X-Message-Number: 4455
Date: 26 May 95 12:01:54 EDT
From: yvan Bozzonetti <>
Subject: SCI.CRYONICS: BONZO 2: Two photons interferometers.

In the BOson New ZOne, intensity interferometers are a first step worth to 
look at. The first systems of that kind was build by the astrophysicist 
Robert Hanbury Brown in UK and then in Australia at the Narrabri site.They 
are a subclass of four waves interferometers where wave are detected in a 
time independant way on two recievers, each one mixes two wave so that it 
get from occupation state a hamiltonian density without time variable. This 
is a probability density or, on a given surface in a given time an energy 
or photon count. The intensity interferometer, as applied to photons, works 
by looking at correlations in the arrival time of different photons on the 
two detectors. The square root of that correlation is an energy, similar to 
the one encountered in frange paterns seen on ordinary, two waves 

The main interest of that system comes from the possibility to trade 
between integration time, sensibility and resolving power without limit. 
The intensity interferometer is a "particle-property" interferometer, that 
is, it does not matter what is the wavelength used to get information. For 
technological reasons, astronomical instruments work with ligth and handle 
it as radio waves. A radio wave could as well be used with sub wavelength 

The current project uses a three steps aproach : First, two telescope will 
be used in remote access operation, one in France the second in western US. 
The objective is to get a common observation from both sites. They will 
produce CCD pictures, photometric data and spectra (at least for the french 
unit). This system must enter into function on INTERNET next year. The 
first trial comming this winter. At the same sites, a second instrument 
made from many plastic mirrors with a total surface near 100 square meters 
will be devotted to photon counting photometry and spectrography. That 
system is in the componemet procurement stage. It must work two years after 
the first system. An upgrade will be to add a clock and register to the 
photon counter. That will turn the photometer into a a transcontinental 
intensity interferometer. All of that is closely related to astronomy and 
has nothing to do with cryonics.

Now, if the photomultiplier tube in the photometer head is removed and a 
sound detector put at its place, we have a sonar intensity interferometer 
(if ther is a sound source).The idea is ten to use a multi channel version 
of the system to get a brain scanner at the 100 nm level. The astronomical 
part of the project is there to develop, and finance the electronics and 
computer parts. A brain reader working on that principe could start to 
function five years from now on an experimental basis.

I am looking for electronics specialists able to build the clock and 
amplifier for the intensity interferometer.

The first "reader system" would be able to scan a frozen rat 's brain in 
one year or so. More advanced systems could scan a man brain many time a 
second, using radio waves.

Intensity interferometers was first used at the end of World War two, but 
forty years later they remain uncommon systems, largely ignored from many, 
including optical specialists. There are some general references on the 
subject :

W . H . STEEL (1983) : "Interferometry", 2nd ed. Cambridge Studies in 
Modern Optics; Camb. Univ. Press, see ch. 6 -6.8 : Higher-order 
correlations, p. 85 and ch. 14 -14.3.2 : Stellar intensity interferometer, 
p. 279.

Collective book : Modern Technology and its Influence on Astronomy, ed. by 
: J. V. WALL and A. BOKSENBERG. Cambridge University Press 1990 p. 6 to 11, 
51, 91, 92, 95, 96, 101 - 103.

Gordon WALKER (1987) : Astronomical Observations : An optical perspective. 
Camb. Univ. Press, p. 37 and 180.

		Y. Bozzonetti.

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