Starship Asterisk*

Galaxy Evolution Tracking Animation

Explanation: How did the universe evolve from such a smooth beginning? To help understand, computational cosmologists and NASA produced the featured time-lapse animated video depicting a computer simulation of part of the universe. The 100-million light-year simulation starts about 20 million years after the Big Bang and runs until the present. After a smooth beginning, gravity causes clumps of matter to form into galaxies which immediately begin falling toward each other. Soon, many of them condense into long filaments while others violently merge into a huge and hot cluster of galaxies. Investigating of potential universe attributes in simulations like this have helped shape the engineering design the James Webb Space Telescope, currently scheduled for launch in late 2018.

<< Previous APOD

This Day in APOD

Next APOD >>

[/b]

A few seconds in and it looks like the universe is turning almost clockwise like a tropical storm. But the big bang should have propelled everything outward. Something isn't right.

How does dark matter/energy feature in this.
if it does ?

dalethorn wrote:A few seconds in and it looks like the universe is turning almost clockwise like a tropical storm. But the big bang should have propelled everything outward. Something isn't right.

Imagine a camera following a horse along. The horse is running forward, but we see it moving in place.

Ann wrote:As for those who say that something isn't right here, what expertise do you have that gives you the qualifications to make that judgment?

Personally, I have to wonder at the size of the black hole at the center of that mass concentration.

Ann

The second link of today's apod http://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=10663 mentions that dark matter is entered into the simulation. But no black hole is mentioned in the paper from 2011 http://arxiv.org/abs/1005.1451 linked inside the third link http://adsabs.harvard.edu/abs/2011ApJ...731...11C of today's apod. In the abstract they say "Overall we show that galactic superwind (GSW) feedback from star formation can transport metals [elements heavier than helium] to the IGM [i.e. intergalactic matter] and that the properties of simulated metal absorbers match current observations." Thus the mass loss from the stars within the galaxies is thrown outwards and leaves its galaxy without help from any black hole, in this simulation.

As for the width of the simulated area (100 million light-years) one should think of the distance to the center of the Virgo Cluster of galaxies, which is about 50 million light-years. And that our galaxy belongs to a local group of galaxies which are gravitationally bound to the Virgo Cluster. So whereever Virgo Cluster goes, goes the Milky Way.

Odd... if Red Shift is a measure of galaxies moving away at speed from us... why is everything in the simulation falling toward the nearest center of mass....even far away sections are falling "inward"... gravity would seem to be winning... we live in a Condensing Universe... while space expands... The nature of matter is to clump... and clump, and make bigger clumps...
We were told many years ago, galaxies are flying away from each other... like blowing up a balloon with spots on it.... not according to this simulation...

Even the filaments appear to become shorter, and I don't think it is just rotating the angle, you would predict that within each filament, the closer clusters should move towards each other on the filament, making the shorter... do filaments move away from each other? Seemingly not, in this 13-14 billion year simulation...

:---[===] *

dalethorn wrote:A few seconds in and it looks like the universe is turning almost clockwise like a tropical storm. But the big bang should have propelled everything outward. Something isn't right.

The Big Bang DID propel everything outward... but that "EVERYTHING" was ENERGY, it was NOT stars and galaxies,... soon it was cooling... expansion is a cooling process, Condensation is a result... collisions with minute particles produced dust, and hydrogen was also created... it condensed further with cooling... thus, after the big bang, while still propelled outward by momentum... things started to solidify, and FALL inward toward each other. The expansion reached vast distances in incredibly fast speed... "a blink of the eye" relatively speaking... like filling a football field with a gas, nearly instantaneously... then cooling as expansion is a cooling process.... it was probably cooling the split second after expanding from a singularity.... I personally think the tremendous heat helped FUEL the expansion. Trillions of Degrees of hot energy is DYNAMIC... not static...

As for the turning... Everything in the Universe spins... meteors tumble, asteroids, planets, stars, clusters, galaxies, so, why not the Universe? IT is after-all... a Synergistic Whole, of Energy... that got started at the same time. Plus, as things FALL, and as things cool... they start to orbit with their movement and momentum, and play off each other... Even The Earth and Moon. Earth transfers energy to the Moon, which recedes from us... but the Earth slows slightly... Earth used to spin faster, and have shorter days... Conservation of angular momentum...Transference and Conversion of Energy... so, smaller and smaller spins... When the Energy came out of the Singularity it was a fantastically hot Energy, it probably "swirled" out... not just in a straight line. And of course in a sphere... thus, as it expands, it has a tendency to "blob" up...as it gets thinned out... like an exploding ball of paint... (see Mythbusters)....
OF COURSE... the film makers themselves... could be TURNING THE CAMERA... for Aesthetics....ART.... which would invalidate my statement above... ... but not so much....

:---[===] *

The understandable confusion among those commenting is because you think this is a simulation of THE WHOLE THING. It is not. It is a simulation of a tiny PART of the whole thing; a part where the dark matter (and the ordinary baryonic matter) is condensing to form the galaxies that we know and love. Just imagine billions of these simulations next to one another: everywhere, galaxies are condensing and forming, while the whole thing is expanding, and these days expanding exponentially, and in due course all of it will vanish into infinity like a puff of smoke. Oops, I'd better sit down!!

I think there is some clarification needed in the text.

"The 100-million light-year simulation starts about 20 million years after the Big Bang and runs until the present"

how does a 100 MY sim cover from 20 MYA the BB to present??

My math says the sim should be ~13,680 MY (given 13.8 BYO universe)

what am I missing???

an incredible feat of physics and programming. at this point the mathematics and relationships may draw reliable conclusions about galactic evolution and the general fabric of space.

valid questions may be asked and simulated such as: what happens in the future approximately 2 billion years from now, or 10 billion years from now.

as a tool of research, the program appears to be sufficiently developed enough to probe planetary physics. entire stellar systems may be simulated to study planetary formation; differentiation of terrestrial planets and gaseous giants, and the fate of asteroids.

in particular, the behaviour of binary planetary systems may be probed with confidence given such input as diameter and mass of primary and secondary bodies, distance of binary planets to parent star, distance between primary and secondary bodies, period of orbit of binary, placement in stellar system, mass of parent star .. ..

evolution of stellar systems was the subject of numerous studies in the past. a computer program was instructed to generate various simulated models of solar system formation. now, that study may be carried out in more detail.

mister T wrote:I think there is some clarification needed in the text.

"The 100-million light-year simulation starts about 20 million years after the Big Bang and runs until the present"

how does a 100 MY sim cover from 20 MYA the BB to present??

My math says the sim should be ~13,680 MY (given 13.8 BYO universe)

what am I missing???

Light-years are a measure of distance. The simulation is occuring inside a cube* the sides of which are 100 million light-years across. The simulation runs for the time you say, ~13,680 MY.

* I'm assuming a cube, since that's the easiest volume in which to program such a simulation, but it could be a sphere I suppose.

Rob

dalethorn wrote:
A few seconds in and it looks like the universe is turning almost clockwise like a tropical storm.

This 100-million light-year simulation is not a simulation of the entire universe.

rstevenson wrote:

mister T wrote:I think there is some clarification needed in the text.

"The 100-million light-year simulation starts about 20 million years after the Big Bang and runs until the present"

how does a 100 MY sim cover from 20 MYA the BB to present??

My math says the sim should be ~13,680 MY (given 13.8 BYO universe)

what am I missing???

Light-years are a measure of distance. The simulation is occuring inside a cube* the sides of which are 100 million light-years across. The simulation runs for the time you say, ~13,680 MY.

* I'm assuming a cube, since that's the easiest volume in which to program such a simulation, but it could be a sphere I suppose.

Rob

once again my insufficient reading comprehension rears it's ugly head

Boomer12k wrote:Odd... if Red Shift is a measure of galaxies moving away at speed from us... why is everything in the simulation falling toward the nearest center of mass.

First, cosmological redshift is not Doppler redshift. It has nothing to do with galaxies moving away from us (except indirectly). Cosmological redshift it caused by the wavelength of light getting stretched out by the expansion of spacetime itself during the time between its emission and its receipt at some other point in the Universe.

Second, we're looking at a gravitationally bound region of space in this simulation, so there is no cosmological expansion. The region is held together by the self-gravity of the energy within it, and the luminous and non-luminous matter is kept together in complex, closed orbits by gravity.

Chris Peterson wrote:

Boomer12k wrote:Odd... if Red Shift is a measure of galaxies moving away at speed from us... why is everything in the simulation falling toward the nearest center of mass.

First, cosmological redshift is not Doppler redshift. It has nothing to do with galaxies moving away from us (except indirectly). Cosmological redshift it caused by the wavelength of light getting stretched out by the expansion of spacetime itself during the time between its emission and its receipt at some other point in the Universe.

Second, we're looking at a gravitationally bound region of space in this simulation, so there is no cosmological expansion. The region is held together by the self-gravity of the energy within it, and the luminous and non-luminous matter is kept together in complex, closed orbits by gravity.

Thanks, Chris... I always wondered about that... I see, and I do comment, on the expansion of space, that space is expanding, while matter is condensing, and falls inward, and I do understand that is "space-time", and should have used that term. I understand that it does not necessarily apply to gravitationally bound areas. (but did not realize the extent of that, clearly... BIG areas...are even affected. I did not realize though about Doppler and Cosmological Red Shifts, as we are GENERALLY given Red Shifts for Galaxies... showing they move away from us... but the simulation shows overall that they fall towards each other, though not necessarily us....
So the lightwave expands into longer waves as the Space-time expands... Light truly rides Space-time... I wonder how much that affects our perception of Distance.... does it?
You know..."objects in mirror may appear closer..."

:---[===] *

Boomer12k wrote:I did not realize though about Doppler and Cosmological Red Shifts, as we are GENERALLY given Red Shifts for Galaxies... showing they move away from us... but the simulation shows overall that they fall towards each other, though not necessarily us....
So the lightwave expands into longer waves as the Space-time expands... Light truly rides Space-time... I wonder how much that affects our perception of Distance.... does it?

That is the basis for our understanding of distance.

Again, to be clear, the redshift only indirectly shows that the galaxies are moving away from us. We can also mix both cosmological redshift and Doppler shift (red or blue) in a measurement. For example, the cosmological redshift gives us the distance to a group of galaxies, while the Doppler shift of each galaxy relative to the others tells us something about how they are orbiting each other.

So from this video representation, I'm getting that we think there were/are huge dense 'nodes' in spacetime?
(That attract all the galaxies?) Or is the super-bright area simply very large area where gravity is more powerful?

bt7design wrote:So from this video representation, I'm getting that we think there were/are huge dense 'nodes' in spacetime?
(That attract all the galaxies?) Or is the super-bright area simply very large area where gravity is more powerful?

Spacetime doesn't have a density as such. Areas containing more mass (mostly dark matter) create stronger gravitational fields, which in turn means they influence other mass more strongly. This is no different from what we observe around us now- the only real difference was that the mass density was higher- there was more stuff in a given volume of the Universe than we observe in the same volume now. Not surprising, given the expansion of spacetime.

One more thing - I don't know it for a fact, but the overall rotation of the whole scene may be just added in (that is, not real) to enhance the "3D" effect.

Ann wrote:In my previous post, where I talked about black holes, I meant that black holes must form at the center of mass concentrations similar to the one we saw in today's APOD.

I don't think that's certain at all. There's a relationship between galaxies and massive black holes, which is not well understood at all. Even less well understood, I think, would be any relationship between black holes and these primordial mass concentrations.

Having done extensive work with simulations of this sort, where the scope includes the effect universe on the creation of one or more galaxies, I can make some observations given some of the comments I have read here.

First, the comment that questions the appearance of rotation following the big bang. Assuming that the distribution of matter following the big bang will not be homogeneous, there will be areas of lesser and greater mass in the blast debris. As some of these areas begin to coalesces into galaxies, other areas of local higher densities of matter interact gravitationally on the proto galaxies from multiple directions. One side of the proto galaxy will be effected more strongly than the other for each given gravity source. This will impart a turning moment on the proto galaxy that will become more pronounced as the proto galaxy collapses in on itself. Conservation of rotational momentum on a galactic scale. Given the initial postulate of disproportionate mass distribution following the bang, it would be extraordinary to assume that turning moments would not breed rotation. Additionally, as the gravitational forces are working in 3 dimensions of space, this will also account for the various orientations (horizontal to vertical) of the galaxies that we have observed. This orientation difference only takes a slight tug early on in order to establish what we perceive today.

Also, with respect to the comment about lack of ejecta from the proto galaxy shown. The video does, in fact, show some larger areas of matter being ejected and apparently dissipating as matter spreads out. However, what cannot be seen is some of the smaller areas of mass distribution. It would be expected that these lighter areas, interacting with much larger mass areas, would be ejected at very high speeds, and would not be expected to show up on the simulation. This ejection of lower masses would also impart their own contribution to the rotational moment and orientation of the proto galaxy. Until things settle down, and then we see what we see today. Those lighter area masses may form their own galaxy a some point, but will be moving so fast, that they will never return.

In virtually every simulation, there is no black hole in existence that contributes to the formation of a galaxy, tho it could happen. The driving force for the creation of a black hole seems to be the collection of matter that is collapsing together thereby forming the black hole. Kind of like a central garbage dump. But as matter collapses inwards, the rotation momentum become more concentrated allowing centripetal force to counterbalance inward gravitational forces, and you get a stable rotating galaxy. If you remove the black hole from the center of the galaxy, aside from a little disruption at the core, the galaxy continues virtually undisturbed. However, the black hole reappears over time as matter continues to spiral in towards the center of mass.

Just some observations from many many simulations of the big bang and galaxy creation. The orientation of the created galaxies was a little unexpected, but in hind sight, it made a lot of sense.

Something I hadnt realized was that many early galaxies appear to get ripped apart and dissipate