APOD: Planck Maps the Microwave Background (2013 Mar 25)

[APOD Robot]

Planck Maps the Microwave Background

Explanation: What is our universe made of? To help find out, ESA launched the Planck satellite to map, in unprecedented detail, slight temperature differences on the oldest surface known -- the background sky left billions of years ago when our universe first became transparent to light. Visible in all directions, this cosmic microwave background is a complex tapestry that could only show the hot and cold patterns observed were the universe to be composed of specific types of energy that evolved in specific ways. The results, reported last week, confirm again that most of our universe is mostly composed of mysterious and unfamiliar dark energy, and that even most of the remaining matter energy is strangely dark. Additionally, Planck data impressively peg the age of the universe at about 13.81 billion years, slightly older than that estimated by various other means including NASA's WMAP satellite, and the expansion rate at 67.3 (+/- 1.2) km/sec/Mpc, slightly lower than previous estimates. Some features of the above sky map remain unknown, such as why the temperature fluctuations seem to be slightly greater on one half of the sky than the other.

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[SouthEastAsia]

Fascinating! Thanks APOD and thanks ESA!

Ok, my first question is: is dark energy connected in any way to formation of new star systems?

And second question is: assuming that our Universe is expanding at roughtly 67 km/sec... what exactly is the matter that it is expanding into?

Thanks in advance!

[bystander]

http://asterisk.apod.com/viewtopic.php?t=30986

[bystander]

Fascinating! Thanks APOD and thanks ESA!

Ok, my first question is: is dark energy connected in any way to formation of new star systems?

And second question is: assuming that our Universe is expanding at roughtly 67 km/sec... what exactly is the matter that it is expanding into?

Thanks in advance!

I don't think dark energy is connected to the formation of star systems. It works on much larger scales.

The universe is not expanding into anything. Nothing exists outside the universe.

[Boomer12k]

I would expect more signal in some places and less in others. Any explosion, expansion, is not necessarily totally, absolutely, uniform in all directions. Watch the paint explosions on Mythbusters. Even if the charge was exactly in the middle, there is tactile connection of the paint, that blocks, slows down, re-directs, pushes, pulls in all directions, and you get more blobs here, and less there, on the walls of the shed. I would expect the same result with the "inflation" of the Universe, to be non-uniform. Unlike a perfectionist, who would expect it to be totally, absolutely, uniform, in all directions, because the Universe is "Perfect". It would therefore have to be steady and consistent in all forms. Well, the data here, suggest otherwise...
Some area's are stronger signal, other weaker, some areas would have been blocked, others opened up.
As the "edges of the Universe" continue to expand, they would get blotchy. Some at a greater or lesser speed than other parts, would cool faster. Expansion is a cooling process.

:---[===] *

[Ann]

bystander wrote:
The universe is not expanding into anything. Nothing exists outside the universe.

May I perhaps sort of disagree.

The universe isn't expanding into anything, no. From our point of view, the universe is everything. From our point of view, there can be nothing outside the universe.

But there just might be other universes. If so, they exist outside our universe.

Of course, we will never be able to see or otherwise detect any of these other, possible universes.

That's how I understand it anyway.

Ann

[inertnet]

Maybe the anomalies indicate that there is, or at least was, something outside our universe.

It would be nice if this map could be mapped onto Google Earth.

[MargaritaMc]

bystander wrote:
The universe is not expanding into anything. Nothing exists outside the universe.

May I perhaps sort of disagree.

The universe isn't expanding into anything, no. From our point of view, the universe is everything. From our point of view, there can be nothing outside the universe.

But there just might be other universes. If so, they exist outside our universe.

Of course, we will never be able to see or otherwise detect any of these other, possible universes.

That's how I understand it anyway.

Ann

http://www.newscientist.com/mobile/article/dn23301

Bruised cosmos
Planck has also confirmed WMAP's detection of a large unexplained cold spot in the CMB, which some cosmologists took as a sign that there are universes beyond our own. One model of inflation, called eternal inflation, suggests that new universes are continually popping into existence (Note by Margarita - see quotation and link below) and expanding. This expansion could cause another universe to collide with ours, creating a "bruise" that would show up as a cold spot in the sky.

http://www.newscientist.com/mobile/arti ... erses.html

Microwave radiation map hints at other universes

Update on 16 August 2011: The researchers ran additional statistical checks on the CMB data, looking at the probability that the bubbles would appear anywhere on the sky. Lead author Stephen Feeney says: "The current data favour no bubble collisions. However, a non-zero number of bubble collisions is still allowed, and there are four patches in the WMAP data where [signals of possible bubble universes] are higher than anything we expect from systematic errors due to instrumental effects, foreground-removal artefacts etc. With data from Planck we expect our pipeline to be sensitive to much weaker collision signals, so we should be able to test whether there is something there or whether they're just weird patches of CMB." The updated analysis appears in Physical Review Letters (DOI: 10.1103/PhysRevLett.107.071301).

expanding_universe.jpeg

Margarita

[zbvhs]

We now know the age of the universe to four significant figures. All very interesting but what do we do with it? The ancient Maya did astronomy for centuries and the only technology produced from it was three calendars. When the crunch came, their calendars weren't much use in preventing the collapse of Mayan society. So, how will knowing the age of the universe prevent the coming collapse of modern society, which some say is inevitable?

[owlice]

Virgil, what makes you think the point of doing something, anything, is to prevent the collapse of a society?

IMHO, knowledge, like virtue, can be its own reward.

[Redbone]

Would we recognize a random distribution of the microwave background if we saw it? Random most definitely does not imply uniform, a random distribution will show patterns of high and low concentrations, just not in any predictable way.

[neufer]

Click to play embedded YouTube video.

We now know the age of the universe to four significant figures.

Three significant figures:

Age of the universe 13.798±0.037 Ga

[Planck - 68% limits (Planck+WP+highL+BAO)]

All very interesting but what do we do with it?

Use it to challenge someone to actually find the age of the universe to four significant figures.

<<Benjamin Franklin observes the first balloon ascension in 1783 while he was Ambassador at the Court of France. Someone asks "What possible use are balloons?" Franklin answers "What use is a newborn baby?">>

The ancient Maya did astronomy for centuries and the only technology produced from it was three calendars. When the crunch came, their calendars weren't much use in preventing the collapse of Mayan society. So, how will knowing the age of the universe prevent the coming collapse of modern society, which some say is inevitable?

The Mayans lasted ~3500 years and they still have descendants & museums; they could have done a lot worse.

<<The Maya is a Mesoamerican civilization, noted for the only known fully developed written language of the pre-Columbian Americas, as well as for its art, architecture, and mathematical and astronomical systems. Initially established during the Pre-Classic period (c. 2000 BC to AD 250), according to the Mesoamerican chronology, many Maya cities reached their highest state of development during the Classic period (c. AD 250 to 900), and continued throughout the Post-Classic period until the arrival of the Spanish. Today, the Maya and their descendants form sizable populations throughout the Maya area and maintain a distinctive set of traditions and beliefs that are the result of the merger of pre-Columbian and post-Conquest ideas and cultures. Millions of people speak Mayan languages today.>>

[Chris Peterson]

Would we recognize a random distribution of the microwave background if we saw it? Random most definitely does not imply uniform, a random distribution will show patterns of high and low concentrations, just not in any predictable way.

Information theory is an advanced area, adept at distinguishing between truly random (i.e. with maximum information content) and less random data. There are many mathematical tools that can be directed at the Planck dataset to determine the likelihood that any structure is random or otherwise (of course, this is a statistical conclusion- it is fundamentally impossible to say with certainty whether data is random or not, only to place a probability on it).

[Chris Peterson]

We now know the age of the universe to four significant figures. All very interesting but what do we do with it?

You could make that argument about nearly everything. Even on a personal scale... you're going to die one day, so why bother even getting out of bed today?

In fact, the important result of this particular work isn't refining the age of the Universe, but refining unknown terms in cosmology models (which is how the shift in ratios between different types of energy came about). This allows certain models to be rejected, and others to be reinforced. It leads to a fundamental improvement in our understanding of how the Universe formed. That will lead to refinements in other areas, such as the Standard Model, which may have concrete ramifications in very practical areas, such as chemistry, biology, or even nuclear engineering. When you learn something fundamental, there is no end to the practical fallout that might appear.

So, how will knowing the age of the universe prevent the coming collapse of modern society, which some say is inevitable?

Even if society collapses, it will be followed up by new civilizations and cultures, which will inherit much from us. It's extremely unlikely that our species will even exist in a few million years, so again, should we simply stop learning?

[Shamanomaha]

Is the cosmic microwave background radiation the same as the Zero Point Field?

[Chris Peterson]

Is the cosmic microwave background radiation the same as the Zero Point Field?

No. A zero-point field is just the lowest energy state for any particular field (EM, gravity, etc). There is no single Zero Point Field. Zero-point energy is a quantum mechanical concept.

The cosmic microwave background is nothing more than the photons emitted (or released) when the Universe became transparent, several hundred thousand years after the Big Bang. They were initially very energetic (shorter wavelength), but have lost most of that energy to 13 billion years of redshift.

[MargaritaMc]

Neufer wrote:
<<Benjamin Franklin observes the first balloon ascension in 1783 while he was Ambassador at the Court of France. Someone asks "What possible use are balloons?" Franklin answers "What use is a newborn baby?">>

Thanks so much for this, Art, and for the Feynman video.
Margarita

[neufer]

Click to play embedded YouTube video.

So, how will knowing the age of the universe prevent the coming collapse of modern society, which some say is inevitable?

Even if society collapses, it will be followed up by new civilizations and cultures, which will inherit much from us.

E.g.,

• 1) Never get involved in a land war in Asia.
  2) Never go against a Sicilian when death is on the line!

Ha ha ha ha ha ha ha! Ha ha ha ha ha ha ha! Ha ha ha...

[BDanielMayfield]

Today’s apod image and the Planck results were the subject of a Sky and Telescope article that came out last Friday:

http://www.skyandtelescope.com/news/Bes ... 10221.html

[Anthony Barreiro]

bystander wrote:
The universe is not expanding into anything. Nothing exists outside the universe.

May I perhaps sort of disagree.

The universe isn't expanding into anything, no. From our point of view, the universe is everything. From our point of view, there can be nothing outside the universe.

But there just might be other universes. If so, they exist outside our universe.

Of course, we will never be able to see or otherwise detect any of these other, possible universes.

That's how I understand it anyway.

Ann

http://www.newscientist.com/mobile/article/dn23301

Bruised cosmos
Planck has also confirmed WMAP's detection of a large unexplained cold spot in the CMB, which some cosmologists took as a sign that there are universes beyond our own. One model of inflation, called eternal inflation, suggests that new universes are continually popping into existence (Note by Margarita - see quotation and link below) and expanding. This expansion could cause another universe to collide with ours, creating a "bruise" that would show up as a cold spot in the sky.

http://www.newscientist.com/mobile/arti ... erses.html

Microwave radiation map hints at other universes

Update on 16 August 2011: The researchers ran additional statistical checks on the CMB data, looking at the probability that the bubbles would appear anywhere on the sky. Lead author Stephen Feeney says: "The current data favour no bubble collisions. However, a non-zero number of bubble collisions is still allowed, and there are four patches in the WMAP data where [signals of possible bubble universes] are higher than anything we expect from systematic errors due to instrumental effects, foreground-removal artefacts etc. With data from Planck we expect our pipeline to be sensitive to much weaker collision signals, so we should be able to test whether there is something there or whether they're just weird patches of CMB." The updated analysis appears in Physical Review Letters (DOI: 10.1103/PhysRevLett.107.071301).

expanding_universe.jpeg

Margarita

I have enough trouble understanding one universe. It seems like asking for trouble to speculate about a multitude of other universes that we will never see. My own personal belief is that we will never know everything, our theories and models will always be imperfect, and even this one universe will always be bigger, more complex, and more mysterious than we can possibly understand. Still, there is great value in striving for greater knowledge and understanding. And to have a better map of the universe 380,000 years after the big bang than we had a few years ago is an impressive accomplishment.

[BDanielMayfield]

... It seems like asking for trouble to speculate about a multitude of other universes that we will never see. My own personal belief is that we will never know everything, our theories and models will always be imperfect, and even this one universe will always be bigger, more complex, and more mysterious than we can possibly understand. Still, there is great value in striving for greater knowledge and understanding. And to have a better map of the universe 380,000 years after the big bang than we had a few years ago is an impressive accomplishment.

I agree Anthony. Nice comment.

[MargaritaMc]

Via a link in the text of today's Apod.

Max Tegmark My research is focused on precision cosmology, e.g., combining theoretical work with new measurements to place sharp constraints on cosmological models and their free parameters. ... Spectacular new measurements are providing powerful tools for this:
...
Every time I've written ten mainstream papers, I allow myself to indulge in writing one wacky one, like my Scientific American article about parallel universes. This is because I have a burning curiosity about the ultimate nature of reality; indeed, this is why I went into physics in the first place. So far, I've learned one thing in this quest that I'm really sure of: whatever the ultimate nature of reality may turn out to be, it's completely different from how it seems.

Tegmark's articles are available at:
http://space.mit.edu/home/tegmark/crazy.html

Click to view full size image

[ignacio_db]

Basic question: When referring to percentages of dark matter, dark energy and "regular" matter, in terms of what is that proportion exactly? Is it in terms of energy, as in E=mc2 for "regular" matter? Or is it in terms of how dark terms weight versus "regular" matter gravity? Or is it some other way of comparing? How does massless radiation enter the picture?

Have been wondering about this for a while now. Thanks.

Ignacio

[Chris Peterson]

Basic question: When referring to percentages of dark matter, dark energy and "regular" matter, in terms of what is that proportion exactly? Is it in terms of energy, as in E=mc2 for "regular" matter? Or is it in terms of how dark terms weight versus "regular" matter gravity? Or is it some other way of comparing? How does massless radiation enter the picture?

The ratios refer to energy only. That is, they take the entire energy content of the Universe and break it up into its three primary constituents: dark energy, dark matter, and ordinary matter (with the energy based on the energy equivalence of the two matter components). While the energy of photons was dominant early in the Universe, it now represents only a fraction of a percent of the energy of matter, so is typically disregarded in the published ratios.

[alter-ego]

Basic question: When referring to percentages of dark matter, dark energy and "regular" matter, in terms of what is that proportion exactly? Is it in terms of energy, as in E=mc2 for "regular" matter? Or is it in terms of how dark terms weight versus "regular" matter gravity? Or is it some other way of comparing? How does massless radiation enter the picture?

The ratios refer to energy only. That is, they take the entire energy content of the Universe and break it up into its three primary constituents: dark energy, dark matter, and ordinary matter (with the energy based on the energy equivalence of the two matter components). While the energy of photons was dominant early in the Universe, it now represents only a fraction of a percent of the energy of matter, so is typically disregarded in the published ratios.

Yes, energy is the unit used to model the "mass" of the universe. Within the ΛCDM model, the matter components are lumped together, so one needs the CMB power spectrum to predict / separate the coupled dark- and ordinary-matter energy components:
 

How do we learn about dark matter from the CMB?
Most of the cosmological information we get from the CMB is found by studying its power spectrum, a plot of the amount of fluctuation in the CMB temperature spectrum at different angular scales on the sky. The upper plot at right shows measurements of the power spectrum as of 2003 - large angular scales are at the left of the plot, while smaller sky features contribute to the right of the plot. 

The shape of this power spectrum is determined by oscillations in the hot gas of the early universe, and the resonant frequencies and amplitudes of these oscillations (which "notes" the universe likes to play!) are determined by its composition. Since we know the physics of hot gases very well, we can compute the properties of the oscillating gas by studying the positions and relative sizes of these peaks. The position of the first peak, for example, tells us about the curvature of the universe (and hence how much total stuff there is in it), while the ratio of heights between the first and second peaks tells us how much of the matter is baryonic (ordinary matter). In practice, there are many variables that affect all parts of the power spectrum, and detailed computer simulations (the red curve in the plot) are used to sort it all out.