# Tag Info

1

In theory, a charged and rotating black hole can generate its own magnetic field. The magnetic (and electric) field can exist and can be measured outside the event horizon of the black hole. I completely agree with both existing answers that magnetic field does not "escape" from black holes, however I would argue that it is extremely unlikely that any real ...

0

You appear to have a thing about linking the magnetic field generated by Jupiter to that around a black hole (note that a field does not "belong" to an object) - the two things are entirely different, the only connection being that magnetic fields are generated in both cases by currents caused by the motion of charged particles. In Jupiter's case, the ...

5

Nothing "escapes" a BH - in the sense that a signal originating inside the event horizon remains forever inside. If something is observed moving away from the BH, then it was generated outside the event horizon. If it was generated inside, it would never be observed at all, forever and ever. Gravity itself does not "escape" a BH - and neither does "not ...

2

No, the galactic magnetic field is very weak, about 0.1nT. It is able to bend the trajectory of highly-energetic charged particles and also to align dust grains across the magnetic field. However, is too weak to affect the rotation of a galaxy. Although the origin of galactic magnetic field is not clear yet, the supermassive black holes do not ...

1

Nothing can escape a black hole, not even gravity. What black holes being inescapable means is just this: if you have any sort of system inside a black hole, there's nothing it can do to send a signal outside. This is true regardless of whether the attempt is made through the gravitational, electric, or magnetic fields. Black holes obviously do have a ...

4

I won't argue with the wikipedia definition (although the NASA Jupiter fact sheet lists it as the radius at 1 bar), but just to point out that the scale height of the atmosphere of Jupiter is given by, $h \sim kT/m g$, where $T$ is the temperature, $m$ is the mean molecular mass and $g$ is local gravity. Putting in some numbers: $g \simeq 24.8 m/s^2$, \$m ...

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