I learned a new word today -- it's 'yrast'.

[eppur_se_muova]

The textbook that uses it has no index entry for that word.

Hey, I didn't say I learned what it *meant*!

[AndJusticeForSome]

1. Context? n/t

[eppur_se_muova]

3. Caption to Figure 13.13.

Two different ways of describing angular momentum for a given nucleus (upper part). In the case of (a), the nucleus acquires angular momentum by a collective rotation, resulting in a simple yrast spectrum. In case (b), the nucleus changes its spin by rearranging individual nucleon orbits resulting in complex energy spectra (Mottelson 1979).

from K. Heyde, Basic Ideas and Concepts in Nuclear Physics; Chapter 13, Deformation in nuclei: shapes and rapid rotation

Of course I Googled yrast, and Wikipedia has the right answer. But it was a little weird. The etymology of 'yrast' turns out to be Swedish, but it kind of reminded me of Middle English 'yclept'.

[emmaverybo]

2. I get Swedish, technical term used in nuclear physics. Nothing under slang. Nt

[backtoblue]

4. Does it itch?

I had a yrast infection once.

[NightWatcher]

5. Say something smart and I'll kick yrast.

[keithbvadu2]

6. I'm afraid this is one word I'm not going to remember.

I'm afraid this is one word I'm not going to remember.

[Harker]

8. Is there an echo in here? n/t

[KY_EnviroGuy]

7. Pretty good definition here...

The Free Dictionary
Link: https://encyclopedia.thefreedictionary.com/yrast

Yrast

Yrast (/ˈɪræst/; Swedish pronunciation: [ˈyːɾast]) is a technical term in nuclear physics that refers to a state of a nucleus with a minimum of energy (when it is least excited) for a given angular momentum. Yr is a Swedish adjective sharing the same root as the English weary. Yrast is the superlative of yr and can be translated whirlingest, although it literally means "dizziest" or "most bewildered". The yrast levels are vital to understanding reactions, such as off-center heavy ion collisions, that result in high-spin states.

Who can beat "whirlingest"?..... ......I can recall some folks from my drinking days that behaved yrast!

Oddly enough, some physics dictionaries did not have reference to that word....

KY..........