Length of the groove in an LP record

There are questions that come up in the course of the day.  Sometimes they should never be uttered and no one really intends to follow up on them.  Then there are questions that I would categorize as ‘Mental Floss’.  I just want to know if anyone else has asked the same questions and if they have, how did they arrive at an answer? . . .

ARE YOU ACTUALLY TAKING TIME AT WORK FIGURING THIS OUT?!
No.  I chose to follow up on this investigation, at home, on my own time.

WHY WOULD I CARE?
Most
people wouldn’t.  There is a short list of people who ask these types
of questions.  If you are not one of these people, please look at my
other blog entries.

WHAT IS AN LP?
Wow!  Really, am I that old?  Guess you had to have been there.

QUESTION:
How long is the groove on one side of a long-play (33 1/3 rpm) phonograph record?

FINDINGS:
It would appear that some others have asked this question and have come up with some pretty elaborate ways to attack the problem.

SOURCE 1
This guy even had a specialized recorded pressed for just this question . . .
http://www.eatock.com/projects/quarter-mile-groove/

SOURCE 2
and this guy . . .http://mathforum.org/library/drmath/view/53769.html

SOURCE 3
and this group of
guys . . .http://audiokarma.org/forums/showthread.php?p=3216509

another person created a Lab Project around this question.
http://www4.uwm.edu/ret/projects/physics/highschool/surface/upload/RECORD-ALBUM-LAB.pdf

ANSWER:
So let’s say . . a 1/4-mile per
side.

And even some pictures of actual record surfaces.
http://en.wikipedia.org/wiki/File:Vinyl_groove_macro.jpg
http://en.wikipedia.org/wiki/File:Vinyl_disc_detail_2.jpg 
(a 45, and the red marks are 1mm apart)

Pretty neat.  Yeah, I thought so too.