WordNet

(cosmology) the cooled remnant of the hot big bang that fills the entire universe and can be observed today with an average temperature of about 2.725 kelvin (同)CBR, cosmic microwave background radiation, CMBR, cosmic microwave background, CMB
(computer science) the area of the screen in graphical user interfaces against which icons and windows appear (同)desktop, screen background
a persons social heritage: previous experience or training; "he is a lawyer with a sports background"
understate the importance or quality of; "he played down his royal ancestry" (同)play down, downplay
information that is essential to understanding a situation or problem; "the embassy filled him in on the background of the incident" (同)background knowledge
extraneous signals that can be confused with the phenomenon to be observed or measured; "they got a bad connection and could hardly hear one another over the background signals" (同)background signal
the part of a scene (or picture) that lies behind objects in the foreground; "he posed her against a background of rolling hills" (同)ground
relatively unimportant or inconspicuous accompanying situation; "when the rain came he could hear the sound of thunder in the background"
the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay (同)radioactivity
energy that is radiated or transmitted in the form of rays or waves or particles
the act of spreading outward from a central source
a radial arrangement of nerve fibers connecting different parts of the brain
the spread of a group of organisms into new habitats
of or from or pertaining to or characteristic of the cosmos or universe; "cosmic laws"; "cosmic catastrophe"; "cosmic rays"
inconceivably extended in space or time

PrepTutorEJDIC

(景色・絵などの)『背景』,遠景 / (模様などの)地 / (事件などの)背景 / (人の)経歴,前歴
〈U〉(光・熱・放射能などの)発散,放射 / 〈C〉放射物;放射線;輻射(ふくしゃ)熱 / 〈C〉(喜び・幸福感などの)発散《+『of』+『名』》 / =radioactivity
『宇宙の』,宇宙に関する / 広大無辺の,(時的・空間的に)無限の

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/03/17 03:19:15」(JST)

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Temperature of the cosmic background radiation spectrum as determined with the COBE satellite: uncorrected (top), corrected for the dipole term due to our peculiar velocity (middle), and corrected for contributions from the dipole term and from our galaxy (bottom).

Cosmic background radiation is electromagnetic radiation from the sky with no discernible source. The origin of this radiation depends on the region of the spectrum that is observed. One component is the cosmic microwave background radiation. This component is redshifted photons that have freely streamed from an epoch when the Universe became transparent for the first time to radiation. Its discovery and detailed observations of its properties are considered one of the major confirmations of the Big Bang. The discovery (by chance in 1965) of the cosmic background radiation suggests that the early universe was dominated by a radiation field, a field of extremely high temperature and pressure.^[1]

The Sunyaev–Zel'dovich effect shows the phenomena of radiant cosmic background radiation interacting with "electron" clouds distorting the spectrum of the radiation.

There is also background radiation in the infrared, x-rays, etc., with different causes, and they can sometimes be resolved into an individual source. See cosmic infrared background and X-ray background. See also cosmic neutrino background and extragalactic background light.

Timeline of significant events

1896: Charles Édouard Guillaume estimates the "radiation of the stars" to be 5.6 K. Ref (PDF)

1926: Sir Arthur Eddington estimates the non-thermal radiation of starlight in the galaxy has an effective temperature of 3.2 K. [1]

1930s: Erich Regener calculates that the non-thermal spectrum of cosmic rays in the galaxy has an effective temperature of 2.8 K

1931: The term microwave first appears in print: ""When trials with wavelengths as low as 18 cm were made known, there was undisguised surprise that the problem of the micro-wave had been solved so soon." Telegraph & Telephone Journal XVII. 179/1"

1938: Nobel Prize winner (1920) Walther Nernst reestimates the cosmic ray temperature as 0.75 K

1946: The term "microwave" is first used in print in an astronomical context in an article "Microwave Radiation from the Sun and Moon" by Robert Dicke and Robert Beringer.

1946: Robert Dicke predicts a microwave background radiation temperature of 20 K (ref: Helge Kragh)

1946: Robert Dicke predicts a microwave background radiation temperature of "less that 20 K" but later revised to 45 K (ref: Stephen G. Brush)

1946: George Gamow estimates a temperature of 50 K

1948: Ralph Alpher and Robert Herman re-estimate Gamow's estimate at 5 K.

1949: Ralph Alpher and Robert Herman re-re-estimate Gamow's estimate at 28 K.

1960s: Robert Dicke re-estimates a MBR (microwave background radiation) temperature of 40 K (ref: Helge Kragh)

1960s: Arno Penzias and Robert Woodrow Wilson measure the temperature to be approximately 3 K. Robert Dicke, P. J. E. Peebles, P. G. Roll and D. T. Wilkinson interpret this radiation as a signature of the Big Bang.

References

^ "First minutes of the Big Bang". What is USA News. 12 March 2014. Retrieved 2013-11-19.

External links

The Diffuse X-ray and Gamma-ray Background & Deep Fields

UpToDate Contents

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1. 小児における放射線被曝の臨床的特徴 clinical features of radiation exposure in children
2. 画像検査の放射線関連リスク radiation related risks of imaging studies
3. 放射線療法誘発性肺障害 radiation induced lung injury
4. 成人における放射線障害の生物学および臨床的特徴 biology and clinical features of radiation injury in adults
5. 原子力災害後の小児における放射線被曝のマネージメント management of radiation exposure in children following a nuclear disaster

English Journal

f(T) teleparallel gravity and cosmology.

Cai YF1, Capozziello S, De Laurentis M, Saridakis EN.
Reports on progress in physics. Physical Society (Great Britain).Rep Prog Phys.2016 Oct;79(10):106901. doi: 10.1088/0034-4885/79/10/106901. Epub 2016 Sep 7.
Over recent decades, the role of torsion in gravity has been extensively investigated along the main direction of bringing gravity closer to its gauge formulation and incorporating spin in a geometric description. Here we review various torsional constructions, from teleparallel, to Einstein-Cartan,
PMID 27599606

Effects of the March 2015 solar eclipse on near-surface atmospheric electricity.

Bennett AJ1.
Philosophical transactions. Series A, Mathematical, physical, and engineering sciences.Philos Trans A Math Phys Eng Sci.2016 Sep 28;374(2077). pii: 20150215. doi: 10.1098/rsta.2015.0215.
Measurements of atmospheric electrical and standard meteorological parameters were made at coastal and inland sites in southern England during the 20 March 2015 partial solar eclipse. Clear evidence of a reduction in air temperature resulting from the eclipse was found at both locations, despite one
PMID 27550771

The incidence of breast cancer among female flight attendants: an updated meta-analysis.

Liu T1, Zhang C2, Liu C3.
Journal of travel medicine.J Travel Med.2016 Sep 5;23(6). pii: taw055. doi: 10.1093/jtm/taw055. Print 2016 Jun.
BACKGROUND: Several studies have indicated an increased risk of breast cancer (BC) among female flight attendants (FFAs); however, the results from epidemiological studies were not consistent. We thus conducted an updated meta-analysis to re-assess the risk of BC among FFAs, according to the MOOSE g
PMID 27601531

The origin, evolution and signatures of primordial magnetic fields.

Subramanian K1.
Reports on progress in physics. Physical Society (Great Britain).Rep Prog Phys.2016 Jul;79(7):076901. doi: 10.1088/0034-4885/79/7/076901. Epub 2016 May 31.
The universe is magnetized on all scales probed so far. On the largest scales, galaxies and galaxy clusters host magnetic fields at the micro Gauss level coherent on scales up to ten kpc. Recent observational evidence suggests that even the intergalactic medium in voids could host a weak ∼
PMID 27243368