Information about Blueshift
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Blue Shift refers to a shortening of a transmitted signal's wavelength, and/or an increase in its frequency. The name comes from the fact that the shorter-wavelength end of the optical spectrum is the blue (or violet) end, hence, when visible light is compacted in wavelength, it is "shifted towards the blue", or "blue-shifted". Since the longer-wavelength end of the visible electromagnetic spectrum is red, the opposite effect, of a lengthening of a signal's wavelength, is referred to as redshifting.
These terms and conventions ("blue" = compaction, "red"=stretching) are used even when referring to signals outside the optical range (for instance, radio waves, x-rays and gamma rays).
These effects are usually associated with relative motion between the signal source and the observer (a Doppler shift or Doppler effect), where a blueshift will be caused by the two moving towards each other. The term is also used informally to refer to a hypsochromic shift in photochemistry.
Astronomy
Redshift is much more noted due to its importance to modern astronomy. While the general redshift of starlight is seen as evidence for an expanding universe, there are a few examples of blue shift in astronomy:- The Andromeda Galaxy is moving towards our own Milky Way Galaxy within the Local Group; thus, when observed from earth, its light is undergoing a blue shift.
- When observing spiral galaxies, the side spinning towards us will have a slight blue shift (see Tully-Fisher relation).
- Also, Blazars are known to propel relativistic jets towards us, emitting synchrotron radiation and Bremsstrahlung that appears blue shifted.
- Nearby stars such as Barnard's Star are moving towards us, resulting in a very small blue shift
Cause of blueshift in astronomy
These are the known possible causes of blue shift in astronomy:- Movement of the source towards us, as seen in
- the edge of a rotating galaxy moving towards us
- In blazars which propel relativistic jets towards us
- Some galaxies http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1969ApJ...157L.155B&db_key=AST&data_type=HTML&format=&high=42ca922c9c07726 and quasars http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2005ApJ...618..601A&db_key=AST&data_type=HTML&format=&high=42ca922c9c07726
- Gravitational effects. See gravitational redshift
See also
Physical cosmology, as a branch of astronomy, is the study of the large-scale structure of the universe and is concerned with fundamental questions about its formation and evolution. Cosmology involves itself with studying the motions of the celestial bodies and the first cause.
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The age of the universe, in physics, is the time elapsed between the Big Bang and the present day. Current observations suggest that this is about 13.7 billion years, with an uncertainty of about +/-200 million years.
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Big Bang is the cosmological model of the universe whose primary assertion is that the universe has expanded into its current state from a primordial condition of enormous density and temperature.
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Blue Shift refers to a shortening of a transmitted signal's wavelength, and/or an increase in its frequency. The name comes from the fact that the shorter-wavelength end of the optical spectrum is the blue (or violet) end, hence, when visible light is compacted in
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In standard cosmology, 'comoving' distance or 'proper distance' is one of several distance measures used by cosmologists to define distances between objects.
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Comoving coordinates
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cosmic microwave background radiation (most often abbreviated CMB but occasionally CMBR, CBR or MBR, also referred to as relic radiation) is a form of electromagnetic radiation discovered in 1965 that fills the entire universe [1].
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In physical cosmology, dark energy is a hypothetical form of energy that permeates all of space and tends to increase the rate of expansion of the universe. [1]
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In astrophysics and cosmology, dark matter is hypothetical matter of unknown composition that does not emit or reflect enough electromagnetic radiation to be observed directly, but whose presence can be inferred from gravitational effects on visible matter.
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Friedmann-Lemaître-Robertson-Walker (FLRW) metric is an exact solution of the Einstein field equations of general relativity; it describes a , isotropic expanding or contracting universe.
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The Friedmann equations are a set of equations in cosmology that govern the expansion of space in homogeneous and isotropic models of the universe within the context of general relativity.
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formation of galaxies is still one of the most active research areas in astrophysics; and, to some extent, this is also true for galaxy evolution. Some ideas, however, have gained wide acceptance.
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Hubble's law is a statement in physical cosmology which states that the redshift in light coming from distant galaxies is proportional to their distance. The law was first formulated by Edwin Hubble and Milton Humason in 1929[1] after nearly a decade of observations.
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In physical cosmology, cosmic inflation is the idea that the nascent universe passed through a phase of exponential expansion that was driven by a negative-pressure vacuum energy density.
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large-scale structure refers to the characterization of observable distributions of matter and light on the largest scales (typically on the order of billions of light-years).
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ΛCDM or Lambda-CDM is an abbreviation for Lambda-Cold Dark Matter. It is frequently referred to as the concordance model of big bang cosmology, since it attempts to explain cosmic microwave background observations, as well as large scale structure
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The metric expansion of space is a key part of science's current understanding of the universe, whereby spacetime itself is described by a metric which changes over time in such a way that the spatial dimensions appear to grow or stretch as the universe gets older.
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In physical cosmology, Big Bang nucleosynthesis (or primordial nucleosynthesis) refers to the production of nuclei other than those of H-1 (i.e. the normal, light isotope of hydrogen, whose nuclei consist of a single proton each) during the early phases of the
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This article or section may contain inappropriate or misinterpreted which do not the text.
Please help [ improve this article] by checking for inaccuracies. This article has been tagged since October 2007.
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Please help [ improve this article] by checking for inaccuracies. This article has been tagged since October 2007.
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redshift occurs when the electromagnetic radiation, usually visible light, that is emitted from or reflected off an object is shifted toward the (less energetic) red end of the electromagnetic spectrum.
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The shape of the Universe is an informal name for a subject of investigation within physical cosmology. Cosmologists and astronomers describe the geometry of the universe which includes both local geometry and global geometry.
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Structure formation refers to a fundamental problem in physical cosmology. The universe, as is now known from observations of the cosmic microwave background radiation, began in a hot, dense, nearly uniform state approximately 13.7 Gyr ago.
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Physical cosmology
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- Age of the universe
- Big Bang
- Blueshift
- Comoving distance
- Cosmic microwave background
- Dark energy
- Dark matter
- FLRW metric
- Friedmann equations
- Galaxy formation
- Hubble's law
- Inflation
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For a timeline of the cosmos (or universe), see .
This timeline of cosmological theories and discoveries is a chronological catalog of the evolution of humankind's understanding of the cosmos over the last two-plus millennia.
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The ultimate fate of the universe is a topic in physical cosmology. Many possible fates are predicted by rival scientific theories, including futures of both finite and infinite duration.
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The Universe is defined as the summation of all particles and energy that exist and the space-time in which all events occur. Based on observations of the portion of the Universe that is observable, physicists attempt to describe the whole of space-time, including all matter and
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Astronomy is the scientific study of celestial objects (such as stars, planets, comets, and galaxies) and phenomena that originate outside the Earth's atmosphere (such as the cosmic background radiation).
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General relativity (GR) (aka general theory of relativity (GTR)) is the geometrical theory of gravitation published by Albert Einstein in 1915/16.[1] It unifies special relativity, Newton's law of universal gravitation, and the insight that gravitational
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Particle physics is a branch of physics that studies the elementary constituents of matter and radiation, and the interactions between them. It is also called "high energy physics"
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Quantum gravity is the field of theoretical physics attempting to unify quantum mechanics, which describes three of the fundamental forces of nature, with general relativity, the theory of the fourth fundamental force: gravity.
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In physics, wavelength is the distance between repeating units of a propagating wave of a given frequency. It is commonly designated by the Greek letter lambda (λ). Examples of wave-like phenonomena are light, water waves, and sound waves.
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