Seret

Why? Do aircraft have armour (well, they do, but very small amounts of it). Spacecraft, like aircraft, need to be designed for minimum weight, and would be facing similar threats to aircraft so would be highly likely to use similar solutions for protection. If you want to know what combat spacecraft would look like, don't think of naval vessels in space, think of actual current spacecraft but with weapons. Less starship Enterprise or Macross and more Soyuz with guns.

The hull of a spacecraft probably can't offer much help as a heat sink. It won't be hundreds of tonnes of steel, spacecraft need to be optimised for weight. You'd need to send your heat to radiators. You won't be getting bigtime heat problems from a gun though. Most of the heat is carried away by the has you vent it the muzzle, and I don't think it's likely that an engagement would require a lot of shots. One hit from any gun larger than about 40mm is going to be curtains for anything in orbit.

High pressure and/or very low temperatures means hydrogen isn't very safe to store or handle. It's also flammable and attacks metals. Petrol is flammable, but it can be stored at room temperature and pressure, which makes it much safer to handle.

Lol, you're just winging it, aren't you? The technology to track stealth aircraft is pretty week understood, and doesn't require what you're taking about. If my knowledge is it of date (which it is) then yours is even less substantial. You cite secret tech, but have you actually ever held any level of security clearance? You might be surprised how few genuinely secret systems military forces actually have. There's an assumption amongst civilians that the military has loads of secret high tech stuff, but that's not generally the case.

Well, I spent most of the 90s in military aviation, and I never saw or heard of anything. Granted, my side of the picture was the missiles not the ECM so I'm not an expert, but I don't think the avionics boys were hiding some magic bit of kit. The only optical countermeasures that directly detect passive sensors I'm aware of are near point blank range and themselves passive acquisition.

Can you give an example of an actual device deployed by the military that can acquire the passive sensor on a missile?

Can you give some examples?

Modern missiles tend to only use active homing in the terminal phase, if at all. No reason you couldn't be using IR missiles in orbit.

K^2 is right in that there's no way in hell they'd detect a 1kg warhead coming in. Depending on the range you're taking about they might detect it during boost. The exact technical capabilities of the ICBM tracking forces are of course a closely guarded secret, but it's not unreasonable to think that they'd have trouble handling things a lot smaller than they were designed to detect. Even if they did spot the thermal signature of the launch it seems likely they'd be unable to predict the trajectory with their enough accuracy to cause alarm. The Hollywood trope of the twitchy finger over the nuclear button has proven to be inaccurate in reality. On at least one occasion in the Cold the Russian early warning system held fire when they thought they had a US missile inbound because a single missile was considered anomalous.

I don't know how much bureaucracy you have to wade through when voting in the states but I voted in the European elections yesterday and I was in and out of the polling station in about 3 minutes flat.

That's an absolutely awesome statistic, must remember that one.

It has about 30 times the global warming potential, not thousands. But you're right that leaks from fracking are a concern. If they're not controlled really tightly it's possible gas from fracking could have indirect emissions on the magntude of coal, and that would be a disaster.

I can't check that site through my work network. If you're saying there's another form of fusion that's looking as promising as either magnetic or inertial confinement then that's news to me, but I'm no expert. JET and ITER aren't designed to be power plants either. They're also just research facilities. That doesn't really change the fact that fusion does look like involving some pretty hefty hardware, which is hardly surprising considering the energies involved.

The only other method in the serious running is laser inertial confinement. The NIF did indeed cost $1 billion to build, and it's just a test rig doing work that's more preliminary than ITER. So yes, it looks like fusion plants will cost billions whatever technology they use. Carbon footprints are generally expressed in terms of COe, which takes account of all the other GHGs.

Indeed. The UK has Europe's best tidal reserves (some of the best in the world, in fact) and offshore wind is booming. The biggest constraint on expansion for them is the availability of barge cranes for erecting them. The will and the money is there, generally speaking they're putting them up as fast as they can. Exactly, it's often possible to throw them up on industrial land with zero impact on the existing industry. Roof-mounted PV has a footprint of zero. Even large parks being erected on agricultural land allow grazing of small livestock like sheep on the same land, so space really isn't a biggy.

??? Wind, solar, and tidal are generally distributed. Certainly tidal stream, maybe not really big barrages. Much of the wind capacity is actually embedded, so it's not even monitored, it just shows up as a reduction in demand. It's the big thermal plants that are centralised. Stuff like coal, fission and when we get it fusion. Large hydro and to a lesser extent geothermal are about the only renewables that are big enough to centralise, and calling geothermal renewable is a bit dubious. Decentralised power systems use solar, wind, small hydro, CHP gas turbines, biomass/EFW, and all the oddballs like digesters. You're not going to see small scale fusion plants.

This one is really good for calculating the output of a single installation anywhere in Europe or Africa: PVGIS

Or at least a portion of them. You should certainly only get partial refunds for partially-full fuel tanks.

Yes. Just mod an existing FPS game.

It ain't rocket science. No, wait...

Sure, but I don't think it's a minority view. Some games are genuinely better than others. Civ 4 is also really popular with Civ fans. Five not so much, although it does have it's strong points (hex map FTW). Ace Patrol is brilliant fun. The two AP games made that bundle worth buying on their own.

Well, this is getting quite OT, but you might be surprised how much output you get from PV in the UK. Typical output is about 800kWh per kWp for an off-the-shelf PV system here. At current electricity prices that means over a 25 year lifespan it'll earn about £2800 per kWp, which is less than what you're currently paying (I've assumed electricity prices rise and the discount rate about even out for simplicity). As panels and inverters come down that equation will tip even further into profit, and that's before you start adding in the money you get from Feed-In Tariffs, which is substantial. The fact that you're starting to see sizeable solar parks being constructed by energy businesses shows that they're definitely not uneconomic. They're actually currently at or near grid parity in the UK. That's a little optimistic. Electronics grade silicon pays back it's embodied energy in about 8-10 years. It doesn't really matter if it's poly- or mono-crystalline, the former has lower embodied energy but is also less efficient so it pretty much evens out. You are however correct that lifetimes are very long and reliability is high. Failures of panels over 20-30 year timescales have been shown to be very low (around 5%) and your 40-year life isn't unreasonable. The weak part of a PV array is the power electronics, these last about 5-10 years, but these represent only a tiny fraction of the array's embodied energy anyway.

Strictly speaking, 50% of people are of above average intelligence...

That was a weird one. You'll have a lot more fun playing Ace Patrol and Civ 3 than you will playing any of the variants of Civ 5. Serious disincentive for generosity there.

It's not unreasonable for people to only care about things which they perceive are proximate to them. I've always found this model useful: Generally speaking you can divide anything demanding your attention into one of the three circles. You can operate most effectively in the centre, with decreasing effectiveness and increasing frustration the more time you spend dwelling on things further from there. The vast majority of people perceive spaceflight as something exotic, distant, and over which they have little control. Which is of course true. So it's actually pretty rational for them to not invest a lot of their time and energy in it. That's not to say there's anything wrong with being interested in space. Just that doing so isn't actually productive. That's no reason why it can't be a fascinating interest or hobby though. Not everything we need to do has to be productive, we need to stimulate our minds and learn too.