Gravitational Wave Detection - Comments?

Has anyone taken a look at the work of Italian boffins P. Galletti and A.
Aluigi concerning their experiments with gravitational wave detectors since
1994? These guys are using cadmium sulphide photo-sensitive resistors in a
special set-up to record gravitational waves associated with distant
cataclysmic events. Their claimed examples are stars falling onto active
galactic nucleii (quasars). I've been following their experimental notes
with interest for some time and am of the opionion they adopt a proper
scientific approach, albeit in what seemed an amateur vein initially.
Opinions are very welcome.

References:
http://www.omirp.it/www/CdS_Detector...l#Construction
http://web.tiscalinet.it/gravitationaldata/test18.htm
http://www.omirp.it/www/Matter+Universe/Index.html

In message , TeaTime
writes
Has anyone taken a look at the work of Italian boffins P. Galletti and A.
Aluigi concerning their experiments with gravitational wave detectors since
1994? These guys are using cadmium sulphide photo-sensitive resistors in a
special set-up to record gravitational waves associated with distant
cataclysmic events. Their claimed examples are stars falling onto active
galactic nucleii (quasars). I've been following their experimental notes
with interest for some time and am of the opionion they adopt a proper
scientific approach, albeit in what seemed an amateur vein initially.
Opinions are very welcome.

References:
http://www.omirp.it/www/CdS_Detector...l#Construction
http://web.tiscalinet.it/gravitationaldata/test18.htm
http://www.omirp.it/www/Matter+Universe/Index.html


Just one comment - if a couple of amateurs can detect gravitational
waves with a photoresistor, why are governments spending hundreds of
millions to build instruments such as LIGO? For instance, it's now
thought that Joseph Weber's experiments weren't nearly sensitive enough,
as they could "only" detect changes of 10^-16 meters
http://en.wikipedia.org/wiki/Weber_bar
Sorry, but I think they are seeing instability in their rig, and I can't
imagine why they think otherwise.

"Jonathan Silverlight" wrote
in message ...
Just one comment - if a couple of amateurs can detect gravitational waves
with a photoresistor, why are governments spending hundreds of millions to
build instruments such as LIGO? For instance, it's now thought that Joseph
Weber's experiments weren't nearly sensitive enough, as they could "only"
detect changes of 10^-16 meters http://en.wikipedia.org/wiki/Weber_bar
Sorry, but I think they are seeing instability in their rig, and I can't
imagine why they think otherwise.

Your sceptism is fair enough. Their findings are based on the highly
controversial conjecture that the dielectric constant of free space is
temporarily altered by the propagation of gravitational waves. Along with
this, they conjecture that the magnetic permeability and local speed of
light are similarly affected, together with the expected change in physical
dimensions of objects in the same field. Unlike the LIGO designs, their
apparatus is crude and presumably not directional, although they have
apparently correlated some of their disturbance data with known astronomical
observations. They do use a very well screened and temperature-controlled
enclosure for the detector and its Wheatstone bridge and the power supply is
sophisticated to say the least. They have also used laser interferometers
to verify mechanical stability. If by some outside chance they had stumbled
on a uniquely simple and sensitive detector, it would be worth knowing about
and attempting to replicate. They themselves are convinced enough to have
persevered for some 12 years with what may well be a fools' errand and it is
fascinating for that reason alone.

"Jonathan Silverlight" wrote
in message ...
In message , TeaTime
writes
Just one comment - if a couple of amateurs can detect gravitational waves
with a photoresistor, why are governments spending hundreds of millions to
build instruments such as LIGO? For instance, it's now thought that Joseph
Weber's experiments weren't nearly sensitive enough, as they could "only"
detect changes of 10^-16 meters http://en.wikipedia.org/wiki/Weber_bar
Sorry, but I think they are seeing instability in their rig, and I can't
imagine why they think otherwise.

A better link to their wild theory and the maths involved:
http://www.omirp.it/www/CdS_Detector/Part_4/Part_4.pdf

In message , Sun, 22 Oct 2006 21:15:03,
Jonathan Silverlight
writes

Just one comment - if a couple of amateurs can detect gravitational
waves with a photoresistor, why are governments spending hundreds of
millions to build instruments such as LIGO?


It's never been clear to me why such as LIGO might work to detect
gravitational waves.

I understand interferometry; it was commonly used by adjacent workers.

I know how, in the absence of other effects, a LIGO could detect
stretching of the light-path in one arm.

I don't know how LIGO deals with earth-movement.

I don't understand why a passing gravitational wave should affect the
light and the structure differently.

--
(c) John Stockton, Surrey, UK. /
Web URL:http://www.merlyn.demon.co.uk/ - FAQish topics, acronyms, & links.
Correct = 4-line sig. separator as above, a line precisely "-- " (SoRFC1036)
Do not Mail News to me. Before a reply, quote with "" or " " (SoRFC1036)

In message , TeaTime
writes

"Jonathan Silverlight" wrote
in message ...
Just one comment - if a couple of amateurs can detect gravitational waves
with a photoresistor, why are governments spending hundreds of millions to
build instruments such as LIGO? For instance, it's now thought that Joseph
Weber's experiments weren't nearly sensitive enough, as they could "only"
detect changes of 10^-16 meters http://en.wikipedia.org/wiki/Weber_bar
Sorry, but I think they are seeing instability in their rig, and I can't
imagine why they think otherwise.

Your sceptism is fair enough. Their findings are based on the highly
controversial conjecture that the dielectric constant of free space is
temporarily altered by the propagation of gravitational waves.

That took me into the idea of the "polarizable vacuum" and Harold
Puthoff! Thanks. The day I stop learning things I'll be dead.

Along with
this, they conjecture that the magnetic permeability and local speed of
light are similarly affected, together with the expected change in physical
dimensions of objects in the same field.

But if the speed of light changed, anything that depended on it would
show the effect. Two exquisitely sensitive systems that come to mind are
GPS and tracking of deep space probes.

Unlike the LIGO designs, their
apparatus is crude and presumably not directional, although they have
apparently correlated some of their disturbance data with known astronomical
observations.

I'm sorry, but I just don't see any sign of correlation with anything!

They do use a very well screened and temperature-controlled
enclosure for the detector and its Wheatstone bridge and the power supply is
sophisticated to say the least. They have also used laser interferometers
to verify mechanical stability.

But how can they test stability when their measuring instruments are
being altered by the effect they claim to see? :-) Anyway, "laser
interferometer" is what the LI in LIGO stands for!

If by some outside chance they had stumbled
on a uniquely simple and sensitive detector, it would be worth knowing about
and attempting to replicate. They themselves are convinced enough to have
persevered for some 12 years with what may well be a fools' errand and it is
fascinating for that reason alone.

In that case where are their peer-reviewed publications?

I'm strictly a dabbler in electronics, but I have a terrible problem
with the statement
"The present measuring range of the instrument is of about 8 orders of
magnitude. The first four orders are given by the direct signal provided
by the sensor, while the remaining four orders are obtained amplifying
10^4 times the first two low order bits." It's irrelevant anyway, as
they are reporting changes of several volts. None of the components of
their system has a stability better than one part in 1000, and I have no
idea why they use a vacuum tube light source (type unspecified).

"a peak value of over 2.2 V which corresponds to an increase of the
speed of light of approx. 130,000 km/s".
Measuring the speed of light is something you _can_ do at home, kids.
Got any marshmallows?
http://www.physics.umd.edu/ripe/icpe/newsletters/n34/marshmal.htm

And the more I read, the worse it gets.

"The Magnetic Sensor changes its weight whenever a gravitational wave
pass through it. Its operating is based on the variations of magnetic
permeability of ``vacuum'' produced by Gravitational Waves. It consists
just of a loudspeaker magnet with aluminium as conducting material
(without any insulating material!) to be placed, mostly, where B is
high."
http://www.omirp.it/www/M_Sensor/Index.html

I seriously doubt that gravitational waves cause earthquakes! BTW, that
page refers to the CdS sensor having a "a slower time-response (due to
chemical processes that take place inside it)"
Indeed. According to www.streetlightonline.co.uk/Photocells/index.htm
"they are also subject to some long-term drift."

"J R Stockton" wrote in message
nvalid...
In message , Sun, 22 Oct 2006 21:15:03,
Jonathan Silverlight
writes

Just one comment - if a couple of amateurs can detect gravitational
waves with a photoresistor, why are governments spending hundreds of
millions to build instruments such as LIGO?


It's never been clear to me why such as LIGO might work to detect
gravitational waves.

I understand interferometry; it was commonly used by adjacent workers.

I know how, in the absence of other effects, a LIGO could detect
stretching of the light-path in one arm.

I don't know how LIGO deals with earth-movement.

I don't understand why a passing gravitational wave should affect the
light and the structure differently.

--
(c) John Stockton, Surrey, UK. /

Web URL:http://www.merlyn.demon.co.uk/ - FAQish topics, acronyms, &
links.
Correct = 4-line sig. separator as above, a line precisely "-- "
(SoRFC1036)
Do not Mail News to me. Before a reply, quote with "" or " "
(SoRFC1036)

My understanding of the core principle is that as gravitational waves
impinge on the L-shaped detector arrays, they will decrease the distance
between the test masses in one arm, while increasing it in the other. These
minute changes are detected by isolating the test masses from all other
movements, such as seismic vibration of the ground and air turbulence and by
reflecting laser beams back and forth between the test masses in each arm
and then interfering the two arms' returning beams with each other. (A
single laser is used, with a beam splitter to divide the beam equally down
each arm). The tiny changes in test-mass distances throw the two arms' laser
beams out of phase with each other, thereby disturbing their interference
and revealing the form of the passing gravitational wave. Local ground
vibration effects are removed by comparing results from two separate arrays,
(disturbances are unlikely to happen simultaneously at widely separated
sites).

"Jonathan Silverlight" wrote
in message ...

Measuring the speed of light is something you _can_ do at home, kids. Got
any marshmallows?
http://www.physics.umd.edu/ripe/icpe/newsletters/n34/marshmal.htm

Only an American would publish a recipe like that without stating whether
they should be of the pink or white variety. Tut!

Interesting link to the firm developing the active vibration isolation
devices for LIGO to sit on:

http://www.hpd-online.com/project_gallery/

In message , TeaTime
writes

"Jonathan Silverlight" wrote
in message ...

Measuring the speed of light is something you _can_ do at home, kids. Got
any marshmallows?
http://www.physics.umd.edu/ripe/icpe/newsletters/n34/marshmal.htm

Only an American would publish a recipe like that without stating whether
they should be of the pink or white variety. Tut!


You can also use chocolate chips. Plain or milk not specified :-)