Photon propulsion (split from 3 facts maybe you don't know about antimatter)

[Moontanman]

21 hours ago, swansont said:

You were the one who said full (pace is full of the stuff we need to live), so you need to define it and provide a reference, and we are talking about interstellar trips. My objection is that we have not yet gone to Mars, and undtil we have, there is no hard data that longer trips are possible.

And therein lies the problem. You cannot have slow expansion. You have to have something at each destination. 

It's like going into the desert — your endpoint of the trip has to be an oasis. Or on the ocean — the endpoint has to be land. You can't go 1 km a year into the ocean to get across it. 

McKendree cylinder represents an unproven technology, and we have never, ever demonstrated a small number of people surviving on their own, in isolation, for any length of time anywhere near to what is required, regardless of the size of their cupboard. Biosphere-2 failed pretty quickly, and the ISS gets resupply on a fairly short interval. Submarines aren't an apt analogy, because they can easily make water and air, but even then, they will run out of food. In space, any mass you want to bring with you has a fuel cost, which, in turn, increases the fuel cost.

 

If the point was colonization of space using the resources contained there there would be no destination. Your habitat would be your home and volatiles can be stored on board, even a smallish Mckendree cylinder of five miles long and one mile think would have nearly 8 square miles of living space, twice that if you could your counter rotating partner cylinder and no attempt at simply simply letting natural processes would be like the biosphere project. The biosphere project assumed no way to add outside materials and it was far too small. At first these habitats would stay inside the solar system near sources of raw materials but as technology advanced I would bet cylinders and even support tech would move out into interstellar space, using EM capaults to send volatiles to passing habitats.

Any largish object would become a refueling station, repair, station and a place to make more habitats.  

[Curious layman]

Whether it can be done or not remains to be seen, but I've no doubt that us Humans will try. Human nature.

we'll  definitely need to change ourselves though. If we were smaller we would need less food, less air... people who are dwarfs or midgets still have the same brain capacity, after all were only the size we are because of of lifestyles/cultures, for instance Asian people are generally smaller than westerners. We don't need to be this big do we.

why not make ourselves only 3 foot tall. sounds stupid but I think it would help a little!

[zapatos]

4 hours ago, swansont said:

And yet I get pushback for pointing this out. And it's not being discussed here, it's being ignored under the assumption that it's a triviality.

We are ignoring the details because there are no details to discuss. The only things we can talk about at this point are generalities. We're 10,000 years (or whatever) from making an attempt at moving outside the solar system and you're shooting down the concept because of an only partially successful test done 25 years ago.

 

Quote

Are you not reading what I wrote?

There's a difference between going to the moon and Mars and a huge difference between going to another body in the solar system and to another star. It's not simply a linear extrapolation.

Again, we all know this. If you are waiting for me to provide a proof of concept the wait is over; it's not coming.

But unless you can provide something better than "it's going to be really hard" I see no reason to assume it cannot be done.