A

David

Darling

Encyclopedia of Science: O

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

 

O star
Oak Ridge Observatory
oak tree
OAO (Orbiting Astronomical Observatory)
oasis
OB association
OB stars
obelus
Oberon
Oberth, Hermann Julius (1894–1989)
objective
oblateness
oblique
obliquity
oblong number
OBSERVATIONAL ASTRONOMY
Observatoire de Haut-Provence
OBSERVATORIES AND TELESCOPES
obsidian
obstetrics
occipital artery
occipital bone
occipitofrontalis
occultation
occulting disk
ocean
ocean basin
ocean currents
ocean planet
ocean trench
ocean waves
oceanographic exploration
oceanography
oceans, origin
ocellus
ocher
Ockham (Occam), William of (c. 1280–1347)
octa-
octagon
octahedrite
octahedron
octane
Octans (constellation)
octonion
octopus
octopus eye
oculomotor nerve
odd
odd radio circle
ODERACS (Orbital Debris Radar Calibration Sphere)
odonatan
oersted (Oe)
Oersted, Hans Christian (1777–1851)
Ofeq
OFO (Orbiting Frog Otolith)
OGLE-2005-BLG-390Lb
OGO (Orbiting Geophysical Observatory)
Ohio State University Radio Observatory
Ohm, Georg Simon (1789–1854)
ohm (unit)
ohmmeter
Ohm's law
Ohzora
OICETS (Optical Inter-orbit Communications Engineering Test Satellite)
oil
oil sands
OKB-1
OKB-52
OKB-586
Okean
Oklo phenomenon
Oko
Olbers, Heinrich Wilhelm Matthias (1758–1840)
Olber's Paradox
oleic acid
olfactory nerve
Oligocene epoch
oligochaete
olive tree
Oliver, Bernard ("Barney") M. (1916–1995)
olivine
Olympus
Olympus Mons
Omega Centauri (NGC 5139)
Omega Nebula (M17, NGC 6618)
one
One Hectare Telescope
one-g spacecraft
O'Neill, Gerard Kitchen (1927–1992)
O'Neill-type colony
one-to-one (correspondence)
Onsager, Lars (1903–1976)
oocyst
oocyte
oogonium
oolith
Oort, Jan Hendrik (1900–1992)
Oort Cloud
oozes
opacity
opal
OPAL (Orbiting PicoSat Launcher)
Oparin, Aleksandr Ivanovich (1894–1980)
Oparin-Haldane Theory
Opel-RAK
open
open cluster
open-hearth process
Operation Paperclip
operator
operon
Ophelia
Ophidia
Ophiuchus (constellation)
Ophuroidea
Öpik, Ernst Julius (1893–1985)
opinion polls, about extraterrestrials
opium
Oppenheimer, (Julius) Robert (1904–1967)
Oppenheimer-Volkoff limit
opposition
ophthalmoscope
ophthalmia
ophthalmic nerve
ophthalmology
optic chiasm
optic nerve
optical activity
optical axis
optical depth
optical fiber
optical illusion
optical SETI
optical SETI at Berkeley
optical SETI at Harvard-Smithsonian
optics
OPTICS AND OPTICAL PHENOMENA
optometry
orange tree
Orbcomm
orbicularis oculi
orbicularis oris
Orbison's illusion
orbit
orbit (eye)
orbit decay
orbital
orbital airship
orbital cycler
orbital element
orbital loop
orbital migration
orbital muscles
orbital node
orbital period
orbital resonance
orbital station-keeping
Orbiting Astronomical Observatory (OAO)
Orbiting Geophysical Observatory (OGO)
Orbiting Solar Observatory (OSO)
OrbView
Orcus
order
ordered pair
ordinal number
ordinary chondrite
Ordovician
Ordway, Frederick Ira III (1927–2014)
ore
Oresme, Nicole (c. 13251382)
organ
organ of Corti
organ system
organic
ORGANIC CHEMISTRY
organic chemistry
organometallic compound
organophosphate
Orgel, Leslie E. (1927–2007)
Orgueil meteorite
orientable surface
ORIGIN AND EVOLUTION OF LIFE
Origins Program
Orion (constellation)
Orion (Crew Exploration Vehicle)
Orion, Project
Orion III Pan Am "Space Clipper" (2001: A Space Odyssey)
Orion Arm
Orion Complex
Orion Nebula (M42, NGC 1976)
Orion variable
Orionids
Orion's Belt
Orion's Sword
ornithischian
ornithopter
orpiment
orrery
Ørsted
orthoclase
orthogonal
orthopedics
orthopteran
orthopyroxenite
OSCAR (Orbiting Satellite for Communication by Amateur Radio)
oscillator
oscilloscope
OSETI
Osler, William (1849–1919)
osmium
osmoregulation
osmosis
osmotic pressure
ossicle
Osteichthyes
osteoarthritis
osteoblast
osteomyelitis
osteopathy
osteoporosis
ostrich
osteosarcoma
Ostwald, Friedrich Wilhelm (1853–1932)
Ostwald process
Osumi
otitis media
otoscope
Otto, Nikolaus August (1832–1891)
Oughtred, William (1575–1660)
outer ear
Outer Space Treaty of 1967
ovary (animal)
ovary (plant)
Ovda Regio (Venus)
overcontact binary
overtone
overweight and obesity
Overwhelmingly Large Telescope
Ovid's Game
oviduct
oviparous animal
ovipore
ovule
ovum
Owens Valley Radio Observatory
owl
Owl Nebula (M97, NGC 3587)
oxalic acid
oxaloacetate
oxbow lake
oxidation
oxidation number
oxide
oxidizing agent
oxime
oxy-acid
oxygen
oxygen therapy
oxytocin
Oyama, Vance I. (1922–1998)
Ozanam, Jacques (1640–1717)
Ozma, Project
ozone
ozone layer