A universe contains immeasurable galaxies. Ours has 11 dimensions but typically only the 3 space dimensions and 1 time dimension are known as spacetime. The creation of a universe is attributed to a Big Bang and ours happened about 14 billion years ago.
Present Day Observable Universe[]
| Property | Value |
|---|---|
| Age | 4.35 × 1017 s, or 13.8 × 109 years |
| Diameter | 8.7 × 1026 m or 9.2 × 1010 light-years |
| Volume | 3.4×1080 m3 |
| Mass | 3 × 1052 kg or 1.5 × 1022 solar masses or 1080 protons |
| Density | 9.9 × 10−27 kg⋅m−3 |
| Temperature | 2.725 K (temperature of the cosmic microwave background radiation) |
| Cosmological constant | 1.1 × 10−52 m−2 |
| Hubble constant | 2.2 × 10−18 s−1 or 67.8 (km/s)/Mpc |