"You Matter. Unless/Until you multiply yourself by the speed of light squared. Then you Energy” is a science joke that has been printed on many images. The saying is based on the famous mass–energy equivalence in physics.

“You Matter - Until you multiply yourself times the speed of light squared. Then you Energy. http://tmblr.co/ZSyWkv1zo9IS2” was posted on Twitter by Patrick Toman on December 12, 2015. “You matter… Unless you multiply yourself times the speed of light squared. Then you energy” was posted on Twitter by Tara Abruzzese (and anoter) on June 25, 2016.

“There’s just no way around this one: YOU MATTER, unless you multiply yourself by the speed of light squared, then YOU ENERGY” was posted on Twitter by American astrophysicist, author, and science communicator Neil deGrasse Tyson on June 18, 2017, and again on Twitter on January 9, 2020. Tyson was not the first to use the saying.


Wikipedia: Mass–energy equivalence
In physics, mass–energy equivalence is the principle that anything having mass has an equivalent amount of energy and vice versa, with these fundamental quantities directly relating to one another by Albert Einstein’s famous formula:

E=mc^2

This formula states that the equivalent energy (E) can be calculated as the mass (m) multiplied by the speed of light (c = ~3×108 m/s) squared. Similarly, anything having energy exhibits a corresponding mass m given by its energy E divided by the speed of light squared c2. Because the speed of light is a large number in everyday units, the formula implies that even an everyday object at rest with a modest amount of mass has a very large amount of energy intrinsically.

Twitter
Patrick Toman
@PatrickAT
You Matter - Until you multiply yourself times the speed of light squared. Then you Energy. http://tmblr.co/ZSyWkv1zo9IS2
1:27 PM · Dec 12, 2015·Tumblr

Twitter
Travis Legge - Yugman’s Guide pt. 1 NOW AVAILABLE!
@TravisLegge
You Matter - patrickat: Until you multiply yourself times the speed of light squared. Then you Energy. http://tmblr.co/ZlGpXl1_UbQC-
5:38 PM · Dec 23, 2015·Tumblr

Twitter
♡
@infinitebiebs
You Matter - patrickat: Until you multiply yourself times the speed of light squared. Then you Energy. http://tmblr.co/Z7eTPx1_X-hB0
2:31 PM · Dec 24, 2015·Tumblr

Twitter
Tara Abruzzese
@tarakat_
You matter… Unless you multiply yourself times the speed of light squared. Then you energy ... Haha! Get it?? No.... K #ineedsleep
6:13 AM · Jun 25, 2016·Twitter for iPhone

Twitter
Clay Adams
@ClayAdamsBand
You Matter
Unless youre traveling at 4 times the speed of light
Then you energy
7:08 PM · Jun 25, 2016 from Eastpointe, MI·Twitter for Android

Twitter
Sarcasm
@sarcastic_us
You matter.
Unless you multiply yourself by the speed of light squared.
Then you energy.
12:26 AM · Jun 26, 2016·Twitter for Android

Twitter
wendell
@tekwendell
You matter. Unless you move at the speed of light. Then you energy
8:55 AM · Sep 7, 2016·Twitter Web Client

Twitter
Pat Ron
@RapGodPatRon
You Matter.... Until you multiply yourself times the speed of light squared… Then you Energy.
8:57 PM · Dec 27, 2016·Twitter for Android

Twitter
Neil deGrasse Tyson
@neiltyson
There’s just no way around this one: YOU MATTER, unless you multiply yourself by the speed of light squared, then YOU ENERGY.
10:00 PM · Jun 18, 2017·TweetDeck

Google Books
Title You Matter Until You Multiply Yourself by the Speed of Light Squared Then You Energy: 110-Page Funny Sarcastic Blank Lined Journal Makes a Great Teacher, Engineer Or Gag Gift Idea, 6x9
Author Tiny Camel Books
Edition illustrated
Publisher Amazon Digital Services LLC - Kdp Print Us, 2018
ISBN 1731562403, 9781731562401
Length 112 pages

Google Books
Title You Matter Unless You Multiply Yourself by the Speed of Light Squared Then You Energy: Science Lab Notebook, Blank Lined Journal, Diaries Gift for Science Lovers, Science Students.
Author Trendy Press
Publisher Independently Published, 2019
ISBN 1693288559, 9781693288555
Length 102 pages

YourTango
50 Positive Quotes From Different People Around The World
Emily Francos
October 27, 2019
(...)
19. You matter above all else.
“You matter. Unless you multiply yourself with the speed of light. Then you energy.” — Farah, 17 years old, Logatec, Slovenia

Twitter
Neil deGrasse Tyson
@neiltyson
You Matter.
Unless you multiply yourself by the speed of light squared.
Then you Energy.
3:03 PM · Jan 9, 2020·Twitter Web App