On Mon, 24 May 2004 17:23:42 -0700, Jim Kelley
wrote:
I don't notice it until it the resulting chemical reaction takes place
on the retina of my eye.

Hi All,

Sorry to intrude with some actual technical content (well I guess this
would be twice, what with the mention of the conjugate mirror that
stumped Cecil). The reaction takes all of 8 femtoseconds whereas the
translation to an electrical signal at a synapse takes the
inordinately long time of 1 millisecond.

My correspondent's characterization is:
"One ms roughly the time constant for the production of the
first activated intermediate in the transduction cascade, the
other steps in the cascade are still slower ( for example, the
single photon response peaks in about 150 ms in mammals)."

Quantum efficiency is a remarkably high 0.7, easily twice the best
instrumentation which barely compares across bandwidth. The
transduction cascade that Dr. Detwiler refers to is much like the
amplification of a PMT whereby the single photon gives rise to a
current of 1000 electrons.

However, to return this to the conjugate mirror; if you looked into
one, not one electron would twitch.

73's
Richard Clark, KB7QHC