That we see nothing implies intellgent life is rare, short lived, or we're early in the age of the universe. For example, red dwarfs will last trillions of years compared to the sun's 5B lifespan.
Or it implies that not everybody's first instinct on seeing a vast galaxy is to try to take it over ASAP.
If you want resources for quality of life— Gas giants are a thing. If you're an explorer driven by curiosity, then take only samples, leave only memories, right.
If you want money— Century-long shipping times with civilization-scaled fuel costs tend to eat into profit margins.
If you're worried about survival— genuinely worried about survival, on a level personal enough to motivate action, not just academically or for fun— then the focus is on people you know and care about; all of those are here.
In fact, I suspect the ones that see other stars and immediately think "Mine mine all mine!" probably have a higher chance of nuking themselves before they even get out of their star system.
> > Or it implies that not everybody's first instinct on seeing a vast galaxy is to try to take it over ASAP.
Or it may simply imply that intelligent life is good at hiding and does not want to be seen e.g. the dark forest hypothesis.
Let’s assume super tech they can build that somehow allows vastly faster speeds than we can today ~120 km/s worth of DeltaV. Half that is spent slowing down so we’re talking 0.02% c.
Now let’s assume half the time is spent in flight and half the time is spent colonizing stars before launching ships. So now we’re down to 0.01% C. Suddenly 1 Billion years is a more reasonable estimate and even that takes super tech we don’t have any idea how to build and assumes nothing fails.
Several more advanced civilizations could be colonizing the galaxy today that are still 10 billion years from finishing.
I don't see how you could rationally justify spending this stupefying amount of resources on sending people into the void where, even if all goes well, you can barely talk to them, have no trade and no social contact with them at all.`
Basically you are paying to split off a one-way branch of the species. Just consider that if we could colonize Alpha Centauri that means that each message has a 8 year or 1/10 of a human life span roundtrip. What would you even talk about with that kind of latency?
This is all done via AI and automated factories that terraform planets into Von Neumann manufacturing hubs, which then each send millions/billions of Von Neumann's out into the galaxy, each Von Neumann probe containing the tech/machinery to terraform another planet into another Dyson Sphere manufacturing hub. If you're really sentimental about humanity, you can include human DNA on the von neumann probess, and while the von neumann probe is terraforming a new planet, it can also grow humans in vitro.
Why would we (or our AI overlords) want to spread through the galaxy like this? Why does cancer spread through it's host? Why did europeans colonize the entire earth? Life is a virus that spreads without limit.
"I don't see how you could rationally justify spending this stupefying amount of resources on sending people into the void where, even if all goes well, you can barely talk to them, have no trade and no social contact with them at all."
Do you not understand why people invested in early merchant ships in like the 1500s? You spend a lot on a ship, send the ship to trade, and they come back with spice, that you sell at a profit, buy more ships, rinse and repeat. Same here: spend a couple quadrillion dollars, send off some von neumann probes, wait 50 million years, and then see if you've colonized a small cluster of the galaxy, or if your von neumann probe fleet was destroyed by a gamma ray burst or an uncharted supermassive black hole.
