“The universe is made of protons, neutrons, electrons and morons” is a jocular saying that has been printed on many images. This line was printed in many publications in 1932:
   
“Scientist says that this universe is made up of protons, photons, electrons, and neutrons. He forgot to mention the morons — Dunbar’s Weekly.”
   
“The universe is made up of electrons, protons, neutrons, and morons. —Andy Dappen” was printed in the book The 2,548 Wittiest Things Anybody Ever Said (2012), but there is no evidence that Andy Dappen was the first person to say this.
   
   
Percentages are sometimes given. “Forget science class - the world is made of 35% protons, 25% neutrons, 20% electrons, and 20% MORONS” was posted on Twitter on May 19, 2009.
       
29 March 1932, Bonham (TX) Daily Favorite, pg. 2, col. 5:
Scientist says that this universe is made up of protons, photons, electrons, and neutrons. He forgot to mention the morons — Dunbar’s Weekly.
 
Google Books 
The Literary Digest
Volume 113
1932
Pg. 12:
SCIENTIST says that this universe is made up of protons, photons, electrons, and neutrons. He forgot to mention the morons — Dunbar’s Weekly.
   
Google Books
14,000 Quips & Quotes:
For Speakers, Writers, Editors, Preachers, and Teachers
By E. C. McKenzie
Grand Rapids, MI: Baker Book House
1990, ©1980
Pg. 461:
Scientists tell us that our universe is made up of protons, electrons, and neutrons. They forgot to mention morons.
 
Google Groups: comp.sys.intel
Electrons & Protons
Chris AWOL Curtis
4/16/94
(...)
But we have but one more thing to note:
The universeis composed of:
13% Electrons,
13% Protons,
14% Neutrons, and
60% Morons.
 
Google Groups: hfx.general
For the science minded
luriko
11/29/05
(...)
Scientists tell us the universe is made up of protons, electrons, and neutrons. They forgot to mention morons.
   
Twitter
RodneyBursiel‏
@RodneyBursiel
@laroja protons neutrons and morons
10:30 PM - 27 May 2008
 
Twitter
Lunatic_Binge‏
@SteveVelky65
forget science class - the world is made of 35% protons, 25% neutrons, 20% electrons, and 20% MORONS
3:54 PM - 19 May 2009
 
Twitter
Harrison Jay‏
@rangison
‘i know a little bit about science; theres protons electrons neutrons and morons.”
7:31 AM - 3 Jun 2009
 
Twitter
michael‏
@taximike
Scientists tell us the universe is made up of protons, electrons, and neutrons. They forgot to mention morons.
—Unknown #quotes
6:19 PM - 11 Aug 2009
 
Twitter
Nick Daudelin‏
@nickdaudelin
the universe is made up of 20% protons, 20% neutrons, 30% electrons, and 30% morons.
4:04 PM - 30 Nov 2009
 
Google Books
The 2,548 Wittiest Things Anybody Ever Said
Selected and compiled by Robert Byrne
New York, NY: Touchstone
2012
Pg. ?:
2,032
The universe is made up of electrons, protons, neutrons, and morons. —Andy Dappen
 
WeKnowMemes
They Forgot Morons
– JULY 24, 2012
POSTED IN: ECARDS, MEMES, PICS
Scientists say the universe is made up of Protons, Neutrons, and Electrons. They forgot to mention Morons. – ecard
 
Google Books
More One Liners, Jokes and Gags
Compiled by Grant Tucker
London, UK: Biteback Publishing Ltd
2013
Pg. ?:
Scientists say the universe is made up of protons, neutrons and electrons. They forgot to mention morons.
 
Twitter
Not Will Ferrell‏
@itsWillyFerrell
Scientists say the universe is made up of protons, neutrons and electrons. They forgot to mention morons.
5:30 PM - 4 Apr 2014
 
Me.Me
UNIVERSE IS MADE OF PROTONS NEUTRONS ELECTRONS MORONS HOW THE UNIVERSE IS MADE MEME
IM 14 & THIS IS DEEP HOW UNIVERSE UNIVERSITY THE UNIVERSE PROTON MORON NEUTRON MADE ELECTRON NEUTRONS ELECTRONICS UNIVERSAL THE MORONS ELECTRONICAL ELECTRONIC
FOUND @ 437690 VIEWS ON 2017-02-24 01:41:40 BY ME.ME
SOURCE: IMGUR