With the power of a dyson sphere I’ll bet a few antimatter starships are on the table. Think about how economically unrealistic the space race was in the cold war.
I got distracted with fun multiplication again
It was around 5% of the federal budget at peak, and according to this weird google thing I don’t trust antimatter production efficiency is one in a billion, and given a dyson sphere output of ~10^26 Watts, that yields 4005.5 kilos of antimatter per hour. The US federal budget keeps getting estimated as a little over 20% of the economy so we could take 20 percent of our energy and take five percent of that, which is ~40 kilos of antimatter per hour. This is pretty sane IMO. Waiting year between rocket launches is sane, and if you wait a year spending your energy on this, you get 351 metric tons of antimatter. This obviously assumes perfect collection, which WE FULLY AND UTTERLY LACK I ADMIT.
I’ll bet some politicians could be fearmongered into believing we need to get our eggs out of one basket.
Kinda. If carbon nanotubes are strong enough the limit becomes making some of those a million times longer. If they aren’t, then yes, we don’t know until we do it. But if, say, we’re within a couple percent, I’d say that falls into the camp where no revolution need take place, only incremental change. Basically I’m saying you can get very sci-fi by changing the rules incrementally or not at all, and the scale revolutionarily.