Space travel? How far can we go?

I am a huge proponent of space travel, and think we should spend more money on it, but in what follows I am only commenting on level of difficulty and practicality.

Our solar system is possible, because it's relatively close, but within our solar system there are unlikely to be other places that have environments in which we can survive without technology to create non-fatal environments.

Colonizing more than a small fraction of the galaxy is a tall order, because it's about a hundred thousand light years along the major axis and contains a couple of hundred billion stars. We might be able to colonize the nearer stars, but, frankly, the technology to get us to the nearest other solar system, 4.3 light years away, is as far above our capabilities as the sky is above the ground.

Other galaxies - forget it. The galaxies are usually quite far apart compared to their sizes. Even if we could develop such unimaginable technologies, why bother when we have a couple of hundred billion stars to play with in our own galaxy?

The most relevant comment I can make, though, is that in order to be able to do something, first you have to be willing to try, and in this case, the people who would have to appropriate the funds are politicians. Politicians are not noted for their great attention to altruistic projects with only long term benefits.

Hi Kickykan,

I agree with Brandon on most points, but I would add a couple of caveats...

One big variable in all this is the amount of time we will have available to do it in. If the human race survives (in some form) for a hundred thousand years, or several millions of years, then I'm sure we'll colonize beyond our own solar system.

Another big variable is our technology. If we find some way to break the light speed barrier then all limits (we currently know of) are off, and we'll probably colonize our galaxy and many others.

The last thing I would like to note is that human physiology itself may become highly maleable for us. With genetic engineering and nanotechnology, the humans of the next thousand years may not resemble a human of today. And it's within reason to expect that humans can be modified to match environments on other planets (such as Mars and some of Jupiter's moons).

Also, if we ever succeed in making sentient machines, then they may colonize even if we are not around any more to do it. Our machines could end up being our only legacy to the stars.

How far?

Thats a big question. I think we could go a long way before we find anywhere as nice as earth. But as we are ****ing up the planet, we may have to.

Even bearing in mind that there are a couple of hundred billion stars in our galaxy alone, and probably similar numbers in the others? So, you're saying we'll, what, colonize a trillion worlds? That sounds a little ambitious to me, even given a million years to do it in. Also, I don't know the exact figures, but it's my impression that even the nearest neighboring galaxies are a few million light years away.

I think we have to, since we are eventually going to destroy this planet. Better find somewhere else to move on to when all the resources on earth have been used up.

Finding somewhere else to move to is a far cry from settling a trillion worlds and travelling millions of light years, when there are several solar systems within 10 or 15 light years.

I mean, there are some rather large practical issues of technology involved. We are not even remotely close to being able to reach the Alpha Centauri system 4.3 light years away (in ships that would take less than many thousands of years). You guys are being kind of glib about the technology and other practical considerations.

I was thinking more in terms of the nearest planets, not travelling all over the galaxy - baby steps. At the rate we are going with this planet, I think some serious thought should be given to doing more than astronauts taking trips to Mars or the Moon. As for being 'glib', I am fully aware that technology and practical considerations are lightyears away - it's not going to happen in my lifetime or many generations after me, but hopefully it should become a serious consideration by then.

Sorry. I assumed your comments were a response to the previous discussion.

OK let's try this.

In 100 years we've gone from about a 12 second flight to sending people to another celestial body and having a permanent orbital outpost. '

Who's to say what we can't do?

All good thinking. I started a new thread with a workable plan to get to some of the near by stars in about one million years. The first humans can leave almost immediately.
Getting there quickly is beyond present grasp, but a major break though may about to be announced. 12 light years in 12 seconds would get us to the outer limits of the visible Universe in about 13. 7 billion seconds = 3,800,000 hours = 158,000 days = 434 years. Neil

The rate of technology is increasing very fast.

We went from no flight to landing on the moon within one lifespan.

Ion drives are being built and tested. Acceleration is slow (you'd weigh about the same as a piece of paper) but it can keep firing long after a chemical rocket would run out of fuel.

Who knows when we'll be able to have warp drive?

Ion drives have long been in use for satellite station keeping. Believe me, the specific impulse isn't remotely close to what you'd need for practical travel to neighboring stars. Maybe photonic propulsion, but even then, you'd need a year or two to accelerate and decelerate in a manner that wouldn't reduce the occupants of the ship to jelly.

Still quicker than a 100 000 year trip on a conventional rocket ship if we could build a powerful enough ion drive.

But let's face it, until we learn enough about gravity and build ourselves a warp drive we aren't going anywhere quick.

Brandon:

Ever see the movie "Event Horizion", why not do something like that to deal with the acceleration and deceleration.

Because sticking a blackhole in a spaceship is bad science.

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Massless particles travel (or exist) at the speed of light, but even that isn't fast enough to cross inter galactic distances in reasonable time, and even getting to stars in our local galaxy would still take many years.

The real payoff is learning to re-define ourselves within space-time without having to move through it to change location. We already know that we cannot use energy and motion to solve the problem because those things are bound up with space-time itself.

Frank Herbert's Dune novels spoke of "folding" space. We don't know how to do this of course, but it's a good analogy for the type of thing which might have to be done.

Spreading through our current solar system with existing technology is reasonable, and will probably happen in a few hundred years at most, but unless our knowledge of theoretical physics changes radically then it will take millions of years to spread through even a portion of our own galaxy.

And despite the fact that we've come a long way in the last 100 years (first flight, to space flight), all of that progress was made by extending the bounds of common physics. In order to get to the next level, we must learn a whole new physics, and that may not be measurable using the knowledge curve of the last hundred years, or even the last ten thousand years. The current boundary (light speed), which lies before us exceeds not only our skills and our engineering, but also our knowledge, and it comes dangerously close to exceeding our reality. To do what we would really like to do (instantaneous translation of position in space) is to step outside of the Universe as we know it... and to hope we can come back again.

Travelling at the speed of light you would get to your destination instantly, from your point of view.

We're going to have to work out what gravity actually is.

Yeah--drives people crazy:) (Good flick BTW)

I meant the "chambers" they travelled in when they were travelling TO the "Event Horizon".

PS. I had a friend who couldn't SLEEP for a few days after seeing that film.