Solid primary mirrors have to sustain their own weight and not deform under gravity, which limits the maximum size for a single piece primary mirror.

Segmented mirror configurations are used to get around the size limitation on single primary mirrors.

For example, the Giant Magellan Telescope will have seven 8. 4 meter primary mirrors, with the resolving power equivalent to a optical aperture.

The largest optical telescope in the world as of 2009 to use a non-segmented single-mirror as its primary mirror is the 8. 2 m ( 8. 7 yards ) Subaru telescope of the National Astronomical Observatory of Japan, located in Mauna Kea Observatory on Hawaii since 1997 ; however, this is not the largest diameter single mirror in a telescope, the U. S ./ German / Italian Large Binocular Telescope has two 8. 4 m ( 9. 2 yards ) mirrors ( which can be used together for interferometric mode ).

Both of these are smaller than the 10 m segmented primary mirrors on the two Keck telescope.

He started building his own reflecting telescopes and would spend up to 16 hours a day grinding and polishing the speculum metal primary mirrors.

Because of the poor reflectivity of the speculum mirrors of that day, Herschel eliminated the small diagonal mirror of a standard newtonian reflector from his design and tilted his primary mirror so he could view the formed image directly.

Bottom center is the non-rotating primary solar mirror, which reflects sunlight onto the angled ring of secondary mirrors around the hub.

The telescope's primary reflecting mirrors are a pair of Gregorian 1. 4m x 1. 6m dishes ( facing opposite directions ), that focus the signal onto a pair of 0. 9m x 1. 0m secondary reflecting mirrors.

In the case of the Keck each of the primary mirrors is composed of 36 hexagonal segments that work together as a single unit.

The radii of curvature of the primary and secondary mirrors, respectively, in a two-mirror Cassegrain configuration are

Historically, primary mirrors were quite thick in order to maintain the correct surface figure in spite of forces tending to deform it, like

The adult basically resembles a small European Herring Gull, the most noticeable differences being the short stubby red bill and " string of pearls " white wing primary tips, rather than the large " mirrors " of some other species.

There are three primary types of optical telescope: Refractors which use lenses ( dioptrics ), reflectors which use mirrors ( catoptrics ), and catadioptric telescopes which use both lenses and mirrors in combination.

Some telescopes use primary mirrors which are made differently.

The Ritchey – Chrétien telescope, invented by George Willis Ritchey and Henri Chrétien in the early 1910s, is a specialized Cassegrain reflector which has two hyperbolic mirrors ( instead of a parabolic primary ).

A variant of the Cassegrain, the Schiefspiegler telescope (" skewed " or " oblique reflector "), which uses tilted mirrors to avoid the secondary mirror casting a shadow on the primary.

The coudé focus was widely used in large telescopes built in most of the Twentieth Century, since limits on optical design and fabrication required high-resolution spectrographs in particular to have large collimating mirrors ( ideally with the same diameter as the telescope's primary mirror ) and very long focal lengths.

They can be used in various ways, including ( after being silvered ) as primary mirrors in reflecting telescopes.

Once this photon beam passes through the film frame, it encounters a series of dichroic mirrors which separate the image into its primary red, green and blue components.

Steward also has one of the few facilities in the world that can cast and figure the very large primary mirrors used in telescopes built in the past decade.

If Af are the projections associated with the primary decomposition of T, then each Af is a polynomial in T, and accordingly if a linear operator U commutes with T then U commutes with each of the Af, i.e., each subspace Af is invariant under U.

The number of electrons in each element's electron shells, particularly the outermost valence shell, is the primary factor in determining its chemical bonding behavior.

The relative size of each atom in the mix plays a primary role in determining which mechanism will occur.

That way each hill would be covered with a single, primary color which represented its spiritual value.

The primary areas in which the charity is now carrying on programs to achieve its charitable purposes, ranked according to the percentage of time and resources devoted to each program area follow:

The alpha component may be used to blend to red, green and blue components equally, as in 32-bit RGBA, or, alternatively, there may be three alpha values specified corresponding to each of the primary colors for spectral color filtering.

The primary areas in which the charity is now carrying on programs to achieve its charitable purposes, ranked according to the percentage of time and resources devoted to each program area follow:

* primary suspension via a coil spring and damper mounted on each axle

The books that were influential in the early development of computational quantum chemistry include Linus Pauling and E. Bright Wilson's 1935 Introduction to Quantum Mechanics – with Applications to Chemistry, Eyring, Walter and Kimball's 1944 Quantum Chemistry, Heitler's 1945 Elementary Wave Mechanics – with Applications to Quantum Chemistry, and later Coulson's 1952 textbook Valence, each of which served as primary references for chemists in the decades to follow.

Unlike the primary wall, the microfibrils are aligned mostly in the same direction, and with each additional layer the orientation changes slightly.

The primary and secondary have a period of 80 years and will be closest to each other as seen from Earth in 2037 and 2038.

Normally, the software in a computer treats the computer ’ s display screen as a rectangular array of square, indivisible pixels, each of which has an intensity and color that are determined by the blending of three primary colors: red, green, and blue.

However, actual display hardware usually implements each pixel as a group of three adjacent, independent subpixels, each of which displays a different primary color.

Almost all flat panels have a perfectly rectangular array of square pixels, each of which contains three rectangular subpixels in the three primary colors, with the normal ordering being red, green, and blue, arranged in vertical bands.

In many object-oriented languages, classes are the primary means of encapsulation and modularization ; each class defines a namespace and controls how and which definitions are externally visible.

In 325 AD Constantine I abolished the system and restored single emperor rule, but following the death of Theodosius in 395 AD, the empire returned to the system of co-emperors, each with primary authority for half the empire.

D: Secondary detonating explosive substance or black powder or article containing a secondary detonating explosive substance, in each case without means of initiation and without a propelling charge, or article containing a primary explosive substance and containing two or more effective protective features.

The terms extermination camp ( Vernichtungslager ) and death camp ( Todeslager ) are interchangeable usages, each referring to camps whose primary function was genocide, not for punishing crime or containing political prisoners, but for the systematic killing of the prisoners delivered there.

In his book, Andreae shows an utopic island in which Christian theosophy and applied science ruled, and in which the spiritual fulfillment and intellectual activity constituted the primary goals of each individual, the scientific pursuits being the highest intellectual calling – linked to the achievement of spiritual perfection.

The author drew on three primary sources, each representing a distinct community: a hypothetical collection, or several collections, of sayings ( called " Q ", and shared with Luke ); the Gospel of Mark ; and material unique to Matthew ( called " M ", some of which may have originated with Matthew himself ).

By 2006, such was the confusion from these multiple Acts, each amending the others ( and not all of which were ever actually commenced and thus were in the public record but not enforced as actual legislation ); and the amendments of Irish firearms legislation by other Acts ranging from the Wildlife Acts ( mostly relating to hunting law ) to the Road Traffic Acts ( relating to how and where firearms could be transported ) and others ; the large amount of secondary legislation ( Statutory Instruments, which set out regulations, the design of application forms for licences and so forth, as well as the details of when various parts of the Acts came into force ); as well as the introduction of EU firearms law into the canon of Irish legislation ; led the Irish Law Reform Commission to recommend that all the extant legislation be restated a legal process by which all the existing primary and secondary legislation would be read as one and a single document produced as the new Firearms Act ( and all prior Acts would be repealed ).

The color definitions in the palette can be drawn from a color space of millions of shades ( 2 < sup > 24 </ sup > shades, 8 bits for each primary ), but the maximum number of colors a frame can use is 256.