Utente:Vale maio/Sandbox3: differenze tra le versioni

Versione delle 02:51, 28 giu 2010

Versione delle 03:16, 28 giu 2010

Riga 282:

==fine Timeline (da CANCELLARE)==

La radiazione di fondo venne predetta nel 1948 da [[George Gamow]], [[Ralph Alpher]], ande [[Robert Herman]]<ref>

{{cite journal|last=Gamow|first=G.|year=1948|title=The Origin of Elements and the Separation of Galaxies|journal=[[Physical Review]]|volume=74|issue=4|pages=505–506|doi=10.1103/PhysRev.74.505.2}}</ref><ref>

{{cite journal|last=Gamow|first=G.|year=1948|title=The evolution of the universe|journal=[[Nature (journal)|Nature]]|volume=162|pages=680–682|doi=10.1038/162680a0}}</ref><ref>

Riga 307:

{{cite journal|last=Bennett|first=C.L.|coauthors=''et al.''|year=1996|title=Four-Year COBE DMR Cosmic Microwave Background Observations: Maps and Basic Results|journal=[[Astrophysical Journal Letters]]|volume=464|pages=L1–L4|doi=10.1086/310075}}</ref>.

Ispirato dai risultati di [[RELIKT-1]] e [[COBE]], nel decennio successico una serie di esperimenti da terra e da pallone aerostatico misureranno la radiazione di fondo su scale angolari più piccole. L'obiettivo primario di questi esperimenti è stato quello di misurare l'entità del primo picco acustico, dato che il COBE non aveva una risoluzione sufficiente per studiarlo a fondo. Questo picco corrisponde a variazioni di densità su grande scala nell'universo primordiale, che vengono creati da instabilità gravitazionale, con conseguente oscillazioni acustiche nel plasma<ref>

{{cite book|last=Grupen|first=C. |coauthors=''et al.''|year=2005|title=Astroparticle Physics|pages=240–241|publisher=[[Springer Science+Business Media|Springer]]|isbn=3540253122}}</ref>. TheIl firstprimo peakpicco innell'anisotropia theè anisotropystata wasprovvisoriamente tentativelyindividuata detected by thedal [[Toco experimentQMAP]] ande theil resultrisultato wasè confirmedstato byconfermato thedal [[BOOMERanG experiment|BOOMERanG]] ande dal [[Millimeter Anisotropy eXperiment IMaging Array|MAXIMA]] experiments.<ref>

{{cite journal|last=Miller|first=A. D.|coauthors=''et al.''|year=1999|title=A Measurement of the Angular Power Spectrum of the Microwave Background Made from the High Chilean Andes|journal=[[Astrophysical Journal]]|volume=521|issue=2|pages=L79–L82|doi=10.1086/312197}}</ref><ref>

{{cite journal|last=Melchiorri|first=A.|coauthors=''et al.''|year=2000|title=A Measurement of Ω from the North American Test Flight of Boomerang|journal=[[Astrophysical Journal]]|volume=536|issue=2|pages=L63–L66|doi=10.1086/312744}}</ref><ref>

{{cite journal|last=Hanany|first=S.|coauthors=''et al.''|year=2000|title=MAXIMA-1: A Measurement of the Cosmic Microwave Background Anisotropy on Angular Scales of 10'-5°|journal=[[Astrophysical Journal]]|volume=545|issue=1|pages=L5–L9|doi=10.1086/317322}}</ref>. TheseQueste measurementsmisurazioni demonstratedhanno thatdimostrato theche la [[Shapeforma of the Universe|geometry of the Universedell'universo]] isè approximatelyapprossimativamente flatpiatto, ratherpiuttosto thanche [[curved space|curved]].curvo<ref>

{{cite journal|last=de Bernardis|first=P.|coauthors=''et al.''|year=2000|title=A flat Universe from high-resolution maps of the cosmic microwave background radiation|journal=[[Nature (journal)|Nature]]|volume=404|issue=6781|pages=955–959|bibcode=2000Natur.404..955D|doi=10.1038/35010035|pmid=10801117}}</ref>. TheyEssi ruledescludono outstringhe [[cosmiccosmiche strings]]come ascomponente aprincipale majordella componentformazione ofdelle cosmicstrutture structurecosmiche, formatione andsuggeriscono suggestedche l'[[cosmicInflazione inflation(cosmologia)|inflazione cosmologica]] wasè thela rightteoria theorygiusta ofper structurespiegare formation.la formazione delle strutture<ref>

{{cite journal|last=Pogosian|first=L.|coauthors=''et al.''|year=2003|title=Observational constraints on cosmic string production during brane inflation|journal=[[Physical Review D]]|volume=68|issue=2|pages=023506|doi=10.1103/PhysRevD.68.023506|bibcode=2003PhRvD..68b3506P}}</ref>.

Inspired by the RELIKT-1/COBE results, a series of ground and balloon-based experiments measured cosmic microwave background anisotropies on smaller angular scales over the next decade. The primary goal of these experiments was to measure the scale of the first acoustic peak, which COBE did not have sufficient resolution to resolve. This peak corresponds to large scale density variations in the early universe that are created by gravitational instabilities, resulting in acoustical oscillations in the plasma.<ref>

{{cite book|last=Grupen|first=C. |coauthors=''et al.''|year=2005|title=Astroparticle Physics|pages=240–241|publisher=[[Springer Science+Business Media|Springer]]|isbn=3540253122}}</ref> The first peak in the anisotropy was tentatively detected by the [[Toco experiment]] and the result was confirmed by the [[BOOMERanG experiment|BOOMERanG]] and [[Millimeter Anisotropy eXperiment IMaging Array|MAXIMA]] experiments.<ref>

{{cite journal|last=Miller|first=A. D.|coauthors=''et al.''|year=1999|title=A Measurement of the Angular Power Spectrum of the Microwave Background Made from the High Chilean Andes|journal=[[Astrophysical Journal]]|volume=521|issue=2|pages=L79–L82|doi=10.1086/312197}}</ref><ref>

{{cite journal|last=Melchiorri|first=A.|coauthors=''et al.''|year=2000|title=A Measurement of Ω from the North American Test Flight of Boomerang|journal=[[Astrophysical Journal]]|volume=536|issue=2|pages=L63–L66|doi=10.1086/312744}}</ref><ref>

{{cite journal|last=Hanany|first=S.|coauthors=''et al.''|year=2000|title=MAXIMA-1: A Measurement of the Cosmic Microwave Background Anisotropy on Angular Scales of 10'-5°|journal=[[Astrophysical Journal]]|volume=545|issue=1|pages=L5–L9|doi=10.1086/317322}}</ref> These measurements demonstrated that the [[Shape of the Universe|geometry of the Universe]] is approximately flat, rather than [[curved space|curved]].<ref>

{{cite journal|last=de Bernardis|first=P.|coauthors=''et al.''|year=2000|title=A flat Universe from high-resolution maps of the cosmic microwave background radiation|journal=[[Nature (journal)|Nature]]|volume=404|issue=6781|pages=955–959|bibcode=2000Natur.404..955D|doi=10.1038/35010035|pmid=10801117}}</ref> They ruled out [[cosmic strings]] as a major component of cosmic structure formation and suggested [[cosmic inflation]] was the right theory of structure formation.<ref>

{{cite journal|last=Pogosian|first=L.|coauthors=''et al.''|year=2003|title=Observational constraints on cosmic string production during brane inflation|journal=[[Physical Review D]]|volume=68|issue=2|pages=023506|doi=10.1103/PhysRevD.68.023506|bibcode=2003PhRvD..68b3506P}}</ref>

The second peak was tentatively detected by several experiments before being definitively detected by [[WMAP]], which has also tentatively detected the third peak.<ref name="hinshaw07"/> As of 2010, several experiments to improve measurements of the polarization and the microwave background on small angular scales are ongoing. These include DASI, WMAP, BOOMERanG, [[Planck (spacecraft)|Planck spacecraft]], [[Atacama Cosmology Telescope]], [[South Pole Telescope]] and the [[QUIET telescope]].