I'm thinking we'd have the technology to get a few people to some other star within the next 100 years. Whether or not they'd be able to settle on another planet and thrive would be another matter altogether. Return trips I think would also be highly unlikely for a few more hundred years.

Quote: Original post by Washu
Yes, that is more correct. Science is not about finding the actual laws (since we cannot actually know said laws, most likely), but about creating theories that explain observable phenomenon in such a manner as to build a simulation that is accurate enough to predict future behavior (which can then be tested and hence disprove said theory).

While we're being philosophical and pedantic I'm going to go ahead and say that this isn't exactly a perfect description, either, as "accurate enough to predict the future" really means absolutely nothing. We can talk about how successful a hypothesis has been in the past, but there's no way to assign a probability of it being true in the future.

Quote: Original post by kseh
Return trips I think would also be highly unlikely for a few more hundred years.

Define space exploration as a one way trip, and things become trivial, or better yet, just a matter of cost.

This is part of the reason powers that be are not interested in. Columbus didn't get funding for exploration - he got it to try to improve trade for the wealthy. Without possibility of return trip, this type of investment cannot exist, hence no interest.


Other way to achieve space exploration is to blow up Earth. Not instantly and at once, but just to push people in the right direction.

Quote: will we ever see the day when we can visit other parts of the galaxies

We? No, unless our lives are somehow extended. Alpha Centauri is about 4 LY away, that is about 8 year trip if ship existed today.

Quote: And then there's the fact that the human body can't stand large acceleration for too long, so we have to accelerate slowly.

1g is enough. Ship is built like a skyscraper, with thrusters at the bottom. Half way, turn the ship around. You also get free normal gravity.

Due to distances and relativity, actual acceleration doesn't make all that much difference on the duration of the trip, could be .1g or 10g.

But even without theoretical anti-matter drive (needed for above constant acceleration), a ship capable of 10% light speed has been designed for such task long time ago, and practical tests were made as far back as the 60s proving that materials exist from which such engine could be made. It's just a bit too blunt to be widely accepted, and would consume much of Earth's nuclear stockpile, so it's mostly a cost-benefit/profit margin type of problem.

Which brings everything back to the start - nobody cares about one way trip, whereas two way trip isn't viable, practical or needed.

To re-iterate, the faster you go, the slower time goes. As you get closer to the speed of light, time on board the ship move much slower. So you could travel very far without experiencing a long time, but that could mean thousands of years have gone by back on earth... And then you get overtaken by some kiddo on his space-warping bike.

The energy requirements to get close to the speed of light would increase immensely, and the acceleration required to get to that point would be bone-crushing. Or it would take you years to arrive at a decent speed at one G acceleration, and then decelerate (yes, I've just done the maths).

So yeah, by conventional means, it's just not practical. But we don't know everything about what can and can't be done yet. Surely we'll be out there some day.

You could probably cut some of the fuel mass needed if you used a solar sail to brake into your target system. Plus, if you can refuel when you're out there, you can do a return trip. Of course, that necessitates a one-way trip for a fuel tanker and depot, so you're still ending up with a one-way trip...

If only Bussard ramjets worked as advertised (I've heard they don't)...

Given our current understanding of physics, it seems highly unlikely we'll ever be able to overcome the already discussed issues.

It's possible that there's something fundamental we haven't discovered but it seems increasingly unlikely. Most sci-fi gets around this by having some sort of "jump", but there's no known physical process that can actually achieve this to any meaningful degree.

That said, who knows? Technology we take for granted today in the computing space would've seemed impossible 100 years ago.

I'm still voting for quantum tunneling transporters. The required energy to enter the tunnel as an evanescent mode for the bandwidth represented by say a human is massive, a light stream however is not. A sufficiently long tunnel could be achieved by a narrow band stream representation of a human. In due time we will be capable of decoding the human and encoding it in a light stream and rebuilding said human on the other side. I'm sure this sounds a little distasteful to some but to me it would be nice to get away from it all, yus? o-o

Maybe we won't care. We'll be too busy hanging out in cyberspace.

Something I can't quite get my head around is this: A spaceship does not accelerate due to an external force, but by a thrust provided from the engine, which of course moves along with the ship. So, if hypothetically the ship accelerates to relativistic speeds, does that mean that the engine, also moving at that speed, will work slower(in reference to Earth), burning less fuel per second, thus providing smaller thrust? Is this real? Or the mass of the fuel will increase the same as time dilates, so even if the engine works 'slower', it burns as much fuel as before? What's happening in reality?

Quote: Original post by mikeman
Something I can't quite get my head around is this: A spaceship does not accelerate due to an external force, but by a thrust provided from the engine, which of course moves along with the ship. So, if hypothetically the ship accelerates to relativistic speeds, does that mean that the engine, also moving at that speed, will work slower(in reference to Earth), burning less fuel per second, thus providing smaller thrust? Is this real? Or the mass of the fuel will increase the same as time dilates, so even if the engine works 'slower', it burns as much fuel as before? What's happening in reality?

It'd seem to work slower from Earth's point of view (if somehow someone on Earth could observe things inside the spaceship). In relation to the spaceship, everything is perfectly normal. Space and time works exactly as if the ship was at rest.