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In physics, redshift happens when light or other electromagnetic radiation from an object is increased in wavelength, or shifted to the red end of the spectrum. In general, whether or not the radiation is within the visible spectrum, "redder" means an increase in wavelength – equivalent to a lower frequency and a lower photon energy, in accordance with, respectively, the wave and quantum theories of light.
Some redshifts are an example of the Doppler effect, familiar in the change of apparent pitches of sirens and frequency of the sound waves emitted by speeding vehicles. A redshift occurs whenever a light source moves away from an observer. A special instance of this is the cosmological redshift, which is due to the expansion of the universe, and sufficiently distant light sources (generally more than a few million light years away) show redshift corresponding to the rate of increase in their distance from Earth. Finally, gravitational redshift is a relativistic effect observed in electromagnetic radiation moving out of gravitational fields. Conversely, a decrease in wavelength is called blueshift and is generally seen when a light-emitting object moves toward an observer or when electromagnetic radiation moves into a gravitational field. However, redshift is a more common term and sometimes blueshift is referred to as negative redshift.
Knowledge of redshifts and blueshifts has been applied to develop several terrestrial technologies such as Doppler radar and radar guns.[1] Redshifts are also seen in the spectroscopic observations of astronomical objects.[2] Its value is represented by the letter z.
A special relativistic redshift formula (and its classical approximation) can be used to calculate the redshift of a nearby object when spacetime is flat. However, in many contexts, such as black holes and Big Bang cosmology, redshifts must be calculated using general relativity.[3] Special relativistic, gravitational, and cosmological redshifts can be understood under the umbrella of frame transformation laws. There exist other physical processes that can lead to a shift in the frequency of electromagnetic radiation, including scattering and optical effects; however, the resulting changes are distinguishable from true redshift and are not generally referred to as such (see section on physical optics and radiative transfer).
The history of the subject began with the development in the 19th century of wave mechanics and the exploration of phenomena associated with the Doppler effect. The effect is named after Christian Doppler, who offered the first known physical explanation for the phenomenon in 1842.[4] The hypothesis was tested and confirmed for sound waves by the Dutch scientist Christophorus Buys Ballot in 1845.[5] Doppler correctly predicted that the phenomenon should apply to all waves, and in particular suggested that the varying colors of stars could be attributed to their motion with respect to the Earth.[6] Before this was verified, however, it was found that stellar colors were primarily due to a star's temperature, not motion. Only later was Doppler vindicated by verified redshift observations.
The first Doppler redshift was described by French physicist Hippolyte Fizeau in 1848, who pointed to the shift in spectral lines seen in stars as being due to the Doppler effect. The effect is sometimes called the "Doppler–Fizeau effect". In 1868, British astronomer William Huggins was the first to determine the velocity of a star moving away from the Earth by this method.[7] In 1871, optical redshift was confirmed when the phenomenon was observed in Fraunhofer lines using solar rotation, about 0.1 Å in the red.[8] In 1887, Vogel and Scheiner discovered the annual Doppler effect, the yearly change in the Doppler shift of stars located near the ecliptic due to the orbital velocity of the Earth.[9] In 1901, Aristarkh Belopolsky verified optical redshift in the laboratory using a system of rotating mirrors.[10]
The earliest occurrence of the term "red-shift" in print (in this hyphenated form) appears to be by American astronomer Walter S. Adams in 1908, in which he mentions "Two methods of investigating that nature of the nebular red-shift".[11] The word does not appear unhyphenated until about 1934 by Willem de Sitter, perhaps indicating that up to that point its German equivalent, Rotverschiebung, was more commonly used.[12]
Beginning with observations in 1912, Vesto Slipher discovered that most spiral galaxies, then mostly thought to be spiral nebulae, had considerable redshifts. Slipher first reports on his measurement in the inaugural volume of the Lowell Observatory Bulletin.[13] Three years later, he wrote a review in the journal Popular Astronomy.[14] In it he states, "[...] the early discovery that the great Andromeda spiral had the quite exceptional velocity of –300 km(/s) showed the means then available, capable of investigating not only the spectra of the spirals but their velocities as well."[15] Slipher reported the velocities for 15 spiral nebulae spread across the entire celestial sphere, all but three having observable "positive" (that is recessional) velocities. Subsequently, Edwin Hubble discovered an approximate relationship between the redshifts of such "nebulae" and the distances to them with the formulation of his eponymous Hubble's law.[16] These observations corroborated Alexander Friedmann's 1922 work, in which he derived the Friedmann-Lemaître equations.[17] They are today considered strong evidence for an expanding universe and the Big Bang theory.[18]
Measurement, characterization, and interpretation[edit]
The spectrum of light that comes from a single source (see idealized spectrum illustration top-right) can be measured. To determine the redshift, one searches for features in the spectrum such as absorption lines, emission lines, or other variations in light intensity. If found, these features can be compared with known features in the spectrum of various chemical compounds found in experiments where that compound is located on Earth. A very common atomic element in space is hydrogen. The spectrum of originally featureless light shone through hydrogen will show a signature spectrum specific to hydrogen that has features at regular intervals. If restricted to absorption lines it would look similar to the illustration (top right). If the same pattern of intervals is seen in an observed spectrum from a distant source but occurring at shifted wavelengths, it can be identified as hydrogen too. If the same spectral line is identified in both spectra—but at different wavelengths—then the redshift can be calculated using the table below. Determining the redshift of an object in this way requires a frequency- or wavelength-range. In order to calculate the redshift one has to know the wavelength of the emitted light in the rest frame of the source, in other words, the wavelength that would be measured by an observer located adjacent to and comoving with the source. Since in astronomical applications this measurement cannot be done directly, because that would require travelling to the distant star of interest, the method using spectral lines described here is used instead. Redshifts cannot be calculated by looking at unidentified features whose rest-frame frequency is unknown, or with a spectrum that is featureless or white noise (random fluctuations in a spectrum).[20]
Redshift (and blueshift) may be characterized by the relative difference between the observed and emitted wavelengths (or frequency) of an object. In astronomy, it is customary to refer to this change using a dimensionless quantity called z. If λ represents wavelength and f represents frequency (note, λf = c where c is the speed of light), then z is defined by the equations:[21]
Based on wavelength | Based on frequency |
After z is measured, the distinction between redshift and blueshift is simply a matter of whether z is positive or negative. See the formula section below for some basic interpretations that follow when either a redshift or blueshift is observed. For example, Doppler effect blueshifts (z < 0) are associated with objects approaching (moving closer to) the observer with the light shifting to greater energies. Conversely, Doppler effect redshifts (z > 0) are associated with objects receding (moving away) from the observer with the light shifting to lower energies. Likewise, gravitational blueshifts are associated with light emitted from a source residing within a weaker gravitational field as observed from within a stronger gravitational field, while gravitational redshifting implies the opposite conditions.
Redshift formulae[edit]
In general relativity one can derive several important special-case formulae for redshift in certain special spacetime geometries, as summarized in the following table. In all cases the magnitude of the shift (the value of z) is independent of the wavelength.[2]
Redshift type | Geometry | Formula[22] |
Relativistic Doppler | Minkowski space (flat spacetime) | for small for motion completely in the radial direction. |
Cosmological redshift | FLRW spacetime (expanding Big Bang universe) | |
Gravitational redshift | any stationary spacetime (e.g. the Schwarzschild geometry) | (for the Schwarzschild geometry, |
Doppler effect[edit]
If a source of the light is moving away from an observer, then redshift (z > 0) occurs; if the source moves towards the observer, then blueshift (z < 0) occurs. This is true for all electromagnetic waves and is explained by the Doppler effect. Consequently, this type of redshift is called the Doppler redshift. If the source moves away from the observer with velocity v, which is much less than the speed of light (v ≪ c), the redshift is given by
- (since )
where c is the speed of light. In the classical Doppler effect, the frequency of the source is not modified, but the recessional motion causes the illusion of a lower frequency.
A more complete treatment of the Doppler redshift requires considering relativistic effects associated with motion of sources close to the speed of light. A complete derivation of the effect can be found in the article on the relativistic Doppler effect. In brief, objects moving close to the speed of light will experience deviations from the above formula due to the time dilation of special relativity which can be corrected for by introducing the Lorentz factor γ into the classical Doppler formula as follows (for motion solely in the line of sight):
This phenomenon was first observed in a 1938 experiment performed by Herbert E. Ives and G.R. Stilwell, called the Ives–Stilwell experiment.[23]
Since the Lorentz factor is dependent only on the magnitude of the velocity, this causes the redshift associated with the relativistic correction to be independent of the orientation of the source movement. In contrast, the classical part of the formula is dependent on the projection of the movement of the source into the line-of-sight which yields different results for different orientations. If θ is the angle between the direction of relative motion and the direction of emission in the observer's frame[24] (zero angle is directly away from the observer), the full form for the relativistic Doppler effect becomes:
and for motion solely in the line of sight (θ = 0°), this equation reduces to:
For the special case that the light is approaching at right angles (θ = 90°) to the direction of relative motion in the observer's frame,[25] the relativistic redshift is known as the transverse redshift, and a redshift:
is measured, even though the object is not moving away from the observer. Even when the source is moving towards the observer, if there is a transverse component to the motion then there is some speed at which the dilation just cancels the expected blueshift and at higher speed the approaching source will be redshifted.[26]
Expansion of space[edit]
In the early part of the twentieth century, Slipher, Hubble and others made the first measurements of the redshifts and blueshifts of galaxies beyond the Milky Way. They initially interpreted these redshifts and blueshifts as due to random motions, but later Hubble discovered a rough correlation between the increasing redshifts and the increasing distance of galaxies. Theorists almost immediately realized that these observations could be explained by a mechanism for producing redshifts seen in certain cosmological solutions to Einstein's equations of general relativity. Hubble's law of the correlation between redshifts and distances is required by all such models that have a metric expansion of space.[18] As a result, the wavelength of photons propagating through the expanding space is stretched, creating the cosmological redshift.
There is a distinction between a redshift in cosmological context as compared to that witnessed when nearby objects exhibit a local Doppler-effect redshift. Rather than cosmological redshifts being a consequence of the relative velocities that are subject to the laws of special relativity (and thus subject to the rule that no two locally-separated objects can have relative velocities with respect to each other faster than the speed of light), the photons instead increase in wavelength and redshift because of a global feature of the spacetime metric through which they are traveling. One interpretation of this effect is the idea that space itself is expanding.[27] Due to the expansion increasing as distances increase, the distance between two remote galaxies can increase at more than 3×108 m/s, but this does not imply that the galaxies move faster than the speed of light at their present location (which is forbidden by Lorentz covariance).
Mathematical derivation[edit]
The observational consequences of this effect can be derived using the equations from general relativity that describe a homogeneous and isotropic universe.
To derive the redshift effect, use the geodesic equation for a light wave, which is
- ds is the spacetime interval
- dt is the time interval
- dr is the spatial interval
- c is the speed of light
- a is the time-dependent cosmic scale factor
- k is the curvature per unit area.
For an observer observing the crest of a light wave at a position r = 0 and time t = tnow, the crest of the light wave was emitted at a time t = tthen in the past and a distant position r = R. Integrating over the path in both space and time that the light wave travels yields:
In general, the wavelength of light is not the same for the two positions and times considered due to the changing properties of the metric. When the wave was emitted, it had a wavelength λthen. The next crest of the light wave was emitted at a time
The observer sees the next crest of the observed light wave with a wavelength λnow to arrive at a time
Since the subsequent crest is again emitted from r = R and is observed at r = 0, the following equation can be written:
The right-hand side of the two integral equations above are identical which means
Using the following manipulation:
we find that:
For very small variations in time (over the period of one cycle of a light wave) the scale factor is essentially a constant (a = anow today and a = athen previously). This yields
which can be rewritten as
Using the definition of redshift provided above, the equation
is obtained. In an expanding universe such as the one we inhabit, the scale factor is monotonically increasing as time passes, thus, z is positive and distant galaxies appear redshifted.
Using a model of the expansion of the Universe, redshift can be related to the age of an observed object, the so-called cosmic time–redshift relation. Denote a density ratio as Ω0:
with ρcrit the critical density demarcating a universe that eventually crunches from one that simply expands. This density is about three hydrogen atoms per thousand liters of space.[28] At large redshifts one finds:
where H0 is the present-day Hubble constant, and z is the redshift.[29][30][31]
Distinguishing between cosmological and local effects[edit]
For cosmological redshifts of z < 0.01 additional Doppler redshifts and blueshifts due to the peculiar motions of the galaxies relative to one another cause a wide scatter from the standard Hubble Law.[32] The resulting situation can be illustrated by the Expanding Rubber Sheet Universe, a common cosmological analogy used to describe the expansion of space. If two objects are represented by ball bearings and spacetime by a stretching rubber sheet, the Doppler effect is caused by rolling the balls across the sheet to create peculiar motion. The cosmological redshift occurs when the ball bearings are stuck to the sheet and the sheet is stretched.[33][34][35]
The redshifts of galaxies include both a component related to recessional velocity from expansion of the Universe, and a component related to peculiar motion (Doppler shift).[36] The redshift due to expansion of the Universe depends upon the recessional velocity in a fashion determined by the cosmological model chosen to describe the expansion of the Universe, which is very different from how Doppler redshift depends upon local velocity.[37] Describing the cosmological expansion origin of redshift, cosmologist Edward Robert Harrison said, "Light leaves a galaxy, which is stationary in its local region of space, and is eventually received by observers who are stationary in their own local region of space. Between the galaxy and the observer, light travels through vast regions of expanding space. As a result, all wavelengths of the light are stretched by the expansion of space. It is as simple as that..."[38] Steven Weinberg clarified, "The increase of wavelength from emission to absorption of light does not depend on the rate of change of a(t) [here a(t) is the Robertson-Walker scale factor] at the times of emission or absorption, but on the increase of a(t) in the whole period from emission to absorption."[39]
Popular literature often uses the expression "Doppler redshift" instead of "cosmological redshift" to describe the redshift of galaxies dominated by the expansion of spacetime, but the cosmological redshift is not found using the relativistic Doppler equation[40] which is instead characterized by special relativity; thus v > c is impossible while, in contrast, v > c is possible for cosmological redshifts because the space which separates the objects (for example, a quasar from the Earth) can expand faster than the speed of light.[41] More mathematically, the viewpoint that "distant galaxies are receding" and the viewpoint that "the space between galaxies is expanding" are related by changing coordinate systems. Expressing this precisely requires working with the mathematics of the Friedmann-Robertson-Walker metric.[42]
If the Universe were contracting instead of expanding, we would see distant galaxies blueshifted by an amount proportional to their distance instead of redshifted.[43]
Gravitational redshift[edit]
In the theory of general relativity, there is time dilation within a gravitational well. This is known as the gravitational redshift or Einstein Shift.[44] The theoretical derivation of this effect follows from the Schwarzschild solution of the Einstein equations which yields the following formula for redshift associated with a photon traveling in the gravitational field of an uncharged, nonrotating, spherically symmetric mass:
- G is the gravitational constant,
- M is the mass of the object creating the gravitational field,
- r is the radial coordinate of the source (which is analogous to the classical distance from the center of the object, but is actually a Schwarzschild coordinate), and
- c is the speed of light.
This gravitational redshift result can be derived from the assumptions of special relativity and the equivalence principle; the full theory of general relativity is not required.[45]
The effect is very small but measurable on Earth using the Mössbauer effect and was first observed in the Pound–Rebka experiment.[46] However, it is significant near a black hole, and as an object approaches the event horizon the red shift becomes infinite. It is also the dominant cause of large angular-scale temperature fluctuations in the cosmic microwave background radiation (see Sachs-Wolfe effect).[47][48]
Observations in astronomy[edit]
The redshift observed in astronomy can be measured because the emission and absorption spectra for atoms are distinctive and well known, calibrated from spectroscopic experiments in laboratories on Earth. When the redshift of various absorption and emission lines from a single astronomical object is measured, z is found to be remarkably constant. Although distant objects may be slightly blurred and lines broadened, it is by no more than can be explained by thermal or mechanical motion of the source. For these reasons and others, the consensus among astronomers is that the redshifts they observe are due to some combination of the three established forms of Doppler-like redshifts. Alternative hypotheses and explanations for redshift such as tired light are not generally considered plausible.[49]
Spectroscopy, as a measurement, is considerably more difficult than simple photometry, which measures the brightness of astronomical objects through certain filters.[50] When photometric data is all that is available (for example, the Hubble Deep Field and the Hubble Ultra Deep Field), astronomers rely on a technique for measuring photometric redshifts.[51] Due to the broad wavelength ranges in photometric filters and the necessary assumptions about the nature of the spectrum at the light-source, errors for these sorts of measurements can range up to δz = 0.5, and are much less reliable than spectroscopic determinations.[52] However, photometry does at least allow a qualitative characterization of a redshift. For example, if a Sun-like spectrum had a redshift of z = 1, it would be brightest in the infrared rather than at the yellow-green color associated with the peak of its blackbody spectrum, and the light intensity will be reduced in the filter by a factor of four, (1 + z)2. Both the photon count rate and the photon energy are redshifted. (See K correction for more details on the photometric consequences of redshift.)[53]
Local observations[edit]
In nearby objects (within our Milky Way galaxy) observed redshifts are almost always related to the line-of-sight velocities associated with the objects being observed. Observations of such redshifts and blueshifts have enabled astronomers to measure velocities and parametrize the masses of the orbiting stars in spectroscopic binaries, a method first employed in 1868 by British astronomer William Huggins.[7] Similarly, small redshifts and blueshifts detected in the spectroscopic measurements of individual stars are one way astronomers have been able to diagnose and measure the presence and characteristics of planetary systems around other stars and have even made very detailed differential measurements of redshifts during planetary transits to determine precise orbital parameters.[54] Finely detailed measurements of redshifts are used in helioseismology to determine the precise movements of the photosphere of the Sun.[55] Redshifts have also been used to make the first measurements of the rotation rates of planets,[56] velocities of interstellar clouds,[57] the rotation of galaxies,[2] and the dynamics of accretion onto neutron stars and black holes which exhibit both Doppler and gravitational redshifts.[58] Additionally, the temperatures of various emitting and absorbing objects can be obtained by measuring Doppler broadening – effectively redshifts and blueshifts over a single emission or absorption line.[59] By measuring the broadening and shifts of the 21-centimeter hydrogen line in different directions, astronomers have been able to measure the recessional velocities of interstellar gas, which in turn reveals the rotation curve of our Milky Way.[2] Similar measurements have been performed on other galaxies, such as Andromeda.[2] As a diagnostic tool, redshift measurements are one of the most important spectroscopic measurements made in astronomy.
Extragalactic observations[edit]
The most distant objects exhibit larger redshifts corresponding to the Hubble flow of the Universe. The largest observed redshift, corresponding to the greatest distance and furthest back in time, is that of the cosmic microwave background radiation; the numerical value of its redshift is about z = 1089 (z = 0 corresponds to present time), and it shows the state of the Universe about 13.8 billion years ago,[60] and 379,000 years after the initial moments of the Big Bang.[61]
The luminous point-like cores of quasars were the first "high-redshift" (z > 0.1) objects discovered before the improvement of telescopes allowed for the discovery of other high-redshift galaxies.
For galaxies more distant than the Local Group and the nearby Virgo Cluster, but within a thousand megaparsecs or so, the redshift is approximately proportional to the galaxy's distance. This correlation was first observed by Edwin Hubble and has come to be known as Hubble's law. Vesto Slipher was the first to discover galactic redshifts, in about the year 1912, while Hubble correlated Slipher's measurements with distances he measured by other means to formulate his Law. In the widely accepted cosmological model based on general relativity, redshift is mainly a result of the expansion of space: this means that the farther away a galaxy is from us, the more the space has expanded in the time since the light left that galaxy, so the more the light has been stretched, the more redshifted the light is, and so the faster it appears to be moving away from us. Hubble's law follows in part from the Copernican principle.[62] Because it is usually not known how luminous objects are, measuring the redshift is easier than more direct distance measurements, so redshift is sometimes in practice converted to a crude distance measurement using Hubble's law.
Gravitational interactions of galaxies with each other and clusters cause a significant scatter in the normal plot of the Hubble diagram. The peculiar velocities associated with galaxies superimpose a rough trace of the mass of virialized objects in the Universe. This effect leads to such phenomena as nearby galaxies (such as the Andromeda Galaxy) exhibiting blueshifts as we fall towards a common barycenter, and redshift maps of clusters showing a Fingers of God effect due to the scatter of peculiar velocities in a roughly spherical distribution.[62] This added component gives cosmologists a chance to measure the masses of objects independent of the mass to light ratio (the ratio of a galaxy's mass in solar masses to its brightness in solar luminosities), an important tool for measuring dark matter.[63]
The Hubble law's linear relationship between distance and redshift assumes that the rate of expansion of the Universe is constant. However, when the Universe was much younger, the expansion rate, and thus the Hubble "constant", was larger than it is today. For more distant galaxies, then, whose light has been travelling to us for much longer times, the approximation of constant expansion rate fails, and the Hubble law becomes a non-linear integral relationship and dependent on the history of the expansion rate since the emission of the light from the galaxy in question. Observations of the redshift-distance relationship can be used, then, to determine the expansion history of the Universe and thus the matter and energy content.
While it was long believed that the expansion rate has been continuously decreasing since the Big Bang, recent observations of the redshift-distance relationship using Type Ia supernovae have suggested that in comparatively recent times the expansion rate of the Universe has begun to accelerate.
Highest redshifts[edit]
Currently, the objects with the highest known redshifts are galaxies and the objects producing gamma ray bursts. The most reliable redshifts are from spectroscopic data, and the highest confirmed spectroscopic redshift of a galaxy is that of GN-z11,[64] with a redshift of z = 11.1, corresponding to 400 million years after the Big Bang. The previous record was held by UDFy-38135539[65] at a redshift of z = 8.6, corresponding to 600 million years after the Big Bang. Slightly less reliable are Lyman-break redshifts, the highest of which is the lensed galaxy A1689-zD1 at a redshift z = 7.5[66][67] and the next highest being z = 7.0.[68] The most distant observed gamma ray burst with a spectroscopic redshift measurement was GRB 090423, which had a redshift of z = 8.2.[69] The most distant known quasar, ULAS J1120+0641, is at z = 7.1.[70][71] The highest known redshift radio galaxy (TN J0924-2201) is at a redshift z = 5.2[72] and the highest known redshift molecular material is the detection of emission from the CO molecule from the quasar SDSS J1148+5251 at z = 6.42[73]
Extremely red objects (EROs) are astronomical sources of radiation that radiate energy in the red and near infrared part of the electromagnetic spectrum. These may be starburst galaxies that have a high redshift accompanied by reddening from intervening dust, or they could be highly redshifted elliptical galaxies with an older (and therefore redder) stellar population.[74] Objects that are even redder than EROs are termed hyper extremely red objects (HEROs).[75]
The cosmic microwave background has a redshift of z = 1089, corresponding to an age of approximately 379,000 years after the Big Bang and a comoving distance of more than 46 billion light years.[76] The yet-to-be-observed first light from the oldest Population III stars, not long after atoms first formed and the CMB ceased to be absorbed almost completely, may have redshifts in the range of 20 < z < 100.[77] Other high-redshift events predicted by physics but not presently observable are the cosmic neutrino background from about two seconds after the Big Bang (and a redshift in excess of z > 1010)[78] and the cosmic gravitational wave background emitted directly from inflation at a redshift in excess of z > 1025.[79]
In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.[80][81]
Redshift surveys[edit]
With advent of automated telescopes and improvements in spectroscopes, a number of collaborations have been made to map the Universe in redshift space. By combining redshift with angular position data, a redshift survey maps the 3D distribution of matter within a field of the sky. These observations are used to measure properties of the large-scale structure of the Universe. The Great Wall, a vast supercluster of galaxies over 500 million light-years wide, provides a dramatic example of a large-scale structure that redshift surveys can detect.[82]
The first redshift survey was the CfA Redshift Survey, started in 1977 with the initial data collection completed in 1982.[83] More recently, the 2dF Galaxy Redshift Survey determined the large-scale structure of one section of the Universe, measuring redshifts for over 220,000 galaxies; data collection was completed in 2002, and the final data set was released 30 June 2003.[84] The Sloan Digital Sky Survey (SDSS), is ongoing as of 2013 and aims to measure the redshifts of around 3 million objects.[85] SDSS has recorded redshifts for galaxies as high as 0.8, and has been involved in the detection of quasars beyond z = 6. The DEEP2 Redshift Survey uses the Keck telescopes with the new "DEIMOS" spectrograph; a follow-up to the pilot program DEEP1, DEEP2 is designed to measure faint galaxies with redshifts 0.7 and above, and it is therefore planned to provide a high redshift complement to SDSS and 2dF.[86]
Effects from physical optics or radiative transfer[edit]
The interactions and phenomena summarized in the subjects of radiative transfer and physical optics can result in shifts in the wavelength and frequency of electromagnetic radiation. In such cases, the shifts correspond to a physical energy transfer to matter or other photons rather than being by a transformation between reference frames. Such shifts can be from such physical phenomena as coherence effects or the scattering of electromagnetic radiation whether from charged elementary particles, from particulates, or from fluctuations of the index of refraction in a dielectric medium as occurs in the radio phenomenon of radio whistlers.[2] While such phenomena are sometimes referred to as "redshifts" and "blueshifts", in astrophysics light-matter interactions that result in energy shifts in the radiation field are generally referred to as "reddening" rather than "redshifting" which, as a term, is normally reserved for the effects discussed above.[2]
In many circumstances scattering causes radiation to redden because entropy results in the predominance of many low-energy photons over few high-energy ones (while conserving total energy).[2] Except possibly under carefully controlled conditions, scattering does not produce the same relative change in wavelength across the whole spectrum; that is, any calculated z is generally a function of wavelength. Furthermore, scattering from random media generally occurs at many angles, and z is a function of the scattering angle. If multiple scattering occurs, or the scattering particles have relative motion, then there is generally distortion of spectral lines as well.[2]
In interstellar astronomy, visible spectra can appear redder due to scattering processes in a phenomenon referred to as interstellar reddening[2] – similarly Rayleigh scattering causes the atmospheric reddening of the Sun seen in the sunrise or sunset and causes the rest of the sky to have a blue color. This phenomenon is distinct from redshifting because the spectroscopic lines are not shifted to other wavelengths in reddened objects and there is an additional dimming and distortion associated with the phenomenon due to photons being scattered in and out of the line-of-sight.
For a list of scattering processes, see Scattering.
- ^ See Feynman, Leighton and Sands (1989) or any introductory undergraduate (and many high school) physics textbooks. See Taylor (1992) for a relativistic discussion.
- ^ a b c d e f g h i j See Binney and Merrifeld (1998), Carroll and Ostlie (1996), Kutner (2003) for applications in astronomy.
- ^ See Misner, Thorne and Wheeler (1973) and Weinberg (1971) or any of the physical cosmology textbooks
- ^ Doppler, Christian (1846). Beiträge zur fixsternenkunde. 69. Prague: G. Haase Söhne. Bibcode:1846befi.book.....D.
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- ^ O'Connor, John J.; Robertson, Edmund F. (1998). "Christian Andreas Doppler". MacTutor History of Mathematics archive. University of St Andrews.
- ^ a b Huggins, William (1868). "Further Observations on the Spectra of Some of the Stars and Nebulae, with an Attempt to Determine Therefrom Whether These Bodies are Moving towards or from the Earth, Also Observations on the Spectra of the Sun and of Comet II". Philosophical Transactions of the Royal Society of London. 158: 529–564. Bibcode:1868RSPT..158..529H. doi:10.1098/rstl.1868.0022.
- ^ Reber, G. (1995). "Intergalactic Plasma". Astrophysics and Space Science. 227 (1–2): 93–96. Bibcode:1995Ap&SS.227...93R. doi:10.1007/BF00678069.
- ^ Pannekoek, A (1961). A History of Astronomy. Dover. p. 451. ISBN 0-486-65994-1.
- ^ Bélopolsky, A. (1901). "On an Apparatus for the Laboratory Demonstration of the Doppler-Fizeau Principle". Astrophysical Journal. 13: 15. Bibcode:1901ApJ....13...15B. doi:10.1086/140786.
- ^ Adams, Walter S. (1908). "Preliminary catalogue of lines affected in sun-spots". Contributions from the Mount Wilson Observatory / Carnegie Institution of Washington. Contributions from the Solar Observatory of the Carnegie Institution of Washington: Carnegie Institution of Washington. 22: 1–21. Bibcode:1908CMWCI..22....1A. Reprinted in Adams, Walter S. (1908). "Preliminary Catalogue of Lines Affected in Sun-Spots Region λ 4000 TO λ 4500". Astrophysical Journal. 27: 45. Bibcode:1908ApJ....27...45A. doi:10.1086/141524.
- ^ de Sitter, W. (1934). "On distance, magnitude, and related quantities in an expanding universe". Bulletin of the Astronomical Institutes of the Netherlands. 7: 205. Bibcode:1934BAN.....7..205D.
It thus becomes urgent to investigate the effect of the redshift and of the metric of the universe on the apparent magnitude and observed numbers of nebulae of given magnitude
- ^ Slipher, Vesto (1912). "The radial velocity of the Andromeda Nebula". Lowell Observatory Bulletin. 1: 2.56–2.57. Bibcode:1913LowOB...1b..56S.
The magnitude of this velocity, which is the greatest hitherto observed, raises the question whether the velocity-like displacement might not be due to some other cause, but I believe we have at present no other interpretation for it
- ^ Slipher, Vesto (1915). "Spectrographic Observations of Nebulae". Popular Astronomy. 23: 21–24. Bibcode:1915PA.....23...21S.
- ^ Slipher, Vesto (1915). "Spectrographic Observations of Nebulae". Popular Astronomy. 23: 22. Bibcode:1915PA.....23...21S.
- ^ Hubble, Edwin (1929). "A Relation between Distance and Radial Velocity among Extra-Galactic Nebulae". Proceedings of the National Academy of Sciences of the United States of America. 15 (3): 168–173. Bibcode:1929PNAS...15..168H. doi:10.1073/pnas.15.3.168. PMC 522427. PMID 16577160.
- ^ Friedman, A. A. (1922). "Über die Krümmung des Raumes". Zeitschrift für Physik. 10 (1): 377–386. Bibcode:1922ZPhy...10..377F. doi:10.1007/BF01332580. English translation in Friedman, A. (1999). "On the Curvature of Space". General Relativity and Gravitation. 31 (12): 1991–2000. Bibcode:1999GReGr..31.1991F. doi:10.1023/A:1026751225741.)
- ^ a b This was recognized early on by physicists and astronomers working in cosmology in the 1930s. The earliest layman publication describing the details of this correspondence is Eddington, Arthur (1933). The Expanding Universe: Astronomy's 'Great Debate', 1900–1931. Cambridge University Press. (Reprint: ISBN 978-0-521-34976-5)
- ^ "Hubble census finds galaxies at redshifts 9 to 12". ESA/Hubble Press Release. Retrieved 13 December 2012.
- ^ See, for example, this 25 May 2004 press release from NASA's Swift space telescope that is researching gamma-ray bursts: "Measurements of the gamma-ray spectra obtained during the main outburst of the GRB have found little value as redshift indicators, due to the lack of well-defined features. However, optical observations of GRB afterglows have produced spectra with identifiable lines, leading to precise redshift measurements."
- ^ See [1] for a tutorial on how to define and interpret large redshift measurements.
- ^ Where z = redshift; v|| = velocity parallel to line-of-sight (positive if moving away from receiver); c = speed of light; γ = Lorentz factor; a = scale factor; G = gravitational constant; M = object mass; r = radial Schwarzschild coordinate, gtt = t,t component of the metric tensor
- ^ Ives, H.; Stilwell, G. (1938). "An Experimental study of the rate of a moving atomic clock". J. Opt. Soc. Am. 28 (7): 215–226. doi:10.1364/josa.28.000215.
- ^ Freund, Jurgen (2008). Special Relativity for Beginners. World Scientific. p. 120. ISBN 981-277-160-3.
- ^ Ditchburn, R (1961). Light. Dover. p. 329. ISBN 0-12-218101-8.
- ^ See "Photons, Relativity, Doppler shift" at the University of Queensland
- ^ The distinction is made clear in Harrison, Edward Robert (2000). Cosmology: The Science of the Universe (2nd ed.). Cambridge University Press. pp. 306ff. ISBN 0-521-66148-X.
- ^ Steven Weinberg (1993). The First Three Minutes: A Modern View of the Origin of the Universe (2nd ed.). Basic Books. p. 34. ISBN 0-465-02437-8.
- ^ Lars Bergström; Ariel Goobar (2006). Cosmology and Particle Astrophysics (2nd ed.). Springer. p. 77, Eq.4.79. ISBN 3-540-32924-2.
- ^ M.S. Longair (1998). Galaxy Formation. Springer. p. 161. ISBN 3-540-63785-0.
- ^ Yu N Parijskij (2001). "The High Redshift Radio Universe". In Norma Sanchez. Current Topics in Astrofundamental Physics. Springer. p. 223. ISBN 0-7923-6856-8.
- ^ Measurements of the peculiar velocities out to 5 Mpc using the Hubble Space Telescope were reported in 2003 by Karachentsev; et al. (2003). "Local galaxy flows within 5 Mpc". Astronomy and Astrophysics. 398: 479–491. arXiv:astro-ph/0211011. Bibcode:2003A&A...398..479K. doi:10.1051/0004-6361:20021566.
- ^ Theo Koupelis; Karl F. Kuhn (2007). In Quest of the Universe (5th ed.). Jones & Bartlett Publishers. p. 557. ISBN 0-7637-4387-9.
- ^ "It is perfectly valid to interpret the equations of relativity in terms of an expanding space. The mistake is to push analogies too far and imbue space with physical properties that are not consistent with the equations of relativity." Geraint F. Lewis; Francis, Matthew J.; Barnes, Luke A.; Kwan, Juliana; et al. (2008). "Cosmological Radar Ranging in an Expanding Universe". Monthly Notices of the Royal Astronomical Society. 388 (3): 960–964. arXiv:0805.2197. Bibcode:2008MNRAS.388..960L. doi:10.1111/j.1365-2966.2008.13477.x.
- ^ Michal Chodorowski (2007). "Is space really expanding? A counterexample". Concepts Phys. 4: 17–34. arXiv:astro-ph/0601171. Bibcode:2007ONCP....4...15C. doi:10.2478/v10005-007-0002-2.
- ^ Bedran,M.L. (2002)"A comparison between the Doppler and cosmological redshifts" Am.J.Phys. 70, 406–408
- ^ Edward Harrison (1992). "The redshift-distance and velocity-distance laws". Astrophysical Journal, Part 1. 403: 28–31. Bibcode:1993ApJ...403...28H. doi:10.1086/172179.. A pdf file can be found here [2].
- ^ Harrison 2000, p. 315.
- ^ Steven Weinberg (2008). Cosmology. Oxford University Press. p. 11. ISBN 978-0-19-852682-7.
- ^ Odenwald & Fienberg 1993
- ^ Speed faster than light is allowed because the expansion of the spacetime metric is described by general relativity in terms of sequences of only locally valid inertial frames as opposed to a global Minkowski metric. Expansion faster than light is an integrated effect over many local inertial frames and is allowed because no single inertial frame is involved. The speed-of-light limitation applies only locally. See Michal Chodorowski (2007). "Is space really expanding? A counterexample". Concepts Phys. 4: 17–34. arXiv:astro-ph/0601171. Bibcode:2007ONCP....4...15C. doi:10.2478/v10005-007-0002-2.
- ^ M. Weiss, What Causes the Hubble Redshift?, entry in the Physics FAQ (1994), available via John Baez's website
- ^ This is only true in a universe where there are no peculiar velocities. Otherwise, redshifts combine as
- ^ Chant, C. A. (1930). "Notes and Queries (Telescopes and Observatory Equipment – The Einstein Shift of Solar Lines)". Journal of the Royal Astronomical Society of Canada. 24: 390. Bibcode:1930JRASC..24..390C.
- ^ Einstein, A (1907). "Über das Relativitätsprinzip und die aus demselben gezogenen Folgerungen". Jahrbuch der Radioaktivität und Elektronik. 4: 411–462. See p. 458 The influence of a gravitational field on clocks
- ^ Pound, R.; Rebka, G. (1960). "Apparent Weight of Photons". Physical Review Letters. 4 (7): 337–341. Bibcode:1960PhRvL...4..337P. doi:10.1103/PhysRevLett.4.337.. This paper was the first measurement.
- ^ Sachs, R. K.; Wolfe, A. M. (1967). "Perturbations of a cosmological model and angular variations of the cosmic microwave background". Astrophysical Journal. 147 (73): 73. Bibcode:1967ApJ...147...73S. doi:10.1086/148982.
- ^ Brill, Dieter (19 January 2012). "Black Hole Horizons and How They Begin". Astronomical Review. 7: 25–35. doi:10.1080/21672857.2012.11519694.
- ^ When cosmological redshifts were first discovered, Fritz Zwicky proposed an effect known as tired light. While usually considered for historical interests, it is sometimes, along with intrinsic redshift suggestions, utilized by nonstandard cosmologies. In 1981, H. J. Reboul summarised many alternative redshift mechanisms that had been discussed in the literature since the 1930s. In 2001, Geoffrey Burbidge remarked in a review that the wider astronomical community has marginalized such discussions since the 1960s. Burbidge and Halton Arp, while investigating the mystery of the nature of quasars, tried to develop alternative redshift mechanisms, and very few of their fellow scientists acknowledged let alone accepted their work. Moreover, Goldhaber et al. 2001; "Timescale Stretch Parameterization of Type Ia Supernova B-Band Lightcurves", ApJ 558:359–386, 2001 September 1 pointed out that alternative theories are unable to account for timescale stretch observed in type Ia supernovae
- ^ For a review of the subject of photometry, consider Budding, E., Introduction to Astronomical Photometry, Cambridge University Press (September 24, 1993), ISBN 0-521-41867-4
- ^ The technique was first described by Baum, W. A.: 1962, in G. C. McVittie (ed.), Problems of extra-galactic research, p. 390, IAU Symposium No. 15
- ^ Bolzonella, M.; Miralles, J.-M.; Pelló, R., Photometric redshifts based on standard SED fitting procedures, Astronomy and Astrophysics, 363, p.476–492 (2000).
- ^ A pedagogical overview of the K-correction by David Hogg and other members of the SDSS collaboration can be found at astro-ph.
- ^ The Exoplanet Tracker is the newest observing project to use this technique, able to track the redshift variations in multiple objects at once, as reported in Ge, Jian; Van Eyken, Julian; Mahadevan, Suvrath; Dewitt, Curtis; et al. (2006). "The First Extrasolar Planet Discovered with a New‐Generation High‐Throughput Doppler Instrument". The Astrophysical Journal. 648: 683–695. arXiv:astro-ph/0605247. Bibcode:2006ApJ...648..683G. doi:10.1086/505699.
- ^ Libbrecht, Keng (1988). "Solar and stellar seismology". Space Science Reviews. 47 (3–4): 275–301. Bibcode:1988SSRv...47..275L. doi:10.1007/BF00243557.
- ^ In 1871 Hermann Carl Vogel measured the rotation rate of Venus. Vesto Slipher was working on such measurements when he turned his attention to spiral nebulae.
- ^ An early review by Oort, J. H. on the subject: Oort, J. H. (1970). "The formation of galaxies and the origin of the high-velocity hydrogen". Astronomy and Astrophysics. 7: 381. Bibcode:1970A&A.....7..381O.
- ^ Asaoka, Ikuko (1989). "X-ray spectra at infinity from a relativistic accretion disk around a Kerr black hole". Astronomical Society of Japan. 41 (4): 763–778. Bibcode:1989PASJ...41..763A. ISSN 0004-6264.
- ^ Rybicki, G. B. and A. R. Lightman, Radiative Processes in Astrophysics, John Wiley & Sons, 1979, p. 288 ISBN 0-471-82759-2
- ^ "Cosmic Detectives". The European Space Agency (ESA). 2013-04-02. Retrieved 2013-04-25.
- ^ An accurate measurement of the cosmic microwave background was achieved by the COBE experiment. The final published temperature of 2.73 K was reported in this paper: Fixsen, D. J.; Cheng, E. S.; Cottingham, D. A.; Eplee, R. E., Jr.; Isaacman, R. B.; Mather, J. C.; Meyer, S. S.; Noerdlinger, P. D.; Shafer, R. A.; Weiss, R.; Wright, E. L.; Bennett, C. L.; Boggess, N. W.; Kelsall, T.; Moseley, S. H.; Silverberg, R. F.; Smoot, G. F.; Wilkinson, D. T.. (1994). "Cosmic microwave background dipole spectrum measured by the COBE FIRAS instrument", Astrophysical Journal, 420, 445. The most accurate measurement as of 2006 was achieved by the WMAP experiment.
- ^ a b Peebles (1993).
- ^ Binney, James; Scott Treimane (1994). Galactic dynamics. Princeton University Press. ISBN 0-691-08445-9.
- ^ Oesch, P. A.; Brammer, G.; van Dokkum, P.; et al. (March 1, 2016). "A Remarkably Luminous Galaxy at z=11.1 Measured with Hubble Space Telescope Grism Spectroscopy". arXiv:1603.00461.
- ^ M.D.Lehnert; Nesvadba, NP; Cuby, JG; Swinbank, AM; et al. (2010). "Spectroscopic Confirmation of a galaxy at redshift z = 8.6". Nature. 467 (7318): 940–942. arXiv:1010.4312. Bibcode:2010Natur.467..940L. doi:10.1038/nature09462. PMID 20962840.
- ^ Watson, Darach; Christensen, Lise; Knudsen, Kirsten Kraiberg; Richard, Johan; Gallazzi, Anna; Michałowski, Michał Jerzy (2015). "A dusty, normal galaxy in the epoch of reionization". Nature. 519 (7543): 327–330. arXiv:1503.00002. Bibcode:2015Natur.519..327W. doi:10.1038/nature14164. PMID 25731171.
- ^ Bradley, L.; et al. (2008). "Discovery of a Very Bright Strongly Lensed Galaxy Candidate at z ~ 7.6". The Astrophysical Journal. 678: 647–654. Bibcode:2008ApJ...678..647B. doi:10.1086/533519.
- ^ Egami, E.; et al. (2005). "Spitzer and Hubble Space Telescope Constraints on the Physical Properties of the z~7 Galaxy Strongly Lensed by A2218". The Astrophysical Journal. 618: L5–L8. Bibcode:2005ApJ...618L...5E. doi:10.1086/427550.
- ^ Salvaterra, R.; Valle, M. Della; Campana, S.; Chincarini, G.; et al. (2009). "GRB 090423 reveals an exploding star at the epoch of re-ionization". Nature. 461 (7268): 1258–60. arXiv:0906.1578. Bibcode:2009Natur.461.1258S. doi:10.1038/nature08445. PMID 19865166.
- ^ http://www.universetoday.com/87175/most-distant-quasar-opens-window-into-early-universe/
- ^ Scientific American, "Brilliant, but Distant: Most Far-Flung Known Quasar Offers Glimpse into Early Universe", John Matson, 29 June 2011
- ^ Klamer, I. J.; Ekers, R. D.; Sadler, E. M.; Weiss, A.; et al. (2005). "CO (1-0) and CO (5-4) Observations of the Most Distant Known Radio Galaxy atz = 5.2". The Astrophysical Journal. 621: L1. arXiv:astro-ph/0501447v1. Bibcode:2005ApJ...621L...1K. doi:10.1086/429147.
- ^ Walter, Fabian; Bertoldi, Frank; Carilli, Chris; Cox, Pierre; et al. (2003). "Molecular gas in the host galaxy of a quasar at redshift z = 6.42". Nature. 424 (6947): 406–8. arXiv:astro-ph/0307410. Bibcode:2003Natur.424..406W. doi:10.1038/nature01821. PMID 12879063.
- ^ Smail, Ian; Owen, F. N.; Morrison, G. E.; Keel, W. C.; et al. (2002). "The Diversity of Extremely Red Objects". The Astrophysical Journal. 581 (2): 844–864. arXiv:astro-ph/0208434. Bibcode:2002ApJ...581..844S. doi:10.1086/344440.
- ^ Totani, Tomonori; Yoshii, Yuzuru; Iwamuro, Fumihide; Maihara, Toshinori; et al. (2001). "Hyper Extremely Red Objects in the Subaru Deep Field: Evidence for Primordial Elliptical Galaxies in the Dusty Starburst Phase". The Astrophysical Journal. 558 (2): L87–L91. arXiv:astro-ph/0108145. Bibcode:2001ApJ...558L..87T. doi:10.1086/323619.
- ^ Lineweaver, Charles; Tamara M. Davis (2005). "Misconceptions about the Big Bang". Scientific American. Retrieved 2008-11-06.
- ^ Naoz, S.; Noter, S.; Barkana, R. (2006). "The first stars in the Universe". Monthly Notices of the Royal Astronomical Society: Letters. 373: L98–L102. arXiv:astro-ph/0604050. Bibcode:2006MNRAS.373L..98N. doi:10.1111/j.1745-3933.2006.00251.x.
- ^ Lesgourgues, J; Pastor, S (2006). "Massive neutrinos and cosmology". Physics Reports. 429 (6): 307–379. arXiv:astro-ph/0603494. Bibcode:2006PhR...429..307L. doi:10.1016/j.physrep.2006.04.001.
- ^ Grishchuk, Leonid P (2005). "Relic gravitational waves and cosmology". Physics-Uspekhi. 48 (12): 1235–1247. arXiv:gr-qc/0504018. Bibcode:2005PhyU...48.1235G. doi:10.1070/PU2005v048n12ABEH005795.
- ^ Sobral, David; Matthee, Jorryt; Darvish, Behnam; Schaerer, Daniel; Mobasher, Bahram; Röttgering, Huub J. A.; Santos, Sérgio; Hemmati, Shoubaneh (4 June 2015). "Evidence For POPIII-Like Stellar Populations In The Most Luminous LYMAN-α Emitters At The Epoch Of Re-Ionisation: Spectroscopic Confirmation". The Astrophysical Journal. 808 (2): 139. arXiv:1504.01734. Bibcode:2015ApJ...808..139S. doi:10.1088/0004-637x/808/2/139.
- ^ Overbye, Dennis (17 June 2015). "Astronomers Report Finding Earliest Stars That Enriched Cosmos". New York Times. Retrieved 17 June 2015.
- ^ M. J. Geller & J. P. Huchra, Science 246, 897 (1989). online
- ^ See the official CfA website for more details.
- ^ Shaun Cole; Percival; Peacock; Norberg; et al. (2005). "The 2dF galaxy redshift survey: Power-spectrum analysis of the final dataset and cosmological implications". Mon. Not. Roy. Astron. Soc. 362 (2): 505–34. arXiv:astro-ph/0501174. Bibcode:2005MNRAS.362..505C. doi:10.1111/j.1365-2966.2005.09318.x. 2dF Galaxy Redshift Survey homepage
- ^ SDSS Homepage
- ^ Marc Davis; DEEP2 collaboration (2002). "Science objectives and early results of the DEEP2 redshift survey". Conference on Astronomical Telescopes and Instrumentation, Waikoloa, Hawaii, 22–28 Aug 2002. arXiv:astro-ph/0209419.
- Odenwald, S. & Fienberg, RT. 1993; "Galaxy Redshifts Reconsidered" in Sky & Telescope Feb. 2003; pp31–35 (This article is useful further reading in distinguishing between the 3 types of redshift and their causes.)
- Lineweaver, Charles H. and Tamara M. Davis, "Misconceptions about the Big Bang", Scientific American, March 2005. (This article is useful for explaining the cosmological redshift mechanism as well as clearing up misconceptions regarding the physics of the expansion of space.)
- Nussbaumer, Harry; Lydia Bieri (2009). Discovering the Expanding Universe. Cambridge University Press. ISBN 978-0-521-51484-2.
- Binney, James; Michael Merrifeld (1998). Galactic Astronomy. Princeton University Press. ISBN 0-691-02565-7.
- Carroll, Bradley W. & Dale A. Ostlie (1996). An Introduction to Modern Astrophysics. Addison-Wesley Publishing Company, Inc. ISBN 0-201-54730-9.
- Feynman, Richard; Leighton, Robert; Sands, Matthew (1989). Feynman Lectures on Physics. Vol. 1. Addison-Wesley. ISBN 0-201-51003-0.
- Grøn, Øyvind; Hervik, Sigbjørn (2007). Einstein's General Theory of Relativity. New York: Springer. ISBN 978-0-387-69199-2.
- Kutner, Marc (2003). Astronomy: A Physical Perspective. Cambridge University Press. ISBN 0-521-52927-1.
- Misner, Charles; Thorne, Kip S.; Wheeler, John Archibald (1973). Gravitation. San Francisco: W. H. Freeman. ISBN 0-7167-0344-0.
- Peebles, P. J. E. (1993). Principles of Physical Cosmology. Princeton University Press. ISBN 0-691-01933-9.
- Taylor, Edwin F.; Wheeler, John Archibald (1992). Spacetime Physics: Introduction to Special Relativity (2nd ed.). W.H. Freeman. ISBN 0-7167-2327-1.
- Weinberg, Steven (1971). Gravitation and Cosmology. John Wiley. ISBN 0-471-92567-5.
- See also physical cosmology textbooks for applications of the cosmological and gravitational redshifts.
External links[edit]
Wikimedia Commons has media related to Redshift. |
- Ned Wright's Cosmology tutorial
- Cosmic reference guide entry on redshift
- Mike Luciuk's Astronomical Redshift tutorial
- Animated GIF of Cosmological Redshift by Wayne Hu
- Merrifield, Michael; Hill, Richard (2009). "Z Redshift". SIXTψ SYMBΦLS. Brady Haran for the University of Nottingham.


text:
SAN FRANCISCO – A San Francisco-area coroner whose office received the bodies of two teenage victims of the Asiana plane crash says officials are conducting an autopsy to determine if one of the girls was run over and killed by a rescue vehicle.
San Mateo County Coroner Robert Foucrault says Sunday that senior San Francisco Fire Department officials notified him and his staff at the crash site on Saturday that one of the 16-year-olds may have been struck on the runaway.
Foucrault says an autopsy he expects to be completed by Monday will involve determining whether the girl's death was caused by injuries suffered in the crash or "a secondary incident."
He says he did not get a close enough look at the victims on Saturday to know whether they had external injuries.

subset: commoncrawl


text:
CAMARILLO, Calif. (AP) — The average U.S. price of a gallon of gasoline has jumped 20 cents over the past two weeks.
The Lundberg Survey of fuel prices released Sunday says the price of a gallon of regular is $3.80. Midgrade costs an average of $3.95 a gallon, and premium is $4.09.
Diesel was up a dime to $4.17 gallon.
Of the cities surveyed in the lower 48 states, Billings, Mont., has the nation's lowest average price for gas at $3.23. Los Angeles has the highest at $4.29.
In California, the lowest average price was $4.02 in Sacramento. The average statewide for a gallon of regular was $4.18, up 20 cents.
Use the CBS13 Pump Patrol tool to find the cheapest gas near you.
(Copyright 2013 The Associated Press.)


text: Most Popular To-Do List Manager: AstridAlan Henry7/10/12 2:15pmFiled to: Hive Five FollowupTo-Doto-do listWebappsweb servicesProductivityOrganizationTo-DosTo-do list managerTo-Do ManagerastridtoodledoRemember the Milkrtmany.DOWunderlistHive Fivein brief691EditPromoteShare to KinjaToggle Conversation toolsGo to permalink The sheer number of options when it comes to to-do list apps can be overwhelming, but the best ones offer a combination of features, reminders, syncing options, and apps that let you stay on top of your list anywhere you go. Last week we asked you which to-do list apps you thought were the best, and then we took at look at the five best to-do list managers based on those nominations. Now we're back to highlight the overall winner. One of our favorite apps for keeping track of your to-dos is also one of yours: Astrid took the top spot with close to 40% of the overall vote. Advertisement Advertisement Hot on its heels in second place is another one of our favorite to-do list apps, Wunderlist, which brought in over 25% of the votes cast. In third place is newcomer Any.DO, which brought in about 15% of the vote. In fourth place is one of our old favorites, Remember The Milk, which collected over 11% of your votes. Bringing up the rear with 9% is Toodledo.The Hive Five is based on reader nominations. As with most Hive Five posts, if your favorite was left out, it's not because we hate it—it's because it didn't get the nominations required in the call for contenders post to make the top five. We understand it's a bit of a popularity contest, but if you have a favorite, we want to hear about it. Have a suggestion for the Hive Five? Send us an email at email@example.com!Reply69 repliesLeave a reply


text:
Posts Tagged ' Day 4 '
Images from Day 4
Sunday, May 15th, 2011Day 4: Dispatch from Ray Arsenault
Friday, May 13th, 2011Historian Ray Arsenault, author of Freedom Riders: 1961 and the Struggle for Racial Justice, writes from the bus of the 2011 Student Freedom Ride.
Day 4–May 11: Augusta, GA, to Anniston, AL
As we left Augusta, I gave a brief lecture on Augusta's cultural, political, and racial history–emphasizing several of the region's most colorful and infamous characters, notably Tom Watson and J. B. Stoner. Then we settled in for the long bus ride from Augusta to Atlanta, a journey that the students soon turned into a musical and creative extravaganza featuring new renditions of freedom songs, original rap songs, a poetry slam–all dedicated to the original Freedom Riders. These kids are quite remarkable.
In Atlanta, our first stop was the King Center, where we were met by Freedom Riders Bernard Lafayette and Charles Person. Bernard gave a fascinating impromptu lecture on the history of the Center and his experiences working with Coretta King. We spent a few minutes at the grave sight and reflecting pool before entering the newly restored Ebenezer Baptist Church. The church was hauntingly beautiful, especially so as we listened to a tape of an MLK sermon and a following hymn. The kids were riveted.
Our next stop was Morehouse College, King's alma mater, where we were greeted by a large crowd organized by the Georgia Humanities Council. After lunch and my brief keynote address, the gathering, which included 10 Freedom Riders, broke into small groups for hour-long discussions relating the Freedom Rides to contemporary issues. Moving testimonials and a long standing ovation for the Riders punctuated the event. Later in the afternoon, we headed for Alabama and Anniston, taking the old highway, Route 78, just as the CORE Freedom Riders had on Mother's Day morning, May 14, in 1961. However, unlike 1961's brutal events, our reception in Anniston, orchestrated by a downown redevelopment group known as the Spirit of Anniston, could not have been more cordial. A large interracial group that included the mayor, city council members, and a black state representative joined us for dinner before accompanying us to the Anniston Public Library for a program highlighted by the viewing of a photography exhibit, "Courage Under Fire." The May 14, 1961 photographs of Joe Postiglione were searing, and their public display marks a new departure in Anniston, a community that until recently seemed determined to bury the uglier aspects of its past. The whole scene at the library was deeply emotional, almost surreal at times. The climax was a confessional speech by Richard Couch, the son of a Klansman who was part of the bus-burning mob in 1961. When Mr. Couch walked over to Hank Thomas, who was savagely attacked in 1961, to embrace him and ask for forgiveness and reconciliation, there were tears all around. The students and everyone else in the room were stunned. I have never seen anything quite like that moment. Later Mr. Couch and Janie Forsyth McKinney, the 12-year old white girlwho braved the mob in 1961 to come to the Freedom Riders' aid, joined the students at our hotel for a two-hour deiscussion of race and reconciliation. I would wager that those of us who were in that room will remember the depth of feeling and searching questions and comments of the students for the rest of our lives. Words can't describe what took place in the hearts and minds of the Freedom Riders, young and old, last night.
Reverend Charles Jones
Thursday, May 12th, 2011Day 4: JoyEllen Freeman
Thursday, May 12th, 2011Day 4: Doaa Dorgham
Thursday, May 12th, 2011Day 4: Davy Knittle
Thursday, May 12th, 2011Day 4: Give Thanks
Wednesday, May 11th, 2011By Diana Mahoney
They are like pieces in a complicated jigsaw puzzle. Daily, we try to piece them together in an effort to capture and convey the chaos of emotion racing and swirling through our minds and hearts. Sometimes we get it right, sometimes we don't. People remember them, repeat them, build hopes and dreams around them, get their heart broken by them. Words. In contrast to the strength of emotion behind them, they seem flimsy in comparison. In syllables, we try to capture and convey what lies beneath our surface. Chaining meaning to sounds, trying to transmit hearts brimming with emotions to those around us.
Thank you. Two short words that seem to ring empty and hollow in nearly every situation that demands them. How can the same two words that are used in response to someone holding a door or ringing up your groceries be used interchangeably to express how you felt the time your friend, who had an exam the next morning, spent the night driving you hours to the hospital to see your grandmother the night she died. That's right, they can't.
That's why I was surprised today when those two simple words came to be the rocking moment of my day. Which, if I'm being honest, I'm beginning to get used to. Being caught off guard and shook up daily in the most unexpected moments, by the least likely of people.
It was during the beautiful luncheon put out in Rock Hill, South Carolina where the infamous Friendship Nine Sit-Ins occurred that it happened. The lights had been dimmed and we were halfway through the documentary on Rock Hill that she walked across the room. Young and beautiful, the well-dressed African-American girl bent down and leaned her head in close to Joan Mulholland's.
"I have to leave early, but I just wanted to come over and say thank you for making this life possible for me." I watched out of the corner of my eye as Joan reached out and wrapped the young girl in her embrace.
"I love you." Joan whispered into her hair. I felt my heart skip a beat. It was just such an incredibly beautiful moment. Suddenly it hit me. That this tiny, beautiful woman sitting next to me played a huge part of life as I know it. I gazed around the room at my fellow student riders and thought of the people that have played parts in my life up to this point. At their varying skin tones, of their diverse ideas, of their unique voices, of how much richer my life has become because they are in it. Of how much of this beautiful life I would have missed had this woman and those like her not stepped up and spoke out.
I feel like my "Thank you." doesn't cut it. Every time I see these incredibly courageous people, I want to convey how each and every day I am appreciative for the world they sacrificed so much for. The world I was lucky enough to grow up in, thanks to them. But somewhere deep down inside, I know that no matter how many times I say it, those words stand almost as a barrier in conveying the swell of emotion, gratefulness and indebtedness I feel I owe to each and every one of the original Freedom Riders. It is humbling to graciously accept this gift the Freedom Riders have given us. I can't fit together words to say thank you properly. As the days roll by I find myself more and more in agreement with author Elizabeth Gilbert who reflects that, "In the end, maybe it's wiser to surrender before the miraculous scope of human generosity and to just keep saying thank you, forever and sincerely, for as long as we have voices."
Day 4: Peter Davis
Wednesday, May 11th, 2011Day 4: Hallelujah, I'm a Travelin'
Wednesday, May 11th, 2011By Samantha Williams
As a kid growing up in a traditional Christian church, there was nothing unordinary about singing hymns every Sunday morning and more often than not, up to three times a week. We were singin' fools. I knew the songs by heart and it became part of my culture and lifestyle.
When I began researching more information about the Freedom Riders, I found that music was an important part of both the Ride itself and the African American community. On the first day of the trip, original Riders Rip Patton and Bernard Lafayette, Jr. led us in a freedom song. I had never heard of such a thing before.
"Buses are a comin', oh yeah. Buses are a comin', oh yeah. Buses are a comin', buses are a comin', buses are a comin', oh yeah." We sang these words with the original Riders, a surreal experience to say the least. They explained to us that singing helped them cope with the emotionally draining circumstances. When the Riders were jailed for breaking segregation laws, they would sing in their cells until they could sing no more. When the prison guard would tell them to keep quiet and threaten to punish them, they would sing louder.
A few minutes after our song began, we had added lines like, "They can take my mattress" and eventually, "They can take my toothbrush." Lafayette, however, had to stop and inform us that when it got to this point they had to remind one another that there were upwards of 20 people in a cell fit for four. Singing with their mouths barely open was the solution they agreed upon. Whatever it took to retain even the smallest ounce of dignity and pride.
Then, when I viewed Stanley Nelson's documentary on the Freedom Rides, I heard a familiar tune. "Hallelujah, I'm a travelin'. Hallelujah, ain't it fine? Hallelujah, I'm a-travelin' down freedom's main line." It sounded familiar. Where had I heard this melody before? My mind traced the tune all the way back to childhood when at church, I would sing the lyrics, "Hallelujah! Thine the glory. Hallelujah! Amen. Hallelujah! Thine the glory. Revive us again." The Riders tweaked the lyrics to fit their experience.
There was something very powerful in knowing that a song I sang as a small kid had been sung decades before by people I consider heroes. Songs that got them through one of the most dangerous events of their lives, got me through my own struggles. In a strange way, it connected us. It was almost as if a symbolic torch was being passed to 39 other students and myself. In a moment, their past met my present.
Day 4: Student Teachings
Wednesday, May 11th, 2011By Raj De
Many of the 1961 Freedom Riders were students, much like me, yet they taught the world about courage, about injustice. Today, a young school teacher spoke to us in Rock Hill, SC and she emphasized that "Students are teachers," using the Freedom Riders as an example.
Tonight at dinner, I had a fascinating conversation with three of my fellow student riders about how to infuse creativity into the American educational system—divergent learning that encompasses diverse solutions, focusing on civic innovation instead of purely service, understanding of self, and emphasis on valuing each student's opinion. Feeling no barriers, we bounced ideas off one another and I found myself learning a lot from my fellow students, while adding to the discussion as well. Our model of conversation was even an example of one of our proposed methods of educational reform—exchange of ideas between students, "Students as teachers." We were practicing what we had heard in Rock Hill, without even realizing it.
Our insistence on positive educational change was particularly special to me because of the work I am doing this summer. I am interning at the Spring Creek Literacy Project, an educational summer camp for middle school girls in the rural mountain community of Madison County, NC, a region where high school graduation rates can run as low as 50%. The project is only a year old and is still very malleable, so I can bring my own ideas to fruition. I left our dinner conversation with concrete ideas to apply within the Spring Creek project and with a renewed energy for social change.
If I could successfully implement some of the ideas we talked about at dinner into the Spring Creek curriculum, the Spring Creek girls would approach learning as integrated with teaching each other, with reflecting, with problem solving, with passion and spirit, without boundaries—"Students as teachers."
Day 4: Michael Tubbs
Wednesday, May 11th, 2011Day 4: Islamophobia: Influence of the Media and Education
Wednesday, May 11th, 2011By Bakrom Ismoilov
Tuesday morning, May 10. Embassy Suites Hotel, Charlotte, North Carolina. Joan Mulholland gathered the student riders for a dialogue on Islamophobia that was brought to her attention by the event happened on Friday. Two imams who were headed to Charlotte for a meeting on 'Islamophobia' were taken off a commercial flight after the pilot refused to fly with them.
My fellow riders joined for a short roundtable discussion, which was decided to be continuingly discussed during the ride. Being a Muslim student, I was glad that this discussion started, as in my view, it is a growing issue that might have serious consequences.
A specific attention was paid to the influence of the media on people's perception of the religion of Islam. Do we consider the media as a deceiver of people's minds that has a political touch to it? Do we see it as a truthful entity that is just and tolerant? Or can we make the media a resource for the civic engagement and educate people properly?
In my opinion media falls into all three categories: it can be an ally, an enemy and a resource. And I do believe in the power of civic engagement in overcoming political interests by love and integrity.
But, how about the institutional education in US? As 15-year-old exchange student in Battle Creek, Michigan, during my American History class, we were asked which is worse, communism or terrorism, after which it was explained to us that Communism was evil and terrorism was an Islamic action. How can we trust what is taught in schools, and how can we change it? I keep replaying the words of Diane Nash in my mind: "The issue that I see in our society is we don't ask ourselves: WHY is it that I believe in what I believe?"
The 2011 Student Freedom Ride really brought us together for a reason — to be the CHANGE we want to see in our future. And it is of my biggest hope that this conversation will be continued during and after the ride.
Verse 49:13 of the Holy Koran states: "O mankind! We created you from a pair of a male and a female, and made you into nations and tribes, that ye may know each other not that ye may despise each other. "
Day 4: Rachael DeMarce
Wednesday, May 11th, 2011Day 4: Will Dale
Wednesday, May 11th, 2011Day 4: Robert Sgrignoli
Wednesday, May 11th, 2011He spoke of sacrifice. He spoke of love. He spoke of dreams fulfilled. He was Charles Jones, a civil rights activist with the wit to organize and the courage to partake in the mass sit-ins of Charlotte, North Carolina of 1960. In reflection of his highly decorated life, Mr. Jones showed no hesitation in expressing his emotions in their most raw form. He would begin a sentence with a laugh and end with tears, providing me a ticket to the only emotional rollercoaster I have ever been on. In conversation with Mr. Jones, there was an underlying theme of prophetic love of all people despite suffering terrorism by many.
I have often wondered if interspersed within those dreams is the increasing frequency of nightmares. He spoke of love; we practice love of self. He spoke of a dream of the "Beloved Community"; we dream of fancy cars. Mainly he spoke of the sacrifice of himself and many others based upon their vision for us. His words resonated much with Diane Nash's "we loved you without knowing you." I wonder if Mr. Jones worries that his accomplishments through sacrifice will be sacrificed by the youth to further their own personal success in life.
Mr. Jones and those who spent years in the trenches drive through the same streets we do. They witness the dilapidated housing, the practice of isolation over inclusion, and the crumbling of our families. Today was a true wake up call for me, one I intend on answering not only for myself, but also in tribute to those before me. I have a bag of quarters to make some calls, at least I know those on the bus will pick up the phone.
Day 4: What Hides Behind Museum Walls
Wednesday, May 11th, 2011By Tariq Meyers
Four walls. Four walls composed of sheet rock, plastered with two coats of paint, graced with plexiglass and topped off with fluorescent lighting beneath images of hate; images of suffering; images with no hope. They call this construction an exhibit. Grade school children and adults alike gaze upon disturbing images but find relief upon exit because the dark images are behind them—the tour goes on. It is convenient to isolate history of pain to a room, easy to believe that bigotry is a thing of the past—that the struggle is over. Museums and exhibits mystify history—presenting it in a way where one is led to believe that what is presented is over. So when one encounters a mob lynching, the death of four little girls, the bullet hole in the windshield of Viola Liuzzo, or the handsome hazel-eyed turned eyeless image of the murdered Emmett Till—one's anxiety fades knowing the suffering is over; that the fear is isolated between images of hate and fluorescent lighting; beneath layers of paint and plexiglass; beneath sheet rock and concrete.
As I connected to the teary eyes of Ernest Rip Patton, I began to realize that our fifty-year sojourn (in the making), our difference in years, no longer mattered. The man who stood before me was 19-year-old Rip Patton, the courageous hero of 1961. Anxious and afraid, confused and connected as I was, the connection (young) Rip and I shared in the museum exhibit revealed the secret that hides behind museum walls. The secret is that history is very much in the present, that history is very much real. In that moment I came to understand that, though the pictures of the abused and the deceased were isolated on the walls, it did not mean the struggle was over; that the pain was gone—rather is very much underway. I stood there with Rip as we gazed upon the face of the beaten Freedom Rider. This may seem typical of museum activity, but understand why this was so significant: I was staring at the face of a beaten Freedom Rider alongside a Freedom Rider. Yes, together we gazed, (young) Rip and I, at the images isolated to plexiglass and fluorescent lights, beneath concrete and drywall—and it is there that I discovered that the mystified "ghosts" of pain and suffering were just images transplanted on paper with ink of different shades to give the illusion of looking aged and old. Yes, it was at that moment I realized that the secret that hides behind museum walls is a living history, that can't be isolated to words on a page, ink on a paper. The (young) Rip and I will forever be connected.


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ForumsQuestionsStart & due interaction
Start & due interaction
Author | Message |
I'm a little confused about the effect of the start date on my Hotlist. (This is on the iPhone app.)
I have daily repeating tasks that I had a start date and a due date on. When I check them off, the due date moves forward a day, and the start date seems to stay AS IT WAS originally set. My Hotlist settings are Has a priority of '3 Top' or higher. Has a due date in the next 1 days. Has a status of 'Next Action' (By the way, some and/or logic here would be WONDERFUL!) Once the start date on these tasks is in the past (even thought the due date is today) -- I don't see them on my Hotlist, anymore! Not sure why... |
Jake Toodledo Admin |
Can you please create a support ticket so that we can get some additional information about your account?
Hmmm... Just checked one, today, and it <u>is</u> showing up on my hotlist.
I'll keep an eye on it, and submit a ticket if I see further problems. |
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SpongeBob SquarePants Candy
Additional Information
Step 1
Tint portions of melted white candy blue, black, pink and yellow. Place all melted candy in cut parchment bags.
Step 2
Use melted blue candy to fill in pupils. Use melted white candy to fill in teeth. Refrigerate until set.
Step 3
Use melted candy to fill in tongue in pink. Refrigerate until set. Use melted candy to fill in mouth in black and eyes in white.
Step 4
Refrigerate until set. Use melted candy in cut parchment bag to fill in face and nose in yellow.
Step 5
Refrigerate for 30 minutes. Unmold.
Step 6
Use melted candy in cut parchment bag to overpipe pupils and eyelashes in black.
©2004 Viacom International Inc. All Rights Reserved. Nickelodeon, SpongeBob SquarePants and all related titles, logos and characters are trademarks of Viacom International Inc.
Created by Stephen Hillenburg.


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CBS Sports: Josh Smith to transfer to Georgetown
January 3rd, 2013, 11:40 am by Ryan Kartje, The Orange County RegisterMuch-maligned big man Josh Smith, who struggled with weight issues in three seasons under UCLA coach Ben Howland, will transfer to Georgetown, per a source from Jeff Goodman of CBS Sports.
According to the report, Smith chose Georgetown over Kansas.
Smith saw his minutes drop severely this season, despite the Bruins having very little depth in the frontcourt. And with little improvement in his conditioning to get back in the lineup, Smith's numbers began to decrease as well. In limited minutes with UCLA in 2012, Smith was scoring 5.2 points per game and collecting 4.2 rebounds, down from 10.9 and 6.3, respectively, from his freshman season.
Once a highly touted prospect, one that many UCLA fans saw as the potential centerpiece of the Bruins' resurgence, Smith's decision to transfer surprised Howland earlier this season. But with a new situation, here's hoping that Smith can get it all figured out in the nation's capital.
Read the rest of this entry »


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WeatherTech's excellent fitting Floor Liners are the ultimate custom fitting floor mat. Designed to keep the floor of your Ford F250 clean with their perfect fit, deep wells and innovative channel design keep fluids and debris off the carpet and away from your feet. These are designed specifically for the front seat floor area of your Ford F250. Simple to clean and maintain, just spray the liners off with a hose and you a done.
Material: | High-density Extruded, Semi-Flexible |
Colors: | Black, Tan & Grey (see options) |
Location: | Front (includes driver and passenger sides) |
Weight: | 15.00 lbs. |
Part 441261 fits: |


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We have always had a close relationship with Heli Adventures, and this week we had the privilege of interviewing�Gemma Heynes on all things airborne. For a first-hand insight into the world of helicopter flying, read on…
Q1. Hi Gemma! So to kick things off, how was HeliAdventures founded?
HeliAdventures provides helicopter tours from a plethora of locations and is part of a long�established Helicopter Company based at Cotswold Airport in Gloucestershire. Further�services from this multifaceted company include helicopter charters and professional�helicopter training.
HeliAdventures was started out of the passion of two pilots who wanted to be able to�share their passion and make available to others the experience of helicopter flights. The�cost of helicopters make it prohibitively expensive to many, but by setting up�HeliAdventures and selling sightseeing tours by the seat we hoped to open up the�opportunity to many others to enjoy.
Q2.�How do you think HeliAdventures stands out from other helicopter companies?
Not only do we operate all our own events, we always use our own pilots, our own�helicopters and operate under our own Air Operators Certificate (AOC), allowing us to�provide seamless customer service throughout the booking process and the experience�itself. Unlike a majority of UK sightseeing flight operators, we use immaculately presented�Airbus Helicopters AS350 aircraft which provides great visibility for all passengers in a�much more modern and spacious cabin compared with the Jet Ranger used by most�others. Our pilots are very familiar with the specific areas within which our range of�helicopter flights and tours are conducted, and they have worked to put together routes�that will give you the very best in excitement and spectacle.
Q3.�What is your favourite part of running HeliAdventures?
Seeing the joy on customers faces after their flight when, in many cases, they have just�realised a life long dream.
Q4. Tell us more about your story and HeliAdventures' success..
HeliAdventures has grown over the years to become one of the largest UK pleasure flight�operators to cover multiple locations throughout the South West and Midlands. Keep an�eye out ...more of the UK to be added soon! As well as this our training division has been�able to satisfy the dreams of many people of becoming a pilot whose initial introduction to�helicopters was a pleasure flight with HeliAdventures.
We flew 450 sightseeing tour in 2015, which equates to more than 2,000 passengers and of�those 2,000 passengers over 90% rate us 4-5 out of 5 and say they would recommend us to�others. We are aiming for 100% in 2016!
Q5. If you could tell every customer one thing, what would you share with them?
" YOLO " .... so make the most of it. Come and have fun with us!
Q6. Is there anything else you'd like to add/ mention?
If there is anything you want to know about helicopters do ask – we love talking�helicopters!
Huge thanks to Gemma for chatting with us, we hope you've enjoyed a little insight into Heli and it's team! Helicopter rides are great ways to see the ground beneath you from great heights, and there are plenty of locations across the country so everyone can have the perfect experience.�Enjoy!


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Tracy Richardson, Ph.D., MT-BC
Professor of Music Therapy, Director of Masters in Music Therapy, Department Chair
- Email:
- Phone: (812) 535-5154
- Ph.D., Indiana State University
- M.S., Indiana State University
- B.S., Saint Mary-of-the-Woods College
- Board-certified music therapist through the Certification Board for Music Therapists
Areas of Specialization, Publication, & Research
- Richardson, T. (2011). The impact of training on music therapists' songwriting knowledge, self-efficacy, and behavior (Doctoral dissertation).
- Richardson, T. (2010). I celebrate my life. Songwriting and recording session with breast cancer survivors. Celebration of Life conference.
- Five-hour Continuing Music Therapy Education (CMTE) sessions for music therapists and regional and national conferences, including:
- Ignite your songwriting: A workshop to build skills and confidence
- I write the songs: Songwriting in/as music therapy
- Regular presenter at state, regional, and national music therapy conferences on topics such as: Distance Education in Music Therapy, Clinical Training of Undergraduate and Graduate Music Therapy Students, Song Writing in Music Therapy, and Music Therapy Research
Recognition and Awards
- 2009 Award of Merit, American Music Therapy Association
- 2009 Spirit of Unification Award, American Music Therapy Association
- 2009 Songwriting Award, American Music Therapy Association
- 2005 Saint Mary-of-the-Woods College Sister Mary Joseph Pomeroy Award for Faculty Excellence for Service
Professional Service / Membership
- American Music Therapy Association
- Great Lakes Region of the American Music Therapy Association (President 2011-present; President-Elect 2009-2011)
- Association for Indiana Music Therapy
- American Counseling Association
- Mu Phi Epsilon, Gamma Psi Alumni Chapter
- 23 years clinical practice;16 years teaching experience


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Spurs and Everton striker target set to open talks on new deal at Chelsea
PUBLISHED: 07:41 24 June 2014
2014 Getty Images
Tottenham and Everton have been dealt a transfer blow after Romelu Lukaku's agent, Oscar Darmiani Jr, revealed that Chelsea don't want to loan the Belgian out and a contract extension appears on the cards.
The Belgian spent last season on loan at the Toffees, after having a successful time at West Brom the year before.
However, Lukaku has struggled at the World Cup, leading to suggestions that the Blues may allow him to leave.
But Darmiani Jr denied these claims saying: "Chelsea doesn't want to loan him out.
"He has two years left on his contract and we would normally look at extending it shortly.
"Did I see him after the match against Russia? Yeah, he was pretty quiet but he is a player who doesn't have anything to prove.
"Of course, the World Cup is the World Cup. I'm sure he'll bounce back in the next game."


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Meal Ideas To Go With Bruschetta
Here are some meal ideas with one of the famous Italian appetizers, originating from central Italy. Before we start, I think bruschetta has to be the most commonly mispronounced words among English speaking fine diners. The Italians pronounce it as broosËketta. Loaded with tomatoes and herbs, bruschetta also sometimes has cured meat and cheese as toppings. This Italian appetizer was mainly devised as a way to salvage left over bread by presenting it as a snack or an appetizer. Authentically, bruschetta is made from garlic bread and sun-dried and fresh tomatoes in equal portions mixed with thyme and a liberal dashing of extra virgin olive oil.
Now that we learnt how simple it's to make bruschetta, let's see what you can do for the rest of the meal if you have bruschetta on your menu. Since bruschetta is traditionally Italian, you would want to serve Italian cuisine for the rest of your dinner with bruschetta. Typically, a simple pasta dish can be followed by the starter.
Try penne arrabiata. It cannot get simpler than this. The arrabiata sauce is one of the simplest to make. Here's how. Take two to three firm tomatoes, slit them and boil exactly for thirty seconds. When they cool, peel them off and mash with your blender. Chop some fresh parsley and crush two pods of garlic. Heat olive oil in a pan and add the parsley – garlic mixture. Add chopped onions into it and sauté it for a few minutes. Add the tomato puree, basil, oregano, salt, pepper and chilli flakes. Slow cook for about half an hour. Your arabiata sauce is ready. Add cooked pasta into it and serve.
Or there's another simple method. Since bruschetta is also a wholesome and yummy dish, try converting it into an open sandwich. For that you might need bigger bread than a regular baguette. Try Ciabatta or Panini to make an open bruschetta sandwich. Take sundried and regular tomatoes in equal quantities and chop them finely. Keep it in a bowl and add a general drizzle of olive oil. Add freshly chopped thyme and basil into the bowl and toss it. Add salt and pepper to taste. Spread it over your bread (Ciabatta or Panini) and your open bruschetta sandwich is ready to eat.
Image Credit: italianfoodnet.com, vegetariansrecipes.org


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William Haley letter on army camp, 1864
Contributed by Sebago Historical Society
William Haley Jr. a private in the Maine 30th Regiment, writes to his daughter, Elzira, and his niece, Mary, from Camp Keyes, Augusta. William states he "was mustured for pay yesterday and they say they are agoing to let the soldiers go home to vote."
He thinks the war news is good and the fact that the price of gold has fallen is a good sign. He states that there are now 75 men in the tents and that 7 of the 30th Maine boys are there.
He encourages the girls to try to do the best they can on their "sailwork" and to be "stidy" and mind their mother. He also asks them to send him a towel and some apples via their Uncle Charles.
Haley writes that he has sole care of the tents as "the other man is gone away."
View/Add Comments
Other Information
- Title: William Haley letter on army camp, 1864
- Creator: Haley Jr., William
- Creation Date: 1864-09-01
- Subject Date: 1864-09-01
- Local Name: Camp Keyes, Convene
- Town: Augusta, Sebago
- County: Cumberland, Kennebec
- State: ME
- Media: ink on paper
- Dimensions (cm): 20.32 x 12.5
- Local Code: W4.4
- Collection: Haley Family Letters
- Object Type: Text
For more information about this item, contact:
Sebago Historical Society
PO Box 59, Sebago, ME 04029
(207) 787-2489
Cross Reference Searches
LC Subject Headings
Maine--History--Civil War, 1861-1865--Social aspects
United States. Army. Maine Infantry Regiment, 30th (1863-1865). Company E
United States--History--Civil War, 1861-1865--Medical care
United States--History--Civil War, 1861-1865--Hospitals
Haley, William H.--Correspondence
Haley family
United States--Civil War, 1861-1865
Maine--Civil War, 1861-1865
United States--History--Civil War, 1861-1865--Personal narratives
Haley, William, Jr.
Haley, Elzira M.
Davis, Charles
Haley, Mary A.
Haley, John (Johny) F.
Haley , Sarah D.
Haley, William (Billy) W.
Haley, Miriam Pugsley
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Just received a note from long-time reader David S. Weikel that Olympus 32MB SmartMedia is finally shipping in the US, which will be a huge relief for C2000Z owners who are struggling on 8 and 16MB SmartMedia cards. Here's an extract of his email:
"After waiting patiently for over a month, I finally received my order for 4 pieces from hardwarestreet.com. Of course the only way the C2000Z will do a locked exposure panoramic series is with Olympus brand media and these work just fine." (Thanks also to David for the picture).
David got four pieces giving him a total of 128MB!!!
Our affiliate State
Street Direct also have stock of
Olympus 32MB SmartMedia at US$94.95 per piece
here for more info


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with Tags:
Your CSP needs its CMO, CIO, and CTO collaborating
In my previous post , I talked about how a Communications Service Provider's (CSP's) network is very much like a SCADA system and how there is a lot of data collected as part of the running of the network. I also finished that discussion with a teaser about moving the collaboration from across the telecom ecosystem to inside the company. Well, here we are... In a blog entry from last August, IBM's Craig Hayman (IBM Software Group's GM of Industry Solutions) discussed how " your business may depend on your CMO and CIO working together... [More]
Tags:  collaboration telecom csp cio telecommunications cto cxo cmo |


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Regional Business NewsCovers publications that include business news from rural and metropolitan areas of the U.S. Types of publications include: newswires, newspapers, and business journals. Dates of coverage vary considerably among the publications. Some publications have full text, some only citations, and some a combination of both citations and full text. |
Audience | College, Adult |
Mobile App Available? | No |


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Find out more information about Arboriculturists, including quotes, reviews or special coupon... read moreoffers in dLook's business listings within Northern TAS. Through dLook search you can refine your preferred search area or results further from national down to a local suburb and then you may vary search terms to find results such as pruning, tree trimming or arboriculturist equipment sales and more in this category and in the areas that match a product or service type. Use the free quotes facility to seek quotes, read reviews, seek discount coupons or learn more about these businesses, products or services. Or just email or call a business displayed using the listing information to find out more about the Arboriculturists range of products and services on offer. Premium listings also feature social media information including Facebook pages, Twitter feeds and often a promotional video from YouTube click through to find more.
Located within Postcode 2 km 5 km 10 km 20 km 50 km 100 km 200 km State Nation
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"To active tree service,I would like to thank you for your commitment to your customers and your employees."
Lenny SANDS on 17th Aug 2011


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Because I had an entire day to play yesterday, I decided that I wanted to do something that was fun but also nurturing. I've been in desperate need of inspiration lately so what better place to refill my soul than at an art museum. I can't say that I consider myself a patron of the arts but I do like to purchase museum memberships so that I can feel like I am supporting access to the world's most amazing artists and their artwork. When I lived in Michigan, I was a member of the Detroit Institute of Arts. For the last few years, I've been a member of the Los Angeles County Museum of Art. The LACMA is exhibiting a retrospective of Stanley Kubrick's work and it seems like everyone I know has already seen it. Yesterday was my day to finally check out the exhibit and spend some time roaming the galleries at the LACMA.
The Stanley Kubrick exhibit is really impressive. Many of the props that were used in his films are on display and there is a lot of information about Kubrick's creative process. I understand the exhibit will be on display thru the end of June so if you live here in SoCal, I highly suggest you check it out.
The rest of the afternoon was spent enjoying some of the other art in the LACMA's collection:
I really love the permanent collection pieces housed at the LACMA and I often like much of the art on display in the Broad Contemporary Art Museum wing but … man, so much of the contemporary art in the BCAM is just so silly … I can't help but roll my eyes. There is an exhibit on display right now that fills a massive room with furniture painted pink. It's not even fancy furniture, it's like Ikea stuff … but it's all painted pink. I mean … art is subjective and clearly someone thinks this kind of thing is art. I think it's silly. But silly or not, it makes the viewer think and that is exactly the point. I'm glad I made the time to visit the LACMA/BCAM yesterday because the trip really made my day much brighter, much happier.
Tonight I'm hoping to meet up with my friend Jen for drinks but I'll spend my afternoon doing laundry. I have a mountain to get thru from my NYC trip and I have to repack for my upcoming weekend visit to Detroit. It's Monday. Happy New Week!!


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B3 Phenom arrives in Damage Labs Just arrived in Damage Labs: our first B3 Phenom, the new silicon revision with the fix for the TLB erratum. |
42 |
Even more CPU stuff I thought I ought to give you guys a quick update on what's cooking in Damage Labs. You've probably seen my Skulltrail review by... |
9 |
Skulltrail overclocking results are in When I posted my Skulltrail review, I didn't have time to include overclocking results, so I promised to add those later. Those results are |
3 |
Talkin' CES on the OCF Podcast I've made an appearance on the latest episode of the OCF Podcast. This time, we talk at some length about the developments in PC... Type: Blog post Tags: CPUs Graphics Displays Input devices |
14 |
A correction to our AMD TLB erratum coverage I was closing some windows on my laptop and came across an unsaved document in an unselected tab in my text editor that had some... |
25 |
Lessons from the difficult birth of the Spider platform We try not to get too much into behind-the-scenes drama here at TR, "inside baseball" stuff like how we deal with public relations types, because... Type: Blog post Tags: CPUs Graphics Chipsets The Tech Report |
152 |
So where's the Phenom review, man? I expect many of you came to TR this morning hoping to see a review of AMD's Phenom processor, since AMD has just launched the... Type: Blog post Tags: CPUs The Tech Report |
18 |
Penryn die shot wallpaper One of you guys wrote in and asked for a higher resolution version of the Penryn die photo that I ran in my Core... |
26 |
A quick look at where things are headed At last, a relaxing Friday evening! I can tell I'm relaxed when I grab the laptop and start catching up on answering my backlogged... |
6 |
Asus GTX 1080 and 1060 cards with faster RAM go the extra mile | 10 |


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Mount Sterling
Mount Sterling Travel Guide
Photos from Mount Sterling
Pictures of Mount Sterling (54)Hotel Deals in Mount Sterling
Hotels in Mount Sterling
Mount Sterling Accommodations (4)Ramada Limited Mount Sterling
115 Stone Trace Dr., Mount Sterling, United States
Comfort Inn and Suites Mount Sterling
105 Stone Trace Dr, Mount Sterling, United States
Days Inn Mt. Sterling Mount Sterling
705 Maysville Road, Mount Sterling, United States
Hotel Parque Las Palmas
517 Maysville Rd, Mount Sterling, United States
Travel Blogs from Mount Sterling
Mount Sterling Travel Blogs (8)Smooth Sixty Closer To New York City
Some serious planning was needed this morning and the campground living room provided the ideal environment for getting our heads together and working out where we are going to be staying for the next few nights. We were helped along by coffee and ...
Get ready, get set...
... free to go. To go anywhere but where I was. (Not surprising for a teenager.) So while I've lived in several states, I always seemed to just get stuck until I moved again. Heck, I've lived in Kentucky for almost ten years and ...
Photo Test & Packing Tidbit #1
Since I have to test a photo, might as well make it worthwhile. PACKING TIDBIT #1 - VEHICLE MEDICAL KIT I packed the medical kit for my truck in an old Betty Boop lunchbox. The mirror is left over from when I carried it as a handbag, but it ...