Neb"u*la (?), n.; pl.
Nebulæ (#). [L., mist, cloud; akin to Gr.
&?;, &?;, cloud, mist, G. nebel mist, OHG. nebul, D.
nevel, Skr. nabhas cloud, mist. Cf. Nebule.]
1. (Astron.) A faint, cloudlike, self-
luminous mass of matter situated beyond the solar system among the
stars. True nebulæ are gaseous; but very distant star clusters
often appear like them in the telescope.
2. (Med.) (a) A white
spot or a slight opacity of the cornea. (b)
A cloudy appearance in the urine. [Obs.]
Neb"u*lar (?), a. Of or pertaining
to nebulæ; of the nature of, or resembling, a nebula.
Nebular hypothesis,
an hypothesis to explain
the process of formation of the stars and planets, presented in
various forms by Kant, Herschel, Laplace, and others. As formed by
Laplace, it supposed the matter of the solar system to have existed
originally in the form of a vast, diffused, revolving nebula, which,
gradually cooling and contracting, threw off, in obedience to
mechanical and physical laws, succesive rings of matter, from which
subsequently, by the same laws, were produced the several planets,
satellites, and other bodies of the system.
Pages:
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640