Posts Made By: Doug Peterson

The three radial screws that scoot one element with respect to the other--may be pinching that element. These of course on the "new" cell, and not the front push pull 6ea used for cell collimation.

I pointed Lindzen to this forum, and asked him to respond to the accusations made. He sent a personalized response, and referred to me to this attachment below. Interestingly in the link that opened this thread he explains how some of this disinformation is disseminated.



Statement concerning support.
My research has never been supported by any industrial source. I have always had research
support from one or more of the following: the National Science Foundation, the National
Aeronautics and Space Administration, and the Department of Energy.
I have accepted two lecture fees from oil and coal firms about 17 years ago. In each case, I
shared the platform with speakers from the environmental movement. The same was true of a
talk I gave at a meeting sponsored by OPEC around the same time. It was claimed that the
publication of that talk was sponsored by OPEC. That is untrue. The lecture had been prepared
earlier as part of a series of lectures delivered at Tel Aviv University where I was a Sackler
Visiting Professor. It was subsequently published by the Cato Institute in their magazine
Regulation.
During the early 90's, I also served for a couple of days as an expert witness for Western Fuels in
a court case in Minnesota. Western Fuels is a small coal cooperative serving publicly owned
utilities in the upper midwest. It is relatively unique among fuel companies in that it has no
customers to pass its expenses on to. It was created under President Carter as part of his policy
of reducing dependence on oil. Again during this period, I responded to a request to testify
before a Senate Committee. After testifying, I discovered that it is the practice of Congress not
to cover any expenses (travel, hotel, preparing 100 copies of testimony, etc.) associated with
testifying. Moreover, one is not permitted to use government grant funds for this purpose. Since
I was broke at the time, I accepted $300 from Western Fuels to cover some of the expenses. I
should add that this policy on the part of Congress has the effect of largely restricting testimony
to government employees and advocates. I covered my own expenses for subsequent
Congressional testimony.
The above represents the totality of my paid association with oil and coal firms.
Richard S. Lindzen
April 5, 2007

The best I've ever seen from PBS, I was seeing things I had never seen before, up there with the the 3 part NOVA, The Elegant Universe. Hale was quite a character.

The Strehl is precisely mathematically related to the RMS wavefront. In an interferometer, the wavefront is a front, that is a continuously varying surface that the software analyses over thousands of points.

By contrast, reading the positions on a micrometer of a handful of zones to compute something that you can give a name is one thing but to call it the Strehl is something else.

The peak intensity of the airy disk to its theoretical maximum is something real you can see at the eyepiece. If you call your magic mojo test on your mirror a Strehl of .999, and yet with interferometry it is actually .95 but believe the higher number than you are dreaming. If you look thru your eyepiece and see that all the energy is not precisely where it is supposed to be than you are seeing the real physics of the situation, and the magic test is nearly meaningless. If the surface is rough energy will be scattered all over the place other than the airy disk and your strehl number is wrong.

Lets say the magic mojo test gives you a number of .95, by itself an excellent result, then what would it measure on the interferometer? .80? .50? Now you would have a test that says the mirror is excellent but actually it is a toy.

BTW, I do work on spaceborne telescopes and stealthy stuff, and in this real defense world nobody uses these goofy magic tests, but real interferometers, encircled energy, etc., MTF, devices using lasers, piezoelectric transducers, stepper motors, exotic detectors and sophisticated programs, in the hundreds of thousands of dollars. The customer wants real results. If these zonal tests were really as precise as is pretended, why would anyone spend a quarter million bucks on an interferometer?

Perhaps we should vote with our wallets, demand more realistic test results, force these guys into the real world. The main problem is they are looking at focal lengths and radii of zones read-off with a micrometer, mechanical distances, not interference patterns which use the tiny wave nature of light itself as a ruler, with divisions on the order of .000,012". Now, these small mirror makers cannot afford state of the art equipment, but they don't need to. Some options that actually use interference, and are therefore capable of high precision and accuracy:

1) There are respected tests such as the Roddier test that are inexpensively set up, essentially a deterministic star test. Everytime you look at a star out of focus with a handful of fresnel rings, you are seeing a tiny interferometer. All you need to do is figure out how to extract the data.

2) The Ceravolo interferometer is another inexpensive and clever solution that relies on off the shelf el-cheapo parts and one precision element that costs a few hundred bucks.

3) Older Zygo interferometer equipment is available on the used market for less than a good used car.

Let's push back against nonsense. Mirror lovers unite!

I attempted to get your attention with two PMs a couple weeks ago to which I received no reply.

And no secondary obstruction! Must be an off axis paraboloid.

Well I see that the only alarmist response to this thread was a no-science hotheaded rant from a chiropractor, fergodsakes. You want to talk about your bogus science, the one I went to was a complete fake. When I asked him about the science behind his claims, he babbled nonsense about liquid nitrogren, something I know much more than him.

Is this the best the alarmist camp has got?

0/1

The models are complex simplifications (?), slicing and dicing the earth into little chunks of atmosphere and water. They are then run from initial condition assumptions. The equations of weather are known to be chaotic. No doubt they are fascinating data structures. Unfortunately they are not yet ready for prime time, because for all their sophistication they cannot predict the present. Here is the current state of the art. To a 95% confidence level, the IPCC models have moved away from the actual data (the tight red and blue squiggles):

http://rankexploits.com/musings/2009/surface-temperature-anomalies-almost-outside-2-sigma-confidence-intervals/

BH Photo video shows it as "accepting orders", at 1100 bux.

http://www.bhphotovideo.com/c/product/597338-REG/Leica_41019_25_50x_WW_Aspherical_Eyepiece.html