Juin 2005

More documents

Recommendations

Info

Images from beyond theedge ofthe visible universeare forcing cosmologistsback to the drawing board.Sharmila Kamat explainstheir dilemmaPostcardslight frOID distant stars or galaxies. Ta anobserver on Earth, light from these distantfrom the edgeabjects appears to come from different partsofthe sky than it really does, producingmagnified,ghostlyimages ofcelestial objects.If a distantquasar, a large galaxy and theEarthare exactly aligned, the bending oflightby the galaxy will cause the quasar to appear asGo a smeared-out ring - an Einstein ring -. aroundthe lensinggalaxy(see Graphie, page 45).But if the threeare not aligned, and the lensinggalaxy is not symmetrical, the cosmic miragecan look hopelesslycomplicated. It takesITSTANDS outlike aneonsign in 30The results say one of them must be wrong. careful study by astronomers like Kochanekthe centreof the image,a thinbluearc Leading the challengeto received wisdom to work out precisely how several strangelytloatingovera golden-redblob. is Christopher Kcchanek, who studies cosmic shaped objects in the sky can be multipleThe blobis a giantelliptica1 galaxysix billion lenses at Ohio StateUniversity in Columbus, images of the same distant quasar.Itbecomeslight years frOID Earthin the constellation TogetherwithPaul Schechter of MIT and even more complicated because quasarsFomax. The arc above it is an illusion - a cosmic ethers, Kochanek analyses lenses that produce-tc change over tirne, altemately brighteningmirage createdas the light frOID a young two, thrce, or more images of distant galaxies and dimnùng. When a quasar flashes, so doblue galaxyup to 10billionlightyearsaway and quasars. The sciencehe uses dates hack its lensed images,but they change at slightlyis draggedintoa sernicircularshapeby the to 1911,when AlbertEinsteinshowed how the differentlimes, because the light rays\0 golden-redgiant'sgravity. presence of a mass bends light rays that pass it. producing the different images take differentCaptured in 2003 by the Hubble Space 40 Aceordingto Einstein'sgeneral theory of paths through space to reach Earth.Telescope,this is just one of many stunning relativity, a large mass like that of a giant It's this time lag that can be used to pingravitationallens images that decorate the galaxywill distortspace-time. The idea of down the ageof the cosmos. By showinghowsky. Gravitationa1lensesare nature's giant distorted space-time is often compared to much longer one path through space istelescopes,givingglimpses ofwhat lies the way a bowling ball rnightmake the elastic comparedwith another, the lime delay revealsbeyond the edge ofthe visible universe. fabricofa trampolinesag.Ifa smallerbail '&7 how far apart the Jens galaxy and the distantBut lookat them in the right way and rolls across the trampoline, its path will bend quasar are. And these distances can be usedthese shining, candy-coloured arcs offer around the largerobject. In the same way, to pin down the most important nurnber inmore thanjust distorted snapshots of young light rays bend when they travel throngh the cosmology, the Hubble constant,!20 galaxies.They can also tell us about the age regions of curved space around massive We live in an expandinguniverse in whichof the cosmos and the strange clark matter Ç'6 objectslike galaxies. galaxies are reced.ing from each other.that is sprinkled thronghout il. Gravity (1) actsas. lens, detlectingthe Think of the universeas a risingloaf of raisinIn the past few years, sorne astronomersstudying cosmic lenses have begun to do justthat Their results have led them to throwdown the gauntlet to their colleegues, pittingone cherished idea against another. One ofthese ideas is the apparentage ofthe universe.The other is our understanding ofclark matter."It would force an upwards revisionin the age of the universe from 14 billion10 20 billion years"42NewlS::';ientist 13f\bvember 2004W#W. newscientist.com
.\ hll~dl1ccnunl ~rl: 1.\\ lbl, )Tt:.; 111l' llXK.01\ 'llil,1IllKl.c.'.l'\ll·:1 di-;[;tll1.~II:I'.;\ 11111);1 rcrtcct Il11~But is th,l\ juxtificd" '111C timc dclavstudies depend criticullv un knoo, lll~ cxactlv110\\ the lcnsmg g
Page 4 and 5:
UNIVERSITE HENRI POINCARE, NANCY-IF
Page 7 and 8:
UNIVERSITE HENRI POINCAREFACULTE DE
Page 12 and 13:
UNIVERSITE HENRI POINCARE, NANCY 1
Page 14:
'
Page 17 and 18:
"f),DEG- t,o~o'+'NORMALEXLSli[.....
Page 19 and 20:
UNIVERSITE HENRI POINCARE, NANCY 1
Page 21 and 22:
Session de Juin 2005Sujet de Biolog
Page 23 and 24:
1. Donner le principe de la CMI liq
Page 25 and 26:
UNIVERSITE HENRI POINCARENANCY 1,Fa
Page 27 and 28:
2) Pétrographie Magmatique (5 poin
Page 29 and 30:
UNIVERSITÉ HENRI POINCARÉ,NANCY 1
Page 31 and 32:
PARTIE 2 : COURS DE B. VITaUXA rend
Page 33 and 34:
UNIVERSITE HENRI POINCARENANCY 1, F
Page 35 and 36:
UNIVERSITE HENRI POINCARE NANCY 1,F
Page 37 and 38:
UNIVERSITE Henri POINCARE • NANCY
Page 39 and 40:
UHP, Nancy 1 zème Session juin-jui
Page 41 and 42:
UNIVERSITE DE NANCY lFACULTE DES SC
Page 43 and 44:
UNIVERSITÉ H. POINCARÉ, NANCY 1FA
Page 45 and 46:
PARTIE 2 : COURS DE J.-L. GAILLARDA
Page 47 and 48:
Exercice 2 : Le jeu de Crapsbarème
Page 49 and 50:
Exercice 3 : VBAbarème: 1 + 3 + 2
Page 51 and 52:
23 Citez trois acides aminés pouva
Page 53 and 54:
UNIVERSITE HENRI POINCARE NANCY 1FA
Page 55 and 56:
Exercice n03Deux souches de Neurosp
Page 57 and 58:
UNIVERSITE HENRI POINCARE NANCY lFA
Page 59 and 60:
Partie C. Formulation de requêtes
Page 61 and 62:
Vue 1Vue 2
Page 63 and 64:
5. Si la population considérée es
Page 65 and 66:
2B.l. Tout ou partie de ce dendrogr
Page 67 and 68:
UNIVERSITE DE NANCY 1FACULTE DES SC
Page 69 and 70:
Page 71 and 72:
UNIVERSITE HENRI POINCARE, NANCY 1,
Page 73 and 74:
2- Indiquer sur le diagramme la ré
Page 75 and 76:
UNIVERSITE HENRI POINCARE, NANCY 1F
Page 77 and 78:
Page 79 and 80:
C 11 •:)1 S"Z81----_vÇ9"681:)Ç8
Page 81 and 82:
Epreuve d'Embryologie descriptive.S
Page 83 and 84:
UNIVERSITE HENRI POINCARE, NANCY 1-
Page 85 and 86:
Exercice 3On considère les transfo
Page 87 and 88:
DEUGSV2Université Henri Poincaré
Page 89 and 90:
UNIVERSITE DE NANCY 1FACULTE DES SC
Page 91 and 92:
UNIVERSITÉ HENRI POINCARÉ, NANCY
Page 93 and 94:
ANGLAIS SV2EXAMEN ANGLAIS 2 ème se
Page 95 and 96:
VIII.LINKWûRDS: Replace each numbe
Page 97 and 98:
Desperate to join in, urban investo
Page 99 and 100:
UNIVERSITE HENRI POINCARE NANCY lFA
Page 101 and 102:
6) Où est-il situé sur le diagram
Page 103 and 104:
Page 105 and 106:
UNIVERSITÉ HENRI POINCARÉ NANCY 1
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
UNIVERSITÉ HENRI POINCARÉ NANCY 1
Page 113 and 114:
UNIVERSITE HENRI POINCARE, NANCY 1F
Page 115 and 116:
Université Henri Poincaré Nancy 1
Page 117 and 118:
Université Henri Poincaré Nancy-I
Page 119 and 120:
Exercice 2 : Filtre CRLe filtre CR
Page 121 and 122:
Exercice 3 : le circuit RLCOn branc
Page 123 and 124:
Exercice 5:courant continu - circui
Page 125 and 126:
Epreuve d'Algèbre. Session d(IoI.
Page 127 and 128:
UNIVERSITE HENRI POINCARE NANCY 1SU
Page 129 and 130:
Question 4 : (1 point)Caractérisez
Page 131 and 132:
3) - Comment ferez-vous pour ajoute
Page 133 and 134:
Question 9 : (1 point)Quelle est la
Page 135 and 136: Donner la table de vérité du syst
Page 137 and 138: Résoudre sur IR l'équation diffé
Page 139 and 140: Mais ils ne sont pas les seuls à t
Page 141 and 142: Sujet1) Vous dégagerez, en 200 mot
Page 143 and 144: UNIVERSITE HENRI POINCARE NANCY 1SU
Page 145 and 146: Exercice IISoit n ): 2 et soient a
Page 147 and 148: nuité en O? (Justifier la réponse
Page 149 and 150: Exercice 31. Donner un automate non
Page 151 and 152: UNIVERSITE HENRI POINCARE NANCY 1FA
Page 153 and 154: - --':>-~vj 1 .. ..l,,".L.... 1.. .
Page 155 and 156: \ii\-)"52.EPREUVE D'ANALYSE 1juille
Page 157 and 158: 1. Montrer que f est une isométrie
Page 159 and 160: Université Henri Poincaré (Nancy
Page 161 and 162: Questions 1 à 6Donnez ce qu'affich
Page 163 and 164: UNIVERSITE HENRI POINCARE. NANCY 1F
Page 165 and 166: UNIVERSITE HENRI POINCARE. NANCY 1F
Page 167 and 168: Exercice 31) On rappelle, en spectr
Page 169 and 170: - enthalpie de fusion de la glace
Page 173 and 174: UNIVERSITE HENRI POINCARE NANCY 1Fa
Page 175 and 176: zème SU jet : TP de Cartographie (
Page 177 and 178: Université H.Poincaré DDEG20220EP
Page 179 and 180: Exercice IILa charge Q est réparti
Page 181 and 182: 5. Calculez les intégrales suivant
Page 183 and 184: l'énergie potentielle de la partic
Page 185: IV Vocabulaire: (12 points)Les verb
Page 191 and 192: 8. Pour l'observateur à l'intérie
Page 193 and 194: UNIVERSITE DE NANCY 1FACULTE DES SC
Page 195 and 196: Exercice 4 (Année bissextile)Un no
Page 197 and 198: 3°) En utilisant la propriété qu
Page 199 and 200: B] les antonymes de:ID Vocabulaire:
Page 201 and 202: Allen measured changes in the pcric
Page 203 and 204: UNIVERSITE HENRI POINCARE, NANCY 1F
Page 205 and 206: \:J>OC \} f)ErJ'HYGIENE DE L'ALIMEN
Page 207 and 208: Problème 3. (5 points)On cherche
Page 209 and 210: médecin pourra ensuite identifier
Page 211 and 212: ID Vocabulaire: (12 points)Les verb
Page 213 and 214: Allen measured changes in the penod
Page 215 and 216: UNIVERSITE HENRI POINCARE, NANCY 1F
Page 217 and 218: , ,METHODES MATHEMATIQUES POUR LES,
Page 219 and 220: Exercice 5Compléter les séquences
Page 221 and 222: exercice 3Le diagramme E-pH ci-dess
Page 223 and 224: UNIVERSITÉ HENRI POINCARÉNANCY 1F
Page 225 and 226: FACULTE DES SCIENCES ET TECHNIQUESS
Page 227 and 228: UNIVERSITE HENRI POINCARE, NANCY 1S
Page 229 and 230: UNIVERSITE HENRI POINCARE, NANCY-IF
Page 231 and 232: UNIVERSITE DE NANCY l - FACULTE DES
Page 233 and 234: 3- Sorne people use text messages f
show all

Juin 2005

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?