I know you've been hanging out since Monday’s post to find out more about black holes.
While I am in no way an expert in this area (hence the links to people who explain it better) I did find out a few things about black holes that I and thought you might find interesting or, at the very least, something that might win you a point in a pub quiz one day.
- The gravitational pull of a black hole can slow down time
- Black holes "evaporate" over time - albeit *vast* periods of time
- Black holes are only dangerous if you get too close
- Black holes come in all sorts of sizes, and are categorized into three so far:
- Primordial (from the size of an atom to the size of a mountain)
- Stellar (a few dozen times as weighty as the Sun)
- Super Massive (millions or billions times as weighty as the Sun)
- We can't see a black hole - the escape velocity required to leave a black hole once you’ve "passed the event horizon” (that’s the technical term for “falling in to a black hole”) is so great that even light can't get out (so you’ll never get out). That's why we can't see them directly - they’re not reflecting any light. X-ray telescopes can see them though, and we can observe the effect of their huge gravitational distortion on objects in the vicinity of the black hole. For instance a black hole can bend light from stars behind them because of the curvature of space and to an observer (you and me) of that star, it (the star) can appear to be in a different place than it is.
- There is a super massive black hole at the centre of the Milky Way (our) galaxy.