“A guy walks into a bar...” is a typical form of what has been called the “bar joke.” A physics version is:

“A time-stretched sinusoid walks into a bar. The bartender asks, ‘Why the long phase?’”

“Why the long phase"” is a pun on the famous “Why the long face?” punchline of the “A horse walks into a bar...” joke. “A wave walks into a bar. The bartender says ‘Why the long phase?’. Wave replies ‘I’m sinusoidal’. This was rather depressing” was posted on Twitter on July 1, 2011. “A 20Hz sine wave walks into a bar, the barman says ‘hey, why the long phase?’” was posted on Twitter on November 9, 2011.

“A time-stretched sinusoid walks into a bar. The bartender asks, ‘Why the long phase?’” was posted on Reddit—Jokes on October 31, 2017.


Wikipedia: Sine wave
A sine wave or sinusoid is a mathematical curve that describes a smooth repetitive oscillation. A sine wave is a continuous wave. It is named after the function sine, of which it is the graph. It occurs often in pure and applied mathematics, as well as physics, engineering, signal processing and many other fields.

Twitter
Sriram Kvlteswaran‏
@srikvlteswaran
A wave walks into a bar. The bartender says “Why the long phase?”. Wave replies “I’m sinusoidal”. This was rather depressing.
3:05 AM - 1 Jul 2011

Twitter
Echidna GTA Records‏
@EchidnaUK
A 20Hz sine wave walks into a bar, the barman says ‘hey, why the long phase?’
8:55 AM - 9 Nov 2011

Twitter
Sarah Jones‏
@sarah_louiji
A 20Hz sine wave walks into a bar and the barman says ‘’Why the long phase?’’ #geek
5:23 PM - 14 Nov 2011 from Nottingham, England

Twitter
Nördar i allmänhet‏
@nerdsingeneral
Fredagsskämt
An ultralow frequency sine wave radiates into a bar.
The barman asks “Hey, why the long phase?”
8:05 AM - 18 Nov 2011

Facebook
TwoThirds
December 11, 2011 ·
A sine wave walks into a bar; the bar man asks, “why the long phase?”
Keep the production jokes coming..

Twitter
Peter Albrechtsen‏
@lydrummet
A 20 Hz sine wave walks into a bar.
“Hey, why the long phase?”
1:54 PM - 28 Jul 2017

Twitter
AUDIGY‏
@Audigyofficial
A 20hz sine wave walked into a bar.
The bartender asked: “Why the long phase?”
3:20 PM - 4 Oct 2017

Reddit—Jokes
A time-stretched sinusoid walks into a bar…
submitted October 31, 2017 by Lore0D
The bartender asks, “Why the long phase?”
COMMENTS
artemisvain
Engineering student here. I get the joke.

Parrek
Physics student here. Same

Twitter
Kelsie Hardy‏
@KelsieHardy2
A time-stretched sinusoid walks into a bar…
9:15 PM - 31 Oct 2017

Twitter
Nitish Shekhar‏
@nitzrulzx412
A time-stretched sinusoid walks into a bar…
9:16 PM - 31 Oct 2017

Twitter
Triston Stein‏
@SteinTriston
A time-stretched sinusoid walks into a bar…
9:32 PM - 31 Oct 2017