.jpg){kind=link}
Same.
If you don't already own a pair, I'd recommend getting a basic pair of binoculars and doing some backyard astronomy. You'd be amazed how much more you can see with even a basic 10x50 pair, even in thoroughly light-polluted skies.
Also SpaceRip [1] collects hundreds of interesting, easily digestible and pretty timely videos.
If you've got the spare cash, get image stabilized ones. I could clearly see the moons around Jupiter with my Canon 12x36 IS binos the other night despite my hand tremors. The real party trick is handing them to a friend and telling them to look at the moon. Blows them away every time - to most people it's just a yellowish glowing thing in the sky, rather than a scarred rocky globe.
For starters, there's this assertion: "The far-fetched version is to use back holes as power sources [1] as this is, as far as I've read anyway, the only remotely viable method of providing propulsion without reaction mass to speak of and reaction mass is the death of any form of interstellar propulsion."
Not true. We can definitely build something with today's technology that allows for propulsion without reaction mass: light-sails pushed by lasers[1]. I can address some of his other points but it's not necessary. If you crunch the numbers, it should be doable to travel to another star in about 150 years.
[1] See Humble's canonical text on space propulsion design: http://www.amazon.com/Propulsion-Analysis-Design-Ronald-Humb...
Btw, if you'd read 'Accelerando' you'd know that Charlie is fully aware of the possibilities offered by laser powered light sails.
I'm trying to show that notion is dead wrong. I didn't say it was a solved problem, if you mean in the sense of the engineering is basically done and we're launching something tomorrow. But certainly it is very reasonable to think that within with 150 years we will have both the technological and economic advancement to do a mission to another star. We know how we'd do it, and it uses real physics and engineering, materials, etc. that already exist.
The main reason Stross is wrong though, is he says we'd need free energy to do it. He's right that the limiting factor is the cost of energy, but he's overlooking what you get for 150 years of economic growth. World GDP has grown at an average annual rate of 3.5% over the last 100 years. World GDP is currently at about $80 trillion. If it grows at 3.5% for another 150 years, it will be $14,000 trillion. You can buy a lot of energy with that. And a lot of spaceships.
Just because something uses real physics and engineering materials that already exist, doesn't mean that it's actually possible in the real world & getting to the stars requires that we solve three or four very hard problems.
Impossible? Of course not. Much, much harder than the 'whee, we're all going to space!' crowd likes to think? I'm afraid so.
NB. GDP is not a good proxy for available energy for hopefully obvious reasons: Just because you have a high GDP doesn't mean that you have a lot of energy available, it may mean that you use the energy you have very effectively.
Most of the reason we haven't is economic; modern fission reactor designs are far more efficient than even the most optimistic estimates of 50 years ago.
Perhaps these problems will be solved in the future, but so far we've spent billions and billions of $ with (relatively) little to show for it in terms of output.
World GDP has grown at an average annual rate of 3.5% over the last 100 years.
[1] http://img641.imageshack.us/img641/1946/gwp.png
edit: corrected the 2000-2011 segment for inflation with CPI data (not int$).
The laser (a bank of lasers, more likely) would need to consume energy at a rate approximately equal to the world's entire current electricity production, basically continuously for the duration of the mission.
That seems absurd of course. But again, you can't underestimate compounded interest applied to GDP growth (see above comment). In 150 years time, the cost to do the mission could easily be the same percentage of US GDP as the Apollo mission was in the 1960's.
Of course if the assumption of continuous future economic growth doesn't hold up, this isn't going to happen. But in that case the world will have much bigger problems... this will be something of a non-issue.
But it seems a lot more likely that we'll just send some strong AI robots to send us back the data until then.
EDIT: I suggest checking out Space Engine. It seems to cover more than one galaxy and being able to change the viewing/moving speed feels like being in a Star Trek starship. Going through space like that feels a bit unsettling:
(3.6 billion years / 13.75 billion years)
I just close my eyes for a minute and think (or try to), what would it be like for those people that are finally able to reach, say, Vega (I know it's not the closest). Sure, this is not a big deal in sci-fi, but for reality, it's pretty mind blowing. This is 100% why I seriously want to live for a few hundred years: to have an opportunity to see the first time we actually go to the nearest star.
In the meantime, I guess this will have to suffice.
I also love this image that is not interactive like this, but still mind blowing: http://en.wikipedia.org/wiki/File:Earths_Location_in_the_Uni...