An infalling object crosses the combined apparent event horizon of a black hole.
the verdict
INSUFFICIENT LEANING
refutedsupported
the weight of evidence
2 sources for · 0 against
AS REPORTEDno primary record reached; this is what the reporting says
The retrieved evidence includes general discussions of objects crossing black hole event horizons from an infalling perspective, but lacks definitive scholarly consensus or direct proof regarding the specific dynamics of crossing a combined apparent event horizon.
(Recalling our discussion of gravitational redshift, we could say that if the infalling astronaut uses a blue light to send his signals every second, we will see the light get redder and redder until its wavelength is nearly infinite.) As the spacing between clock ticks approaches infinity, it will appear to us that the astronaut is slowly coming to a stop, frozen in time at the event horizon. In the same way, all matter falling into a black hole will also appear to an outside observer to stop at the event horizon, frozen in place and taking an infinite time to fall through it. But don’t think that matter falling into a black hole will therefore be easily visible at the event horizon. The tremendous redshift will make it very difficult to observe any radiation from the “frozen” victims of the black hole. This, however, is only how we, located far away from the black hole, see things. To the astronaut, his time goes at its normal rate and he falls right on through the event horizon into the black hole.
# Does an object approaching a black hole ever cross the combined event horizon of the black hole and itself?
- Tags: general-relativity, black-holes, event-horizon, causality
- Score: 21
- Views: 4,002
- Answers: 5
- Asked by: Giorgos G (364 rep)
- Asked on: May 20, 2024
- Last active: Mar 27, 2025
- License: CC BY-SA 4.0
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## Question
Once you start studying black holes, one of the first things you'll probably hear is that from an outsider's perspective objects falling into the black hole take an infinite time to do so due to time dilation. The object will asymptotically approach, but never reach the event horizon.
As far as I understand the typical description of this, people are referring to the event horizon of the black hole as it was before the approach of the new object. However, my understanding is also that you can calculate a Schwarzschild radius for the total mass $M+m$ (where $M$ is the mass of the black hole and $m$ is the mass of the falling object) which would constitute the radius for the event horizon formed by the combined mass.
This new radius would be only very slightly larger, but positively so. Initially, this new event horizon would be inside the tot
Everything we examined (2)
This check searched the claim as stated. It did not run a separate search for evidence against it.