On Tuesday, Yuri Milner and Stephen Hawking announced Starshot, a $100 million dollar research initiative. The goal is to lay the groundwork for a very ambitious, but surprisingly plausible project: sending probes to the nearest star, Alpha Centauri. Their idea is to have hundreds of ultra-light probes, each with a reflective sail a few meters in diameter. By aiming an extremely powerful laser at these sails, it should be possible to accelerate the probes up to around a fifth of the speed of light, enough to make the trip in twenty years. Here’s the most complete article I’ve found on the topic.
I can’t comment on the engineering side of the project. The impression I get is that nothing they’re proposing is known to be impossible, but there are a lot of “ifs” along the way that might scupper things. What I can comment on is the story.
Milner and Hawking have both put quite a bit of effort recently into what essentially amounts to telling stories. Milner’s Breakthrough Prizes involve giving awards of $3 million to prominent theoretical physicists (and, more recently, mathematicians). Quite a few of my fellow theorists have criticized these prizes, arguing that the money would be better spent in a grant program like that of the Simons Foundation. While that would likely be better for science, the Breakthrough Prize isn’t really about that. Instead, it’s about telling a story: a story in which progress in theoretical physics is exalted in a public, Nobel-sized way.
Similarly, Hawking’s occasional pronouncements about aliens or AI aren’t science per se, and the media has a tendency to talk about his contributions to ongoing scientific debates out of proportion to their importance. Both of these things, though, contribute to the story of Hawking: a mascot for physics, someone to carry Einstein’s role of the most recognizable genius in the world. Hawking Inc. is about a role as much as it is about a man.
In calling Hawking and Milner’s activity “stories”, I’m not dismissing them. Stories can be important. And the story told by Starshot is a particularly important one.
Cosmology isn’t just a scientific subject, it contributes to how people see themselves. Here I don’t just mean cosmology the field, but cosmology in the broader sense of our understanding of the universe and our place in it.
A while back, I read a book called The View from the Center of the Universe. The book starts by describing the worldviews of the ancients, cosmologies in which they really did think of themselves as the center of the universe. It then suggests that this played an important role: that this kind of view of the world, in which humans have a place in the cosmos, is important to how we view ourselves. The rest of the book then attempts to construct this sort of mythological understanding out of the modern cosmological picture, with some success.
One thing the book doesn’t discuss very much, though, is the future. We care about our place in the universe not just because we want to know where we came from, but because we want to have some idea of where we’re going. We want to contribute to a greater goal, to see ourselves making progress towards something important and vast and different. That’s why so many religions have not just cosmologies, but eschatologies, why people envision armageddons and raptures.
Starshot places the future in our sight in a way that few other things do. Humanity’s spread among the stars seems like something so far distant that nothing we do now could matter to it. What Starshot does is give us something concrete, a conceptual stepping-stone that can link people in to the broader narrative. Right now, people can work on advanced laser technology and optics, work on making smaller chips and lighter materials, work that would be useful and worth funding regardless of whether it was going to lead to Alpha Centauri. But because of Starshot, we can view that work as the near-term embodiment of humanity’s interstellar destiny.
That combination, bridging the gap between the distant future and our concrete present, is the kind of story people need right now. And so for once, I think Milner’s storytelling is doing exactly what it should.
4 gravitons 
Right, we need more of this. Public funding of science via grants is fine, but the public needs something graspable in return, sometimes. I think “story” diminishes this a great deal though. It is indeed a story, but it is a story of exploration, so the subject, “exploration” is a more apt description of this effort.
LikeLike
FWIW, not a huge fan of Hawking. I found his statements about aliens (and god) pretty dumb.
The idea reminds me a bit of the SF novel Rocheworld by Robert L. Forward. They use a (rather more powerful than considered here) solar-system-based laser to send a ship to a distant planet, and they use a clever trick to use the same laser for braking once their.
If you’re not familiar with Forward, I think you’d like him. He’s a physicist who wrote some pretty decent diamond-hard SF. His novel Dragon’s Egg is one of my favorites.
LikeLiked by 1 person
You have written it very nicely, 4gravitons. It’s the bridge between our tangible present and the hot future that defines the progress or at least the people’s perception of it. I am happy you wrote this mostly supportive thing because your views on the superiority of the “physics of decimals” may lead one to predict that you would only encourage relatively mundane engineering tasks. I must be misunderstanding your broader “way of reasoning” that leads you to the “physics of decimals” opinions, right?
What’s your estimate when “comparably ambitious” things, if not exactly this one, become possible and successful? I think it’s many decades if not centuries. Even most of the “pieces” haven’t been tried separately, and a combination requires quite a safe mastery of all of them. On the other hand, I agree that the project is surprisingly plausible from a physics viewpoint. There may still be some “not quite understood” even fundamentally physical obstacles that make things like that impossible even in principle.
But there are surely many things that may be done, perhaps even with the 2016 technology, sort of, even though no one has been commercially pushed to bring them to reality.
LikeLike
I don’t mind ambitious, and I don’t mind wacky. I encourage both. But I think that the best ambitious and wacky ideas tend to build on what we have, while the worst are made in ignorance of it.
Part of what I find compelling about Starshot is that it takes things we’re already making a lot of progress on (miniaturization, lasers, novel materials) and marshals them in support of its (breathtakingly ambitious) goal.
Because of that, I’d be optimistic for how soon this sort of thing could be possible. Milner uses vague language like “within a generation”. Demographers like to think of generations as twenty year blocks. I don’t know enough on the engineering front for my opinion to carry any weight here…but if he’s claiming that we’ll be able to do something “comparably ambitious” in twenty years, or at least have tested enough of the pieces to be confident in it by then…then that doesn’t sound unreasonable to me, honestly.
LikeLiked by 1 person