
            v = H d