polarization.

Polarization, among other things, heavily influences the way light bounces and scatters

- that's why horizontally polarized light reflects off of a lake or car windshield,

which in turn is why sunglasses with a vertical polarizing filter can block that light.

And in the hot plasma of the baby universe, light was bouncing off of electrons left and

right - until the plasma cooled enough to become transparent so the light could start

traveling through space.

But before heading out on its 13+ billion year journey, this light bounced one last

time off of the plasma, and the direction each photon went was influenced by how its

polarization interacted with the precise temperature, density and motion of the plasma.

So if we measure the polarization of light coming from this cosmic background radiation,

it can tell us about the big bang.

The details are complicated, but roughly speaking, clumps in the plasma of the early universe

created polarization aligned along or across the direction from hot to cold, while jiggles

created polarization at 45° angles to the hot-cold direction.

And by jiggles I mean the stretching and squeezing of space due to gravitational waves passing

through.

Anyway, starting with the results from the BICEP telescope at the South Pole, we see

that while a majority of the polarization came from clumps in the early universe, about

15% of it seems to come from jiggles.

And these jiggles are a big deal - they were caused just fractions of fractions of a second

into the life of the universe by quantum fluctuations of the gravitational field, so not only does

their discovery mark the first confirmation that gravity is indeed a quantum mechanical

phenomenon, but it also opens the door for us to look 380,000 years farther back than

ever before, into the very birth of our cosmos.

Congrats to the BICEP collaboration! - assuming of course, that their results are confirmed

by other experiments.