Material

Mass $m_0$ (kg)

Density (kg/m³)

Classical Radius (meters)

$r_{loc}$ in steady-state universe $H_0=2.2\times {10}^{-18}$ (meters)

Critical mass for average density of universe

$1.7\times {10}^{-20}$

$3\times {10}^{-28}$

350

350

Critical mass for Air

$1.86\times {10}^{-9}$

1.225

$1.04\times {10}^{-3}$

$1.04\times {10}^{-3}$

Critical mass for a Styrofoam ball

$8.20\times {10}^{-9}$

50

$5\times {10}^{-4}$

$5\times {10}^{-4}$

Critical mass for interstellar dust grain (amorphous SiO₂)

$3.59\times {10}^{-8}$

2000

$2.4\times {10}^{-4}$

$2.4\times {10}^{-4}$

Critical mass for neutron star density

0.01

10¹⁷

$4\times {10}^{-7}$

$4\times {10}^{-7}$