## Thursday, April 03, 2008 ... //

### Max Tegmark: We all believe in relativity

SPECIAL RELATIVITY

Römer measured the speed of light,
and something basic just wasn’t right.
because Michaelson and Morley
showed that aether fit data poorly.

In Einstein’s brain, ideas thrive:
“The laws of nature must be the same
in every inertial frame”

We all believe in relativity, relativity, relativity.
Yes we all believe in relativity, 8.033, relativity.

Einstein’s postulates imply
that planes are shorter when they fly.
Their clocks are slowed by time dilation,
and look warped from aberration.

Cos theta-prime is cos theta minus beta ... over one minus beta cos theta.
Yes we all believe in relativity, 8.033, relativity.

With the Lorentz transformation,
we calculate the relation
between Chris’s and Zoe’s frame,
but all invariants, they are the same.
Like B dot E and B-squared minus E-squared,

... and the rest mass squared which is E-squared minus p-squared.
’cos we all believe in relativity, 8.033, relativity.

for using relativity.
But nukes made us all scared
because E = mc2.

Everything is relative, even simultaneity,
and soon Einstein’s become a de facto physics deity.
’cos we all believe in relativity, 8.033, relativity.

GENERAL RELATIVITY

and in nineteen sixteen
between gravity and acceleration.
He said physics ain’t hard at all
as long as you are in free fall,
’cos our laws all stay the same
in a locally inertial frame.

And he called it general relativity, relativity, relativity.
And we all believe in relativity, 8.033, relativity.

If towards a black hole you fall
tides will make you slim tall,
but your friends won’t see you enter
a singularity at the center,
because it will look to them
like you got stuck at radius 2M.
But you get squished, despite this balking,
and then evaporate, says Stephen Hawking.

We all believe in relativity, relativity, relativity.
Yes we all believe in relativity, 8.033, relativity.

We’re in an expanding space
with galaxies all over the place,
and we’ve learned from Edwin Hubble
that twice the distance makes redshift double
We can with confidence converse
about the age of our universe.
Rival theories are now moot
thanks to Penzias, Wilson, Mather & Smoot.

We all live in an expanding universe, expanding universe, expanding universe.
Yes we all live in an expanding universe, expanding universe, expanding universe.

But what’s the physics of creation?
There’s a theory called inflation
by Alan Guth and his friends,
but the catch is that it never ends,
making a fractal multiverse
which makes some of their colleagues curse.
Yes there’s plenty left to figure out

but at least we believe in relativity, relativity, relativity.
Yes we all believe in relativity, 8.033, relativity.
Max Tegmark (MIT course 8033, preprint) decided to replace boring calculations by the Beatles, with the guitar help by Tali Figueroa. Let's hope that the students, including those in the Yellow Submarine, will get the point faster than ever before. :-)

Besides several equations, they also mention that the laws of Nature must be the same in every reference frame. Too bad that most of the blogosphere is outside any reference frame. ;-)