<< < -es -iv -ti 21 a p abe abs abs aca acc acc acr act ada adh Adr aer AGB air Alf Alg all alp alt AM amo ana And ang ani ano Ant Ant apa apo app app Ara Arc ari Arr ash ass ast ast asy atm ato att aut ave axi Bab bal Bal bar bar bea Bek Bes bia Big bin bin bip biv bla bli blu Boh Bol Bos bou bra bri bro buo cal cal can cap car Car cat cat CCD Cen cen CH cha cha che Che chr cir cir cit cla clo clo clu Coa coe coh col col col com com com com com com com com Com con con con con con con con con con con con con Cop Cor cor cor cos cos cou cou Cow cre cri cro cry cur cya Cyg dan dar dat de- deb dec dec ded def deg del dem den dep des det dev dia dif dif dih dio Dir dis dis dis dis dis dis DO don dou dow dro dur dwa dyn Dys ear ebb ecl edg egg Ein Ela ele ele ele ele ell eme emp enc eng ent epi equ equ equ esc eth Eur Eve exa exc exe exi exp exp ext ext ext fac fal far fed Fer fer fie fin fir fis fla flo flu fol for for fou fra fre Fre fro fut G-t gal gal gam gas Gau Gem gen geo geo geo gia Gli Gol gra gra gra gra gre gri gui H I Hag hal har hat He- hea hel Hel her Hes hie hig his hom hor hot Hub Hug hur hyd hyd hyg hyp ice ide ima Ima imp imp inc inc ind ine inf inf inf ing inn ins ins int int int int int int int int inv Io ion iro isl iso iso Jac jet jud jur Kel Kep kil Klo Kui Lag lam Lap Lar lat law lea len lep Lib lig lim lin lin Lio lit loc LOF lon Lor low lum lun Lup Lyo mac mag mag mag mag mag mai man Mar mas mas mat Max mea mec Meg Mer Mer met met Met mic Mid Mil min Mir mit mod mod mol mon Mor mou mul mul mys nan Nat nau nec neo neu nev New NGC no nom non non nor not nuc nuc num nut obj obs obs occ ocu oft ome Oor ope opp opt opt orb ord ori ort osc out ove oxi pai pan par par par par pas pea pen per per per per Per per pha phi pho pho pho phy pio Pla pla pla pla Pla plu Poi pol pol pol poo pos pos pot pra pre pre pre pre pri pri pro pro pro pro pro Pro pro pse pul pur qua qua qua qua que rac rad rad rad rad rad rad ran rar ray rea rea rec rec red red ref ref reg rel rel rel ren res res res res ret rev Ric rig rin roc roo rot rot Rus Sac sal sat sca sca Sch sci Scu sec sec Sed sel Sel sen ser Sex Sha she sho sid sig sil sim sin siz sla Sma sno sof sol sol sol sol sou sou spa spa spe spe spe sph spi spi spr squ sta sta sta sta ste ste ste Sto Str str str sub sub suc sun sup sup sup sup sur swa syn syn tab tar tek tem ter tes the the the the Tho thr tid tim Tis Too Tor tra tra Tra tra tra tri tri tru Tul tur two Typ ult un- und uni uni unk upp Urc utt val var vec vel ver vib vio vir vis voi vor wan wat wav wax wea Wei whi Wil win WN9 wor X-r yel you zer zod > >>
A specialist in → physics.
The science that deals with matter and energy and their interactions.
M.E. fisyk(e), phisik(e), from O.Fr. fisique, from L. physica (fem. sing.) "study of nature," from Gk. physike episteme "knowledge of nature," from fem. of physikos "pertaining to nature," from physis "nature," from phyein "to bring forth, produce, make to grow," Gk. phy- "to become;" L. fui "I was," futurus "that is to be, future;" Ger. present first and second person sing. bin, bist; E. to be; O.Ir. bi'u "I am;" Lith. bu'ti "to be;" Rus. byt' "to be."
Loan from Fr. physique, as above.
adad-e pi (π)
Fr.: nombre pi (π)
Symbol, π, for the ratio of the circumference of a circle to its diameter in Euclidean geometry; a fundamental mathematical constant, equal to 3.14159... π is an → irrational number (Lambert, 1761) and also a → transcendental number (von Lindemann, 1882). The most accurate determination of π prior to the Scientific Revolution belongs to the Iranian mathematician Jamshid Kashani, who gave 16 correct decimal places in A.D. 1424. With the advent of → calculus and more recently the invention of powerful computers, the decimal representation of π has now been computed to more than 1012 digits.
The π notation, representing the first letter of the Gk. word περιμετρον → perimeter, was first used by the British mathematician William Jones (1675-1749) in 1706. Its use was generalized after its adoption by the Swiss mathematician Leonard Euler (1707-1783) in 1737; → number.
Piazzi's Flying Star
setâre-ye parande-ye Piazzi
Fr.: étoile volante de Piazzi
Giuseppe Piazzi (1746-1826) was the first to notice the large → proper motion of the star, in 1804. His observations over a period of 10 years revealed the largest proper motion ever detected for any star at the time, leading him to baptize it the "Flying Star;" → fly; → star.
seri-ye Pikering (#)
Fr.: série de Pickering
A series of → spectral lines of → singly ionized helium, observed in very hot → O-type and → Wolf-Rayet stars associated with transitions between the → energy level with → principal quantum number n = 4 and higher levels: n = 4-5 (10124 Å), n = 4-7 (5412 Å), n = 4-9 (4541 Å), n = 4-9 (4522 Å), and n = 4-11 (4200 ˚). The 4-6 (6560 Å) and 4-8 (4859 Å) transitions were originally not included in this series because they coincided with the hydrogen → Balmer series of lines and were thus obscured.
In honor of Edward C. Pickering (1846-1919), American astronomer and physicist; → series.
A prefix denoting 10-12.
From It. piccolo "small."
The Painter's Easel. A faint constellation in the southern hemisphere, at 5h 30m right ascension, 50° south declination. Its brightest star is of magnitude 3.2. Its second brightest star, → beta Pictoris, is famous for its → circumstellar disk of gas and dust. Abbreviation: Pic; genitive: Pictoris.
Pictor, short for Equuleus Pictoris "painter's easel," from L. pictor "painter," from pingere "to make pictures."
Negârgar "painter," from negâr present stem of negâštan "to paint," negâr "picture, figure," from prefix ne- "down; into" (O.Pers./Av. ni- "down; into;" cf. Skt. ni "down," nitaram "downward;" Gk. neiothen "from below;" E. nether; O.E. niþera, neoþera "down, downward, below, beneath," from P.Gmc. *nitheraz; Du. neder; Ger. nieder; PIE *ni- "down, below") + gâr, from kar-, kardan "to do, to make" (Mid.Pers. kardan; O.Pers./Av. kar- "to do, make, build;" Av. kərənaoiti "he makes;" cf. Skt. kr- "to do, to make," krnoti "he makes, he does," karoti "he makes, he does," karma "act, deed;" PIE base kwer- "to do, to make").
Any visible image, however produced. → photograph.
From L. pictura "painting," from pictus, p.p. of pingere "to make pictures, to paint."
Fartur "picture, image; reflexion, inversion" (Dehxodâ, Steingass); maybe from partow, → ray.
Fr.: pièce, morceau, tache
1) A portion of an object or of material, produced by cutting, tearing, or breaking
M.E. pece, peece, from O.Fr. piece, from V.L. *pettia, probably from Gaulish (cf. Welsh peth "thing;" Breton pez "piece").
Teké "piece, patch."
Fr.: par morceaux
piecewise continuous function
karyâ-ye peyvaste-ye tekke-yi
Fr.: fonction continue par morceaux
A function f(x) in an interval if :1) the interval can be divided into a finite number of pieces in each of which f(x) is continuous, and 2) the limits of f(x) as x approaches the boundary point of each piece are finite. In other words, a piecewise continuous function is one that is made up of a finite number of continuous pieces.
Fr.: effet piézoélectrique
The property exhibited by some crystals (notably quartz) that develop an electric charge or potential difference across them when subjected to mechanical strain; and conversely produce mechanical forces when a voltage is applied to them in a suitable manner.
An assemblage of things laid or lying one upon the other (Dictionary.com).
M.E., from M.Fr. pile and directly from L. pila "pillar, mole of stone."
Tal "heap; hill," maybe related to Gk. tylos "a hard and thickened area on the skin, callus, lump," tymbos "burial mound, grave, tomb;" Av. tuma- "fat;" L. tumere "to swell," tumulus "raised heap of earth," tumidus "swollen;" tumor "a swelling."
An elongated structure often found at the interface between an → H II region and its associated → molecular cloud. Also called → elephant trunk. The most famous examples are the "pillars of creation" in the → Eagle Nebula, which are several → light-years in length. There are indications for star formation at the tips of the pillars. In general the pillars point like fingers toward the young → massive stars ionizing the nebula. Most of the mass is concentrated in the head which has a bright rim facing the young stars.
M.E. pillare, O.Fr. piler, from M.L. pilare, from L. pila "pillar, stone barrier."
Sotun "pillar," → column.
The component of a → planispheric astrolabe that is inserted in the back of the → mater. The pin enables the main parts of the instrument (the → alidade, the → rete, and the → rule) to rotate freely around the common center of the mater and the → tympanum (online museo galileo, VirtualMuseum).
M.E. pinne, from O.E. pinn "peg, bolt," from L. pinna "a feather, plume."
&ACIRC;sé, → axis.
Fr.: effet de striction
The constriction of a current-carrying plasma column caused by its external self-magnetic field.
M.E. pinch, from O.Fr. pincier "to pinch," possibly from V.L. *punctiare "to pierce," from L. punctum "point," and *piccare "to pierce."
Penk "pinch, squeezing or compressing between the finger and thumb" (Dehxodâ), cf. (Tabari) pendik, pecelik, (Kermâni) perenju "pinch," maybe related to panjé "the palm of the hand with five fingers; fist," from panj "five," from Mid.Pers. panj; Av. panca; cf. Skt. pánca; Gk. pente; L. quinque; O.E. fif, from P.Gmc. *fimfe (O.S. fif, O.H.G. funf); from PIE base *penkwe "five."
Fr.: distorsion en coussinet
An → aberration of a → lens → system in which → magnification increases with → distance from the → optical axis, whereby → horizontal and → vertical lines bend inward toward the → center of the → field. Opposite of → barrel distortion.
Pincushion, from pin, from M.E. pinne, O.E. pinn "peg;" cf. D. pin, Ger. Pinne; perhaps from L. pinna "feather, quill" + cushion, M.E. cuisshin, O.Fr. coissin (Fr. coussin) a variant of V.L. *coxinum, either from L. coxa "hip, thigh," or from L. culcita "mattress;" → distortion.
Cowlegi, → distortion; bâleštaki, adj. of bâleštak, diminutive of bâlešt, variant bâleš "cushion, pillow," Mid.Pers. bâlišn, bâlên "cushion, pillow;" Av. barəiš- "pillow, cushion;" cf. Skt. barhis- "straw, a bed or layer of kusa grass strewed over the sacrificial ground."
In a → planispheric astrolabe, a vane on an end of an → alidade with a hole, slot, or other indicator through which one can view a distant object. There may also be a pointer or pointers on the alidade to indicate a position on a scale.
Diminutive of L. pinna "feather, wing, fin;" + → -ule.
Fr.: moulin à vent
A child's toy consisting of a wheel or leaflike curls of paper or plastic loosely attached by a pin to a stick, designed to revolve when blown by or as by the wind (Dictionary.com).
Ferferé "pinwheel," of unknown origin.