The same logic saying biofuel is inefficient (requires a lot of land for low energy yield) is the same logic saying meat is inefficient (which is true, meat is energy inefficient) because it requires a large amount of crops for the livestock.

It's worse than that. A comparison purely on efficiency ignores another vital factor - cost. Yes solar panels might be 50x more efficient than plants at capturing solar energy. But they're infinitely more expensive. You have to manufacture the solar panels. Plants manufacture themselves. Why build shiny 50-story high rises at the cost of billions, if "magical" one-story houses which build themselves and self-replicate are widespread?

That's what biofuel is. Its reputation has been tarnished badly in the U.S. by the corn lobby using it to put themselves on the public dole.* But their fundamental basis is sound. The cheapest and most prolific solar collectors in the world are plants. Not only do they cost nothing, they will spread by and maintain/repair themselves. Nature has spent hundreds of millions of years working and plants are the most efficient solution it came up with for harvesting solar energy. They are so successful that all life on earth (except at hydrothermal vents deep underwater) get their energy from plants. Heck, all oil and coal originally came from plants.

All biofuels are is taking the energy in plants and converting it into alcohol fuel, instead of an alcohol drink or ATP. The only impediment I can think of is that plants are such an attractive energy source, they've had to evolve defenses against being consumed for hundreds of millions of years. Consequently, modern plants store that energy in a form where it's exceedingly difficult to extract (cellulose). But there should be workarounds: Certain animals like termites have cultivated bacteria which breaks down cellulose into its component sugar molecules. Or we might be able to genetically engineer a plant which keeps more of its energy in the form of sugar than cellulose. Or we can take a plant which already does that (e.g. sugar cane) and engineer it to grow in a wider variety of climates.

* Corn ethanol began because of the Dust Bowl during the Great Depression. Food shortages led to price increases and starvation. To prevent a recurrence, the government began subsidizing farming (mainly corn) to insure there was always overproduction. This crashed the price of corn, so the government set it up so it buys all the corn from farmers at a price which can keep the farms in business, then resells it. Since there is more supply than demand, there is always corn left over. This excess corn would otherwise rot in silos, so a variety of uses for it have been found - feed for cattle, HFCS, foreign aid. And during the 1973 Arab Oil Embargo, someone came up with the bright idea - why don't we convert it into alcohol for fuel?

It's a fine idea for excess corn. The cost of growing and harvesting that corn is a sunk cost. You're never gonna recover that cost, so it's better to do something with it than nothing. So turning it into ethanol makes sense. But the moment you start growing corn for the sole purpose of turning it into ethanol, the economics of it completely breaks down because now it's no longer a sunk cost. Not only has the corn lobby been looting our country's treasury for decades, it's been impeding the growth of other legitimate and more efficient ethanol crops by distorting market prices with their subsidy.

State governors can't exercise Federal Executive powers - such as commanding the Army, or supervising the Federal courts or the Postal Service, or... well, you get the picture.

They're part of the fragile balance of our precious, vulnerable ecosystem

That's a myth dreamt up by people wanting to protect the environment, but who had never taken any higher-level math or engineering courses and had no clue how dynamic systems function. Fragile balances are almost impossible to find in nature, for the simple reason that if something is fragile enough that any perturbation would upset it enough to destroy it, it would've self-destructed long ago before man ever showed up.

Nearly all surviving balances in nature are stable equilibria. They're not fragile at all. If you perturb them, it just re-stabilizes at a new equilibrium point. e.g. If you tilt the bowl in the wiki picture, the ball doesn't fall off the top of the bowl like in the first picture or roll away like in the third picture.. It just settles in at a different spot on the bottom of the bowl in the second picture, now-tilted slightly.

Technically speaking? He probably doesn't, but that doesn't really matter. Like it or not, the VC-25 is part of the image that the presidency presents to the rest of the world. If you want to present an image of strength and the supremacy of the American Ideal, showing up in a European aircraft is not the way to do it. Also, showing up in a smaller aircraft (787 or 777) doesn't help either. Like it or not, it's partially dick waving, and the 747-800i is really the only choice.

I hope it's well taken care of. Those are beautiful aircraft, and one of the aircraft that truly built Canada. You are very lucky. :)

The last I looked, the state of remote-sensing algorithms for limb profiling is something between bad and "are you kidding?".

But they are not doing much "remote sensing". All they are doing is recording when a GPS signal is received. That's it. That shouldn't be too hard. The delay between when the GPS should have been received, and was actually received, will tell them the index of refraction of the atmospheric cord it passed through, and from that, a ground computer can calculate the humidity, temperature, and pressure.

That sound you heard is the OP's point whooshing over your head. Limb profiling (what you describe) is a remote sensing technique, and it's not one that works really well.

The problem isn't receiving the signal (well, it's not a problem in this sense though it has challenges of it's own), the problem is analyzing the signal. You have three different variables (all of which vary with altitude to boot), with no way to significantly constrain any one of them - meaning arriving at an accurate value for one (let alone three) is a Very Hard and Poorly Understood problem.

If the two-engine planes are such a risk, how the hell have they got air safety certificates?

Because the certification for twin-engine planes only looks at engine reliability and environmental factors like rain and hail. It doesn't consider being shot at with missiles and small arms fire, which is a required safety criteria for Air Force One.

Even if Boeing stopped building 747 variants tomorrow, they'd be around for ages. They're the mainstay for long-haul travel, and dwindling sales probably are more related to market saturation - as in, there are enough in the air now to meet current demand - than any inherent shortcoming in the design.

An individual airframe is typically retired before 100,000 pressurization cycles. This is a limitation of the aluminum used to make the skin, which unlike other ferrous metals does not have a fatigue limit. In other words, aluminum always grows weaker with use. As you get closer to 100,000 cycles, you increase the odds of a catastrophic fatigue failure where the aluminum literally unzips like plastic shrinkwrap after you've cut a notch in it. (Aloha 243 had nearly 90,000 cycles due to its short-duration island-hopping history.)

The 747 is typically used on long-haul overseas flights lasting 10+ hours. This drastically reduces the rate at which airlines can rack up pressurization cycles. Even if one were flown 2x a day every day, it would take over 130 years to reach 100,000 cycles. By comparison, a 737 used for the 40-minute LAX to Las Vegas route may fly 10x a day and reach 100,000 cycles in a little over 25 years. This is why 747s are hanging around - their skins simply have less wear and tear on them despite being in service for more years and logging more flight hours than other planes.

The 747-8 was always a bit dodgy. When Boeing made the original 747, they weren't planning to make it with a partial second deck. It was supposed to be a stepping stone to future models with a full second deck (designing the 747 nearly bankrupted the company). Boeing pitched the full two-decker model to the airlines for decades but could never get enough interest to justify actually building it. Then Airbus came with its "who cares if we'll sell enough to make money, our governments will pay for it if it doesn't so let's build it" A380, and Boeing threw together the 747-8 as a possible alternative.

The slow rate of A380 sales (nearly 10 years old, 318 orders, 147 deliveries) seems to substantiate Boeing's marketing research that there just wasn't sufficient demand (yet) for such a large plane. By comparison, the 747-400 had 465 deliveries in its first 10 years. The 747-8 has 119 orders, 83 deliveries in the same timeframe as the A380. As you state, in the 400-525 passenger category, the market is pretty well-saturated by older 747s which are still airworthy.

I suspect that there are more refinements to come - it's just too useful an airframe to discard. It may take Boeing a bit to roll in some of the working dreamliner tech but it seems reasonable that they'd try to do that when time and demand permit.

In terms of airline operating economics, the number of passenger per flight nearly always has a larger magnitude of effect than efficiency gains for new technology. For an airline you are almost always nearly best-off flying a plane with slightly more capacity than the number of passengers. Airbus tried to claim the A380 would be so efficient this wouldn't matter, and you could fly a 747-sized number of passengers on a A380 for cheaper than a 747. I was very skeptical, and the fact that airlines aren't tripping over themselves to replace their old 747s with A380s is a pretty good indication that it's still cheaper to fly a 747 for 747-sized passenger capacities.

The next place to watch is to see if Airbus will roll out a twin-engine competitor to the 777 (maybe a longer A350-1000?). Airbus' competitor to the 777 had been the A340 (both are in the 300-450 passenger range). But the A340 is a 4-engine plane which uses much more fuel. Consequently, the 777 beat the A340 into a bloody pulp in the market. The 777 has had 1827 orders in 20 years, vs 379 orders for the A340 in 20 years. Right now, that's the gap in Airbus' lineup

A320 = 100-200 passengers.
A330/A350 = 250-370 passengers.
* A340 = 300-420 (retired in 2011)
A380 = 500-625 passengers.

That leaves a gap between 370-500 passengers which is currently being filled by the 777 and legacy 747s. Airbus claims you can configure the A380 for as few as 407 passengers, but no sane airline is gonna do that when they can configure the exact same plane for 500-650. I suspect they're holding off on a 777 competitor in hopes of directing more sales to the A380, but such sales inevitably end up going to the 777. In contrast, Boeing's lineup tightly covers all passenger capacities pretty well right now:

737 = 100-200 passengers
787 = 240-360 passengers
777 = 315-450 passengers
747 = 467-525 passengers

Wasn't there a Dr. Who episode based on something like that? Where the public got to decide at any time if an elected official's performance was not in their best interests. And if they voted that it wasn't, he was summarily executed?

This sort of thing is more easily prevented by prohibiting the provider of the pipes from also selling what's sent through the pipes, and vice versa. So if you sold cellular data service, you wouldn't be able to also sell a video streaming service. That's how electricity and natural gas is sold in most places. One company gets an exclusive contract to lay down the wires/pipes, but are prohibited from selling electricity or gas. Instead, other companies sell those utility services (sometimes using the pipe-owner as a billing intermediary, other times adding an "access fee" to their bill to cover what they have to pay the pipe owner).

Unfortunately, we're in a funny in-between state right now because phone service is moving from point-to-point to packet-based. That is, your phone calls used to require a dedicated line(s) between you and the call recipient - a line you had total and exclusive access to for the duration of the call. There is no distinction between pipes and the content in the pipes in this model. Now we're switching more to a VoIP model where voice traffic is sent as data packets over shared pipes, and the distinction makes sense. Until this transition is finished, entrenched companies will be able to argue against separation of the pipe business and content business.

Yeah, who would have thought that European 'socialism' would be more effective at bringing the internet to the masses than American private enterprise?

Unfortunately, the Internet service market in "socialist" Europe is actually more free market than in the U.S. You guys have multiple companies vying to provide and improve internet service. In the U.S., most local governments have regulated the market (under the guise of limiting unsightly wires by restricting who can build in public easements) so most Americans typically have only one choice of phone company and one choice of cable company.

MobileTechReview covered the non-touch 1920x1080 version here:
https://www.youtube.com/watch?v=sP6oTd_OhoA

The size comparison to the Surface Pro 3 (12") is very impressive, almost hilarious.

The Achilles heel of the Macbook Air has always been the display. Not only is it lower resolution (currently 1440x900), but it's a TN panel with poor color gamut (about 60% sRGB). I suspect this is deliberate market stratification by Apple, to give people a reason to pay extra the Macbook Pro. So the MBP gets a retina IPS panel covering 100% sRGB. The MBP gets a low-res TN panel covering 60% sRGB.

The Surface Pro 3 took square aim at this chink in Apple's armor, by putting in a 95%-100% sRGB screen. The Dell does as well by using a 1920x1080 Sharp IGZO panel with 98% sRGB coverage. That increases pressure for Apple to put a retina panel on their MBA, at the risk of cannibalizing MBP sales (basically any artist who does color-sensitive work right now is forced to pay extra for the MBP). Comparison to the Dell with the MBA here:
https://www.youtube.com/watch?v=_2FPvHFLSOI

Unless you have enough room for a proper GPU, low end discrete GPUs are increasingly somewhat pointless, since they always add complexity and cost; but don't necessarily outperform integrated ones by all that much.

Here are game benchmarks for the Intel HD5500, nVidia 820m, and AMD R7 M265 (older 35 Watt tech I throw in only for comparison since their current lowest-end R9 is equivalent to an 840m).

The 820m is a 15 Watt part, and best case hits nearly 2x the framerate of the HD5500. Probably about 1.7x faster on average, with a few titles being CPU-bottlenecked. The R9 M265X is also a 35 Watt part like the 840m and performs slightly better, so I imagine if/when AMD puts out 15 Watt version of the R9 to compete with the 820m, it'll roughly double the HD5500's FPS as well.

Having a discrete GPU does complicate the cooling solution (the iGPU on the Intel gets cooled by the CPU's cooler). But if you're planning to do some gaming, you should still opt for the dGPU over the iGPU if at all possible. The exception would be if you only play titles not needing powerful GPUs, like Sims, DOTA, LOL, WoW.

Yeah, well, I'm an Engineer. Misuse of technical terms is one of my pet peeves. :)