[pedrolll]

I can't tell if you're joking or not. Dyson spheres, space mining, superstructures... Currently we have sent a handful of people to a rock orbiting this planet, then gave that up because it was uninteresting. At the moment there is no incentive to send anyone to space because machines can do better that little bit of exploring that is currently being done.

I'd be surprised if in a hundred years there's enough resources or motivation to do any space exploration. To me it seems far more likely that we have spent our fortunes on earthly matters such as wars and the like.

[mike-cardwell]

A hundred years ago we'd only just managed to get airborne... If we look at the technological advances of the past hundred years, I think you're being pessimistic.

[mechanical_fish]

One wonders if this argument will ever get old. It was being used in exactly this form forty years ago, when aviation (not to mention rocketry) had - perhaps unbenownst to most people at the time - essentially reached the state that it would remain in for the next fifty years, at least. [1] But after forty years on the plateau, it still gets trotted out.

My hypothesis is that this argument will die with the baby boomers, who have a living memory of the day when 2001 really felt like a documentary beamed back from the future, but I could be wrong.

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[1] We had supersonic passenger aircraft and moon rockets in 1972. Then we gave them up, on purpose: They didn't pay their own way.

And I don't want to minimize the hard work of aviation engineers since then: Better avionics, better navigation systems, computerized scheduling, pilotless drones, fly-by-wire... But these are refinements, not fundamental breakthroughs in travel technology.

[Retric]

Sending people to the moon was an incredibly expensive process that gained us nothing. If we are going to spend significant resources on colonizing space it must either be economically viable or at worst a small net cost that can be reasonably subsidized for the long term. So while we are not there yet, there has been fundamental progress on 5 significant technology's for actually developing space since 1972.

Step 1: LEO Scram Jet's which can dramatically increase payload to orbit. http://en.wikipedia.org/wiki/Scramjet

Carbon Nano-tubes, which is the first material that could enable a realistic space tether. http://en.wikipedia.org/wiki/Carbon_nanotube http://en.wikipedia.org/wiki/Tether_propulsion

Step 2: After LEO Ion Thrusters http://en.wikipedia.org/wiki/Ion_thruster which when coupled with high efficiency solar panels enables better delta V than chemical rockets. And makes mining the asteroid belt a reasonable possibility.

Solar Sail's which could enable realistic travel to nearby stars by probes or robots to build infrastructure. http://en.wikipedia.org/wiki/Solar_sail The delta V on slowing down is a major issue if you want to do more than a simple fly by which makes Solar Sail's the best non nuclear option for colonization.

Step 3: Power Fission makes living in space between stars viable. The power requirements for a colonizing the ort cloud and then moving further to the next star(s) only work when you can acquire ridiculous amounts of power, store it for long periods of time, and then tap it on demand. Of the 5 fusion is both the most important and the furthest from fruition but it's still on the path to viability in the next 100 years.

[Retric]

Edit: Fusion not Fission. There is a lot of Fission energy available but not enough to be the basis of infrastructure for the long term when we start trying to build real deltaV aka anywhere close to .01c and beyond.

PS: Voyager 1 was also launched in 1977 which is the first Interstellar craft ever built. Not that it pushes back the end of the 'golden' time period of space travel that far, but it's still outside of the window your thinking about.

[rayiner]

Aerospace technology plateaued decades ago. There was a rapid improvement from 1920 to 1970, and since then we aren't any closer to colonizing the solar system than we are today.

You see this pattern all over the place (exponential growth followed by a plateau). Medical technology, for example, as impressive as it is is really only improving at the margins today. In the 40 years between 1970 and 2010, life expectancy at birth for whites has gone up around 5 years. In the 40 years before that, it went up 10 years. In the 40 years before that, it went up almost 20 years.