It's aliens what done it!
Planck Upholds Standard Cosmology
By: Camille M. Carlisle | February 10, 2015
The Planck team has finally released its full-mission data, revealing a remarkably detailed view of our universe and our galaxy.
The moment I’ve been waiting months for is finally here: the full-mission data from ESA’s Planck satellite are public. Scientists presented the results at a Planck conference in Ferrara, Italy, in December, but the official analysis papers are only now coming out. Most were posted on the Planck Publications website on February 5th, with a few stragglers still in the wings.
Planck polarization and temperature maps
Planck's full-mission data, released in February 2015, provide a breathtakingly precise map of the polarization (top) and temperature (bottom, with scale in kelvin) patterns in the cosmic microwave background.
Credit: Planck Collaboration
Planck launched in 2009 to study the cosmic microwave background (CMB), the relic radiation from the universe’s birth. Density fluctuations in the universe’s earliest moment spawned the splotchy pattern we see in the CMB and, in turn, served as seeds for the growth of cosmic structure. Understanding why the CMB looks the way it does therefore helps us understand the entire universe (more on that later).
Observing in nine frequencies spanning 30 to 857 GHz, Planck mapped the CMB’s temperature and (in seven frequencies) polarization, with angular resolutions between 33 and 5 arcminutes, depending on the frequency. It shut down on schedule four years later in 2013.
The team released the temperature observations from the mission’s first 15 months in 2013. These data were mostly in beautiful agreement with the predictions of the standard cosmological model. Since then, the team has been working fiendishly to analyze the full, four-year data set.
How Astronomers Find the Universe in the CMB
Planck power spectrum
The strength of temperature variations (vertical) is plotted against their angular sizes (horizontal, approximate). The red line is the standard cosmological model, the blue dots are Planck data.
Credit: Planck Collaboration
This endeavor is a challenging one, explains Planck team member Charles Lawrence (JPL). Cosmologists start with the splotchy CMB pattern. From that they calculate what’s called the power spectrum, which reveals the strength of the CMB’s fluctuations at different angular scales. (The power spectrum is the wiggly graph at right.) The power spectrum is the cornerstone of the whole effort: it’s this statistical map that cosmologists base their CMB analysis on.
The cosmologists then make some assumptions about what kind of universe they’re dealing with — in astrospeak, they assume the standard lambda-CDM model, which includes (1) a particular solution to the general relativistic equations of gravity, (2) a universe that looks basically the same on large scales and is expanding, (3) an early period of stupendous expansion called inflation, and (4) quantum fluctuations that seeded today’s large-scale matter distribution.
From there, they start tweaking the assumptions, like a dressmaker tucking and letting out a dress pattern until it fits right. They could even chuck any assumption that proves to be bad. Eventually, they find the pattern that most successfully fits the CMB.
The amazing thing is, this method works. It works really well. That’s because back when the universe cooled down enough to become transparent to the CMB’s radiation (about 380,000 after the Big Bang), the universe was simple. By simple, I mean the universe was basically a hot, bland soup of particles and dark matter and there weren’t any chemical reactions going on. So scientists can actually figure out, to very high precision, the exact setup that would create the CMB we observe.
The Punchline: Planck’s Cosmology Results
Milky Way Galaxy
This composite map of the Milky Way Galaxy from the Planck mission combines several types of emission: synchrotron (from charged particles corkscrewing in magnetic fields), free-free (from electrons scattering off ions), spinning dust, and warm dust. Planck scientists must subtract out all galactic emission in order to see the cosmic microwave background.
Credit: Planck Collaboration
For those of us who have been impatiently squirming for the Planck team to finish this herculean task, the new data deluge justifies the wait. These data are gorgeous. Like, disgustingly gorgeous. Even the foreground maps, which include things that sullied Planck’s view of the CMB (such as our galaxy’s dusty disk), are exquisite.
The 2015 release upholds that of 2013, with only slight tweaks to various cosmological parameters. It still overwhelmingly favors an early universe defined entirely by six parameters, no matter how many ways the team pushed and prodded the data. These parameters are
The density of baryonic matter (a.k.a. normal, like you and me) in the first few minutes of the universe
The density of cold dark matter at that same time
How far sound waves had traveled when the CMB photons were released — also known as the “sound horizon” or the size of baryon acoustic oscillations
The fraction of CMB photons over the universe’s history that have scattered off particles set free by radiation from stars/quasars ionizing the neutral hydrogen filling the cosmos
How the strength of the density fluctuations on various scales at the end of inflation changes with scale
The slope of #5 when plotted as a spectrum
From these, the team can calculate just about anything you please, such as the universe’s age and its expansion rate. The exact values depend on which data subsets you want to include, but here are some notable ones from the team’s overview paper:
Age of universe: 13.799 +/- 0.038 billion years (note: that means we know the age of the universe to within 38 million years. Just think about that for a second)
Hubble parameter: 67.8 +/- 0.9 km/s/megaparsec (this is the universe’s rate of expansion, more on this in a minute)
Fraction of universe’s content that is “dark energy”: 69.2 +/- 1.2%
The So What
The latest Planck data say some interesting things about the universe. For one, the universe’s expansion rate, called the Hubble parameter, is still lower than what astronomers previously calculated using supernovae (about 73 km/s/Mpc). That was a surprise in the 2013 release, and it’s still odd. Several other measurements have also been pushing the Hubble constant down, so it looks like a lower expansion rate is here to stay. Maybe there’s some new physical ingredient at work, but we don’t know yet.
In the discussion of what dark matter is, one idea is that it’s its own antiparticle and so if two of its particles collide, they’ll go poof. There’s no sign of dark matter annihilation in the physics needed to explain the CMB observations, although Planck does leave the door open for the level of annihilation suggested as an explanation for diffuse gamma-ray emission from the Milky Way’s center. And it looks like there are definitely only 3 flavors of neutrino (in case you were still holding out hope).
There’s still the strange problem of the missing galaxy clusters. The Planck team finds a certain lumpiness in the CMB, which should match up with the lumps in the distribution of matter in the universe (a.k.a. cosmic structure, which is made up of galaxy clusters). But Planck predicts about 2.5 times more clusters than are actually observed. This could be due to error in the estimates from either side, or due to new physics.
One neat result is that the era of reionization — basically, when the universe’s galaxies really started lighting up with stars — is later than estimated using data from Planck’s predecessor, WMAP. WMAP had favored reionization at a redshift of 10 (470 million years after the Big Bang), but Planck pegs it at 8.8 (560 million years after the Big Bang).
“For many cosmologists, I would say that it is a relief,” says David Spergel (Princeton), who worked on the WMAP team. Scientists studying early star formation had a hard time explaining the earlier start time from WMAP, so a slightly later start is a good thing.
Then there are the implications for inflation. No. 5 in the list of parameters (how the strength of the density fluctuations changes with angular scale), is called ns, or the scalar spectral index. It’s important because it describes the state of affairs at the end of inflation, and the fluctuations it measures are the ones that started sound waves sloshing in the universe’s primordial plasma and ultimately led to the CMB we see. Planck finds a value of 0.968, which means that the strength of the fluctuations is slightly larger on larger scales—predicted by most inflation models. This offset has a slight effect on galaxies’ formation rate over time.
The Planck team also did its own analysis of how big any gravitational waves triggered by inflation would be in their data, an analysis separate from (but including the data of) the joint analysis done with the BICEP2/Keck Array folks. The team found an upper limit on the ratio of gravitational waves’ strength to the density fluctuations’ strength of 0.08, slightly lower than the one from the joint analysis (0.12) and the Planck 2013 analysis (0.11).
These results home in on some of the simpler types of inflation. (Take a look at the number of inflation models out there.) These involve an inflation spawned by the decay of a single energy field, a field that decreased slowly compared to the universe’s expansion rate. (Given that the observable universe expanded at least 5 billion trillion times in 10 nano-nano-nano-nanoseconds, that’s not that slow.) The energy scale implied for inflation is less than 2 x 1016 gigaelectron volts, on par with the level expected for the merger of the strong, weak, and electromagnetic forces into one (called the Grand Unified Theory). Physicists think these forces were united in the first mini-moment of the universe, then broke apart. Their breakup might somehow be connected to inflation.
FBM wrote:This is nothing but general talk - moreover too general. Where are your lab experiments and math inferences, proving that:There's tons and tons of experimental evidence to support the Standard Model.
1. The Big Bang possesses the ability to launch the Time out of Nothing and out of Nowhere;
2. The Big Bang has the capacity to create 3D space out of no Time & out of whatever else ... that you will have to prove that could have existed without Time;
3. The Big Bang and the red shift have any correlation at all, justified by physical interpretation;
4. The Big Bang has disposed a priori with all that energy (no matter the form), required for the creation and for the maintaining subsequently in operation of the Universe;
5. The Big Bang is in any correlation with the CMB, and that correlation has physical interpretation in the real world;
6. The Big Bang has ever existed or is existing and there has ever been anything happening in connection with it;
7. The Univrse 'is expanding' (and your room is expanding and your laptop is expanding, etc.) - not only on the grounds of the measurements of red shift in light, but this can be observed with other emissions, of other particles as well; ... and also that the light could be subject to the Doppler effect at all;
8. The Big Bang in the capacity of being absolute stochastics, has been able to acquire, to manage, to control and to handle all that Information, necessary for the structuring of the Universe; ... and how will that happen without any Intelligence; meta-Intelligence; ILF or ID of any kind? Can you give an example in the real world of a control system without any Information ... performing the control just so, on the grounds of some stochastics?
From where automatically follows that the score becomes: 4:8
*cough*
Herald wrote:
... my personal ... and perhaps 25% of the Big Bang and the theory that we are made out of star dust ...
So...You're giving 25% credibility to something that you simultaneously claim is false. Interesting.
