Lightyears is a measurement of time not units. Again I said it may not be done in our lifetime, but bit will be done eventually. The enter history of humanity has been making the impossible possible; even if it wasn't for the right reason. This is just another trial we face to continue to grow.

The thing is Fusion and fission aren't the only means of power, and is also by far the most dangerous. While we are capable of harnesing the water, wield, and sunlight itself as a form of power. On the other hand we can simply drilll the fuck out of antarctica and steall all the natural resources it has under all that ice.

This is definitely one of those pages where so-called liberals and conservatives can be in complete agreement (or disagreeement). I was born in 1964 and my folks didn't have a TV until 1969, so their wee kids could watch the unbelievably historic moment when the LLM touched down.

I'm also a pretty big skeptic of the face-based side of the space race. Much better to radically improve the automation before we go to the expense of letting individuals take outrageous personal risks in the name of space exploration. Our first human expedition to Mars should go in a ship built primarily with minerals harvested from space by robots.

Don't get me wrong, I'm as interested in a cloud city on Venus as the next guy, but I don't think we're going to leave our own solar system in the next century. I seriously doubt we'll ever make it out of the Milky Way. There's no evidence to suggest that any other race has ever made it out of their own near space, on some level you've gotta admit the odds are against us being the first.

I hate it, but I just don't think we're going to last as a civilization until that point unless some much nearer habitable planets/moons turn up. The near future and probably the long-term future of exploration is unmanned vehicles/probes. The other day I was reading an article about how the most practical way to get people Mars is to send a one-way mission. It's hard to tell if that's worth it or if people could even function the way we'd need them to in those circumstances.

It's not very romantic, but it's cheaper, simpler, and infinitely more practical to send the robots. Best case scenario we'll find a reliable means of data transfer that far exceeds the speed of radio waves and we'll have virtual reality interfaces to control anthromorphic robots.

Limitations of Long Distance Space Travel:

1. Gravity - Our bodies are designed to be under the weight of gravity. Every single one of our organ systems will shut down if we spend twenty or thirty years in space with no gravity. The lack of gravity also makes exercising all of our muscles very difficult. Forget a muscle group and it will atrophy so badly you won't be able to use it. The best short term solution is special exercise equipment, but there is no long term answer
2. Speed vs. Weight - long distance space travel requires tons of food, water, oxygen, and fuel. All of these things have weight. The more weight there is, the more energy it takes to move the spaceship (and the more energy you need, the more fuel, and the more fuel gives more weight, which means you need more fuel) There is no solution for this. The best idea so far is to use solar power to cut down on the amount of supplies you need to take (but you can't stay within the range of a star while leaving the galaxy or the solar system for that matter)
3. Speed vs. Time - There is no way to travel faster than the speed of light, it would take an infinite amount of energy. Humans have about 70 useful years of life where they can operate the spacecraft, meaning if you go slow, you can't make it out of the galaxy in the lifetime of a human. Cryogenics is a long way off, despite what anyone tells you, but that's the best hope we have.

There is no way to get machines out of our galaxy either. Machines need power, there is no power in some parts of space. Right now we're trying to drive from VA to CA with a car that gets 1mpg and tank that holds 4mL of gasoline. Also, there are only four or five gas stations left in the country, and if you accidentally get too close to one, you die. And after the first few miles you lose control of your car. And you driving on a crowded highway with trucks all around you (which are all filled with dynamite). This is space travel.

I've heard a great idea for a futuristic battery using carbon nano tubes. They're made of a single strand of carbon atoms that link together in a way that gives them metallic properties. They're tiny,indestructable, and they conduct electricity 1000 times better than copper (or something like this figure) Even so, energy = mass, so the more energy you store, the slower you travel

Seriously.

That we know of today.  I am reminded of the US Patent offices 19th century claim to go out of business because "everything that is worth inventing has been invented'.  It is what we do not know that will get us there, not what we know today.

Scientist are already exploring dark matter and dark energy.  Things we have not conceptualized today, will be the driving force and the "no duh!" things of tomorrow.

The only thing that will stop us from getting to other galaxies is if we kill ourselves before we do.

Kinetic Barriers and Warp Fields.

We just need more power to do it. Somehow.

*taps on shoulder*

http://www.youtube.com/watch?v=xaW4Ol3_M1o

http://www.youtube.com/watch?v=1-ReuLZ2quc

Besides... "useful things" probably will again include saving our poor bankers chrismas bonus after they gambled away all the money of their customers resulting in a worldwide financial crisis or funding another war. No, thanks.

We won't get mass effect technology until we uncover hidden alien ruins on Mars.  Just one more reason to get there.