Cosmic Microwave Background Radiation's Polarization Detected at Last

Scientific American ^ | 19 December 2002 | Sarah Graham

[PatrickHenry]

Although it was discovered less than 40 years ago, the cosmic microwave background (CMB) radiation has been around a lot longer than that. A relic from the early days of the Universe more than 14 billion years ago, the CMB is the oldest radiation on record. Current cosmological models posit that the CMB should be slightly polarized but this property has never been observed--until now. Researchers have successfully detected the CMB's polarization and found that it agrees with the theoretical estimates.

Erik Leitch and John Kovac of the University of Chicago and their colleagues used the Degree Angular Scale Interferometer (DASI), which is located at the Amundsen-Scott South Pole Station, to study the CMB radiation. Over a two-year period, this array of radio telescopes collected radiation signals coming from deep space in two patches of blank sky. The resulting 271 days worth of useable data revealed the light's polarization (the direction in which the light's field oscillates as it travels toward an observer on the ground). Writing in the journal Nature, the scientists report that the CMB radiation's level and spatial distribution are in excellent agreement with the predictions of the standard theory. "If the light hadn't been polarized, that would mean that we would have to throw out our whole model of how we understand the physics of the early universe," Leitch notes. In an accompanying commentary, Matias Zaldarriaga of New York University calls the findings "both a remarkable technical achievement and a wonderful consistency check for the theory."

[PatrickHenry]

Big bang ping.

[This ping list for the evolution -- not creationism -- side of evolution threads, and sometimes for other science topics. If you want to be included, or dropped, let me know.]

[BenLurkin]

Everyone be careful not to let the polarizer cross-foot with the flux capacitor and get dis-grontified or you might end up like this:

[mlo]

Please add me to your ping list.

[RightWhale]

"If the light hadn't been polarized, that would mean that we would have to throw out our whole model of how we understand the physics of the early universe,"

Here's something for some physicist somewhere. What is polarization? I don't mean it's something detected by transparent crystal arrays or created by reflection off specular surfaces. I mean, what is it that lines up in a preferred direction? You can throw in photons to your explanation, even though the jury is still out on Einstein's mind baby.

[PatrickHenry]

Done.

[PatrickHenry]

I mean, what is it that lines up in a preferred direction? You can throw in photons to your explanation, even though the jury is still out on Einstein's mind baby.

I'm not at all up to speed on the issue involved here. I'm hoping someone will show up and give us some more info. It would appear that big bang theory has just passed an important test, but I was unaware that the problem existed. I guess I've led a sheltered life.

[biblewonk]

CMB proves the big bang like belly buttons prove evolution from monkeys.

[PatrickHenry]

CMB proves the big bang like belly buttons prove evolution from monkeys.

It doesn't prove the big bang. It's something that is predicted by big bang theory, and when it was discovered, it was powerful support for the theory. And it's a physical fact that distinguishes big bang theory from its one-time rival, steady-state theory, which is now dis-proved, because it's inconsistent with the CMB.

[PatrickHenry]

Some explanation of the polarization issue is at the bottom half of this site:
The Cosmic Microwave Background - an Introduction.

[RightWhale]

Maybe you have led a sheltered life. Find a physicist and ask what it is that is being polarized, and then find shelter because you will need it to avoid flying chalkboard erasers and chalk. Radio amateurs might have an idea. After all, they use polarization and deal with it mathematically. But what is it that lines up this way or that way when photons move at their normal speed?

[Doctor Stochastic]

Caveat: Physicist is invited to correct me here. Light has both particlelike and wavelike characteristics. It acts like a transverse wave (like water waves) where the oscillation of the waves is perpendicular to the line of travel. In polarized light, the angles of the oscilations are lined up in time. That is, each successive photon in a photon train not only oscillates perpendicularly to the line of travel, each one has the same polar angle as the others.

Polarization Link

Polarization Link

If one looks down the line of travel of a light beam, the sideways oscillations of the photons is aligned in polarized light.

[BikerNYC]

CMB proves the big bang like belly buttons prove evolution from monkeys.

I'd love to know what theory you propose that does a better job incorporating the observable features of the CMB into it.

[BikerNYC]

But what is it that lines up this way or that way when photons move at their normal speed?

Fields, no?

[Moonman62]

Depending on the detail observed, this could be another indirect observation of gravity waves.

[js1138]

And it's a physical fact that distinguishes big bang theory from its one-time rival, steady-state theory, which is now dis-proved, because it's inconsistent with the CMB.

Does that make Fred Hoyle, officially, the patron saint of lost causes?

[Mr_Magoo]

Big Bang = "In the beginning, God said and there was . . ."

[BikerNYC]

"In the beginning, God said and there was . . ."

...a quantum mechanical fluxuation followed closely by inflation.

[Redcloak]

Well?? Do we live in a more P-polarized universe or a more S-polarized universe? What's the extinction ratio? Enquiring minds and all...

[biblewonk]

It doesn't prove the big bang. It's something that is predicted by big bang theory, and when it was discovered, it was powerful support for the theory. And it's a physical fact that distinguishes big bang theory from its one-time rival, steady-state theory, which is now dis-proved, because it's inconsistent with the CMB.

I have a book called Galaxies, I think that's the one, which states that galaxies are all perfectly evenly distributed throughout the universe exactly as predicted by the Big Bang theory. Isn't it interesting how the BB Theory is updated to predict the latest things observation shows us.