An artist is a person engaged in one or more of any of a broad spectrum of activities related to creating art, practicing the arts and / or demonstrating an art.

Black is the color of objects that do not emit or reflect light in any part of the visible spectrum ; they absorb all such frequencies of light.

* The spectrum of any bounded linear operator on a Banach space is a nonempty compact subset of the complex numbers C. Conversely, any compact subset of C arises in this manner, as the spectrum of some bounded linear operator.

For instance, a diagonal operator on the Hilbert space may have any compact nonempty subset of C as spectrum.

* The spectrum of any commutative ring with the Zariski topology ( that is, the set of all prime ideals ) is compact, but never Hausdorff ( except in trivial cases ).

Spectroscopic studies revealed absorption lines in the Jovian spectrum due to diatomic sulfur ( S < sub > 2 </ sub >) and carbon disulfide ( CS < sub > 2 </ sub >), the first detection of either in Jupiter, and only the second detection of S < sub > 2 </ sub > in any astronomical object.

These are capable of the most severe types of molecular damage, which can happen in biology to any type of biomolecule, including mutation and cancer, and often at great depths from the skin, since the higher end of the X-ray spectrum, and all of the gamma ray spectrum, are penetrating to matter.

Fascists have commonly opposed having a firm association with any section of the left-right spectrum, considering it inadequate to describe their beliefs, though fascism's goal to promote the rule of people deemed innately superior while seeking to purge society of people deemed innately inferior is identified as a prominent far-right theme.

Individuals were categorized according to their so-called " rejection spectrum " which allowed doctors to counter any immune system responses to the new organs, allowing transplants to " take " for life.

We can also show that the possible values of the observable A in any state must belong to the spectrum of A.

In linguistics the term orthography is often used to refer to any method of writing a language, without judgment as to right and wrong, with a scientific understanding that orthographic standardization exists on a spectrum of strength of convention.

Pacifism covers a spectrum of views ranging from the belief that international disputes can and should be peacefully resolved ; to calls for the abolition of the institutions of the military and war ; to opposition to any organization of society through governmental force ( anarchist or libertarian pacifism ); to rejection of the use of physical violence to obtain political, economic or social goals ; to opposition to violence under any circumstance, including defense of self and others.

Pacifism covers a spectrum of views, including the belief that international disputes can and should be peacefully resolved, calls for the abolition of the institutions of the military and war, opposition to any organization of society through governmental force ( anarchist or libertarian pacifism ), rejection of the use of physical violence to obtain political, economic or social goals, the obliteration of force except in cases where it is absolutely necessary to advance the cause of peace, and opposition to violence under any circumstance, even defense of self and others.

If the surface has any transparent or translucent properties, it refracts a portion of the light beam into itself in a different direction while absorbing some ( or all ) of the spectrum ( and possibly altering the color ).

Fundamental strings exist in 9 dimensions and the strings can vibrate in any direction, meaning that the spectrum of vibrational modes is much richer.

As with any religious movement, a theological spectrum exists within Adventism comparable to the fundamentalist-moderate-liberal spectrum in the wider Christian church and in other religions.

In general, any particular instrument will operate over a small portion of this total range because of the different techniques used to measure different portions of the spectrum.

Each observed new lines in the color spectrum of air but were unable to identify the element responsible for the lines.

For example, the spectrum of an element of a complex Banach algebra can never be empty, whereas in a real Banach algebra it could be empty for some elements.

The spectrum of an element x ∈ A, denoted by, consists of all those complex scalars λ such that x − λ1 is not invertible in A.

Moreover, the spectrum of an element x is non-empty and satisfies the spectral radius formula:

where is the Gelfand representation of x defined as follows: is the continuous function from Δ ( A ) to C given by The spectrum of in the formula above, is the spectrum as element of the algebra C ( Δ ( A )) of complex continuous functions on the compact space Δ ( A ).

Certain Boer nationalists have asserted that they do not consider themselves a right-wing element of the political spectrum.

This element had recently been discovered in the solar spectrum by Bunsen and Kirchoff.

Indium was discovered in 1863 and named for the indigo blue line in its spectrum that was the first indication of its existence in zinc ores, as a new and unknown element.

Neon was the second of these three rare gases to be discovered, and was immediately recognized as a new element from its bright red emission spectrum.

In 1861, Crookes discovered a previously unknown element with a bright green emission line in its spectrum and named the element thallium, from the Greek thallos, a green shoot.

Light from the star is analyzed by splitting it up by a diffraction grating, subdividing the incoming photons into a spectrum exhibiting a rainbow of colors interspersed by absorption lines, each line indicating a certain ion of a certain chemical element.

The presence of a certain chemical element in such an absorption spectrum primarily indicates that the temperature conditions are suitable for a certain excitation of this element.

The spectrum was read and indicated the absence of the element 43 and the presence of the element 75 ( rhenium ).

Our calculation of the amount of element 43 required to produce their spectrum is quite similar to the direct measurements of natural technetium abundance in uranium ore published in 1999 by Dave Curtis and colleagues at Los Alamos.

* August 18 – The element later named as helium is first detected in the spectrum of the Sun's chromosphere by French astronomer Jules Janssen during a total eclipse in Guntur, India, but assumed to be sodium.

* October 20 – English astronomer Norman Lockyer observes and names the D < sub > 3 </ sub > Fraunhofer line in the solar spectrum and concludes that it is caused by a hitherto unidentified element which he later names helium.

At first it was hypothesized that the line might be due to an unknown element, which was named nebulium — a similar idea had led to the discovery of helium through analysis of the Sun's spectrum in 1868.

According to Smithsonian curator Dr. Jeffrey Post, the element boron may be responsible for causing the blue color of the stones after tests using infrared light measured a chemical spectrum of the gems.

Since there are no lines of lithium in the spectrum, this element must have already been consumed by fusion at the core.

Let B be a complex Banach algebra containing a unit e. Then we define the spectrum σ ( x ) ( or more explicitly σ < sub > B </ sub >( x )) of an element x of B to be the set of those complex numbers λ for which λe − x is not invertible in B.

When the spectrum is reckoned per frequency interval, the Sun's peak emission appears at a frequency of 3. 43 x 10 < sup > 14 </ sup > Hz ; this means that the peak emission per unit frequency is at 3. 43 x 10 < sup > 14 </ sup > Hz, which corresponds to a wavelength of 883 nm and is well into the infrared.

For homogeneous turbulence ( i. e., statistically invariant under translations of the reference frame ) this is usually done by means of the energy spectrum function, where k is the modulus of the wavevector corresponding to some harmonics in a Fourier representation of the flow velocity field u ( x ):

We now say that x ∈ V is an eigenvector of M if x is an eigenvector of T. Similarly, λ ∈ K is an eigenvalue of M if it is an eigenvalue of T and the spectrum of M, written σ < sub > M </ sub >, is the set of all such eigenvalues.

So the spectrum includes the set of approximate eigenvalues, which are those λ such that is not bounded below ; equivalently, it is the set of λ for which there is a sequence of unit vectors x < sub > 1 </ sub >, x < sub > 2 </ sub >, ... for which

For example, the spectrum of &# 8477 ; consists of closed points ( x − a ), for a in &# 8477 ;, ( x < sup > 2 </ sup > + px + q ) where p, q are in &# 8477 ; and with negative discriminant p < sup > 2 </ sup > − 4q < 0, and finally a generic point ( 0 ).

In the 4F correlator, the system transfer function H ( k < sub > x </ sub >, k < sub > y </ sub >) is directly multiplied against the spectrum F ( k < sub > x </ sub >, k < sub > y </ sub >) of the input function, to produce the spectrum of the output function.

Geometrically, this corresponds to the fact that the spectrum of this ring, which is the union of the lines x