Comment by bena | Hacker News Reader

Comment by bena | Hacker News Reader

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Yes, it's incredibly easy to do these things once you've done all these other, incredibly difficult things first.

The furthest a human has been is 250k miles (far side of the moon). The fastest a human has traveled is only 0.0037% the speed of light.

The ISS is about 260 miles from the Earth. At that height, the gravity is actually roughly the same as on the surface, it's only because it is in constant freefall that you experience weightlessness on it.

Mars is 140 million miles away. And not exactly hospitable.

I like how you treat "the fusion problem" with a throwaway, "Yeah, we'd have to solve that" as if we just haven't sufficiently applied ourselves yet.

All of those incredibly difficult things we have not even begun to do are the technical reasons we have not gone interstellar and may be the reason we will never do so.

And even if we solve the issue of accelerating a human being to acceptable speeds to reach another star, the next closest star is 4 light years away. That means light takes 4 years to reach. Even if you could average half the speed of light, that's 8 years, one way. Anything you send is gone.

It's 2025. The first heavier than air flight was barely more than a century ago. The first human in space was less than 70 years ago.

These enabling technologies are very, very hard. No doubt about it. That's why we can't do this today, or even a century from now.

But the physics show it's possible and suggest a natural evolution of capabilities to get there. We are a curious species that is never happy to keep our present station in life and always pushes our limits. If colonizing the solar system is technically possible, we'll do it, sooner or later, even if it takes hundreds or even thousands of years to get there.

> I like how you treat "the fusion problem" with a throwaway, "Yeah, we'd have to solve that" as if we just haven't sufficiently applied ourselves yet.

If you'd read my comment, you'd see I didn't say that. Fusion rockets would help, but we don't need them. Nuclear pulse propulsion or fission fragment rockets could conceivably get us to the 0.01-0.05c range, and the physics is well understood.

> And even if we solve the issue of accelerating a human being to acceptable speeds to reach another star, the next closest star is 4 light years away. That means light takes 4 years to reach. Even if you could average half the speed of light, that's 8 years, one way. Anything you send is gone.

Getting to 0.5c is essentially impossible without antimatter, and we have no idea how to make it in any useful quantity. Realistically, we're going there at less than 0.1c, probably less then 0.05c. Nobody who leaves is ever coming back, and barring huge leaps in life sciences, they probably aren't going to be alive at the destination either. It'd be robotic probes and subsequent generation ships to establish colonies. But if you get to the point where you are turning the asteroid belt into O'Neill cylinders, a multi-century generation ship starts to sound feasible.

First, what's the return on that?

You are talking about massive investments to shoot off into space never to return. Who's paying for that? The only way you do that is if you're so fucked, it's your only option and the profit in it is the leaving.

Not to mention, we need to solve the problems of living in space. Which we haven't yet. According to NASA. The space people.

And it very well could be an insurmountable problem. We do not know. We do know that living in microgravity fucks you up. We know that radiation fucks you up. But we don't even know all the types of radiation one might encounter.

> But if you get to the point where you are turning the asteroid belt into O'Neill cylinders

That right there is an example of "solve this impossibly hard problem and the rest is easy". We are nowhere near doing anything close to that.

Class 1 civilization has a lot of resources

My response to the money aspect of this it's just like any other business: money needs to be invested, and then a return will be realized. Resource extraction (i.e, asteroid mining) is one obvious example.

The human compatibility issues with microgravity are well known, as is the solution, which has even been proposed by NASA: centripetal force to create 1G for the astronauts.

As far the the radiation goes, we do indeed know exactly what kinds of radiation they would encounter. And the easiest way to shield humans from it in space is lots of water, or metal. We know this from extensive real work done on earth re: nuclear power plants.

The real issue is money, not technical feasibility. Once the dough rolls in from asteroid mining, it bootstraps the financing issue and pays for itself many times over.

https://www.nasa.gov/humans-in-space/the-human-body-in-space...

NASA seems less sure than you do. And considering we have to get to the asteroids before we even start to think about mining them, talking about the money from asteroid mining is putting the cart before the horse.

Asteroid mining is one thing. Exploring the nearest star system is science expedition where the payback is in societal scientific knowledge and subsidizing technology development that is then made available here for various things (eg a lot of the space exploration tech in the 60s made its way into consumer tech)

There is another way. Irrationality. People spend a lot on religion. Like a whole lot.

What if there was a faith system of ultimatley going to interstellar medium. You have faith, you automatically pay, like the rest of the people and you dont question it. You get tax breaks. It will help you in the end of times or something.

Just decide the ultimate goal to be interstellar medium touching in all directions.

You are a farmer? Well now you continue to farm to feed budding spacers. You are a game dev? Well, people are going to get bored in space, continue developing games for the ultimate goal.

And once you have done those incredibly difficult things it is possible that the game changes entirely. A significant number of humans could live in space and have limited contact with planets.

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