The Prandtl–Glauert singularity (sometimes referred to as a "vapor cone"), is the point at which a sudden drop in air pressure occurs, and is generally accepted as the cause of the visible condensation cloud that often surrounds an aircraft traveling at transonic speeds, though there remains some debate. It is an example of a mathematical singularity in aerodynamics. One view of this phenomenon is that it exhibits the effect of compressibility and the so-called "N-wave". The N-wave is the time variant pressure profile seen by a static observer when a sonic compression wave passes. The overall three-dimensional shock wave is in the form of a cone with its apex at the supersonic aircraft. This wave follows the aircraft. The pressure profile of the wave is composed of a leading compression component (the initial upward stroke of the "N"), followed by a pressure descent forming a rarefaction of the air (the downward diagonal of the "N"), followed by a return to the normal ambient pressure (the final upward stroke of the "N"). The rarefaction may be thought of as the "rebounding" of the compression due to inertial effects.
Can you say what is on the pics? They was made in California. Man, who does made them, has sent them to any newspaper, but they have not believed him. Then he has developed activity on the Internet and it has appeared that he is not unique who saw this.
Near Kharkov (Ukraine) was found a hole in the forest. The depth of hole is about 18 meters, diameter of 1.2 meters. Nearby there is no heap of the chosen earth. Radiation doesn`t measure. In the bottom of branch in the parties of 2-3 meters, width 40х60 see.
For the moderate price, all in some rupees, street stomatologists treat caries the sufferer directly on the way to work. Service has received at once wide popularity among the population. Besides, treatment at legal physicians – the stomatologists owning own office, in India costs much, only very provided citizens can allow themselves it. First street dentists practised only at a distance painful teeth, but, thanks to prompt growth of a competition, for today the majority of doctors are ready to put on a problem tooth a crown and even to make a set of false teeth.
In the USA steam vein, both of them served in army. One fine day they have left to have a rest, and the mistress of apartment has decided to check up a dwelling status.
Here the mountains above, all rivers deeper, wildlife is much more richer than in any other place in the world. There are only a few places in the world where you can see nature as it was many centuries ago - untouched and endless, where forests and summer nights never end.