Age and structure of the Universe

[Orion1]

A recommended lecture on the age and detailed structure of the Universe, listed in reference 1.

George Smoot is a Nobel Prize in Physics laureate for his work on COBE.Primordial fluctuations simulation by Andrey Kravtsov:

1. The simulation begins where linear equations break down-about 13 billion years ago. Algorithms based on the initial conditions predicted by inflationary models of the universe reveal what appears to be a uniform blanket of dark matter.

2. That which appears uniform is not: there are small fluctuations in the density of matter created by a quantum stir billions of years ago. In a snowball effect, the fluctuations grow in size by many orders of magnitude during the inflationary expansion of the universe.

3. Galaxy distribution is strongly "biased": galaxies tend to form in clusters rather than forming uniformly across space.

4. The evolution of the cosmic structure is hierarchical: gravitational collapse first builds small objects-galaxies-and then larger structures-clusters of galaxies. Clusters tend to move toward each other and form filamentary structures, flat and elongated.

5. Voids develop between intersecting filaments, and clusters grow larger. Galaxy clusters are the most massive self-gravitating objects in the universe and therefore provide the most clues about its age, size, and ultimate fate.

6. The "present day" distribution of dark matter: if the nonbaryonic matter in the final frame were "dressed" with ordinary matter, this image would look very much like the distribution of galaxies and galaxy clusters observed in the real universe.

Reference:
http://video.ted.com/talks/podcast/GeorgeSmoot_2008P_480.mp4"
http://cosmicweb.uchicago.edu/filaments.html"
http://www.astro.princeton.edu/~aes/AST105/Readings/blueprints_of_creation.pdf"
http://astrophysics.gsfc.nasa.gov/outreach/gwu/Spring05/lectures/lecture14_cosmology.pdf"
http://magazine.uchicago.edu/0204/features/think.html"

 

[marcus]

Good find! thanks.
Here's an alternative link
http://video.ted.com/talks/podcast/GeorgeSmoot_2008P_480.mp4
this mp4 version is slow to download but higher resolution, I think.

beautiful fly-through representiations of the wispy structure of the universe
with colorcoded ordinary matter superimposed on dark matter (shown by different color)

voids, superclusters, cobweb strands, zooming into individual galaxies

and in one case he shows a simulation of how the structure could have formed---in this case only the skeleton of dark matter is shown, with it starting at around Z=25 or 30
nearly uniform, and then gradually coagulating by the action of gravity into strands separated by voids, and superclusters condensing where strands happen to cross.

Apparently the talk was given in May 2008 in Pasadena, and posted online Novemeber, just recently.

 

[marcus]

Primordial fluctuations simulation by Andrey Kravtsov:

Reference:
http://video.ted.com/talks/podcast/GeorgeSmoot_2008P_480.mp4"
http://cosmicweb.uchicago.edu/filaments.html"
http://www.astro.princeton.edu/~aes/AST105/Readings/blueprints_of_creation.pdf"
http://astrophysics.gsfc.nasa.gov/outreach/gwu/Spring05/lectures/lecture14_cosmology.pdf"
http://magazine.uchicago.edu/0204/features/think.html"

Thank also for these! The Kravtsov computer simulations are excellent. I like this especially:
http://cosmicweb.uchicago.edu/filaments.html
I see that Smoot used Kravtsov's movies in his TED talk.
This was a good one too:
http://cosmicweb.uchicago.edu/group.html
I watched the halfsize MP4 version of the movie because it is very easy to download, only about 2.4 MB.

 

[g33kski11z]

In the video, George Smoot mentions how the 3D animation of the 'filaments' was rendered using a desktop. I'm talking about the Kravtsov computer simulations, not the one requiring the 100 cpu supercomputer.

What software is needed for that..?

 

[Orion1]

Andrey Kravtsov simulation software...


The Andrey Kravtsov simulation software used P3D, which is a collection of simple and efficient fortran 77 routines, which can be used with the PGPLOT graphics library with a standard fortran 77 compiler.

Any qualified computer programmer should be able to compile and plot three-dimensional particle distributions and the same routines using the reference information listed below.

An example of output generated using the P3D routines: 3D view of the formation of structures in a simulation of CDM model with cosmological constant. The size of shown box is 30/h Mpc. 10% of the total number of particles (2,097,152) is shown. Particles are color-coded with local density at the position of the particle.

Reference:
http://cfcp.uchicago.edu/~andrey/"
http://cfcp.uchicago.edu/~andrey/soft/p3d/p3d.html"
http://www.astro.caltech.edu/~tjp/pgplot/"
http://www.astro.caltech.edu/~tjp/pgplot/install.html"

 

[tommy dee]

Good find! thanks.
Here's an alternative link
http://video.ted.com/talks/podcast/GeorgeSmoot_2008P_480.mp4
this mp4 version is slow to download but higher resolution, I think.

beautiful fly-through representiations of the wispy structure of the universe
with colorcoded ordinary matter superimposed on dark matter (shown by different color)

voids, superclusters, cobweb strands, zooming into individual galaxies

and in one case he shows a simulation of how the structure could have formed---in this case only the skeleton of dark matter is shown, with it starting at around Z=25 or 30
nearly uniform, and then gradually coagulating by the action of gravity into strands separated by voids, and superclusters condensing where strands happen to cross.

Apparently the talk was given in May 2008 in Pasadena, and posted online Novemeber, just recently.

this file is 232mb. anything within my lifetime spring to mind?

 

[marcus]

this file is 232mb. anything within my lifetime spring to mind?

Ten or 15 minutes should suffice. You can have it do that in the background while you do other stuff. That is how I did it.

You click on the link and a TED image comes up, with a bar underneath. Don't start the media until the bar is at least halfway full. To see how long it takes I just started it at 3:25 and then created a second screen and am talking to you. In a while I will go back and look and see how much has filled up.

OK it is now 3:30 and it is about 1/4 filled up. So that will make it about 10 minutes to fill halfway. Then it is safe to start watching. So you click on the small triangle that means "play".

The point is you don't have to wait around during those ten minutes. You can do other stuff and come back to it at your convenience. I think I will go watch now. It is fantastic to see the first largescale structures of the universe take shape from the barest quantum ripples.