I'm not entirely sure what you mean by this. The stab trim motor uses electric power to spin the wheel and move the stab trim. The autopilot and a couple other stability systems move that wheel frequently throughout the flight on all 737s. Aside from using the handles on the wheel and manually spinning it, there is no other way to move the stabilizer. MCAS is just an additional system on the Max that has an input into the stab trim motor. As it was originally designed, when MCAS activates, it moves the stab trim a certain number of units nose down and will stop. If the pilot then uses the switches on the yoke to move the stab trim the other way, in other words, trimming back to nose-up, the software governing MCAS resets its initial index to the point that it originally moved the trim to. Let's say MCAS activates when the trim is currently set at 6 units. It activates, spinning the wheel nose down to 3 units. The pilot uses the switches on the yoke to spin the trim back to 6 units. MCAS still senses a stall, so a couple seconds after the pilot releases the yoke switches, MCAS activates again. But this time, its little brain is now set to consider 3 units as its starting point, so it spins the wheel back to 3 units and then goes beyond, and now gets all the way to the stops. Why Boeing programmed it this way, you'd have to ask them. I've read that the software update removes this index-resetting so it won't be as likely to wind up trimming the nose fully nose down. Depending on the airspeed, the airplane can be flown like this, but it's really difficult. You'd have the yoke all the way back just to maintain altitude, and it would take a lot of strength to do it. Because of the aerodynamic force you're putting on the stabilizer like this, it would be very difficult, if not impossible, to use the handle on the trim wheel to manually spin that wheel back to nose up. Assuming you have enough altitude to play with, the proper thing to do, once you've disabled the electric trim motor, is accept a little altitude loss, relax the back-pressure on the yoke and let the nose fall, control the airspeed so you don't get too much aerodynamic force on the stabilizer, and now you'd be able to manually spin the wheel with the handle. You might have to do two or three up and down maneuvers like this to get the stab trim spun back to nose-up enough to really regain complete control over the airplane. This would be the case on any 737, including the Max, regardless of what system put the airplane into that full-nose-down trim.

737 pilot here. MCAS is not there to help the pilot recover from a stall, its primary purpose is to change the way the airplane handles during a stall to more closely match the way the older generation airplanes handle. When you take an older gen airplane, like a 737-800, into a stall, you can pretty much just let go of the yoke and the nose is going to fall down quite nicely on its own. The stall recovery maneuver we train isn't quite that simple, of course, but this is just for purposes of illustration.

The problem with the Max has to do with its engines. They are a larger diameter. In order to avoid having the bottom of the cowl too close to the ground, which would create lots of problems during takeoff and landing, Boeing moved the engine a little more forward on the mounting. That allowed them to mount the engine a little higher because the back of the engine cowl slopes downward toward the rear of the motor. They incidentally also made the nose gear a little longer, and that helped get the front of the engine cowl a little more up off the ground.

During flight testing, they discovered that this new engine configuration caused an unexpected problem. The engine cowl is curved from front to back: it curves just like a wing does. Sticking the thing farther out and farther up meant that the cowl was actually generating a little bit of lift just like the wing does. The center of lift that the cowl generates is enough forward of the airplane's center of gravity that during a stall, the lift off the cowl has enough force to make the nose of the airplane go up, which is certainly not a desired characteristic during a stall: you want what I described with the older generation airplanes: if you just let go of the yoke, the airplane's nose should naturally fall.

In order to mitigate this problem, Boeing came up with MCAS: if this system determines the airplane is beyond the critical angle of attack, and thusly is in a full-on stall (not just approaching a stall, but really fully stalled), it activates, rapidly moving the horizontal stabilizer on the tail to a airplane-nose-down trim. If you were standing out on the ramp when someone was trimming the airplane like this, you'd see the entire horizontal stabilizer changing its angle upwards. That has the aerodynamic effect of causing that small wing on the tail to generate more lift, which means the tail flies upward, which means the nose points downward.

This isn't an attempt to fly the airplane for the pilot, it's to make the airplane handle the same basic way the older generation airplanes handle: MCAS trims the nose down so that if you just let go of the yoke, the nose will drop, just the way all the other airplanes do. That preserves the type rating for all 737 pilots to be able to fly all the different variants of the type: one thing the FAA demands if Boeing wants an airplane certified with a common type rating is that all the variants have to handle the same basic way. And for all I know about the certification process, it's quite likely the FAA wouldn't certify a transport category airplane in the first place with a known handling characteristic of being so dynamically unstable during a stall that the nose pitches up rather than down: the Feds are pretty conservative when it comes to stuff like that, and so MCAS might have been needed even if Boeing were to have abandoned the quest for a common type.

However, that's not a bad idea. Most new cars these days come with at least an option to slam on the brakes for you if the car detects a hazard in front of you. Such a system would be inherently redundant if drivers were perfect. We all know that's not the case. The Airbus flight control laws, for example, will not allow the pilot to stall the airplane so long as it's operating in Normal Law. You can haul the stick back to the stop and the airplane will certainly increase pitch in response, but only to a point. In the simulator, the instructor has to disable several computers in order to do a stall demonstration and a stall recovery maneuver. The Air France A330 that crashed was in a deep stall all the way down, but that was because the airplane had degraded to Alternate Law, in which you can stall the thing. Such a system isn't a half-bad idea, really. No matter how experienced the pilot is, they're only human.

You're thinking about United 173 that crashed outside Portland, OR. Different accident from the "lightbulb" Eastern Airlines flight.

You must not have a lot of experience with the world. Being rich and being smart have very little to do with one another.

Consider this scenario. You are a two dimensional creature. You are only able to experience your reality as a flat plane. Up and down have no meaning to you; these are concepts quite beyond your comprehension. You cannot imagine a 3 dimensional object any more than we, in our 3 dimensional world, can imagine what a 4 dimensional object would look like.

Now, in your 2 dimensional world, creature, I, as a 3 dimensional God-like character, am going to take a circle, anything round, and shove it down through your plane of existence. What would you experience? You would experience at the very first, a single point suddenly appearing as if out of nowhere. This single point splits into two points that diverge from each other at a steady rate. Yet if I stopped pushing the ring through your plane for a moment and let you examine one of those two points that you can see, you would find that if you shoved on one point, the other point moved exactly the same. From my God-like perspective, all you did was shove the ring a bit. You, on your flat plane, see spooky action at a distance, because you're shoving one point and the other one is moving, too.

Given enough time and experimentation with these points that keep appearing in your plane of experience as I keep shoving rings and perhaps even more complex objects through your plane, you might even be able to come up with some really complicated mathematics and physics that describe all this bizarre motion and behavior in your 2 dimensional world. To you, it all appears incredibly complex and horribly incomprehensible, even utter nonsense, but you can manage to describe it in such a way that is at least consistent with the weird behavior you keep seeing. To me, in my 3rd dimension, I'm just chuckling over all that hard work you're going to, because to me it's just a simple ring I'm shoving through your plane and watching you go batshit crazy trying to figure out what's going on.

The point is simply that quantum physics appears bizarre to us because we are limited to experiencing 3 spatial dimensions and are forced to constantly move in a single direction on an axis of time. All the weirdness of quantum physics really just means that there are almost certainly many more spatial dimensions and more complete freedom of motion through time than what we are limited to experiencing. What you're seeing a lot of times is just the weirdness of seeing something that almost certainly "completely" exists in several more higher dimensions intersecting limited reality you are able to witness.

That's about like crowing "called it" on reading a headline that says "Rossi's E-Cat Proven A Hoax".

It was a broad view of what humanity could accomplish once their petty differences of race were resolved and the race was looking forward through exploration. The series episodes nearly always involved a serious moral dilemma that the crew would solve through a combination of pragmatism and idealism. The action and comedy of the episodes were merely wrappers around the real message Roddenberry wanted to convey: that if we humans would only just stop fighting each other over trivial nonsense, we could make tremendous progress in exploring the universe around us, revel in the wonder of finding new things we couldn't possibly imagine at the moment, and discover that there are a lot bigger and more interesting things out there that worrying about whose skin happened to be a slightly different color.

The JJ Abrams movies especially simply ignored this basic concept and just went with the action aspect with a little extremely surface glossy history thrown in to make it look just a tiny little bit less like a completely 2 dimensional sci-fi flick of no substance worthy of consideration. As simple standalone sci-fi adventure movies with no tradition or history behind them, they were fairly decent - glossy, amusing, decent action, a reasonable stab at making a futuristic movie look "real" (except for that totally moronic throttle on Sulu's panel), fairly well-done and reasonably well-acted - in short, worth killing two hours of your time for - but they had virtually nothing to do with the original concept of Roddenberry's series beyond the names of the characters.

Who cares? You're missing the point of the whole punishment aspect of a law like this. If you're dumb enough to think you can safely text while driving, then I for one wouldn't have much sympathy for you bitching later on that you can't text while you're a passenger. You deserve what you got. This sort of law and punishment would be sort of like making it illegal to be stupid. I suppose the problem is that stupid people, by definition, are too stupid to understand that they're being punished for being stupid, but at least it would keep you from texting while you're driving and turning your stupidity into an active menace to society.

That reminds me of an old SF book called Dragon's Egg, about life that developed on the surface of a neutron star. The molecular structure of this life was based on particles interacting via the strong force rather than the electromagnetic force, and because of that their chemical processes ran about a million times faster than ours. The main bulk of the story took place over a couple of months of our time, in which a spacecraft of ours was orbiting this neutron star. In that two-month timeframe, the beings on the star evolved from primitive savages to a highly advanced civilization, far more technologically advanced than ours. We were able to communicate with them, but from their standpoint it would take nearly a whole lifetime for just a few messages to be exchanged back and forth. Interesting story.

Of course, the fact that he's being followed around by a film crew has nothing to do with his success at bartering his bacon. That's a pretty ridiculous stunt. He might as well just go up to all these people and say, "Hey, if you'll give me decent seats to this game, I'll let my film crew here get a clip of you handing me the tickets and you might wind up on national TV!"

Hmmm. When you get right down to it, what really is the difference between distance and time when either is expressed as a function of the speed of light?

That's only in normal law - you need to research your details before you start bashing something you have no experience with. Stall protections are lost in alternate law, and recovering from a stall in alternate law is part of standard Airbus training.

That's because it took you 30 minutes to descend. They descended in 4 minutes. The cabin altitude doesn't descend anywhere near the rate the airplane is descending. They would have noticed a small pressure change, but not much.

That's because once the airspeed drops below 60 knots, the input from the angle of attack vane is ignored by the flight computer. The computed angle of attack is how the flight computer determines the airplane is approaching a stall, so without a valid input from the AOA vane, the computer can't sound the stall warning. The AOA vane is just a triangle-shaped piece of metal sticking off the side of the airplane on a little lever, so the airflow naturally positions it, just like a weather vane. As the angle of attack changes, the vane moves, providing an input to the computer. Below about 60 knots, though, there isn't enough airflow to move the AOA vane to a reliable, steady position, so the information is discarded by the computer.

In this case, you're right, it was unfortunate because it provided a confusing result to the crew. They had pulled the airplane's nose up into a stall, and when the airspeed dropped below 60 knots, the stall warning stopped. At one point, the crew did lower the nose of the airplane, which caused an increase of airspeed, which is of course precisely what they needed, but as the airspeed increased beyond 60 knots, the stall warning suddenly started back up. That made them think that what they were doing was making the situation worse, not better, when in fact they were doing the right thing. They pulled the nose back up and then never got it back down until they hit the water. Even when valid, the AOA vane never indicated an angle of attack of less than 35 degrees - generally speaking, almost any general or commercial aviation wing will be well into a stall by about 15 or 16 degrees AOA.

No. A GPS does not provide attitude information. It merely gives you your three-dimensional position (lat/long/altitude). In any case, on a commercial airplane such as the A330, the GPS data is not generally presented directly to the crew - you can find it, but it's buried in some menus on the computer. In fact, unless you look through the menus on those computers, you have no direct indication that GPS is even installed on the airplane or not.