Ripples in the cosmic background

September 7, 2010
Faint ripples in the cosmic microwave background radiation as seen mapped on a full-sky projection. Colors represent tiny temperature deviations from the average (red regions are warmer and blue regions are colder). Credit: NASA and the WMAP mission

(PhysOrg.com) -- The universe was created 13.73 billion years ago in a blaze of light -- the big bang. We also think that, about 380,000 years later, after matter (mostly hydrogen atoms) had cooled enough for neutral atoms to form, light was able to travel through space relatively freely. We see that light today as the cosmic microwave background radiation (CMBR). The light appears extremely uniform in brightness across the sky. Astronomers have discovered, however, that the radiation has very faint ripples and bumps in it, at a level of only about one part in one hundred thousand.

These ripples reflect the architecture of the universe when the light was freed, and the subsequent cosmic structures (galaxies and clusters of galaxies) as the light passed by them on its journey through space and time. These ripples hold clues, therefore, to the and how it has evolved, and are consequently among the top priorities of modern astronomy research.

The wavelengths of the CMBR ripples span a continuous range of sizes. The larger ones (which are also brighter) are the result of the waves in the cosmic structure when the light was released; the universe has stretched in size so much since then (a factor of about 1000) that they are now comparatively big. The smaller ones imposed on the light later, as it was scattered by or other objects, are shorter and dimmer. Over the past few decades astronomers have been able to measure the larger ripples with great accuracy, and to use that information to substantiate and refine many details of the big bang scenario. The smaller bumps have been harder to pin down.

Writing in this month's , a large team of scientists including SAO astronomers Brian Stalder and Tony Stark report the successful measurement of CMBR ripples using the the South Pole Telescope, a ten-meter-diameter submillimeter telescope located at the Amundsen-Scott South Pole station in Antarctica.

The team was able to make the first significant measurements of the weakest, shortest wavelength yet studied. They discovered that the amplitude of the fluctuations is only about half that previously measured (or indicated by other related, previously measured parameters) -- a significant deviation. Moreover, their uncertainties of 35% are the smallest yet, yielding further refinements to big bang models. The results imply that although the formation of the first galaxies is still poorly understood, continuing improvements to the observations are rapidly enabling astronomers to zero in on these basic puzzles of cosmic origins.

Explore further: Penn astrophysicist outlines a multi-pronged approach in the hunt for dark energy

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6 comments

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Davinci_is_me
1.3 / 5 (7) Sep 07, 2010
Seriously, you call that an article? Pretty soon Physorg will be down to just bumper stickers.
Pyle
4.9 / 5 (9) Sep 07, 2010
@D_i_m,

Did you read the abstract of the article? There is a reason the "article" is like it is. Only an astrophysicist would understand the actual research, and interested astrophysicists should go read the research paper. The synopsis is about as good as it gets if you aren't in the field.

Physorg just gathers what it thinks are important publications from many different fields and points us in the right direction if we are so inclined. If you think the summary doesn't do the research justice, criticize it substantively with what you think is missing and down rate it. That is what the ratings are for.

MrPressure
Sep 08, 2010
This comment has been removed by a moderator.
DamienS
4.5 / 5 (8) Sep 08, 2010
sorry about terrible english.

You should be sorry for far more than your English.
genastropsychicallst
1 / 5 (5) Sep 08, 2010
Hahaha, 0 jet/ray. Fourthing of 'this' can only by machines like popping out fifthse electrons [also to be read as half], that's why w/z boson(s).
genastropsychicallst
1 / 5 (5) Sep 08, 2010
Mean, w/z is for the differents. Otherwise no past until future to let us see, hear, feel, taste after etc.

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