[GlentoranMark (OP)]

And disprove Einstein?

I've a maths 'O Level' just curious like

[evan_au]

Yes, someday a speeding black hole could pass between Mercury and the Sun, but it would devastate the orbits of the inner Solar System, throwing planets into eccentric orbits, maybe throwing some out of the Solar System, and crashing some into the Sun or other planets.

No, a black hole cannot now be orbiting between Mercury and the Sun, as the inner Solar System would have disintegrated  long ago. The more distant planets (Jupiter and beyond) would not be dramatically affected because:
- The new mass would be close to the Sun
- Instead of orbiting the Sun, they would be orbiting a point between the Sun and the black hole.
- They would have much shorter orbits than they do at present (because of the more-than-doubled mass in the center of the Solar system)
- Because the black hole would have a mass greater than the Sun (3 or more times the mass of the Sun), it would be more correct to say that the Sun would be orbiting the black hole, rather than the reverse

See: https://en.wikipedia.org/wiki/Black_hole

[Bill S]

Whatever might be possible, in principle, the smallest BH identified to date would probably have a significantly disruptive influence on the solar system, if it were where you suggest.

https://www.space.com/5191-smallest-black-hole.html