| slovo | definícia |
Roentgen rays
(gcide) | X ray \X ray\, X-ray \X-ray\([e^]ks"r[=a]`), n. [so called by
its discoverer because of its enigmatical character, x being
an algebraic symbol for an unknown quantity.] (Physics)
Originally, any of the rays produced when cathode rays strike
upon surface of a solid (as a copper target or the wall of
the vacuum tube); now defined as electromagnetic radiation
with a wavelength of 0.1 to 10 nanometers. X-rays are noted
for their penetration of many opaque substances, as wood and
flesh, their action on photographic plates, and their
fluorescent effects. They were called X rays by their
discoverer, W. K. R["o]ntgen, but were also referred to for
some time as Roentgen rays. The term X-ray has become the
most common designation. They also ionize gases, but cannot
be reflected, or polarized, or deflected by a magnetic field.
They are used in examining objects opaque to visible light,
as for imaging bones or other structures inside the human
body, and for detecting flaws in metal objects, such as in
welds.
[Webster 1913 Suppl. +PJC] X ray |
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