I always assumed they were pinhole lenses, but then I realized I really don't know (and don't want to break apart a perfectly good phone).

Some engines can operate at higher temperatures/pressures than the human body. On the other hand, vehicles have extra weight, possibly have different drag characteristics, etc. For "normal" speeds and loads, what would be the properties of a vehicle at a crossover point equal to the efficiency of an average human?

The sun's radiation can be concentrated to a focus using a curved mirror, and an object at the focus can be heated intensely. Is it possible to do the reverse? If a solar collector is pointed at the sky at night, when there is little incoming radiation, would an object placed at the focus of the mirror radiate heat away in to space and become very cold. If so could the principle be used to devise a method of refrigeration? Presumably it would be necessary to arrange insulation to minimise heat leaking in to the object from the surroundings.

It's generally said that QWERTY keyboards were originally designed to be inefficient, to slow down some keystrokes to prevent jamming of typebars in mechanical typewriters. On the other hand, there are some free market think tanks that claim the QWERTY keyboard really is the most efficient, though their claims may be biased. 

Being old enough to have used an old "typebar" typewriter, the most common jams I seem to remember were associated with typing numbers such as "12" (which might be consistent with Benford's Law). If an empirical approach was used to prevent jams, one might have expected the numbers across the top of the keyboard (or separate calculator-like keypads, if such machines used similar mechanisms) to have been scrambled as well (though old typewriters did seem to use something like the letter "I" for the number one).

Since one commonly hears people bringing up QWERTY keyboards as an example of "entrenched inefficiencies," has newer technology (and the advent of "thumb typing" and the like) caused new keyboard formats to flourish?

In Tenerife we can view the terrestial English TV channels. Around 9pm they start breaking up to the extent that they become unwatchable.

Why is this and is there a remedy please?

In Tenerife we can view the english terrestial channels. Most evenings around 9pm the pictures start breaking up to the extent that they become unwatchable. Why is this

I've heard from a few sorces that we can now input computational images into the eye. The sources didn't go into much detail on how to do this, but I am buessing that they figured out how visual images are processed through our Optical Nerve, and - after some lengthy reasearch - were able to imitate these electrical nerve pulses and hook up a wire directly into the part of the brain which processes images.

Is this right, and if so, then why does it work? Shouldn't the patient feel some sort of electrical current flowing throught their brain? Why does the patient's brain recieve the image as if it were a normal image from out eyes?