Science Focus
original post »Normally, noise is something we scientists try to avoid. In the most advanced physics experiments, the goal is usually to measure something new. If you ever ask the experimenters why it took them so long to do a measurement, the most common answer is "finding a way to defeat the noise."
Sometimes, though, the noise becomes more interesting than the signal, telling us new things about the physical system we are studying. The study of noise is not new, of course, but with our increasingly precise control of quantum systems, we can study it in ever finer detail.
In this case, researchers studied Johnson noise, otherwise known as white noise. In a metal, there is a sea of electrons that is free to travel around in constant motion—the fact that the temperature is above absolute zero is enough to keep electrons in motion. Because of this motion, the density of electrons varies slightly from place to place at any given time. These fluctuations create small attractive and repulsive forces that drive electrons to attempt to neutralize the fields. In doing so, they create new density fluctuations and fields in an endlessly repeating cycle.
Read 11 remaining paragraphs | Comments
#science
» see original post http://feeds.arstechnica.com/~r/arstechnica/science/~3/B7ftKiwJMh4/
See Zazzle gifts tagged with 'science'
No comments:
Post a Comment