Einstein's Proof of E=mc²

Ever wonder how Einstein proved E=mc²? This is how.

Pi day (3.14) is Albert Einstein's Birthday! To celebrate, we'll explain 4 of his most groundbreaking papers from 1905, when he was just 26 years old.

And twitter - @minutephysics

Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!

Music by Nathaniel Schroeder

Thanks to Nima Doroud and Alex Yale for contributions and to Perimeter Institute for support. Created by Henry Reich

[rustysan]

The teacher: Any questions?
Me: Yeah, what the fck?

[gol.drodger]

Literally all I understood was light cat and spaceship

[Fjerid]

Just when I was about to crack the code with the cat he moved on to a freakin' spaceship.

[Octane]

Teacher: How could you not understand, the instructions were clear

The instructions:

[nottomentionanyone]

Before: hope could understand more
After: cat, energy, spaceship

[Tzadokite]

some problems with the derivation: 1) the expression for relativistic doppler effect with v^2 means that there can only be "blue" shift for a light source moving towards the observer or away from the observer. obviously this is not true, 2) one cannot use relativistic doppler expression and combine it with non-relativistic kinetic energy expression where v<<c. with this the doppler expression becomes E=E and we get E=0, 3) you need to show the derivation for the relativistic doppler effect as it is derived from E=MC^2 and the time dilation expression which makes the derivation shown tautological.

[Yashodhan]

I understood this perfectly. After watching it twice. After having done a General relativity course.

[JoakimKanon]

I’m even more confused now. Never heard of catnetic energy before.

[chem]

This is beautiful! I love how you do not need to use any calculus, as well as how short it is

[InsecureCreator]

That was surprisingly simple to understand so I assume you did a great job explaining it.

[tycoon]

Literally i thought i was dumb when i didn't understand anything..but now i feel relaxed when any of us understood nothing...

[AirCommandRockets]

Looks like the cat got out of the box again and is causing all kinds of havoc in the universe.

[conanngan]

Can someone explain to me how this relates to the regular doppler effect. Like the dominant effect of an object moving away from you is to red shift it, so when we measure the light it should have lost energy instead of gaining it like the video suggests. Also, can we know that KE + energy of the light accounts for all the energy in the system?

[m.elkhodeery]

*Top 10 scientists Eminem was afraid of :*

[Y.A]

E=MC2 = Explanation Might Confuse Too

[Hyporama]

This was simply amazing. Thank you so much for this. 00:38-1:00 that's where I began to understand the kernel of the idea.

[giannismalakos]

At this time i want to thank 0.25× for supporting me through this video

[theimprovingnoob]

Where can I found a radioactive floating cat

[guitarttimman]

I knew it was related to Kinetic Energy because the formulas are closely related. This is a good interpretation. Thank you.

[xxNavi]

Loved this video years ago when I had no clue what was happening and love it now even more rewatching it after a year of engineering thermo