On the virtual particle issue, see:

https://profmattstrassler.com/articles-and-posts/particle-physics-basics/virtual-particles-what-are-they/

So in a gravitational field, these would move away from the centre of mass?

crank wrote:I wish I had the citation handy, I think it was newolder who posted it, a piece on fields and how virtual particles are not really particles, the fields are entirely different. They sorta act/appear like particles but fundamentally are a different beast.

Now that I've discovered how to search through my browser history... I think this is the link you are trying to remember:
https://www.physicsforums.com/insights/ ... particles/

Rumraket wrote:So in a gravitational field, these would move away from the centre of mass?

If I understand Hawking radiation correctly, it is the tidal force that would cause the virtual particles to move away from their mutual center of mass,where one would pass the event horizon, the other no longer having a shared center of mass would itself become a real particle (or positive mass). The other would reduce the mass of the black hole. The smaller the black hole, the stronger the tidal forces near the event horizon and the stronger the effect.

CdesignProponentsist wrote:

Rumraket wrote:So in a gravitational field, these would move away from the centre of mass?

If I understand Hawking radiation correctly, it is the tidal force that would cause the virtual particles to move away from their mutual center of mass,where one would pass the event horizon, the other no longer having a shared center of mass would itself become a real particle (or positive mass). The other would reduce the mass of the black hole. The smaller the black hole, the stronger the tidal forces near the event horizon and the stronger the effect.

The way I see it, Hawking radiation is CAUSED by the tidal force that separates the two "virtual particles", but it is not the tidal force itself.