An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

The act or process of putting in a particular position or determining the psition of.

Verbal noun of → position; → -ing.

1) General: Explicitly stated, stipulated, or expressed.
2) Capable of being measured, detected, or perceived.
3) Math.: Noting a quantity greater than zero.
4) Physics: Having an electrical charge of the same polarity as that of a proton.
5) Photography: Having colors or values of dark and light corresponding to the subject.
6) Philosophy: Relating to the theory that knowledge can be acquired only through direct observation and experimentation, and not through metaphysics or theology. → positivism.
7) Law: Conclusive and beyond doubt or question; irrefutable.
8) Opposite of → negative.
See also:
→ positive charge, → positive correlation, → positive feedback, → positive skewness, → positiveness, → positivism.

M.E., from O.Fr. positif, from L. positivus "placed, settled; positive" (opposed to naturalis "natural"), from posit-, from positus "placed, put," p.p. of ponere "to put, place, set" + -ivus a suffix of adjectives.

Dâhidâr, from dâhid- + -âr. The first component is the past stem of *dâhidan "to put, create, determine," variant of dehidan, dâdan "to give;" from Mid.Pers. dâdan, dahidan "to give; to create;" O.Pers. dā- "to give, grant, yield;" Av. dā- "to give, grant; put; create; determine;" dāhi "he would give/put" (single second person, subjunctive transitive), dadāiti "he gives;" cf. Skt. dadáti "he gives;" Gk. tithenai "to place, put, set," didomi "I give;" L. dare "to give, offer," facere "to do, to make;" Rus. delat' "to do;" O.H.G. tuon, Ger. tun, O.E. don "to do;" PIE base *dhe- "to put, to do." The second component -âr, accusative suffix; on the model of gereftâr "captive, involved (in trouble)," didâr "exposed to view."

A charge having sign opposite to that of the electron.

→ positive; → charge.

Same as → direct correlation.

→ positive; → correlation.

A → feedback process in which the → output reacts on the → input so as to increase the initial → effect.

→ positive; → feedback.

Of a distribution function, a skewness in which the right tail (tail at the large end of the distribution) is more pronounced than the left tail (tail at small end of the distribution). → negative skewness.

→ positive; → skewness.

The quality or state of being positive; positivity.

→ positive + → -ity.

Any doctrine that excludes a priori affirmations and admits only positive truth, i.e. factual knowledge gained through observation.

From Fr. positivisme, from positif, → positive, in its philosophical sense of "imposed on the mind by experience;" → -ism.

The → antiparticle of the → electron, which has the same → mass, → spin, and → electric charge as the electron, but the charge is → positive. Positrons may be generated by → radioactive decay or by → pair production from energetic → gamma ray photons.

From posi(tive), → positive + (elec)tron→ electron.

A short-lived bound state of a positron and an electron.

From → positron + -ium (as in barium, titanium), from N.L., from L. neuter suffix.

Of a fluid parcel at pressure P, the density that it would acquire if adiabatically brought to a reference pressure.

→ potential; → density.

Same as → spectral density.

→ power; → spectral; → density.

A word used with a noun or pronoun to mark its relation with another word.

From L. praepositionem "a putting before," from praepositus, p.p. of praeponere "put before," from prae "before," → pre-, + ponere "put, set, place," → position.

Pišhel, from piš-, "before," → pre-, + hel-, helidan, heštan "to place, put," → leap.

A mathematical function whose integral over any interval gives the probability that a continuous → random variable has values in this interval. Also known as → density function, frequency function, → probability function.

→ probability; → density; → function.

1) The act of offering or suggesting something to be considered, accepted, adopted, or done.
2) A plan or scheme proposed.
3) Logic: A statement in which something is affirmed or denied, so that it can therefore be significantly characterized as either true or false.
4) Math.: A formal statement of either a truth to be demonstrated or an operation to be performed; a theorem or a problem (Dictionary.com).

Verbal noun of → propose.

Logic: Of, relating to, or in the form of a → proposition.

→ proposition; → -al.

Logic: A → propositional symbol that represents a → specific → proposition.

→ propositional; → constant.

A branch of logic that deals with the → truth values of logical statements (→ sentences, → propositions) and uses → logical connectives to build more complex → expressions. The distinctive feature of propositional logic is that it does not deal with logical relationships and properties that involve the parts of a statement smaller than the simple statements making it up. The propositions are evaluated as → true or → false. A more expressive system is provided by the → first-order logic.

→ proposition; → -al; → logic.

An upper case letter, e.g. "A," "B," "C," etc. representing a → proposition. Propositional symbols are divisible into two sorts: → propositional constants and → propositional variables.

→ propositional; → symbol.

Logic: A → propositional symbol that represents any → proposition whatsoever.

→ propositional; → variable.