You're right, but you've misunderstood my point. If A, B and C are all "far" apart then all the distances are increasing at an accelerating velocity and the situation is as I described it. The last paragraph deals with the special case where B and C are close enough that they are not accelerating apart. In this case B and C will remain in contact forever, and so A will lose touch with both of them at the same time.

Doesn't work. If you try and relay light (or any other message) along the line from the distant galaxy to us, what happens is that it reaches each relay station just as the relay station loses contact with us. It never arrives.

Both true, but these interactions don't combine. Suppose you have three galaxies in a line A--- B---C and A and C are just leaving causal contact.
Suppose a light-speed message is sent from A towards B and C. B will indeed receive it, and be able to reply to it (maybe) but that will happen just as B and C leave causal contact (the universe having carried on expanding), so that if that message is forwarded towards C it will still not arrive. The photons in the forwarded message cannot overtake those in the original message that are still flying from B towards C.

If B and C are close enough to be gravitationally bound then A will lose contact with both of them at the same time.

Real-time audio translation is just taking off. By 2115 everyone should be able to speak and hear others speak in whatever language they like, including perhaps one that they and their personal AI made up as they were growing up.

If you go back to the original papers you will (by and large) find all the disclosure you want. The problem is that that mans reading and understanding tens of thousands of pages of complex mathematical arguments to see how each aspect of the data analysis was arrived, at, validated, etc. You are (probably) reading summaries of summaries of summaries of review articles of the papers. Complete disclosure there would make the documents thousands of times longer and completely unreadable.

On current trends solar and wind are set to hit that goal within a decade or so. There are some interest engineering problems around storage/demand management and power transmission, but the trend lines look quite good. Especially if you enforce even reasonable local environmental standards on mining and burning coal.

Just about all European players have or do reprocess -- France at Cap de la Hague, the UK at Sellafield. It turns out to be
remarkably messy, difficult and expensive, and very prone to radiation leaks of one kind or another. It was only really economic when there was a military market for the plutonium at basically "any price".

The problems are not fundamental, they are all engineering, but there were lots of them, and they never really stopped. You're working with something that has a horribly mixed chemical composition, and was designed (as a fuel element) to be tough enough to survive inside a reactor for a few years. You have to dissove everything in loads of hot concentrated nitric acid just to get started, so now you've got industriial quantities of hot radioactive acid laced with a not exactly known mixture of salts, plus insoluble sludge of one kind or another gunging everything up. And you can't ever go into the plant to unjam a conveyer, clear a stuck valve or clean a filter.

A modern wind turbine in typical European conditions generates enough energy to "repay" the costs of building and installing it in about six months. http://www.theguardian.com/env...

Backup can mostly be other renewable sources (solar, hydro, biomass) demand management and storage (pumped water at the moment). For the rare but real occasions when none of this covers the need, cheap gas turbines designed for a low duty cycles seem like the best option.

It's not a line. It's roughly a spiral. See https://www.skatelescope.org/l.... 3000 sqkm is probably the area of the radio-quiet park. But it's population, apart from the astronomers and engineers is tiny

The telescope when finished (2025) will need more total bandwidth between its antennae than the entire remainder of the internet is projected to need at that time.

It will be dedicated fibre, about 50 000 km of it.

What we're talking about here is connecting the (very few) isolated farms and villages within one or two hundred miles of an antenna. With a population that
distributed it isn't a last mile issue it's a last hundred miles issue.

The population is VERY spread out -- that's why they put the telescopes here in first place. Think rural Nevada, then take 90% of the people away.

Why stop at the moon? You could put half the array at Neptune's leading Trojan and the other half the the trailing one and synthesise a REALLY big aperture.

Seriously, the answer is cost. It's expensive enough building this many super-high-quality dishes and associated support structures and installing and operating them in empty (almost) deserts in Australia and South Africa, plus the 50 thousand kilometers of optical fibre to link them up and the multi million core supercomputer to do the aperture synthesis.

Putting all of that on the moon would cost trillions and take decades. The signal would be cleaner (except that you are outside the Van Allen belts so you have to worry about solar radiation) but the signal on Earth is good enough to do the science. Also the moon is actually too small. Even if you spread the dishes over the whole far side you couldn't get as big an aperture as they get with part of the array in Australia and part in Africa.

What they're going to get is years of work associated with the building and more years, but of less work associated with the operation, plus probably things like roads.

The area is extremely empty in the first place. That's why they chose it for (part of) the SKA.
The antennae will have dedicated fibre connections (the bandwidth needed for the aperture synthesis is, um, scary, but I suspect
running fibre or copper from there to every village and isolated farm would be stupidly expensive. Carefully chose satellite equipment will broadcast very
little outside it's beam, and on quite specific wavebands.

The article admits that it's not perfect (latency, download caps) but it's better than nothing and imposing radio quiet was an absolute condition of South Africa getting part of this very high prestige project.

It's even better than that. In exchange for a discount, most people would settle for a charging outlet that guaranteed (say) net full charge between 8pm and 6am. That is it might charge for three hours, draw for one and then charge for two, or charge at half-rate for 8 or whatever suited the grid.

More overall capacity might be needed, but this kind of thing makes it very flexible.

Really?

Hard to know where to start. Firstly the whole landing was just a small part of the mission. The orbiter is still up there and, all being well, will follow the comet in to
perihelion, observing all the way.

Secondly, think about the trade-offs of planning a space probe. You can make things more robust and more redundant, design more conservatively, etc. reducing the risk of things failing, but that costs you mass and power (and possibly money) which are rigidly limited. So you would have to take fewer instruments. The design optimises the expected science return by taking some risks.

The lander was intrinsically high risk, because no one had any idea what the surface of a comet is like. They had to gave it a bunch of different ways of hanging on designed around some plausible guesses. The lander has no propulsion at all (those mass trade-offs again), so it has to put up with wherever it hits. They knew solar power on the surface was uncertain, so they had enough juice in the non-rechargable battery to do the highest priority science.

In the event, two systems failed -- the cold gas hold down thruster and the harpoons. No one knows why yet, but building systems on a very tight mass budget that can work after 10 years in space is not easy. In addition, the surface of the comet seems to be harder than anyone really expected.

Given the challenges, getting any science at all back from the lander is amazing and a bonus to the main mission which is the orbiter.