General Yeager said:
In various Yogic teachings.
Like the ones that teaches how to merge with the brahman?
If you would have know this from your GD or Satan I would say okay, but it doesn't sounds like something possible.
The gods do manifest in every dimension therefore in this physical dimension too. We pretty much know that IN THIS dimension something like that what you said wouldn't be possible, maybe in higher dimensions.
What do you mean by gross matter? Like any atom- protons neutrons, electrons, ect..? because without this basically you arent physical and light is just the vibration of photons, at least in the physical dimension.
The siddhis aren't physical accomplisments therefore you can't reduce your physical body size to a size of a atom in the physical dimension. The siddhis only possible in the astral and way more higher dimensions, but this in natural, as somebody on a level of a god, they can be just in any dimensions at any time and accomplish the siddhi any time, but their physical body in this 3rd physical dimensions will stay the same.
Therefore their physical body can die like if it would be inside a sun, but their higher bodys survive the amount of energy in a sun.
I do remember also that it was written somewhere that a gods body can die like in a disaster. however Im pretty sure they never died and never going to die (their physical body) as on their advancement they are protected against disasters in any way.