Ultimate space simulation software

 
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midtskogen
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31 Mar 2021 12:30

By the way, the pattern generated in 15:46 could be an awesome analog for animating stellar surface granules
Probably way too expensive, but interesting to see how simple rules with feedback resembles nature in so many ways.

More SE related was this video from the same guy:
[youtube]lctXaT9pxA0[/youtube]
NIL DIFFICILE VOLENTI
 
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01 Apr 2021 03:17

David Attenborough showing how lack of biodiversity and deforestation is an even bigger problem than climate change

https://www.pbs.org/show/extinction-facts/

Watched it on PBS last night.

https://www.mindfood.com/article/david- ... the-world/
 
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01 Apr 2021 03:21

I love slime molds!  Our architecture mimics theirs startlingly well!
 
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16 May 2021 21:37

Thanks for this!  I've always been fascinated with slime molds because some of their structures mimic human architecture!  It's an example of fractal behavior in action and as you have stated, how complex behavior can emerge from simpler processes.
 
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Watsisname
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16 Sep 2021 20:15

[youtube]4rTv9wvvat8[/youtube]

This video sets the bar now for how to explain this extremely counter-intuitive subject. Absolutely wonderful. 

4K VR journey:
[youtube]17tEg_uTF_A[/youtube]
 
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16 Sep 2021 21:07

I'm fascinated by these supermassive black holes that don't crush us, we might not even know we were inside one.....
 
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midtskogen
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17 Sep 2021 02:10

It's fascinating how the entire intuitive concept of time and contemporaneity falls apart.  Once crossing the horizon, we can still see the spaceship and the universe, but we've detached from that universe which in one sense is expired and gone.
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17 Sep 2021 16:21

I never believed that space and time were fundamental in the first place mid, neither really exists at the fundamental quantum level and black holes are awesome as being macro representations of quantum particles, I think.  In reality black holes represent the unification of the macro with the micro, relativity and quantum mechanics.

One thing I wanted to ask--  I was reading  about the far future "collision" between M31 and our galaxy resulting in a giant elliptical galaxy (like M87) in the far future- are the supermassive black holes of both galaxies going to collide or is one just expected to absorb the other (likely the M31 supermassive black hole will absorb ours because it's more massive.)
 
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17 Sep 2021 16:23

It's fascinating how the entire intuitive concept of time and contemporaneity falls apart.  Once crossing the horizon, we can still see the spaceship and the universe, but we've detached from that universe which in one sense is expired and gone.
you might be even more right than you think if black hole cosmology proves to be true
 
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18 Sep 2021 01:47

One thing I wanted to ask--  I was reading  about the far future "collision" between M31 and our galaxy resulting in a giant elliptical galaxy (like M87) in the far future- are the supermassive black holes of both galaxies going to collide or is one just expected to absorb the other (likely the M31 supermassive black hole will absorb ours because it's more massive.)
There's little sense of one black hole falling into or being absorbed by the other. Instead a new, larger event horizon forms that encompasses both and quickly settles down into its final shape.

It won't be a direct collision of the black holes, either. Supermassive black holes are still extremely small relative to the sizes of the galaxies, so even a tiny amount of sideways motion of the two will mean they miss each other at first. When the galaxies merge the black holes will likely end up in a widely separated and very elliptical orbit about each other, then eventually migrate inward and spiral together by scattering stars and radiating gravitational waves.

Here's a plot of the distances between the two black holes throughout a simulation of the galaxy merger. The top shows this for three different initial sideways velocities of Milky Way and Andromeda (for which we do not know the true value), while the bottom shows how much the result depends on the resolution of the simulation (it indeed looks quite robust). The figure is from a study earlier this year: https://arxiv.org/pdf/2102.10938.pdf

Image

Once the black holes get to a few hundred light years of each other, the N-body galaxy merger simulation is no longer useful for calculating the evolution of the black hole binary, and a different type of simulation including gravitational wave emission is necessary. The next figure shows a plot of that phase of the evolution. Notice the extremely high eccentricity at first (it is close to 1). This phase of the merger is comparatively quick -- about ten million years or so. 

Image
 
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19 Sep 2021 03:17

One thing I wanted to ask--  I was reading  about the far future "collision" between M31 and our galaxy resulting in a giant elliptical galaxy (like M87) in the far future- are the supermassive black holes of both galaxies going to collide or is one just expected to absorb the other (likely the M31 supermassive black hole will absorb ours because it's more massive.)
There's little sense of one black hole falling into or being absorbed by the other. Instead a new, larger event horizon forms that encompasses both and quickly settles down into its final shape.

It won't be a direct collision of the black holes, either. Supermassive black holes are still extremely small relative to the sizes of the galaxies, so even a tiny amount of sideways motion of the two will mean they miss each other at first. When the galaxies merge the black holes will likely end up in a widely separated and very elliptical orbit about each other, then eventually migrate inward and spiral together by scattering stars and radiating gravitational waves.

Here's a plot of the distances between the two black holes throughout a simulation of the galaxy merger. The top shows this for three different initial sideways velocities of Milky Way and Andromeda (for which we do not know the true value), while the bottom shows how much the result depends on the resolution of the simulation (it indeed looks quite robust). The figure is from a study earlier this year: https://arxiv.org/pdf/2102.10938.pdf

Image

Once the black holes get to a few hundred light years of each other, the N-body galaxy merger simulation is no longer useful for calculating the evolution of the black hole binary, and a different type of simulation including gravitational wave emission is necessary. The next figure shows a plot of that phase of the evolution. Notice the extremely high eccentricity at first (it is close to 1). This phase of the merger is comparatively quick -- about ten million years or so. 

Image
Wow this is absolutely fascinating.  I spent about 6 hours today reading 150 research articles on ER=EPR and its amazing and deep relationship to the holographic principle via quantum entanglement, quantum entanglement via microwormholes leading to emergent spacetime, fractal properties of spacetime, the 8 colors combinations of gluon interactions with quarks and antiquarks, a recent close to 5 sigma possible discovery of sterile neutrinos, different types of black holes, black holes in 5 dimensional space leading to naked singularities, traversable wormholes in 6 dimensional Randall Sundstrum II space, about two dozen of Sean Carroll's blog entries on MWT and its relation to quantum superposition and the conservation of energy across the multiverse and even a discovery of what appears to be negative mass.  Seems like new developments are coming quickly!
And how do I know I read 150 research articles in one sitting (didn't even realize 6 hours had passed by!), as I was about to close my browser I got a gentle warning "Are you sure you want to close 150 tabs" LOL.  I guess I left them all open because I wanted to save all the links to cite later.  Here's the weird thing, ER=EPR was formulated in 2013 by Maldacena, but when I went back across my own writing going all the way back to 2009, I remember mentioning an idea I had after I had read about quantum foam, that hmmm, here is a possible vehicle that could drive quantum entanglement, what if micro wormholes in quantum foam acted as tunnels for quantum entanglement?  At any rate Maldacena is a real superstar, he formulated the duality AdS/CFT which linked relativity to quantum field theories using string theory while he was still in grad school and then the holographic principle and now ER=EPR.

https://news.wsu.edu/2017/04/10/negativ ... ed-at-wsu/

ULLMAN, Wash. – Washington State University physicists have created a fluid with negative mass, which is exactly what it sounds like. Push it, and unlike every physical object in the world we know, it doesn’t accelerate in the direction it was pushed. It accelerates backwards.

The phenomenon is rarely created in laboratory conditions and can be used to explore some of the more challenging concepts of the cosmos, said Michael Forbes, a WSU assistant professor of physics and astronomy and an affiliate assistant professor at the University of Washington. The research appears today in the journal Physical Review Letters, where it is featured as an “Editor’s Suggestion.”

Hypothetically, matter can have negative mass in the same sense that an electric charge can be either negative or positive. People rarely think in these terms, and our everyday world sees only the positive aspects of Isaac Newton’s Second Law of Motion, in which a force is equal to the mass of an object times its acceleration, or F=ma.

In other words, if you push an object, it will accelerate in the direction you’re pushing it. Mass will accelerate in the direction of the force.

“That’s what most things that we’re used to do,” said Forbes, hinting at the bizarreness to come. “With negative mass, if you push something, it accelerates toward you.”

Conditions for negative mass

He and his colleagues created the conditions for negative mass by cooling rubidium atoms to just a hair above absolute zero, creating what is known as a Bose-Einstein condensate. In this state, predicted by Satyendra Nath Bose and Albert Einstein, particles move extremely slowly and, following the principles of quantum mechanics, behave like waves. They also synchronize and move in unison as what is known as a superfluid, which flows without losing energy.

Led by Peter Engels, WSU professor of physics and astronomy, researchers on the sixth floor of Webster Hall created these conditions by using lasers to slow the particles, making them colder, and allowing hot, high energy particles to escape like steam, cooling the material further.

The lasers trapped the atoms as if they were in a bowl measuring less than a hundred microns across. At this point, the rubidium superfluid has regular mass. Breaking the bowl will allow the rubidium to rush out, expanding as the rubidium in the center pushes outward.

To create negative mass, the researchers applied a second set of lasers that kicked the atoms back and forth and changed the way they spin. Now when the rubidium rushes out fast enough, if behaves as if it has negative mass.

“Once you push, it accelerates backwards,” said Forbes, who acted as a theorist analyzing the system. “It looks like the rubidium hits an invisible wall.”

Avoiding underlying defects

The technique used by the WSU researchers avoids some of the underlying defects encountered in previous attempts to understand negative mass.

“What’s a first here is the exquisite control we have over the nature of this negative mass, without any other complications” said Forbes.  Their research clarifies, in terms of negative mass, similar behavior seen in other systems.

This heightened control gives researchers a new tool to engineer experiments to study analogous physics in astrophysics, like neutron stars, and cosmological phenomena like black holes and dark energy, where experiments are impossible.

“It provides another environment to study a fundamental phenomenon that is very peculiar,” Forbes said.

Forbes’ colleagues on the Physical Review Letters paper include WSU research assistants Mohammad Khamehchi, Khalid Hossain and Maren Mossman, as well as Thomas Busch in Japan and Yongping Zhang in China and Japan. The work was supported in part by a WSU New Faculty Seed Grant and the National Science Foundation.
Last edited by A-L-E-X on 19 Sep 2021 03:37, edited 2 times in total.
 
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19 Sep 2021 03:31

One thing I wanted to ask--  I was reading  about the far future "collision" between M31 and our galaxy resulting in a giant elliptical galaxy (like M87) in the far future- are the supermassive black holes of both galaxies going to collide or is one just expected to absorb the other (likely the M31 supermassive black hole will absorb ours because it's more massive.)
There's little sense of one black hole falling into or being absorbed by the other. Instead a new, larger event horizon forms that encompasses both and quickly settles down into its final shape.

It won't be a direct collision of the black holes, either. Supermassive black holes are still extremely small relative to the sizes of the galaxies, so even a tiny amount of sideways motion of the two will mean they miss each other at first. When the galaxies merge the black holes will likely end up in a widely separated and very elliptical orbit about each other, then eventually migrate inward and spiral together by scattering stars and radiating gravitational waves.

Here's a plot of the distances between the two black holes throughout a simulation of the galaxy merger. The top shows this for three different initial sideways velocities of Milky Way and Andromeda (for which we do not know the true value), while the bottom shows how much the result depends on the resolution of the simulation (it indeed looks quite robust). The figure is from a study earlier this year: https://arxiv.org/pdf/2102.10938.pdf

Image

Once the black holes get to a few hundred light years of each other, the N-body galaxy merger simulation is no longer useful for calculating the evolution of the black hole binary, and a different type of simulation including gravitational wave emission is necessary. The next figure shows a plot of that phase of the evolution. Notice the extremely high eccentricity at first (it is close to 1). This phase of the merger is comparatively quick -- about ten million years or so. 

Image
Wow that is one steep curve!
Notice the extremely high eccentricity at first (it is close to 1). This phase of the merger is comparatively quick -- about ten million years or so. 

I was wondering about the extreme eccentricity of the curve, that's why that phase of the merger is so quick isn't it?
I've also been doing a lot of reading about supermassive black holes being mostly Kerr black holes and I know this is going to be extremely speculative (on both our parts), but how do you think mergers like these affect the interior geometry and multiple horizons (if these are indeed both Kerr black holes)?  One of the articles I had read mentioned that supermassive black holes of the Kerr variety were most likely to host traversable wormholes (but we know that is an extremely small possibility because that geometry is extremely unstable and anything that enters it is likely to choke off the wormhole unless it is propped up with a lot of negative energy density or negative mass, although I did read one piece that showed the opening to the wormhole outside of the event horizon, I think that was in the Randall Sundstrum II model.  Interesting thing it mentioned is that any traveler who ventured through such a wormhole would still exhibit the effects of time dilation, in other words if the exit point of the wormhole was 10,000 light years away, although he/she would only experience less than a second of time passage, outside observers would have experienced the full 10,000 years.)

This is the piece on supermassive wormholes, but since it looks like they're actually replacing the central black holes with worm holes in this model, it seems extremely unlikely to me, but certainly a novel detection method using high energy gamma rays!

https://www.space.com/black-holes-as-wo ... ay-flashes
 
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07 Oct 2021 07:33

Wat, I've been reading Quanta Magazine extensively and one of the things I've become interested in are the two point correlations we've found in Hubble deep space images.  Is there any way to see these in SE?  I'm interested in it because it shows how galaxies evolved in the earliest days of the universe from two particles that spontaneously appeared very early on and then inflation and expansion separated them.  Also interested in finding three point correlations and higher, even though none have been discovered yet.
 
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01 Dec 2021 17:56

I thought this was a pretty fun and interesting video. The science of how snow crystals get their shapes. :) 

Veritasium: The Guy Who Figured Out How Snowflakes Work

What's especially interesting is how the incredible diversity among ice crystals is not so much due to randomness about crystal growth itself, but that the conditions the crystals are exposed to during their time in the cloud can be so different from one another (since they can follow different paths). But if you grow a few crystals together so that they are exposed to the same (even if changing) conditions over time, then their shapes are incredibly similar. 

Another possible surprise for many people is that snow crystals are not all shaped like the iconic snowflake (which are actually somewhat uncommon as snow crystals go), but also plates, columns, columns with plates on the ends, needles, pyramids, and so on. One of my favorite things about ice halos (one of Midtskogen's favorite topics too) is that the type of display you see in the sky reveals a lot of information about the shapes and orientations of ice crystals in the cloud, which in turn tells about the conditions within the cloud.

Image
 
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01 Dec 2021 22:18

Wat, I've talked to a few "snow snobs" over the years who think anything besides dendrites are corrupted adulterated snow lol.  They want the highest possible water equivalent ratios (like 20 to 1 or higher).  What are the conditions necessary to produce the perfect unadulterated snow that maximizes these ratios?

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