forbidden line

forbidden line

[fər¦bid·ən ′līn]
(atomic physics)
A spectral line associated with a transition forbidden by selection rules; optically this might be a magnetic dipole or electric quadrupole transition.
References in periodicals archive ?
If there is any consistency in Duterte's boastful words and braggadocio, it is this: his Machiavellian approach to governance-that he will not hesitate to kill people who cross the forbidden line of crime or get in the way of his initiatives on national discipline.
The announcements raise the prospect that the countries' nuclear programs could come under the microscope of international inspectors to ensure that they don't cross the forbidden line into weapons programs.
If the role of religious beliefs is exaggerated in the [standards], schools run the risk of crossing that forbidden line."
"I'm now crossing this forbidden line. More people will follow me....
"I am now crossing this forbidden line."Roh was expected to offer a package of incentives that could boost the North's economy and make reunification eventually possible between the suffering Stalinist nation and its wealthier neighbor.
''I, as president, cross this forbidden line. As I do this, more people will be able to visit (North Korea) and return and the line will be gradually erased and the barrier will be torn down,'' Roh said before taking his symbolic walk over the border.
Some of the features observable with this phenomenon include strong Balmer line emissions, forbidden line emissions from low-ion elements and the presence of an infrared excess due to hot circumstellar dust.
Religious leaders cross a forbidden line when they use church resources to intervene in a partisan election or distribute a candidate's campaign literature.
However, when state legislators decided to appropriate a few Christian symbols for their political purpose (never too unhealthy to pander to the state majority in a turmoil-filled election year), they crossed a forbidden line. They were now promoting Christianity over all other faiths.
In practice, two consecutive sides of a frame are called 'forbidden lines' and nothing cut by these lines is considered in the counts (Fig.
Later studies showed that these were the "forbidden lines" of doubly ionized oxygen.
The tables are arranged in order of decreasing wavelengths, and they include so-called forbidden lines, which are very important for plasma diagnostic applications.