I've re-read it recently, and I think you should give it another go; I agree that the two first books kinda complete an arc, but (minor spoiler) the third book totally throws a wrench into the happy ending of the second book.
> the countries of Earth were essentially a united front for 450 years.
That's not how it happens at all. (spoilers ahead!) The UN originally comes up with the Wallfacer plan in the first year or so after they learn of the fleet that's coming, in a time of utter despair. This is also a back-up plan, in case the "classical" space war fleet plan doesn't pan out. The first three Wallfacer end up thinking up heinous plans and spending a ton of resources, so the plan is essentially dismantled shortly after Luo Ji sends out his "spell" on that other star. They also mention the "great ravine", a very dark period of history, but we never get that much detail on that part.
Regarding your Sophons hypothesis, at speed of light you can go 7 times around the earth in 1 second; you'd have to be pretty precise with your timing to make your plan work. Moreover, Trisolaris was constantly building new ones, so by the time we'd build enough particle accelerators, there would be even more sophons on Earth.
And as for your last point, I think Luo Ji had only an hypothesis at this point, and wanted to be 100% sure before calling the bluff (and besides, he had time).
I agree with you that the characters don't have much depth, but this is a book you read for the concepts & ideas presented in it, not for the character interaction.
> I've re-read it recently, and I think you should give it another go
I'm afraid found it to be one of the worst books I've ever read. As I said, I bounced off this one hard.
> Regarding your Sophons hypothesis, at speed of light you can go 7 times around the earth in 1 second; you'd have to be pretty precise with your timing to make your plan work.
A second is a huge amount of time by the standards of modern physics. We wouldn't even need to separate out the colliders by any great distance; even a foot of separation would take a whole nanosecond for a sophon to cover.
Another approach would be to design a collider that could measure many collisions at once. Can the Trisolarans produce a thousand sophons on short notice? What about a million, or a billion? And given the latency the Trisolarans have to work with, they'd have to plan at least four years in advance.
Now maybe the Trisolarans have ways to prevent this, but the idea is never discussed, despite it being an obvious thing to try first.
For that matter, there's very few things that are tried. The idea that all the countries in the world would band together and try only one or two things over the course of 400 years is just bizarre.
> And as for your last point, I think Luo Ji had only an hypothesis at this point, and wanted to be 100% sure before calling the bluff (and besides, he had time).
He had time because he implemented a backup plan after the Trisolarans prevented the Sun from being used as a broadcasting station. But why take the risk? What does he have to lose? Either he's right and the Trisolarans will bargain with him, or he's wrong and nothing will happen. Given that Earth is doomed anyway, there's no reason not to try immediately before the Trisolarans are in a position where they can stop him.
Also it seems bizarre that in 400 years no-one once considered calling for help.
"Pretty sure" is not a good position to bluff from. Especially given the events of the third book, it's obvious that it wouldn't have worked unless the Trisolarans knew you knew.
I haven't read the third book, but I have read the Wikipedia synopsis. My understanding is that in the third book there's a new swordholder who the Trisolarans think won't go through with MAD, so they call Earth's bluff and turn out to be correct.
However, the swordholder doesn't need to be certain of the consequences in order for the scheme to work. All that's required is that the Trisolarans are certain of the consequences, and they believe that the swordholder will push the proverbial button.
If Luo Ji said, "Look, I'm like 60% sure that if I broadcast our location we'll all be killed, but I will do it if you continue." What could the Trisolarans do? Call his bluff? Then he'd say, "Okay then. I'm actually more likely to do this while I'm unsure, since there's a 40% chance nothing will happen. My being unsure has only made it more likely I'll press the button. Here we go..."
The Trisolarans would need to respect the threat regardless, which would confirm Luo Ji's theory without the need to wait a century to get results.
> the countries of Earth were essentially a united front for 450 years.
That's not how it happens at all. (spoilers ahead!) The UN originally comes up with the Wallfacer plan in the first year or so after they learn of the fleet that's coming, in a time of utter despair. This is also a back-up plan, in case the "classical" space war fleet plan doesn't pan out. The first three Wallfacer end up thinking up heinous plans and spending a ton of resources, so the plan is essentially dismantled shortly after Luo Ji sends out his "spell" on that other star. They also mention the "great ravine", a very dark period of history, but we never get that much detail on that part.
Regarding your Sophons hypothesis, at speed of light you can go 7 times around the earth in 1 second; you'd have to be pretty precise with your timing to make your plan work. Moreover, Trisolaris was constantly building new ones, so by the time we'd build enough particle accelerators, there would be even more sophons on Earth.
And as for your last point, I think Luo Ji had only an hypothesis at this point, and wanted to be 100% sure before calling the bluff (and besides, he had time).
I agree with you that the characters don't have much depth, but this is a book you read for the concepts & ideas presented in it, not for the character interaction.