I have seen many models showing the jet-streams shot out of black holes, and even some images. However, it is always said that a black hole has so strong of a gravity field, that not even light can escape it.

So how can matter accelerated to the speed of light, which is heavier than light escape the black hole in such "jets"? The acceleration of the jets must have an energy higher than the gravitational pull of the black hole, but how is that possible?


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    $\begingroup$ Nothing can escape once it has crossed the event horizon of a black hole. The jet streams are being released outside the event horizon. $\endgroup$
    – Prahar
    Commented Jan 29 at 17:14
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    $\begingroup$ The jet is emitted from the accretion disk of matter falling into the black hole but not yet inside its event horizon. See en.wikipedia.org/wiki/Accretion_disk and en.wikipedia.org/wiki/Astrophysical_jet. $\endgroup$
    – gandalf61
    Commented Jan 29 at 17:37
  • $\begingroup$ @Prahar “Nothing can escape once it has crossed the event horizon of a black hole.” - This is meaningless since nothing can cross the horizon for as long as the universe exists. $\endgroup$
    – safesphere
    Commented Jan 30 at 2:07
  • $\begingroup$ @safesphere - Nothing can indeed cross the horizon in finite time from the p.o.v. of an external observer. For an infalling observer, things cross the horizon in finite proper time. $\endgroup$
    – Prahar
    Commented Jan 30 at 10:06

1 Answer 1


Because we have no black holes close enough to us to study in detail, physicists are not exactly sure how the jets are formed. Several mechanisms are possible and are described in the book Gravity's Engines by Caleb Scharf.


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