Chapter 58 — Bubbles in SpaceTime
The Curve of Time, Chapter 58 —— Bubbles in SpaceTime, in which Saskia wonders about bubbles in the fabric of space-time.
Followed a quick shout out for International Women’s Day.
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— 58 —
Bubbles in SpaceTime
“Remember, the other day, you tried to stop time still?” Wassily asked Saskia. “But you couldn’t. What if stationary time is an asymptote?”
Saskia extended her index finger into the space between them. Then, as she contemplated, the finger, almost of its own accord, floated up until something clicked and Saskia returned it to pointing at Wassily.
Mica squinted at Wassily and then glanced over at Saskia. “What’s an asymptote?”
“The explosion that happens when you get really close to something impossible,” Saskia explained. “Like getting really close to one divided by zero. It’s an unstable point.”
“Another way of thinking about it,” Wassily added, “is: it’s like our first order way of thinking about space-time branching. You’re coming up to a decision point and you have to fall one side or the other.” He pulled a pen out of his pocket and scanned about.
On Saskia’s dining table he spied the flier for a tree-trimming service. Picking it up, he checked the back side, which was indeed blank. He glanced Saskia’s way, for permission to use it.
Saskia smiled and nodded at him, and Wassily drew a quick sketch:
“When the universe branches——imagine that moment; the whole world forks off in two different directions. It falls either side of that decision. Goes one way or the other. There is no in between.”
Mica nodded that she followed, but as Wassily reflected on his picture his brow furrowed.
“You know what, though? That doesn’t make sense.” To Wassily, it made more sense that if there were two you’s, each making different choices at some point in time, then the changed circumstances that they generated would take time to ripple out. It made no sense that the whole world would fracture, there and then. “Maybe a better mental model looks something like this.” He demonstrated with a second sketch.
“The point being that the fracture of our timeline filters out——even trying to bring the timelines back together might just force your ripple to widen faster.”
“What if the universe has a will?” Mica asked. “Some path, or destiny, it tends towards?”
Saskia nodded at Mica’s question, recalling their conversation back at the hospital. She’d been wondering herself if the untimely demise of her double was the universe’s way of cleaning house? Then, all at once, she saw a way to synthesize both Wassily’s idea with Mica’s objection. “Maybe the world reverts. Rather than a split or a branch of the universe, maybe there’s a bubble within space-time. Seems crazy, but . . . ” She trailed off, picked up Wassily’s pen, and added another side to Wassily’s drawing. “What if the shape of the universe looks more like this.”
“But which path would you remember?” Wassily objected. “Different paths to the same point in space-time would mean different in memories.”
“Maybe,” Saskia shrugged non-commitally, “Can we trust our memory, anyway? We think we remember things accurately, but think of somewhere you visited a year ago. Try remembering how you got there. Maybe you drove? walked? Whatever the case, try visualizing the path you took. Now have a look at the street view on the map app on your phone. It won’t match up. And that was just last year.” She sighed. “Point is, just because there are two potentially different paths that the world took to get here, doesn’t mean the here can’t be the same.”
They all sat in contemplation. Was this what it meant to have different memories of the same event? Maybe our memories were less faulty than we always imagined; maybe people really did experience different paths to the shared here and now.
What if all those years ago Saskia hadn’t turned her back on Wassily? Could the three of them still be here today? Having traveled different paths? And if that were the case, could Saskia have arrived here today with Wassily, and not Mica? Her lived past felt incontrovertible ...but ...it was not so strange that there might be different paths to the same location, and other than memory, what did we have?
Saskia wondered how she could test her hypotheses, without having to risk everything by turning time around.
If she kissed Mica now, surely that would make sense for Mica, and her memory of her path here. And Wassily’s too. Saskia had no real doubt, they’d all traversed the same history she had, to arrive at their shared present.
She looked into their eyes. Could she tell what someone wanted from the way their pupils dilated? Could she tell whether that want was filled with expectation? Or, if it expected to remain unrequited?
Wassily turned to Saskia. “Bubbles would change the global topology.”
His statement punctured her reflections. She blinked. She wondered if she was losing her grip on reality. Reality, there was a word whose meaning had shifted.
“You two keep talking about topology like it’s a thing.” Mica put her hands on her head in exasperation. “What is topology?”
Wassily gave the mathematicians’ classic definition of what topology was: it measured the shape of an object or manifold, up to squishing and stretching. “So, the topologist can’t distinguish between her donut and her tea cup, since both are solids with one hole in them, and are thus essentially the same.”
Mica frowned, clearly wrestling with Wassily’s words.
“Imagine the donut was made of putty,” Saskia intervened. “You could squish a cup-bowl from one side, without tearing it, and what’s left would be the handle.”
“OK.” Mica didn’t look entirely appeased. “But if the universe strives for a path, changing our minds just creates bubbles in space-time. It doesn’t destroy the basic shape of the universe.”
“Unless you can inflate one of those bubbles.” Wassily corrected her. “At what point does it become macro structure? To a topologist all holes——a bubble is a three dimensional hole——all holes are macro structure.”
“It could be a dynamic system is a better model for the universe,” Saskia offered. “You can nudge it. Bump it. And it’ll just return to its equilibrium state. And you only get one side of any bubble.”
“Problem is,” Wassily was stuck on the topology, “if you knock it hard enough or give it enough simultaneous bumps, you maybe force it off the road altogether. Like hitting a rock while you’re riding your bike; most times you get back to a smooth roll after a short wobble. But if you’re on a dirt trail the compounding sequence of nudges——pretty soon you’re in a catastrophic shudder.”
“Was this what you were so excited about when you texted?” Saskia asked.
“No.” There was a twinkle is Wassily’s eyes. “I think you have another superpower. One hidden in plain sight.”
That was chapter 58, Friends, I hope you enjoyed it!
Today, I wanted to take a moment to remind you that International Women’s Day will be celebrated later this week. This year’s theme is to `accelerate action’, and honestly, one of my hopes with The Curve of Time is that it play a small part in doing precisely that.
How exactly? Well, I’m a big believer in the power and importance of role models.
Growing up, I kind of believed you got a PhD and then figured out what you wanted to do with your life, so that’s what I did. I’m not sure I’d recommend that approach, but my point is if you grow up in a bakery then, of all the jobs you’re likely to have later in life, baker is overwhelmingly the leading contender.
And though the household a persons grows up in likely accounts for the majority of their influences, society at large is not without its sway. Princeton and Yale, for instance, did not admit women into their colleges until 1969 (though they were among the slowest).
For me, it was in this context that I decided to make Saskia a machine learning specialist. I think it’s important to have characters in roles where things like gender and sexual orientation are simply taken as read and not made a big deal of. It would be easy to spend time highlighting the struggles of women in machine learning (and I’m sure there are women who feel that I’m being disingenuous by not sunshining such travails), but to me there is a lot of power in placing a character in a situation and making believe that that is just the way things are. Science fiction as a north star, if you will. Perhaps teleporting, flying cars, or even self driving cars are not yet ubiquitous, but smartphones and video conferencing with the people on the other side of the world are.
I’d like a world where there were more women doing mathematics and science, so I’ve just made believe that to be the case.
We all have agency; we can make and choose the reality we want to live in.
Until next week, be kind to someone and keep an eye out for the ripples of joy you’ve seeded.
Cheerio
Rufus
PS. If you think of someone who might enjoy joining us on this experiment, please forward them this email. And if you are one of those someone’s and you’d like to read more
