However, if someone fell into a supermassive black hole with a low density, there would be no such tidal forces to contend with. In that case, the relativistic effects of being near the event horizon of a black hole would become apparent. As the person fell closer and closer to the event horizon, his or her speed would get closer and closer to the speed of light, and the passage of time would get slower and slower. Eventually, the person would move so slowly through time that he or she would effectively freeze, never reaching the event horizon. In fact, the event horizon will grow outward to meet the person. As it did so, the person’s body would change from matter into energy, following the formula E = mc2, and disappear into the black hole forever.
| Black Holes in the Milky Way Galaxy |
| Name |
Probable Mass in solar masses |
Approx. Distance from Earth in light-years |
| A0620-00 |
9–13 |
3,000–4,000 |
| GRO J1655-40 |
6–6.5 |
5,000–10,000 |
| XTE J1118 480 |
6.4–7.2 |
6,000–6,500 |
| Cygnus X-1 |
7-13 |
6,000–8,000 |
| GRO J0422 32 |
3–5 |
8,000–9,000 |
| GS 2000-25 |
7–8 |
8,500–9,000 |
| V404 Cygnus |
10–14 |
10,000 |
| GX 339-4 |
5–6 |
15,000 |
| GRS 1124-683 |
6.5–8.2 |
17,000 |
| XTE J1550-564 |
10–11 |
17,000 |
| XTE J1819-254 |
10–18 |
less than 25,000 |
| 4U 1543-475 |
8–10 |
24,000 |
| Sagittarius A* |
3,000,000 |
Center of the Milky Way |
