Is gravity repulsive at particle scales?

[Tipped]

A while back (several years ago), I recall reading that when two particles are placed in very close proximity to each other, gravity begins to act as a repulsive force. I began looking for that source recently, but can find no reference to it (except one source of dubious credulity). Could someone inform me whether I am recalling correctly? Or perhaps incorrectly, as I suspect?
As a side note, I do know that the state of quantum gravity is still incomplete/unknown, so any pointers to hypotheses/theories (defunct or still in debate) where what I recall is actually correct would be great.

 

[bcrowell]

This doesn't sound right to me. The closest I can come is what Leonard Susskind calls the infrared-ultraviolet connection. This is the idea that you can probe shorter and shorter distance scales by using particles of higher energy and shorter wavelength, but at some point the high-energy projectile hits the target you're imaging so hard that it forms a black hole. Once you start forming black holes, the radius of the black hole actually *increases* with energy, so you aren't probing shorter distance scales anymore.

 

[Tipped]

Cool. But I'm pretty sure that what I was reading about wasn't about things that could really be probed with light. Perhaps more theoretical?

 

[Vanadium 50]

I think it will be very hard to address the details without a reference. It certainly sounds like you are misremembering.