Powder Toy is likely never going to be changed to fit realism, simply because it was initially designed as an air flow simulator and isn't really built to emulate real-life physics. Most requests that describe something for the purpose of realism are routinely ignored because of the fact that even if they were implemented in the game, they don't really add to the fun of playing unless they present some new mechanic that the older elements did not, like the introduction of White Hole and Black Hole, which are anything but realistic.

Trying to introduce realism of any kind into TPT is bound for failure. Seriously.

Ever wondered how heavy three particles of Plutonium are?