It was a beautiful day in Berkeley where Dallas sat at a patio table outside the cafe at the undergraduate library. It was a little after three and he was just getting to lunch — he tried to time his break for when the place wasn’t overrun with students. On the whole, Dallas thought highly of the university’s students. Many of them, from challenging socioeconomic backgrounds, were the first in their families to go to college. And, being accepted here — the top public university in the country, if not the world — was a doubly impressive feat. Dallas respected that.

The undergrads, though, were still young, with outsized enthusiasm for — and inexperience with — everything. For Dallas, prematurely old-man cranky at 29, the students’ energy was infrequently inspiring and oftentimes annoying.

His coordinates in space-time on this occasion were unfortunate. Dallas’ favored spot, a table and chair partially obscured by a support column at the back of the patio, was removed enough to be out of comprehensible earshot of the rest of the seating. On this day, though, someone or thing had left a sizable and unidentifiable mess on the chair. The tables and chairs all being fixed, Dallas chose his second-favorite of the patio’s rectangular array of seating, the corner spot furthest from the door to the cafe. But, the adjacent table was soon occupied by three noisy freshmen. Before it became clear that they were going to chatter nonstop through their and Dallas’ break, the other tables had filled up, leaving Dallas with no alternative.

The freshmen’s energetic conversation bounced from TV shows they were watching to classes they were taking to politics and social justice (or injustice) to the world at large.

The young man seated nearest to Dallas was in the midst of changing topics. “I’ve figured it out,” he said.

Seated diagonally across the table for four, the second young man answered, “What?”

“The dark stuff that’s making the universe expand,” the first freshman explained. “I’ve figured out what it is.”

The third freshman, sitting across the table from the first, was finishing the last of his milk tea. “Dark matter, not stuff.” He slurped his drink. “Or, is it dark energy?”

The second young man turned to the third. “I thought dark matter and dark energy were the same thing?”

The third responded, “No, they’re separate. He’s saying ‘stuff,’ so…” he turned to the first freshman, “You must mean dark matter.”

The first freshman, sidetracked, asked mainly to himself, “Dark matter or dark energy?” He stared, blankly, into his memory, attempting to recall from astrophysics what was dark matter and what was dark energy. His two friends glanced at each other.

Reaching over the table between them, the third freshman shook the first out of his trance. “Hey, genius, what’s your theory?”

Brought back to the conversation, the first answered, “Oh. Right.” He blinked his tablemates back into focus. “The expansion of the universe is caused by…” He paused dramatically, “…alternate timelines.”

The third freshman grimaced. “What?” he said. The second added, “Timelines?”

The first freshman leaned across the table. “Think about it! Something is causing the universe to expand, right? It’s actually expanding faster and faster!”

The third freshman, remembering the dark matter/energy difference that was eluding his friend, said, “Dark energy is causing the acceleration of the expansion of the universe. Dark matter is the mass that’s keeping galaxies from flying apart.”

“Yes!” said the first freshman. “The universe is expanding at an accelerating rate. We can’t determine what’s causing it, so we’re calling the force dark energy — ”

“And, by ‘we,’ you mean actual scientists,” interjected the second freshman.

“Of course,” said the first freshman. He continued, “I think dark energy is actually all of our alternate timelines. As the timelines branch, they take up more room causing the universe to expand. As timelines branch exponentially, the expansion grows faster and faster!”

It was the second freshman’s turn to make a face. “You’re saying alternate realities take up space.”

The first replied, “Why not? They have to go somewhere.”

The second freshman did not agree. “Brilliant theory, Star Trek.”

The third freshman, mulling it over out loud, said to the first, “The entire universe, in any moment, has a certain mass. You’re saying anytime the timeline branches — like when someone flips a coin — another universe we can’t see and with equal mass is created in our universe, and that extra mass is growing the universe at an accelerating rate.”

The first freshman was excited. “Yes, that’s it!”

The third freshman continued, “Sure. So your idea of all timelines occupying the same universe could explain all this mass we can’t see — dark matter. Dark matter and dark energy would be the same thing.”

Reaching across the table again, this time to clasp his friend on one shoulder, the third freshman said, “You’re on your way to getting a Nobel Laureate campus parking space, my friend. As soon as you can prove and publish all of this, I’m sure the prize committee in Sweden will call you up to let you know you’ve won. I offer you pre-congratulations.”

Dallas, his attention sucked into the conversation, realized he had been staring at the same page of his book for at least 10 minutes. He appreciated the leaps in thinking that the students were displaying, but decided he needed to find a different time and place to have lunch if he was ever going to get through his book.