<p><a href="http://en.wikipedia.org/wiki/Rotating_black_hole">1) Nearly all black holes are Kerr black holes.</a></p>

<p><a href="http://hubblesite.org/explore_astronomy/black_holes/encyc_mod3_q7.html">2) There are roughly 100 million black holes estimated in our galaxy.</a></p>

<p><a href="http://www.space.com/7678-black-hole-closer-earth-thought.html">3) There is a confirmed black hole about 7800 light years away.</a></p>

<p><a href="http://io9.com/5949616/is-earths-closest-black-hole-hiding-inside-this-nebula">4) There is a potential black hole about 1500 light years away.</a></p>

<p><a href="http://io9.com/5949616/is-earths-closest-black-hole-hiding-inside-this-nebula">5) It is very likely that there are black holes even closer than that, but they are difficult to detect.</a></p>

<p>Some of your assumptions are wrong, but for now the closest known potential black hole is still a pretty good distance away. Traveling that far with our current technology is impossible, and overcoming that hurdle is not trivial. Regardless, using a Kerr black hole for time travel <a href="http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/041130a.html">may not be feasible anyway</a>.</p>

CC BY-SA 3.0
2014-04-14T20:28:16.443Z
2014-04-14T20:28:16.443Z
called2voyage
<p>I understand that Kerr Black Holes are purely theoretical and have not been found anywhere in the Universe. However, they are theorized for possible means of time travel.</p>

<p>I am attempting to prove in a research paper that controlled time travel is statistically improbable for the human species. Therefore if scientists have evidence that there does not exist a black hole within a distance of X from Earth, and it is statistically improbable for the human species to ever be able to travel a distance of X, I can rule out time travel by means of kerr black holes with a significant degree of certainty.</p>

<p>However, I cannot find this "X" threshold, which is why I am asking this question. Have scientists verified that there are no kerr black holes within a distance of X from earth for some X?</p>

<black-hole>
Finding a Kerr Black Holes
user1380792
# Finding a Kerr Black Holes

(Asked by: username_0 on 2014-04-14)

I understand that Kerr Black Holes are purely theoretical and have not been found anywhere in the Universe. However, they are theorized for possible means of time travel.

I am attempting to prove in a research paper that controlled time travel is statistically improbable for the human species. Therefore if scientists have evidence that there does not exist a black hole within a distance of X from Earth, and it is statistically improbable for the human species to ever be able to travel a distance of X, I can rule out time travel by means of kerr black holes with a significant degree of certainty.

However, I cannot find this "X" threshold, which is why I am asking this question. Have scientists verified that there are no kerr black holes within a distance of X from earth for some X?

**Tags:** black-hole

---

## 1 answers

### Answer by username_1 on 2014-04-14. Score: 5

[1) Nearly all black holes are Kerr black holes.](http://en.wikipedia.org/wiki/Rotating_black_hole)

[2) There are roughly 100 million black holes estimated in our galaxy.](http://hubblesite.org/explore_astronomy/black_holes/encyc_mod3_q7.html)

[3) There is a confirmed black hole about 7800 light years away.](http://www.space.com/7678-black-hole-closer-earth-thought.html)

[4) There is a potential black hole about 1500 light years away.](http://io9.com/5949616/is-earths-closest-black-hole-hiding-inside-this-nebula)

[5) It is very likely that there are black holes even closer than that, but they are difficult to detect.](http://io9.com/5949616/is-earths-closest-black-hole-hiding-inside-this-nebula)

Some of your assumptions are wrong, but for now the closest known potential black hole is still a pretty good distance away. Traveling that far with our current technology is impossible, and overcoming that hurdle is not trivial. Regardless, using a Kerr black hole for time travel [may not be feasible anyway](http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/041130a.html).


---

