Are you still working on spin casting? Ever since reading (about ten years ago) about spinning pools of mercury being used as a lens, I've wondered about spin casting. I think there are significant problems with trying to cast a resin mirror. Besides the hardware and electronics involved there's also the problem of applying a reflective coating to the surface of the final cast. I'm not sure how you would make a reflective coating on a resin surface. I've played a little with casting (not spinning) resin prisms. I wanted to add a reflective coating to one of these prisms. My thought was to add the reflective film used on car windows but the person at Tap Plastics told that all plastics "out gas" and the film would likely develop bubbles rather quickly. I'm very curious to know how you have or plan to add a reflective coating to any plastic surface you have in the past or may in the future cast. I have wondered about evaporative plating but that is not a simple process (I've seen it done). I'm not sure if bubbles would still form under a layer of the deposited metal. Do you have pictures of this iGlass you've written about. Any images taken with plastic mirrors? Duane
Duane, I did a lot of work with spin casting resin telescope mirrors in the 1970s when I made several 52 inch telescopes. I began casting mirrors again about 2 years ago for a Parallax project. The posts are still there. Reflective coating a resin mirror is not a problem. It can be silvered or aluminized. The process of silvering can be dangerous if the mix rises above 80-degrees. It will explode like TNT. It also tarnishes in about 6 months.
To aluminize a mirror, find a center with a vessel large enough to contain the mirror. The process works well as the aluminum is deposited as a mist evaporated onto the surface. The are no known proplems of outgasing during aluminizing. Outgassing may occur during resin curing. Resin mirrors and optics are aluminized all the time. In the 1970s, the companies were aluminizing mirrors as large as 72 inches. With popularity of big Dobsonians, coating will be even more easy for large mirrors.
Bubbles can develop when mixing the agent. Spinning the mix by centrifuge will help get rid of bubbles. The biggest challenge is not bubbles but mold shrinkage and dealing with astigmatic sections.
Yes I have some photos but it will be a while as they are on the other computer in the other country. I can post when this travel period is complete. In the mean time, I can say resin telescope mirrors will perform optically and will meet my requirements for ultra large low cost telescope mirrors.
I'm very excited about making the ULT. I did some number crunching and the fast curve of a mirror that's 5 to 40 feet in diameter could provide significant light gathering power to do some remarkable studies and maybe make a new discovery.
Results from the Aluminized Plasic Bag Mirror
Reflective Mylar & Polymer Material
In post 1645 we examined a 5.5 inch section of aluminized material from the food store. Results from this study and experiment are in. It is learned that the ability to stretch is an important function of the material in making a reflective telescope mirror. The reason for this is all about the curve and material thickness plus size dimensions. When a smaller (6-inch diameter or less) material which is thicker MIL material (8 or more, estimated) is placed over an aperture, the material stays relatively flat, and when the spherical curve is imparted, the edges must form rippled points of stress. This happens when the material cannot stretch enough to form the curve without deformation.
The solution may encompass several approaches.
Use larger diameter mirrors and automatically mask the outer edge where deformation results
Use thinner MIL thickness material to minimize or prevent wrinkling
Stretch the material so that a telescope mirror shape results
Big Brain Established Telescope Mirror Definitions
The size diameter of a telescope mirror is extremely significant. It determines the telescope's resolution, ability to collect light and do useful science. One thing the field of telescope astronomy is lacking is the class of various telescopes and mirror sizes by definition. At least for the Big Brain, definitions should be established.
Some terminology is already in effect. For example, the Brain is working towards the ULT Ultra Large Telescope. In the past, Humanoido worked on the VLT Project. Here's a preliminary idea of terms. Some size ranges may overlap. All sizes are diameters given in inches unless otherwise noted.
Small Size - 1, 2, 3, 4.25, 6, 8
Standard Size - 3, 4.25, 6, 8, 10, 12.5
Big Dob - 14, 16, 18, 20, 24, 30 to 43
Large Telescope - 18 to 50
Very Large Telescope VLT - 30 to 60
Ultra Large Telescope ULT - 60, 72, 80, 100, 120, 200 (4 feet to 20 feet)
Spectacularly Giant Telescope SGT - 500, 1000 (20 feet to 100 feet)
The Brain is working on several different types of telescopes. The technology overlaps. Developments for one type of telescope may often be applied to others. Here is a small list of telescope types the Brain is developing and studying.
Dobsonian - Design by John Dobson
Folded Newtonian
Fly Eye Refracting Telescope
Schmidt - Fast Telescope Camera Design
RFT - Rich Field Telescope
LFT - Long Focal Length Telescope
Resin Spin Cast
Fragmented Mirror Telescope
Slumped Substrate
Liquid Oil Telescope
H2O Water Drop Refractor Telescope
Aluminized Mylar Pneumatic Telescope
Ultra Thin Mirror (glass)
MMT Multiple Mirror Telescope
MLT Multiple Lens Telescope
ET's - Electronic Telescopes
AET - Artificially Enhanced Telescope
Spherical Telescope
Encapsulated Membrane Telescope
Highest Precision Parabolic Glass
Another visit to the grocery Mart has found another piece Aluminized "polymer material." The material is about 12 x 18 inches which will make a 12 inch mirror or a fragmented 18 inch mirror. This is an unfolded Lays potato chip bag turned inside out and cut carefully along the top and bottom and side. The material is estimated two or 3 times thinner than the peanut mirror. It appears this material also will not visibly stretch.
If an aluminized membrane stretches, won't the reflectance be diminished proportionately as the aluminum particles separate? Obviously, the aluminum isn't going to stretch, too -- just the substrate.
The Brain now has telescopes in 4 labs in 3 countries and work has proceeded in at least 7 countries and 12 cities. In special cases, work proceeded over the North Pole and the Rain Forrest. Expansion into China Lab 4 includes water lenses and telescopes, and various reflective material mirrors. Taiwan Lab 3 has the Multiple Lens Telescope and Telescope Systems Design. Lab 2 has resin cast. USA Lab 1 has glass and spin mirrors. The Dob from Lab 4 is transferred to Lab 2 which has the GOTO computerized telescope. Lab 2 now has the most powerful computers. MSP was developed in Labs 2 & 3. Lab 4 planned & completed the trip into space. Lab 1 will host the ULT. Lab 2 had the 1st rocket launch & developed the airport, flying two helicopters. Lab 3 did the first flight camera tests.
If an aluminized membrane stretches, won't the reflectance be diminished proportionately as the aluminum particles separate? Obviously, the aluminum isn't going to stretch, too -- just the substrate.-Phil
Phil, I agree with you, it does seem that's the obvious result. Scientists studying this effect found the vapor aluminizing deposits molecules into the substrate which becomes part of it. When the substrate is stretched, the reflective aluminum "stretches along with it." The reflectivity won't change, only the distance between the molecules will change.
This also raises some questions. Does the new molecular lattice deviate its orientation alignment? If yes, then I think reflectivity could be reduced.
Another question, can the molecular lattice be stretched an exact amount to create constructive interference of light waves? If yes, then the surface could actually be enhanced and would increase light reflectivity in a manner similar to enhanced mirror dielectric coatings.
Enhanced mirrors can perform much like larger mirrors, for example, a 12.5 inch is typically said to perform like a 16 inch. Perhaps we could just stretch our mirror by a certain amount to enhance it. But stretch it too little or the wrong amount could induce destructive interference for the opposite result.
Will the spherical or parabolic shape of the mirror significantly change upon stretching and alter the light focus? This could reduce contrast and image brightness by increasing wavefront error, even if reflectivity remains a constant.. More tests and experiments will be needed to answer many of these questions.
Constructive Interference of Light
Telescope Mirror Enhancement Method
In the previous post we introduced the topic of enhanced mirrors. In Physics and Optics class, we derived the equation for the constructive interference of light as reflected on a mirror's surface. By adjusting the coating layer thickness, the constructive interference condition is met. This is opposed to destructive interference of reflected light which is useful for minimizing lens reflections but not useful for enhancing a mirrors reflective ability.
Discussion here. http://en.wikipedia.org/wiki/Thin-film_interference
An anti-reflection coating eliminates reflected light and maximizes transmitted light in an optical system. A film is designed such that reflected light produces destructive interference and transmitted light produces constructive interference for a given wavelength of light. In the simplest implementation of such a coating, the film is created so that its optical thickness
dncoating
is a quarter-wavelength of the incident light and its refractive index is greater than the index of air and less than the index of glass.
nair < ncoating < nglassd = λ / (4ncoating)
A 180° phase shift will be induced upon reflection at both the top and bottom interfaces of the film because
nair < ncoating and ncoating < nglass.
The equations for interference of the reflected light are:
for constructive interference
for destructive interference
If the optical thickness
dncoating
is equal to a quarter-wavelength of the incident light and if the light strikes the film at normal incidence
(θ2 = 0)
the reflected waves will be completely out of phase and will destructively interfere.
Further reduction in reflection is possible by adding more layers, each designed to match a specific wavelength of light. It should also be noted that interference of transmitted light will be completely constructive for these films.
In this continuing series project, the Brain will outline methods, tried and true, that make an existing reflector telescope enhanced, by the sum of several techniques, to increase its effective diameter to at least ten times larger.
The Brain says, "If you don't buy into the idea, now is the time to get out of the kitchen if you can't stand the heat." For those who are open minded and wish to gain from the benefits of enhancement, welcome to the future of new telescope technology.
INTRODUCTION Make a telescope mirror perform like a much larger mirror. In this continuing series of investigations of concatenating techniques, the Brain will show various methodology to enhance a telescope and make it perform like one that's ten times larger. This is one step of several that will add together to enhance a telescope mirror to increase its effective diameter by a factor of approximately ten or more. The results of this can open up new benefits by extending the range of existing telescopes, and in some cases, new science.
This will be useful in converting the ULT Ultra Large Telescope from its chosen diameter, let's say 100 inches, to that of a 1,000 inch telescope. In the case of a larger 200 inch mirror or MMT, the effective aperture becomes 2,000 inches in diameter. In the case of other ultra large optics, a 72 inch becomes a 720 inch.
The Brain's goal is in reaching new levels of science and technology, best accomplished with telescope tools that have the necessary power, not only in terms of incredible light gathering ability, but resolution and as will be shown, other effects of remarkable enhancements.
The objective is to created the right tool for the right job. In the case of the Big Brain, it has big requirements. But size, weight, cost, and time are all factors the Brain must minimize. One way to minimize these factors while ramping up benefits is through telescope enhancement.
Types of Enhancements Various methods of enhancing a telescope mirror and its image will be introduced.
Examples of Enhancements Examples will be given showing how each step is possible. Anyone can DIY enhancement and those ambitious enough can follow examples of the Big Brain and create the ultimate project.
Verifications of Enhancements We will cite letters of recognition and verification from observatories and professional astronomers indicating the techniques work in terms of 10X aperture gains.
The Gains from 10X Enhancement This section will project the possibilities of a grander exploration into the void and unknown, and she light on the discovery possible with massive diameter enhancements.
Existing Discoveries A review of previous discoveries made with 10X aperture enhancement will be reviewed.
Going Beyond 10X Constructing and developing methods that go beyond 10X will be examined.
The 10X Telescope Enhancement
Exactly what is Enhanced?
In the 10X telescope diameter enhancement, there are a series of telescope elements that can be effectively enhanced. Some enhancements are physical applications such as the coating on the mirror's surface while others may involve electronics, hardware, software, and processing. Each offer a degree of enhancement - some are 10X immediately and others are less than 10X. In the summation of more than one technique, it's possible to exceed 10X. Exceeding 10X may be reviewed at a later date.
In reviewing a list of enhancements possible, we see there are a large number of techniques. (see list of enhancements)
Overview List of Possible Telescope Enhancements that may or may not be Reviewed
Constructive Interference Enhancement For details, refer to post 1660 on the previous page. Constructive interference of light is the first enhancement reviewed. This details how a reflector telescope can have its mirror enhanced by special coating to reflect more light.
Ocular Optics Ocular Optics use refracting lens elements and can employ destructive coatings on surfaces where reflections need to be minimized, reduced and eliminated. This minimizes and prevents light loss at the ocular.
Charged Coupled Device CCDs offer solutions with cameras to enhance existing telescopes to reach greater limiting magnitudes
Incomplete Optics Resolution Acceleration Technique Based on Whole Mirror, Reconstructive Mirror, or Fragmented Mirror designs by Humanoido
Image Intensification Intensifiers use cascading electronics to see in darkness
Secondary Device Enhancer Enhancement takes place on secondary mirrors or other refracting and reflecting optics
Resolution Aperture Enhancement The technique of increasing resolution by doubling apertures and separation
Real Time Field Reconstruction A method of reconstructing the image to enhance brightness, contrast, resolution
Inventive Image Enhancement Methods of image enhancement using a new type of machine to be discussed
Speckled Technique Well known Speckle technique to increase results
Additive Surfaces One surface can have additive surfaces
Additive Imagery One image is added to another in the "darkroom phase"
Photo-Visual Well know, techniques developed by Humanoido at the Observatory, and the Association of Lunar and Planetary Observers
Cloning Duplication of optical collection agents, includes all various types of agents
Enhancement by Computer Data Reduction Data obtained from sensors are enhanced by computer data reduction techniques
Enhancement by Successive Aquisition Summing Technique Humanoido's techniques developed in the 1980s to increase light gain by use of two telescopes or one telescope used twice with successive image aquisition and image summing software developed on the Mac. 1 image was 1X while two images were 2X in terms of light bucketing process. Could take blank star field and turn it into thousands of stars.
...Another visit to the grocery Mart has found another piece Aluminized "polymer material."...This is an unfolded Lays potato chip bag turned inside out and cut carefully along the top and bottom and side. ....
A Lays potato chip bag?
You must be freakin kidding me!
Mister, you need to drag yourself up out of the snack food section, brush the Dorritos out of your hair, pluck the peanuts out of your peduncles, and get busy on something that has a snowball's chance of actually working someday!
The Lays potato chip bag worked well for numerous telescope primary mirror experiments after removing the salt and carefully brushing off the potato chip crumbs, though iIt took longer to remove the oil. Many discoveries were made about not only this material's physical attributes but the behavior and response of reflective plastic membranes in general for use as telescope mirrors.
Stretch One experiment examined the response of a material without any significant stretch. It appears smaller diameter mirrors experience more wrinkle and larger diameter less wrinkle near the circular edge. Material without stretch wants to remain flat and introduced curve also introduces distortion most notable at the edges. The edge distortion can take on the shape of wrinkles, sometime parallel in direction. Such distortion could be masked. It is proposed to automatically mask the out rim of the mirror. Another conclusion is to create larger mirrors with less edge distortion.
Curve Formation Another experiment involved the formation of a curve and examined the amount of distortion. The curve is not necessarily parabolic as elements to deepen the center zone do not exist unless artificially created. As observed, the curve crosses from center spherical to an outer ring differential. A spherical mirror is very useful if homogneous across the surface as the correction is not complex.
Diffusion Another experiment examined the reflectivity with image formation and began the study of the optical variable - "diffusion." It was discovered that mirrors with great diffusion can form images objects positioned close to the surface but not of objects placed at farther distances.
Whole Mirror VS Fragmented Mirror The final experiment introduced the new concept of whole mirror and fragmented mirror. More on this new idea will follow in another post. The chip bag made a 56cm fragmented mirror for study. This made a 22-inch mirror. Based on whole width of the material, a whole 32.5cm mirror (12.5 inches) was made.
Thanks for the link - this is very interesting and useful research. They mention several concepts which are useful in the type of work we are doing. Although the sources and formulas for the mixtures are not given, perhaps they can be located or the wheel could be reinvented. The research regarding the distance between the reflective elements agrees with our findings of stretching mirrors and diffuse mirrors.
...you need to drag yourself up out of the snack food section, brush the Dorritos out of your hair, pluck the peanuts out of your peduncles, and get busy on something that has a snowball's chance of actually working someday!
You will be happy to know the cerebral peduncles are now toothbrush clean. Tonight I went by taxi deep into the industrial section of Shanghai and found a store that specializes in materials. A professional 2-meter length roll of highly reflective and very thick aluminized polymer sheet was purchased. The cost was reasonable at US$9.24 and it will make a fragmented 2 meter telescope mirror (79-inch diameter), or two one-meter whole mirrors. There's plenty of this material available as the roll looks like it could be 150-feet long. I could go back for more.
The material has a high quality high resolution mirrored surface on both sides. Diffusion is minimal as the material passes the distance imaging test. It's possible to choose the side with the best coating and condition. This is a real bonus and may have additional applications of a two sided mirror. The initial length material at the beginning of the roll was rejected as it had a blackened section of the aluminum coating and some roll stretch marks. This was on the outer section of the full roll. The inner section which I purchased is excellent.
The substrate is very thick (though I currently have no way to measure this thickness, it may be compared to the number of sheets of 20 pound bond printer paper to get a rough estimate) and will make a much more stable telescope mirror, and a very large one if we decide not to cut up all the material into smaller mirrors. This will make a massive one meter telescope. But here's the catch 22. I'm located in a tiny top floor apartment with a big telescope mirror and no land available below - plus access for transportation is by narrow elevator, train, subway or taxi. Building a telescope that large in such a small space will be very challenging but not impossible.
How about a telescope design that collapses flat for transport and the mirror rolls up like a map or window shade? For shipping the mirror, even when rolled up, it's too large to fit into the largest luggage. Other options may be available.
The recent purchase of a double sided mirror raises a new question. Is it possible to use both sides of a telescope mirror? In this example, one side is concave and the other side is convex.
A giant convex mirror could image the entire night sky showing all horizon points, study galactic glow, gegenshine, zodiacal light, the shape of the galaxy, mapping of star clouds and nebular regio, the distribution of black matter, and numerous other studies.
1,800-Inch Telescope in a Roll Unroll Your Telescope Multiple Mirror by Mirror
The 150-foot foot roll of reflective substrate is 1,800 inches long by one meter wide. One meter is 39.3701 inches. This makes a roll of forty-six 1-meter mirrors. This can make a telescope with resolution equivalent to a 1,800-inch telescope. If a one meter mirror costs US$4.62 each, the 1,800 inch primary multiple mirror will cost (for the complete 150-foot roll of reflective substrate) US$212.52. I can probably get a discount for buying the entire roll.
Results are in for the first study examination of dry aluminized polymer substrate roll. The material is coated reflective aluminum on both sides and oversized to 2.2 meters (220cm or 86.6 inches). The material unrolls and exhibits electrostatic charge and collects dust in the given environment. The plastic must be carefully handled and scratches easily. If it is allowed to fold or twist, a permanent pinch point may form. A one meter mirror mount is being constructed for testing. The substrate roll will be cut, making a one meter mirror and a leftover section 1.2 meters.
Excellent find! Inflatables is another term for thin aluminized film formed by pressure and this is what we are working on and is likely the ultimate goal.
A negative pressure is applied to the back side while the front side has a positive pressure causing planar mirror deformation towards a sphere.
This study raises many applicable points and engages in exact research related to the Brain's ULT Ultra Large Telescope project. Introductory considerations are summarized below.
"...monolithic, but rolled, hyper-thin primary mirror..."
"we develop the rationale for ultralightweight, large-aperture camera systems."
"This is a high-risk, very high payoff project whose specific implementation is strongly dependent on the success of
a comprehensive technology development program."
"One would expect a membrane to inflate into a spherical surface, like a child's balloon. Unfortunately, when the edge is defined by a rigid ring, the actual surface is not a spherical surface, but an aspheric one, and one distorted in the opposite direction from the difference between a sphere and a paraboloid."
"Successful implementation of this program will enable cost savings of 10 to 100 times over
conventional space optics systems..."
"...and will enable the 25-meter-class space-optical systems previously thought to be impossible."
"Applications for...stretch technology..."
"NASA deployed an inflatable, 14-meter microwave, parabolic dish..."
"No experiment resulted in a near-parabolic inflated mirror."
"The obvious answer to the challenge of an inflatable mirror is to accept the surface that naturally results-and not insist on obtaining an aspheric or parabolic mirror."
Memory Erasing of a Large 2.2-Meter Mirror It's not as simple as anti-rolling
Thick rolled mirrors have the disadvantage of tenaciously taking on and remembering the characteristic shape of the roll. These roll diameters are ofter 10-inches to 16 inches, while the unrolled mirror has a diameter of one meter (about 40 inches) to 2.2 meters (86.6 inches) obviating the take-on shape of a smaller 10 to 16 inch periodic curvelet.
Laying out the substrate on a clean washed backing simply induced abrasion scratching during the process. It also picked up airborn dust. Rolling in the opposite direction to impart an anti-roll took on pinch marks due to the thick material being less manageable. Imparting an anti-roll applies substrate to substrate pressure and abrading against the surface and permanent scratching results along with paches of buffing marks.
Anti-rolling is not an effective solution to derolling a large 2.2 meter mirror. The recommendation is to lay the surface flat on a scrubbed floor with some edge weighting to curtail and stabilize the material, then cut the material into a circle, and lay the circle across the mirrror mount with the curve tendancy facing down, then attach clamping and sealing at the perimeter making the mirror as flat as possible before applying forming pressure.
In the future, the roll should be held suspended above the mirror mounting by two people and slowly and methodically unrolled from the one edge of the mount to the other and then cut based on the circular shape of the mount. The curve can face down during this process and once complete, the mirror can be flipped to curve up if necessary. More tests are needed to determine this exact configuration.
In any case, this process is very challenging, and the recommendation is to practice on less expensive material first. This 2.2-meter mirror is considered a less expensive research mirror fragment of this project's much larger mirror goal, and it will facilitate experimentation and study so induced scratching, buffing, pinching, curving, dust collectives, and other anomalies will be good references to solve before constructing the ultra telescope.
Mirror Polymer Substrate Anti Curl Heat Experiment
Experiment Location On the cutoff side of the reflective mirror substrate polymer roll, several parallel fold stretch marks an a very irregular cut exist. This is the perfect location to run the anti curl heat test with no need to cut off the material at this time.
Heat Machine Heat is provided to the small section on the mirror by using a hair dryer.
Applications to Small Mirrors Applications for small mirrors can use one or more hair dryers.
Applications to Large Mirrors Applications for one meter mirrors can use a tall vertical space heater to distribute large even areas of heat at one time. If using a radiative heater, make sure it has a convective feature.
Equipment Use hair dryers, space heaters
Do not use flame or gas heaters, torches, microwave ovens
Results Application of heat was provided to a section of the aluminized polymer substrate with a hair dryer on the hottest 1875 watt setting. When the materal was fully heated, it became flat and flexible and pliable, easy to shape and handle. When the heat was removed, the material cooled and was again susceptible to curve.
Cooling a small section removed the curve but the adjacent curve still affected the piece that was originally heated. It will be necessary to cut off a piece of the material and heat it without the influences of adjacent unheated areas.
A 17cm section (good for making a 6-inch telescope mirror) section was cut off. The large curl of this section was 4cm above the baseline. Heat was applied and the material became soft, pliable, maleable, and easy to handle. Heat was continued until forming made the mirror flat. The heat was removed and the behavior of the mirror polymer substrate was observed as it cooled. The edge curled up again.
This time the substrate was set on a large glass table top and heated at the highest heat level. The material set perfectly flat and conformed to the flat table top. The heat was removed and the substrated cooled. After cooling, the curl came back and was measured to be the same 4cm above the planar baseline.
In conclusion, to form the mirror into its spherical surface, one will need to heat it to a planar state, then attach the edges to the mounting, then deform the mirror into the curve under heat and pressure and remove the source of heat. The pressure must be maintained as the mirror is allowed to cool and as the mirror is in use.
Based on the thickness of a single sheet of 20 pound copy paper at 4 mil, the substrate has comparable thickness to three sheets of paper, or approximately 12 MILs.
Wikipedia
Paper thickness, or caliper, is a common measurement specified and required for certain printing applications. Since a paper's density is typically not directly known or specified, the thickness of any sheet of paper cannot be calculated by any method. Instead, it is measured and specified separately as its caliper. However, paper thickness for most typical business papers might be similar across comparable brands. If thickness is not specified for a paper in question, it must be either measured or guessed based on a comparable paper's specification. Caliper is usually measured in micrometres (1/1000 of a mm), or in the United States also in mils. (1 mil = 0.001 inch = 25.4 µm)
http://inksupply.helpserve.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=68
[h=3]How is the weight of a paper specified Paper weights are expressed as either pounds, grams per square meter (GSM), or in MILS.[/h]Let's take the easy ones first. A MIL is 1/1000 of an inch or 0.001 inches. It is a measurement of the thickness of the paper being measured, sometimes called the Caliper. Mils are usually measured using a Micrometer, which is a tool found in all machine shops. Copier paper is typically 4 mils thick. Business cards are about 11 mils thick. A human hair is about 3 mils thick. Our glossy papers come in 3 thicknesses, 6, 8 and 10 mils. Photographs are printed on 8 mil paper. The thickness in MILS or Caliper says nothing about the quality of the paper or the coatings, just the thickness.
Another Optical Telescope Consideration
Going Grade A+ Optics
This involves laying down the cash for extended labor and skill, to the finest optician in the world, and having one of the finest grade A+ telescope mirrors made, let's say of medium-large aperture around 24-inch diameter. Then the Brain builds the telescope and proceeds to enhance the mirror-telescope combination to amplify it from 10 to 20X thus producing the equivalent telescope of 240 to 480-inch aperture. The F4 speed would create a manageable 8-foot long tube assembly, it would still be portable, and it could be transported to the some of the darkest skies in the world for cutting edge astronomy. The same research to the boundaries of the Universe would be possible. However, such fine optics can take up to 2 years to make and the 10X to 20X amplification equipment would come with a price. Any comments on this approach?
...This involves laying down the cash for extended labor and skill, to the finest optician in the world, and having one of the finest grade A+ telescope mirrors made... Any comments on this approach?
As for telescopes, you can get started with fundamentals by purchasing very good mirrors and then assemble the scope in your apartment with relatively simple tools. An oldie but goodie book is Texereau's http://www.willbell.com/tm/tm3.htm. Of course you can also learn a lot by just buying a scope ready-made and tinker with it. When advancing technology, I think it's important to develop a strong intuition about whatever you're working on, and to develop that intuition (I think) requires lots of hands-on experience, learning a multitude of ways of not how to solve the problem. So if you want to push the envelope on what's possible, I think you first need to learn how to do basic things yourself.
In my humble opinion, it's possible to achieve cutting edge developments via DIY but it requires learning the basics first. You know, we all must learn to walk before we can run. And learning theory is just one aspect of it - there is the practical side, too: the all-too-often aggravating nuts and bolts of things. Flitting from one whimsical thing to another might make for fun science fiction and keep the puer aeternus happily at play, but it rarely results in much more than a pile of useless scribbles, notes and dreams.
But if you want to develop something totally new, then, if I were you, I would focus on a single, very specific component or material property of a specific telescope design and dedicate myself for the 5-10 years that a typical breakthrough requires. Hire a small army of people to work with you, or form a local club or create a local hackerspace or something of that sort and get other people charged up about your project. But you first need to identify what exactly your project really is, what exactly are you trying to achieve, then stick with it for more than a month or two.
If you want to show off your money, You should have the optics made for you...
If you want to show off your skills, You should prolly keep plugging away with your own construction...
Of course you could do both, and see if you could keep pace with the optician...
Comments
Duane, I did a lot of work with spin casting resin telescope mirrors in the 1970s when I made several 52 inch telescopes. I began casting mirrors again about 2 years ago for a Parallax project. The posts are still there. Reflective coating a resin mirror is not a problem. It can be silvered or aluminized. The process of silvering can be dangerous if the mix rises above 80-degrees. It will explode like TNT. It also tarnishes in about 6 months.
To aluminize a mirror, find a center with a vessel large enough to contain the mirror. The process works well as the aluminum is deposited as a mist evaporated onto the surface. The are no known proplems of outgasing during aluminizing. Outgassing may occur during resin curing. Resin mirrors and optics are aluminized all the time. In the 1970s, the companies were aluminizing mirrors as large as 72 inches. With popularity of big Dobsonians, coating will be even more easy for large mirrors.
Bubbles can develop when mixing the agent. Spinning the mix by centrifuge will help get rid of bubbles. The biggest challenge is not bubbles but mold shrinkage and dealing with astigmatic sections.
Yes I have some photos but it will be a while as they are on the other computer in the other country. I can post when this travel period is complete. In the mean time, I can say resin telescope mirrors will perform optically and will meet my requirements for ultra large low cost telescope mirrors.
I'm very excited about making the ULT. I did some number crunching and the fast curve of a mirror that's 5 to 40 feet in diameter could provide significant light gathering power to do some remarkable studies and maybe make a new discovery.
Reflective Mylar & Polymer Material
In post 1645 we examined a 5.5 inch section of aluminized material from the food store. Results from this study and experiment are in. It is learned that the ability to stretch is an important function of the material in making a reflective telescope mirror. The reason for this is all about the curve and material thickness plus size dimensions. When a smaller (6-inch diameter or less) material which is thicker MIL material (8 or more, estimated) is placed over an aperture, the material stays relatively flat, and when the spherical curve is imparted, the edges must form rippled points of stress. This happens when the material cannot stretch enough to form the curve without deformation.
The solution may encompass several approaches.
Use larger diameter mirrors and automatically mask the outer edge where deformation results
Use thinner MIL thickness material to minimize or prevent wrinkling
Stretch the material so that a telescope mirror shape results
The size diameter of a telescope mirror is extremely significant. It determines the telescope's resolution, ability to collect light and do useful science. One thing the field of telescope astronomy is lacking is the class of various telescopes and mirror sizes by definition. At least for the Big Brain, definitions should be established.
Some terminology is already in effect. For example, the Brain is working towards the ULT Ultra Large Telescope. In the past, Humanoido worked on the VLT Project. Here's a preliminary idea of terms. Some size ranges may overlap. All sizes are diameters given in inches unless otherwise noted.
Small Size - 1, 2, 3, 4.25, 6, 8
Standard Size - 3, 4.25, 6, 8, 10, 12.5
Big Dob - 14, 16, 18, 20, 24, 30 to 43
Large Telescope - 18 to 50
Very Large Telescope VLT - 30 to 60
Ultra Large Telescope ULT - 60, 72, 80, 100, 120, 200 (4 feet to 20 feet)
Spectacularly Giant Telescope SGT - 500, 1000 (20 feet to 100 feet)
The Brain is working on several different types of telescopes. The technology overlaps. Developments for one type of telescope may often be applied to others. Here is a small list of telescope types the Brain is developing and studying.
Dobsonian - Design by John Dobson
Folded Newtonian
Fly Eye Refracting Telescope
Schmidt - Fast Telescope Camera Design
RFT - Rich Field Telescope
LFT - Long Focal Length Telescope
Resin Spin Cast
Fragmented Mirror Telescope
Slumped Substrate
Liquid Oil Telescope
H2O Water Drop Refractor Telescope
Aluminized Mylar Pneumatic Telescope
Ultra Thin Mirror (glass)
MMT Multiple Mirror Telescope
MLT Multiple Lens Telescope
ET's - Electronic Telescopes
AET - Artificially Enhanced Telescope
Spherical Telescope
Encapsulated Membrane Telescope
Highest Precision Parabolic Glass
Another visit to the grocery Mart has found another piece Aluminized "polymer material." The material is about 12 x 18 inches which will make a 12 inch mirror or a fragmented 18 inch mirror. This is an unfolded Lays potato chip bag turned inside out and cut carefully along the top and bottom and side. The material is estimated two or 3 times thinner than the peanut mirror. It appears this material also will not visibly stretch.
-Phil
World Expansion
The Brain now has telescopes in 4 labs in 3 countries and work has proceeded in at least 7 countries and 12 cities. In special cases, work proceeded over the North Pole and the Rain Forrest. Expansion into China Lab 4 includes water lenses and telescopes, and various reflective material mirrors. Taiwan Lab 3 has the Multiple Lens Telescope and Telescope Systems Design. Lab 2 has resin cast. USA Lab 1 has glass and spin mirrors. The Dob from Lab 4 is transferred to Lab 2 which has the GOTO computerized telescope. Lab 2 now has the most powerful computers. MSP was developed in Labs 2 & 3. Lab 4 planned & completed the trip into space. Lab 1 will host the ULT. Lab 2 had the 1st rocket launch & developed the airport, flying two helicopters. Lab 3 did the first flight camera tests.
Stretching, Reflectivity, Enhancement, Contrast, Image Brightness
Phil, I agree with you, it does seem that's the obvious result. Scientists studying this effect found the vapor aluminizing deposits molecules into the substrate which becomes part of it. When the substrate is stretched, the reflective aluminum "stretches along with it." The reflectivity won't change, only the distance between the molecules will change.
This also raises some questions. Does the new molecular lattice deviate its orientation alignment? If yes, then I think reflectivity could be reduced.
Another question, can the molecular lattice be stretched an exact amount to create constructive interference of light waves? If yes, then the surface could actually be enhanced and would increase light reflectivity in a manner similar to enhanced mirror dielectric coatings.
Enhanced mirrors can perform much like larger mirrors, for example, a 12.5 inch is typically said to perform like a 16 inch. Perhaps we could just stretch our mirror by a certain amount to enhance it. But stretch it too little or the wrong amount could induce destructive interference for the opposite result.
Will the spherical or parabolic shape of the mirror significantly change upon stretching and alter the light focus? This could reduce contrast and image brightness by increasing wavefront error, even if reflectivity remains a constant.. More tests and experiments will be needed to answer many of these questions.
Telescope Mirror Enhancement Method
In the previous post we introduced the topic of enhanced mirrors. In Physics and Optics class, we derived the equation for the constructive interference of light as reflected on a mirror's surface. By adjusting the coating layer thickness, the constructive interference condition is met. This is opposed to destructive interference of reflected light which is useful for minimizing lens reflections but not useful for enhancing a mirrors reflective ability.
The diagram for this film interference is here.
http://en.wikipedia.org/wiki/File:Thin_film_interference_-_soap_bubble.gif
The forumla for the constructive interference of light is here.
http://en.wikipedia.org/wiki/Thin-film_interference
Discussion here.
http://en.wikipedia.org/wiki/Thin-film_interference
An anti-reflection coating eliminates reflected light and maximizes transmitted light in an optical system. A film is designed such that reflected light produces destructive interference and transmitted light produces constructive interference for a given wavelength of light. In the simplest implementation of such a coating, the film is created so that its optical thickness
dncoating
is a quarter-wavelength of the incident light and its refractive index is greater than the index of air and less than the index of glass.
nair < ncoating < nglassd = λ / (4ncoating)
A 180° phase shift will be induced upon reflection at both the top and bottom interfaces of the film because
nair < ncoating and ncoating < nglass.
The equations for interference of the reflected light are:
for constructive interference
If the optical thickness
dncoating
is equal to a quarter-wavelength of the incident light and if the light strikes the film at normal incidence
(θ2 = 0)
the reflected waves will be completely out of phase and will destructively interfere.
Further reduction in reflection is possible by adding more layers, each designed to match a specific wavelength of light. It should also be noted that interference of transmitted light will be completely constructive for these films.
Propeller-Driven Brain's Progression into 10X Telescope Enhancement
In this continuing series project, the Brain will outline methods, tried and true, that make an existing reflector telescope enhanced, by the sum of several techniques, to increase its effective diameter to at least ten times larger.
The Brain says, "If you don't buy into the idea, now is the time to get out of the kitchen if you can't stand the heat." For those who are open minded and wish to gain from the benefits of enhancement, welcome to the future of new telescope technology.
INTRODUCTION Make a telescope mirror perform like a much larger mirror. In this continuing series of investigations of concatenating techniques, the Brain will show various methodology to enhance a telescope and make it perform like one that's ten times larger. This is one step of several that will add together to enhance a telescope mirror to increase its effective diameter by a factor of approximately ten or more. The results of this can open up new benefits by extending the range of existing telescopes, and in some cases, new science.
This will be useful in converting the ULT Ultra Large Telescope from its chosen diameter, let's say 100 inches, to that of a 1,000 inch telescope. In the case of a larger 200 inch mirror or MMT, the effective aperture becomes 2,000 inches in diameter. In the case of other ultra large optics, a 72 inch becomes a 720 inch.
The Brain's goal is in reaching new levels of science and technology, best accomplished with telescope tools that have the necessary power, not only in terms of incredible light gathering ability, but resolution and as will be shown, other effects of remarkable enhancements.
The objective is to created the right tool for the right job. In the case of the Big Brain, it has big requirements. But size, weight, cost, and time are all factors the Brain must minimize. One way to minimize these factors while ramping up benefits is through telescope enhancement.
Types of Enhancements
Various methods of enhancing a telescope mirror and its image will be introduced.
Examples of Enhancements
Examples will be given showing how each step is possible. Anyone can DIY enhancement and those ambitious enough can follow examples of the Big Brain and create the ultimate project.
Verifications of Enhancements
We will cite letters of recognition and verification from observatories and professional astronomers indicating the techniques work in terms of 10X aperture gains.
The Gains from 10X Enhancement
This section will project the possibilities of a grander exploration into the void and unknown, and she light on the discovery possible with massive diameter enhancements.
Existing Discoveries
A review of previous discoveries made with 10X aperture enhancement will be reviewed.
Going Beyond 10X
Constructing and developing methods that go beyond 10X will be examined.
Exactly what is Enhanced?
In the 10X telescope diameter enhancement, there are a series of telescope elements that can be effectively enhanced. Some enhancements are physical applications such as the coating on the mirror's surface while others may involve electronics, hardware, software, and processing. Each offer a degree of enhancement - some are 10X immediately and others are less than 10X. In the summation of more than one technique, it's possible to exceed 10X. Exceeding 10X may be reviewed at a later date.
In reviewing a list of enhancements possible, we see there are a large number of techniques. (see list of enhancements)
Overview List of Possible Telescope Enhancements that may or may not be Reviewed
Constructive Interference Enhancement
For details, refer to post 1660 on the previous page. Constructive interference of light is the first enhancement reviewed. This details how a reflector telescope can have its mirror enhanced by special coating to reflect more light.
Ocular Optics
Ocular Optics use refracting lens elements and can employ destructive coatings on surfaces where reflections need to be minimized, reduced and eliminated. This minimizes and prevents light loss at the ocular.
Charged Coupled Device
CCDs offer solutions with cameras to enhance existing telescopes to reach greater limiting magnitudes
Incomplete Optics Resolution Acceleration Technique
Based on Whole Mirror, Reconstructive Mirror, or Fragmented Mirror designs by Humanoido
Image Intensification
Intensifiers use cascading electronics to see in darkness
Secondary Device Enhancer
Enhancement takes place on secondary mirrors or other refracting and reflecting optics
Resolution Aperture Enhancement
The technique of increasing resolution by doubling apertures and separation
Real Time Field Reconstruction
A method of reconstructing the image to enhance brightness, contrast, resolution
Inventive Image Enhancement
Methods of image enhancement using a new type of machine to be discussed
Speckled Technique
Well known Speckle technique to increase results
Additive Surfaces
One surface can have additive surfaces
Additive Imagery
One image is added to another in the "darkroom phase"
Photo-Visual
Well know, techniques developed by Humanoido at the Observatory, and the Association of Lunar and Planetary Observers
Cloning
Duplication of optical collection agents, includes all various types of agents
Enhancement by Computer Data Reduction
Data obtained from sensors are enhanced by computer data reduction techniques
Enhancement by Successive Aquisition Summing Technique
Humanoido's techniques developed in the 1980s to increase light gain by use of two telescopes or one telescope used twice with successive image aquisition and image summing software developed on the Mac. 1 image was 1X while two images were 2X in terms of light bucketing process. Could take blank star field and turn it into thousands of stars.
Computer Image Processing
Image light curve enhancements
Cascading Physics
Hardware does enhancing
Electronic Applicatory Device
Electronic devices enhance
Other
A Lays potato chip bag?
You must be freakin kidding me!
Mister, you need to drag yourself up out of the snack food section, brush the Dorritos out of your hair, pluck the peanuts out of your peduncles, and get busy on something that has a snowball's chance of actually working someday!
Here, have a look at this.
http://arxiv.org/pdf/physics/0301053
A Good Mix of Discoveries
The Lays potato chip bag worked well for numerous telescope primary mirror experiments after removing the salt and carefully brushing off the potato chip crumbs, though iIt took longer to remove the oil. Many discoveries were made about not only this material's physical attributes but the behavior and response of reflective plastic membranes in general for use as telescope mirrors.
Stretch
One experiment examined the response of a material without any significant stretch. It appears smaller diameter mirrors experience more wrinkle and larger diameter less wrinkle near the circular edge. Material without stretch wants to remain flat and introduced curve also introduces distortion most notable at the edges. The edge distortion can take on the shape of wrinkles, sometime parallel in direction. Such distortion could be masked. It is proposed to automatically mask the out rim of the mirror. Another conclusion is to create larger mirrors with less edge distortion.
Curve Formation
Another experiment involved the formation of a curve and examined the amount of distortion. The curve is not necessarily parabolic as elements to deepen the center zone do not exist unless artificially created. As observed, the curve crosses from center spherical to an outer ring differential. A spherical mirror is very useful if homogneous across the surface as the correction is not complex.
Diffusion
Another experiment examined the reflectivity with image formation and began the study of the optical variable - "diffusion." It was discovered that mirrors with great diffusion can form images objects positioned close to the surface but not of objects placed at farther distances.
Whole Mirror VS Fragmented Mirror
The final experiment introduced the new concept of whole mirror and fragmented mirror. More on this new idea will follow in another post. The chip bag made a 56cm fragmented mirror for study. This made a 22-inch mirror. Based on whole width of the material, a whole 32.5cm mirror (12.5 inches) was made.
The material has a high quality high resolution mirrored surface on both sides. Diffusion is minimal as the material passes the distance imaging test. It's possible to choose the side with the best coating and condition. This is a real bonus and may have additional applications of a two sided mirror. The initial length material at the beginning of the roll was rejected as it had a blackened section of the aluminum coating and some roll stretch marks. This was on the outer section of the full roll. The inner section which I purchased is excellent.
The substrate is very thick (though I currently have no way to measure this thickness, it may be compared to the number of sheets of 20 pound bond printer paper to get a rough estimate) and will make a much more stable telescope mirror, and a very large one if we decide not to cut up all the material into smaller mirrors. This will make a massive one meter telescope. But here's the catch 22. I'm located in a tiny top floor apartment with a big telescope mirror and no land available below - plus access for transportation is by narrow elevator, train, subway or taxi. Building a telescope that large in such a small space will be very challenging but not impossible.
How about a telescope design that collapses flat for transport and the mirror rolls up like a map or window shade? For shipping the mirror, even when rolled up, it's too large to fit into the largest luggage. Other options may be available.
The recent purchase of a double sided mirror raises a new question. Is it possible to use both sides of a telescope mirror? In this example, one side is concave and the other side is convex.
A giant convex mirror could image the entire night sky showing all horizon points, study galactic glow, gegenshine, zodiacal light, the shape of the galaxy, mapping of star clouds and nebular regio, the distribution of black matter, and numerous other studies.
How can both sides be used at the same time?
Unroll Your Telescope Multiple Mirror by Mirror
The 150-foot foot roll of reflective substrate is 1,800 inches long by one meter wide. One meter is 39.3701 inches. This makes a roll of forty-six 1-meter mirrors. This can make a telescope with resolution equivalent to a 1,800-inch telescope. If a one meter mirror costs US$4.62 each, the 1,800 inch primary multiple mirror will cost (for the complete 150-foot roll of reflective substrate) US$212.52. I can probably get a discount for buying the entire roll.
Results are in for the first study examination of dry aluminized polymer substrate roll. The material is coated reflective aluminum on both sides and oversized to 2.2 meters (220cm or 86.6 inches). The material unrolls and exhibits electrostatic charge and collects dust in the given environment. The plastic must be carefully handled and scratches easily. If it is allowed to fold or twist, a permanent pinch point may form. A one meter mirror mount is being constructed for testing. The substrate roll will be cut, making a one meter mirror and a leftover section 1.2 meters.
http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/19145/1/98-0391.pdf
Aluminized Film
Excellent find! Inflatables is another term for thin aluminized film formed by pressure and this is what we are working on and is likely the ultimate goal.
A negative pressure is applied to the back side while the front side has a positive pressure causing planar mirror deformation towards a sphere.
This study raises many applicable points and engages in exact research related to the Brain's ULT Ultra Large Telescope project. Introductory considerations are summarized below.
"...monolithic, but rolled, hyper-thin primary mirror..."
"we develop the rationale for ultralightweight, large-aperture camera systems."
"This is a high-risk, very high payoff project whose specific implementation is strongly dependent on the success of
a comprehensive technology development program."
"One would expect a membrane to inflate into a spherical surface, like a child's balloon. Unfortunately, when the edge is defined by a rigid ring, the actual surface is not a spherical surface, but an aspheric one, and one distorted in the opposite direction from the difference between a sphere and a paraboloid."
"Successful implementation of this program will enable cost savings of 10 to 100 times over
conventional space optics systems..."
"...and will enable the 25-meter-class space-optical systems previously thought to be impossible."
"Applications for...stretch technology..."
"NASA deployed an inflatable, 14-meter microwave, parabolic dish..."
"No experiment resulted in a near-parabolic inflated mirror."
"The obvious answer to the challenge of an inflatable mirror is to accept the surface that naturally results-and not insist on obtaining an aspheric or parabolic mirror."
It's not as simple as anti-rolling
Thick rolled mirrors have the disadvantage of tenaciously taking on and remembering the characteristic shape of the roll. These roll diameters are ofter 10-inches to 16 inches, while the unrolled mirror has a diameter of one meter (about 40 inches) to 2.2 meters (86.6 inches) obviating the take-on shape of a smaller 10 to 16 inch periodic curvelet.
Laying out the substrate on a clean washed backing simply induced abrasion scratching during the process. It also picked up airborn dust. Rolling in the opposite direction to impart an anti-roll took on pinch marks due to the thick material being less manageable. Imparting an anti-roll applies substrate to substrate pressure and abrading against the surface and permanent scratching results along with paches of buffing marks.
Anti-rolling is not an effective solution to derolling a large 2.2 meter mirror. The recommendation is to lay the surface flat on a scrubbed floor with some edge weighting to curtail and stabilize the material, then cut the material into a circle, and lay the circle across the mirrror mount with the curve tendancy facing down, then attach clamping and sealing at the perimeter making the mirror as flat as possible before applying forming pressure.
In the future, the roll should be held suspended above the mirror mounting by two people and slowly and methodically unrolled from the one edge of the mount to the other and then cut based on the circular shape of the mount. The curve can face down during this process and once complete, the mirror can be flipped to curve up if necessary. More tests are needed to determine this exact configuration.
In any case, this process is very challenging, and the recommendation is to practice on less expensive material first. This 2.2-meter mirror is considered a less expensive research mirror fragment of this project's much larger mirror goal, and it will facilitate experimentation and study so induced scratching, buffing, pinching, curving, dust collectives, and other anomalies will be good references to solve before constructing the ultra telescope.
Got a heat gun?
http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/33720/1/94-0447.pdf
Experiment Location
On the cutoff side of the reflective mirror substrate polymer roll, several parallel fold stretch marks an a very irregular cut exist. This is the perfect location to run the anti curl heat test with no need to cut off the material at this time.
Heat Machine
Heat is provided to the small section on the mirror by using a hair dryer.
Applications to Small Mirrors
Applications for small mirrors can use one or more hair dryers.
Applications to Large Mirrors
Applications for one meter mirrors can use a tall vertical space heater to distribute large even areas of heat at one time. If using a radiative heater, make sure it has a convective feature.
Equipment
Use hair dryers, space heaters
Do not use flame or gas heaters, torches, microwave ovens
Results
Application of heat was provided to a section of the aluminized polymer substrate with a hair dryer on the hottest 1875 watt setting. When the materal was fully heated, it became flat and flexible and pliable, easy to shape and handle. When the heat was removed, the material cooled and was again susceptible to curve.
Cooling a small section removed the curve but the adjacent curve still affected the piece that was originally heated. It will be necessary to cut off a piece of the material and heat it without the influences of adjacent unheated areas.
A 17cm section (good for making a 6-inch telescope mirror) section was cut off. The large curl of this section was 4cm above the baseline. Heat was applied and the material became soft, pliable, maleable, and easy to handle. Heat was continued until forming made the mirror flat. The heat was removed and the behavior of the mirror polymer substrate was observed as it cooled. The edge curled up again.
This time the substrate was set on a large glass table top and heated at the highest heat level. The material set perfectly flat and conformed to the flat table top. The heat was removed and the substrated cooled. After cooling, the curl came back and was measured to be the same 4cm above the planar baseline.
In conclusion, to form the mirror into its spherical surface, one will need to heat it to a planar state, then attach the edges to the mounting, then deform the mirror into the curve under heat and pressure and remove the source of heat. The pressure must be maintained as the mirror is allowed to cool and as the mirror is in use.
Based on the thickness of a single sheet of 20 pound copy paper at 4 mil, the substrate has comparable thickness to three sheets of paper, or approximately 12 MILs.
Wikipedia
Paper thickness, or caliper, is a common measurement specified and required for certain printing applications. Since a paper's density is typically not directly known or specified, the thickness of any sheet of paper cannot be calculated by any method. Instead, it is measured and specified separately as its caliper. However, paper thickness for most typical business papers might be similar across comparable brands. If thickness is not specified for a paper in question, it must be either measured or guessed based on a comparable paper's specification. Caliper is usually measured in micrometres (1/1000 of a mm), or in the United States also in mils. (1 mil = 0.001 inch = 25.4 µm)
http://inksupply.helpserve.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=68
[h=3]How is the weight of a paper specified
Paper weights are expressed as either pounds, grams per square meter (GSM), or in MILS.[/h]Let's take the easy ones first. A MIL is 1/1000 of an inch or 0.001 inches. It is a measurement of the thickness of the paper being measured, sometimes called the Caliper. Mils are usually measured using a Micrometer, which is a tool found in all machine shops. Copier paper is typically 4 mils thick. Business cards are about 11 mils thick. A human hair is about 3 mils thick. Our glossy papers come in 3 thicknesses, 6, 8 and 10 mils. Photographs are printed on 8 mil paper. The thickness in MILS or Caliper says nothing about the quality of the paper or the coatings, just the thickness.
Going Grade A+ Optics
This involves laying down the cash for extended labor and skill, to the finest optician in the world, and having one of the finest grade A+ telescope mirrors made, let's say of medium-large aperture around 24-inch diameter. Then the Brain builds the telescope and proceeds to enhance the mirror-telescope combination to amplify it from 10 to 20X thus producing the equivalent telescope of 240 to 480-inch aperture. The F4 speed would create a manageable 8-foot long tube assembly, it would still be portable, and it could be transported to the some of the darkest skies in the world for cutting edge astronomy. The same research to the boundaries of the Universe would be possible. However, such fine optics can take up to 2 years to make and the 10X to 20X amplification equipment would come with a price. Any comments on this approach?
http://www.gammapc.com/gammascopes.html
http://spie.org/x26677.xml?ArticleID=x26677
http://www.iceinspace.com.au/forum/archive/index.php/t-62744.html
http://books.google.com.hk/books?id=sEyCQEqLAnIC&pg=PA15&lpg=PA15&dq=mylar+mirror+telescope&source=bl&ots=ytoLDTW1ud&sig=zi4pWUftDD_tNcEQXal6a5xHcwk&hl=en&ei=6cDATuunK7GaiQeQ5YnxBA&sa=X&oi=book_result&ct=result&resnum=3&ved=0CDAQ6AEwAjgK#v=onepage&q=mylar mirror telescope&f=false
As for telescopes, you can get started with fundamentals by purchasing very good mirrors and then assemble the scope in your apartment with relatively simple tools. An oldie but goodie book is Texereau's http://www.willbell.com/tm/tm3.htm. Of course you can also learn a lot by just buying a scope ready-made and tinker with it. When advancing technology, I think it's important to develop a strong intuition about whatever you're working on, and to develop that intuition (I think) requires lots of hands-on experience, learning a multitude of ways of not how to solve the problem. So if you want to push the envelope on what's possible, I think you first need to learn how to do basic things yourself.
In my humble opinion, it's possible to achieve cutting edge developments via DIY but it requires learning the basics first. You know, we all must learn to walk before we can run. And learning theory is just one aspect of it - there is the practical side, too: the all-too-often aggravating nuts and bolts of things. Flitting from one whimsical thing to another might make for fun science fiction and keep the puer aeternus happily at play, but it rarely results in much more than a pile of useless scribbles, notes and dreams.
But if you want to develop something totally new, then, if I were you, I would focus on a single, very specific component or material property of a specific telescope design and dedicate myself for the 5-10 years that a typical breakthrough requires. Hire a small army of people to work with you, or form a local club or create a local hackerspace or something of that sort and get other people charged up about your project. But you first need to identify what exactly your project really is, what exactly are you trying to achieve, then stick with it for more than a month or two.
If you want to show off your skills, You should prolly keep plugging away with your own construction...
Of course you could do both, and see if you could keep pace with the optician...
-Tommy
And here's one big improvement, making a projector with a laser pointer. Check that video, cool stuff!
http://makeprojects.com/Project/Laser-Projection-Microscope/413/1