The story is quite simple. The propeller pushes against the air, its positive effect is affected by the difference in speed between the craft and the air. The propeller is driven by the wheels, so its negative effect on the craft is due the the difference in speed between the craft and the ground.

If you have a wind, the craft-to-ground speed is different from the craft-to-air speed. The vehicle can extract energy from this difference - like any sailboat, really - and pull ahead of the wind.

1. Force equations? The force backwards on the wheels is proportional to the groundspeed, the force forwards on the propeller is proportional to the airspeed. If groundspeed exceeds airspeed, as it does travelling downwind, there is an unbalanced force. If losses could be eliminated, the craft could travel at infinite speed (until relativism takes effect!)
2. If you give it a shove, without wind, airspeed == groundspeed, so there is no unbalanced force. Losses are all there is, so it slows down.

Of course, if you are like me you begin to think about the speed rating of the tyres and bearings, but that is beyond the scope of the stupid question.

A treadmill is motion is no different to a still surface being affected by a wind. The ground is moving relative to the air, and vice versa. The movement of the treadmill would drive the wheels, the wheels would drive the propeller, and it would move forward relative to the air.

Rolling out new copper in this day and age would be madness. But the decision to rely on wireless as anything other than a short-term emergency measure is wrong. They should, of course, be rolling out new fiber as a matter of urgency.

As long as the raw materials are priced in tens of dollars per kilogram, printing out random stuff is always going to be too expensive. Really, it is bulk plastic. It should be priced nearer 40 kilograms per dollar than 40 dollars per kilogram.

Although the choir starts singing on the large downward movement of the baton, that is not the cue the choir is using - if the started singing after seeing the downward movement, they would always be late. They are actually taking their cue from the very subtle upward movement just before the downward sweep. Even detecting this would be difficult. The size of this movement, and the delay between this movement and the drop, whether a movement is the of the 'get ready' upward sweep... all very difficult and confusing things. And the nature of the movements will change depending on conductor, the nature of the music, or even the conductors mood. The human brain sorts all of these things out just fine. The best idea is one I read from another poster here - have the neighbour of blind singer give them their cue.

That explains why we are all being pushed onto a schizophrenic mess that nobody wants called Windows 8.

My reason for stating that a patent would be 'reasonable' is that they would have been given a patent if the current laws stood when the drug was developed. Perhaps "not unreasonable" would be the correct term.

Oh, hear here. But that law has not been followed for years. The art of writing a patent these days is the art of making the wording so complex that it provides the reader with no benefits, and so ambiguous that you can extend it to cover things others invent later. "Full, clear, concise and exact". Yeah. That's why we need 'claim construction' arguments to work out what a patent means.

In this case, the original patent could not be granted because India's laws did not recognize patents on drugs at the time. Now India has passed laws recognizing patentable drugs, the company wanted a patent, and claimed one for the existing drug, unpatented because of previous laws, slightly changed.

In this case, a patent would have been reasonable. But if allowed, it would be a precedent that would have been used for evergreening other drug patents in the future. So it was quite rightly disallowed.

There are more egregious examples of evergreening, for instance, where a party gains a patent on a drug, and, just before the drug's patent expires, a second patent is applied for covering an essential process or precursor for making the drug. This second patent works if they have been careful to make sure that information about the process or precursor has been kept as a trade secret, which means simply that everyone that has been informed about it has signed an NDA.

How about "No, it doesn't, because before they finished development MegaResourcedCorp had been selling their unlicensed product for 6 months, and had been given other patents that prevent anyone (including the original inventor) from producing a competing product."

At the moment this is possible, but only just. As mining moves to ASICs (custom silicon that mines very fast with little power), the mining that could be done, even on a planet full of x86 bots, would not be worth that much.

Mining won't stop when the subsidy stops, although we might think of something else to call it. The reward for 'mining' will then be only the fees that are included with transactions.

The subsidy is only part of the block creation process. It so happens that the network allows the host that creates a new block to award itself free coins, as well as collecting any fees. When the network no longer allows this, the blocks can still be created, and they will still collect the fees.

Hemp does not contain much free sugar. Almost all of it is converted into cellulose, which is still proving difficult to break down into sugars for conversion to fuels.

The summary (and probably the article as well) does not make this clear. Invert sugars are mixtures of glucose and fructose, generated by applying acids, heat or enzymes to sucrose.

So the sentence should be read "...meaning sucrose as well as (glucose, fructose and other minor sugars,) called invert sugars.

The GST exemptions just make everyone's live difficult. Many lives would be made a lot easier if GST applied everywhere.

And there is some real strangeness. Try a business selling live fish. Fish in a store is considered a basic food item. But a live fish requires processing - killing - before it becomes a basic food item, and so is liable for GST. So what happens if they ship a live fish, which attracts GST, and it dies en-route? I think the official answer is "Who knows?"

Oh, and if it cooked and sold wrapped in paper, it's now fast food, and attracts GST once more.