Rainbow Science

"So it's a bridge."

Thor waved a hand, blinking up at the clear sky. "It's..." he frowned. "You wouldn't understand.

Tony chewed the blade of grass in his teeth. "Try me."

"How much do you know about the mathematics of curved-space structures?"

"Enough."

"It's all about the... manifolds of nontrivial topology."

Tony sighed. Thor was drunk out of his mind, but he had centuries of knowledge locked in that mind.

"...so then... the regions contains a quasi... permanent intrathingy. Universe."

"And that looks like a rainbow."

"Stripes," Thor agreed.

"The Bifrost is magic stripes." Tony sighed.

"That's what I said."