Anonymous , 7/27/2007
Question: How Dreams Work
Premonitions in DreamsThe science of dreams is obviously not a clear-cut one. While many believeAnonymous , 7/27/2007
Question: How Dreams Work
Recurring Dreams and Nightmares
Many people have the same or a similar dream many times, overAnonymous , 7/27/2007
Question: How Dreams Work
What do our dreams mean?Those on the physiology side of the "why we dream" argument see dreams asAnonymous , 7/27/2007
Question: How Dreams Work
Controlling Dreams
Lucid Dreaming
There is a lot of research being done in dream control,Anonymous , 7/27/2007
Question: How Dreams Work
Dream Recall
Photo courtesy MorguefileIt is said that five minutes after the end of a dream, weAnonymous , 7/27/2007
Question: How Dreams Work
Dreams and REM SleepPhoto courtesy DVI
A U.S. Army soldier gets some sleep at a compound in Samara,Anonymous , 7/27/2007
Question: How Dreams Work
Dreaming and the BrainWhen we sleep, we go through five sleep stages. The first stage is a veryAnonymous , 7/27/2007
Question: How Dreams Work
Dreams: The Theoretical Divide
Physiological theories are based on the idea that we dream in orderAnonymous , 7/27/2007
Question: How Dreams Work
Our dreams combine verbal, visual and emotional stimuli into a sometimes broken, nonsensical butJosyvan , 7/10/2007
Question: How radar works?
Clutter is what radar users call radar signals that do not come from actual targets. Rain, snow, and the surface of the earth reflect energy, including radar waves. Such echoes can produceJosyvan , 7/10/2007
Question: How radar works?
Early radar systems were capable only of detecting targets and making a crude measurement of the distance to the target. As radar technology evolved, radar systems could measure more and moreJosyvan , 7/10/2007
Question: How radar works?
Radar ScreenRadar displays indicate the presence and movement of objects out of the range of vision, which is particularly useful for navigators. Electronic equipment records the behavior ofJosyvan , 7/10/2007
Question: How radar works?
Most modern radar systems use digital equipment because this equipment can perform many complicated functions. In order to use digital equipment, radar systems need analog-to-digital convertersJosyvan , 7/10/2007
Question: How radar works?
The duplexer enables a radar system to transmit powerful signals and still receive very weak radar echoes. The duplexer acts as a gate between the antenna and the receiver and transmitter. ItJosyvan , 7/10/2007
Question: How radar works?
The receiver uses an antenna to gather the reflected radar signal. Often the receiver uses the same antenna as the transmitter. This is possible even in some continuous-wave radar because theJosyvan , 7/10/2007
Question: How radar works?
A radar receiver detects and often analyzes the faint echoes produced when radar waves bounce off of distant objects and return to the radar system. The antenna gathers the weak returning radarJosyvan , 7/10/2007
Question: How radar works?
After the transmitter amplifies the radar signal to the required level, it sends the signal to the antenna, usually a dish-shaped piece of metal. Electromagnetic waves at the proper wavelengthJosyvan , 7/10/2007
Question: How radar works?
The radar system’s transmitter increases the power of the oscillator signal. The transmitter amplifies the power from the level of about 1 watt to as much as 1 megawatt, or 1 million