I think the reason is that on a small scale, it is possible to control a quadcopter or quadrotor by changing the relative speed of the rotors, which is much simpler because there is no cyclic pitch, or swashplate mechanism, but this technique doesn't scale well. On a man-sized quadrotor, it would be difficult to accelerate and decelerate the rotors fast enough to have agile control, and so the use of cyclic pitch becomes the better method to control thrust. If you are using cyclic pitch, then it becomes simpler to have one (or 2) rotors instead of 4. Also, when a rotor tilts, it generates large gyroscopic forces. On a small model, these are small compared to the strength of the rotors, but on a man-sized vehicle, the rotors need to be able to "flap" in order to reduce stress on the blades, which again is simpler if you only have to deal with one rotor.

I don't think this is even about whether it is hate speech or not. The majority of the people in the world have tough enough skin and don't care, but unfortunately there are a few crazy people in Pakistan, who will definitely do real things that harm everyone else in the world as a result of this, such as recruit more terrorists, and kill innocent people. If the only risk here was whether this offends some people, then go ahead and do it, but at some point, we have to look at the risk vs. benefit of each option. If burning the books results in more killing in the world, and does not help in any way, then it's not a wise choice. Others have argued that it is cowardice to not burn the books - this might be true if there was some identifiable benefit from burning them, but making a choice that only leads to bad things is typically referred to as "stupid". Of course, the identifiable benefit to this guy might just be publicity.

The question wasn't "why is he allowed to pack heat" the question was "why does he _need_ to pack heat." Of course people are allowed to carry guns if they feel it is necessary for protection, but many people would consider themselves more "free" if they can live a life that doesn't require a deadly weapon to stay safe.

The problem is that if there aren't enough disabled folks, then no businesses will have any motive to serve them, so the handicapped people will be severely limited in their options. Apparently when all things are considered, requiring businesses to be more accessible is viewed as being less of an infringement of freedom than completely preventing disabled people from functioning in society.

It's not the Earth's circumference, but the change in air density. The speed of sound is highly dependent on air density, so the groundspeed corresponding to a given Mach number varies with altitude significantly.

That's the whole point of the patent - the lights tell the car when the optimal time to start is so that everyone can promptly begin moving again when the light actually changes.

A mass with angular momentum experiences a moment in a direction perpendicular to both the angular momentum, and the rate of change of the angular momentum. I'm not sure if I stated that correctly, I may be off, but what it means is that if the flywheel is mounted horizontally (the angular momentum vector pointed straight up or down) then when the car rolls, it will generate a pitching moment, and when the car pitches, it will generate a rolling moment. I don't know if it would be likely that the car would experience high enough pitch or roll rates for this to be a factor. A stabilizer could rotate the flywheel internally in the car pitch axis to generate a rolling moment when going around corners.

ironed

Here is a hint, right now the pollution from the manufacture and use of all of these products is embedded in the air you are breathing, and you currently have no way to avoid it.

This is merely charging people for their actual use of public property - air - which has been overused. You will be charged no extra if you only use the air you breathe.

I have no idea how the specific control laws in the A330 work, but on other aircraft there is an artificial spring force that varies with airspeed and other factors to give the pilot a good feel on the controls for the particular flight condition.

From the chart at airbusdriver, it looks like there are backup mechanical controls for the elevator and rudder only. It says the elevator control is via a trim wheel, which would only allow very slow changes, and would be really awkward to try to regain control in a difficult situation.

The software should limit the control inputs to levels that won't break the aircraft at the given flight condition, but, if say the air data unit was malfunctioning, the control laws may have thought the aircraft was moving much slower, and given the pilot greater authority to move the rudder, and led to a structural failure. This is all complete speculation, but, just a thought.

Kids have always been required to do work at school, but this one thing which is more applicable to everyday life than most school work, is a problem?

I think you are taking this a way too seriously. First, no one is forcing anyone, or even really compelling anyone to volunteer, if you don't want to do it, you don't have to, with no negative effects whatsoever.

I think the goal is just to make a time where it is more socially acceptably and when people are encouraged to do volunteer work. Many people might have a slight interest, or be unsure of how to get involved, so maybe this day will make that easier, and make them realize how to volunteer more often, out of their own free will.

The same goes for requiring some community service in school. In real life no-one can make you volunteer, but they also can't make you write papers or finish assignments. In school, you get grades for learning, and trying out some volunteer work can be educational.

The pressurized air in the cabin of a plane typically enters just after the compressor stage (but obviously before combustion) in the engines, thereby not requiring a separate compressor, and then goes through a pressure regulator (and filters, I would guess) before entering the cabin. In flight, all the air entering the engine is clean, but at startup, it's probably possible for a some exhaust from the engine, or from other ground vehicles to enter the system.

So the article is saying that older people with dimentia may not recognize sarcasm, but you appear to recognize sarcasm when it's not actually there.

Maybe this is another possible research topic?