sig virus = S = silicon   Used by hackers in a generalization of
its technical meaning. `Signal' refers to useful information
conveyed by some communications medium, and `noise' to anything
else on that medium. Hence a low ratio implies that it is not
worth paying attention to the medium in question. Figures for
such metaphorical ratios are never given. The term is most often
applied to Usenet newsgroups during flame wars. Compare
bandwidth. See also coefficient of X, lost in the noise.   Often
written as S/N ratio or SNR, and is basically a measure of
signal strength relative to background noise, used principally
in communications. Mathematically it is expressed:  or in dB
(NOISE POWER ) Often the powers involved are not known, but the
voltage amplitude is. In this case it is possible to substitute
V2/R for P. This gives us the much more common:   Hence, if the
power of the noise is equal to the power of the signal the SNR
would be zero and the information would be almost unreadable. In
communi