The answers I could find on the web are split about 50% “we genuinely don’t know” and 50% “yes we do know”; only with the latter then equally split between “yes it does” and “no it doesn’t”. Superficially, if Hawking radiation is a generalization of Unruh radiation then any source of gravity should create it. However, while it’s easier to see for a black hole because externally at least a black hole is nothing BUT spacetime curvature, for a physical object the question has to be asked of where the energy for the radiation is coming from. For example a neutron star, at some point mass would have to be dissolved to supply the energy, and what mechanism would be doing that?
I think that, if it doesn’t involve an event horizon, then it would by definition not be Hawking radiation. You can get similar phenomena with other sorts of horizons, but I think you always need a horizon of some sort.
Perhaps quantum super-positioning could also do that perhaps with a chance entanglement with the environment but I don’t think it would be the same name.
That’s my layman’s take on it too - the event horizon is intrinsic to the Hawking radiation model.
Keep in mind that an event horizon is not like a chalk mark on the pavement, with a definite location. A particle-antiparticle pair could be generated light years away from the singularity, and if one of them is destined towards it, the other is Hawking radiation.
Except that physicists now vehemently deny that the “particle-antiparticle” thing is valid, even though Hawking himself used it as an analogy trying to dumb down the math to layperson level. In theory all you need is strongly curved space; the question is whether neutron stars etc. count.
No, the particle-antiparticle thing is valid. It’s just not the most elegant way to describe it.
But Hawking’s explanation isn’t just misleading, it’s completely incorrect.
This statement identifies the author as more concerned about argumentation than solving problems, because this is not the approach physicists use. We don’t use Feynman diagrams to solve badminton trajectories–overly complicated and intractable. Simplifying a situation to the essentials is the criterion for success. A simple explanation is not incorrect (and especially not completely incorrect); it instead highlights the essential behavior in a tractable way.
It’s an interesting one, because I do see both sides.
The explanation given in a Brief History of Time is easier to understand IME than any attempt I’ve seen of explaining Hawking radiation with regards to Unruh radiation. And it’s not like it’s completely tangential to reality…it’s still at least referencing vacuum energy. If the book is aimed at non-physicists, what’s the harm?*
OTOH, bad analogies do exist, and at least some people who go on to study physics have to spend time “re-learning” Hawking radiation. So, for those people, it is harmful and I see why it’s a bugbear.
* Apart from the general problem with pop-sci books on theoretical physics: that people often think the metaphors or analogies are the science and therefore that they can make inferences or hypotheses just on that basis. Books like that need to be taken as just entertainment and that’s not immediately obvious for us non-scientists.
I don’t think that I would say that the explanation in terms of particle-antiparticle pairs is a “bad analogy”, because it isn’t really an analogy. It’s as valid as any other formulation. It’s just not the easiest formulation to actually do calculations with.
It’s common in any problem in modern physics to change between different formulations of a problem, in order to make some task or other easier.
So why are so many scientists so against this description?
Is it just a case of “I know a thing”, like when people lament that kids are taught “incorrect” models of an atom?
I’m not sure many scientists are, instead of students of science. Students, at all levels, tend to conflate a description of something with the thing itself. Science doesn’t actually care what a thing is; scientists care about having a useful description of what is happening. With “useful” highly dependent on the use.
The linked article was written by an astrophysicist and references other articles written by scientists with the same complaint.
Whether it constitutes “many” I don’t know, but it seems a more common target for ire than other formulations.
Even if the formulations are ultimately equivalent, some are easier to work with than others. Scientists prefer the one that’s easier.