Starship Asterisk*

bls0326 wrote:
Nice 3D visualization.

really looks like random fluctuations,

but looks can be deceiving.

slashdot.org wrote:Damien George, of Cambridge University, has created a 3D visualization of the latest data from the Planck mission. Using WebGL, it lets you spin and zoom a 3D model of the Cosmic Microwave Background, and select different wavelength bands.

geckzilla wrote:Seems to be a good way to map a sphere onto a 2d surface. You could make it a rectangle like a map of the earth but then the poles get pretty distorted.

stephen63 wrote:

geckzilla wrote:
Hey, you never know how many inconceivably tiny and fleeting parts of the universe is thinking about itself. Could be a lot.

And wondering if they are the only one.

geckzilla wrote:Hey, you never know how many inconceivably tiny and fleeting parts of the universe is thinking about itself. Could be a lot.

Anthony Barreiro wrote: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.

tardigradess wrote:why is the microwave back ground map egg shape and not triangular or hexagon or rectangular or a circle or a random dynamic amoeba shape?

Chris Peterson wrote:

bls0326 wrote:Why the egg-shaped universe picture? Is the universe really that way or is this just a representation of a 3 dimensional sphere in 2 dimensions?

The data represents the 2D surface of a sphere, not the 3D volume. We are seeing the projection of a spherical surface onto a plane. This map uses a Mollweide projection because it preserves area proportions.

bls0326 wrote:Why the egg-shaped universe picture? Is the universe really that way or is this just a representation of a 3 dimensional sphere in 2 dimensions?

Welcome to the Planck ‘toolkit’ – a series of short questions and answers designed to equip you with background information on key cosmological topics addressed by the Planck science releases. The questions are arranged in thematic blocks

ignacio_db wrote:Thanks for the explanation. So, to be clear, one should think this as matter (dark and regular) measured in its energy equivalence via mc^2 and then compared with dark energy? In that case, the importance of dark energy strikes me as even more impressive, given the huge conversion factor involved.

Chris Peterson wrote:

ignacio_db wrote: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.

http://cosmology.berkeley.edu/Education/CosmologyEssays/The_Cosmic_Microwave_Background.html wrote:
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.

ignacio_db wrote: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?

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.

Anthony Barreiro wrote:... 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.

MargaritaMc wrote:

Ann wrote:

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