[swilhelm73]

For example, right this second, untold trillions of neutrinos are coursing through your body. There's quite a bit of energy there, but essentially none of it gets deposited in your body, because the neutrinos don't interact electromagnetically.

Well, the difference, to my mind, is that they aren't annhilating themselves with anti-neutrinos while moving through my body. I would imagine that in an atmosphere, a significant percentage of the energy released, from theoritical dark anti-dark particles, would be measureable in the form of 'heat', no?

[Physicist]

Well, the difference, to my mind, is that they aren't annhilating themselves with anti-neutrinos while moving through my body.

Annihilating themselves into what?