She succeeds. "You've got it."

She makes a happy noise.

"So, was there anything in particular you wanted to experiment with?"

"Explosions under different conditions! Especially if I can figure out how to play around with the nuclear forces..."

"Atomic explosions are an exciting place to start. I have several designs for fission and fusion weapons. You can also directly play around on an atomic scale if you prefer."

"Oooo, fission and fusion sounds fun! Probably best to start with normal physics?"

"All physics is normal, but if you'd prefer chemical explosions we can start with either traditional explosives like C4 or more exotic compounds like FOOF."

"Atomic seems funnest."

"Would you prefer to have a bomb design or play with things at the atomic scale?"

"Play around, I think..."

"Would you prefer to start with fission or fusion?"

"Hmmmm... Fusion."

Addy conjures a canister with a mix of Deuterium and Tritium. "This is probably the easiest form of fusion to start with. The key is to push together one Deuterium atom and one Tritium atom with enough force to make them fuse. It's a good exercise in focusing down to the atomic scale."

"Anywhere special we should do this?"

"Fusing a few atoms here and there is pretty hard to notice at the macroscopic scale. If you wanted to fuse that whole canister at once it'd still be fine with a checkpoint and our safeties but I can also make a more fitting environment if you want ambiance."

"Let's go for ambiance. Mad science deserves it."

"Well then. To testing area 17!" Addy move the two of them to one of her testing areas. There are bright red lights shining from red spirals on the gunmetal ceiling at least twenty meters above their heads. Before them is globe which is gently pulsing with a dim white light, at the center of the circular room. The floor is an industrial grating, if there is a floor below that it is lost in shadow. In the center of the ceiling there's a tremendous glass window occasionally lit by a silent thunderstorm above.

She laughs. "Very properly atmospheric! I need a lab coat, and then we can do science!" She makes a lab coat - not white, the idea gives her a shiver, but bright cherry red with little flairs at the bottom.

Addy makes a matching coat for herself. "Alright, then, one second while I set up." Addy replaces the ordinary air in the orb in front of them with the same deuterium tritium mix found in the canister she made in the library. "There, an orb is much more dignified than a canister and you can also get some visual feedback. Oh, also the floor here is indestructible so it won't disappear from under us, the walls and ceiling can't fall on us either." 

"Sweet."

And she tries pushing the atoms together.

The atoms fuse, there is now a helium atom and a neutron flying apart. "You got it, maybe we should slow down time, it's a bit hard to see how it all works in real time."

Heeee. "Alright!"

Addy slows down time to a hundredth the normal speed, "Feel free to try again."

And: boom!

Addy watches happily, she's glad River is enjoying herself.