Return whether or not two spheres intersect each other.

    Parameters
    ----------
    ar, br: array-like, shape (n,) in n dimensions
        Coordinates of the centres of the spheres `a` and `b`.
    aR, bR: float
        Radiuses of the spheres `a` and `b`.

    Returns
    -------
    intersecting: boolean
        True if the spheres intersect.

def spheres_intersect(ar, aR, br, bR):
    """Return whether or not two spheres intersect each other.

    Parameters
    ----------
    ar, br: array-like, shape (n,) in n dimensions
        Coordinates of the centres of the spheres `a` and `b`.
    aR, bR: float
        Radiuses of the spheres `a` and `b`.

    Returns
    -------
    intersecting: boolean
        True if the spheres intersect.
    """
    return vector.vector_mag_sq(ar - br) < (aR + bR) ** 2