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Forum » SpaceEngine » Feedback and Suggestions » Possible big bang? [lock please] (Reversing time.)
Possible big bang? [lock please]
ScruffygamerDate: Saturday, 04.07.2015, 07:50 | Message # 1
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Okay. I highly doubt this will be possible to implement. Because it will take ALONG time to make.

But I just thought of a suggestion, to make a button to make another universe. Causing the player to appear in the middle of nothing.

Then when you unpause time, the big bang will start. And you can make time go faster.

If the developers were EVER to implement it,

hek you would need a good computer.


Edited by Scruffygamer - Tuesday, 14.07.2015, 21:34
 
HandbananaDate: Sunday, 05.07.2015, 01:08 | Message # 2
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Why bother mentioning this when you yourself even admitted you already know the answer? Vladimir (the developer) has stated in the FAQ that he will strive to add whatever real phenomena he possibly can. Believe me, I'm sure we'd all like to see something like this implemented into SE, but these kinds of quickly-thought-out suggestions that are ultimately redundant to the end goal don't really do anything.

I hope I don't appear to be on the attack, but the thing about software development is that the devs almost always have these basic suggestions in mind already.





Tonight... you.
 
WatsisnameDate: Sunday, 05.07.2015, 06:37 | Message # 3
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Quote
hek you would need a good computer.


Uh, yeah. tongue

If you're curious about what it would look like to watch the evolution of the universe from the Big Bang (and if you are also able to see the dark matter), it would be something like this.

Now let's put the computational problem of implementing this in Space Engine into perspective. This one video required using a supercomputer to simulate motions of over a hundred million particles. I don't know how much time it took to run that simulation, but I imagine it was on the order of "several hours to days". It is not possible to do such a thing on a standard home PC, let alone on a timescale such that you could watch it at a reasonable frame rate.

And that's only simulating the evolution of large-scale structure, and even then just a small slice of the full observable universe. It doesn't show individual stars, which would multiply the particle count by about a factor of 100 billion, and require introducing additional physics for their formation and evolution. And we haven't even begun to consider planets and their surfaces, atmospheres, and biology yet!

In short, simulating full scale universe evolution on a modern PC is beyond impossible. You can't even achieve the first order of cosmic scale. smile

Added:
There's one other thing I'd like to point out regarding regarding the above video. You might notice that, unlike almost every other visualization of the Big Bang seen in popular media, this one does NOT look like an explosion of stuff from a point, spreading out into surrounding blackness. Instead it looks like you're always inside of a space which basically looks the same everywhere, but gets less dense over time. This is how it actually would be! The Big Bang happens "everywhere"! You don't get to see it from the outside because there is no outside.

The simulation also shows how at first, the universe seems bright and opaque, so you can't see very far. It's like being inside of a luminous fog. As time goes on, the fog seems to dim and recede. This is the surface of last scattering, which happens when the universe is ~380,000 years old and became cool enough for electrons and nuclei to combine to form atoms, thus turning space transparent. It dims and redshifts because of the universe's expansion, and it recedes because of the look-back time (photons from the 380,000 year old universe arrive to you from ever more distant locations). Today, we know it as the cosmic microwave background.





 
ScruffygamerDate: Sunday, 05.07.2015, 08:24 | Message # 4
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Quote Watsisname ()
Uh, yeah.

If you're curious about what it would look like to watch the evolution of the universe from the Big Bang (and if you are also able to see the dark matter), it would be something like this.

Now let's put the computational problem of implementing this in Space Engine into perspective. This one video required using a supercomputer to simulate motions of over a hundred million particles. I don't know how much time it took to run that simulation, but I imagine it was on the order of "several hours to days". It is not possible to do such a thing on a standard home PC, let alone on a timescale such that you could watch it at a reasonable frame rate.

And that's only simulating the evolution of large-scale structure, and even then just a small slice of the full observable universe. It doesn't show individual stars, which would multiply the particle count by about a factor of 100 billion, and require introducing additional physics for their formation and evolution. And we haven't even begun to consider planets and their surfaces, atmospheres, and biology yet!

In short, simulating full scale universe evolution on a modern PC is beyond impossible. You can't even achieve the first order of cosmic scale.

Added:
There's one other thing I'd like to point out regarding regarding the above video. You might notice that, unlike almost every other visualization of the Big Bang seen in popular media, this one does NOT look like an explosion of stuff from a point, spreading out into surrounding blackness. Instead it looks like you're always inside of a space which basically looks the same everywhere, but gets less dense over time. This is how it actually would be! The Big Bang happens "everywhere"! You don't get to see it from the outside because there is no outside.

The simulation also shows how at first, the universe seems bright and opaque, so you can't see very far. It's like being inside of a luminous fog. As time goes on, the fog seems to dim and recede. This is the surface of last scattering, which happens when the universe is ~380,000 years old and became cool enough for electrons and nuclei to combine to form atoms, thus turning space transparent. It dims and redshifts because of the universe's expansion, and it recedes because of the look-back time (photons from the 380,000 year old universe arrive to you from ever more distant locations). Today, we know it as the cosmic microwave background.


Okay. Maybe you can make a Big Bang in SpaceEngine

It won't take a CRAP load of particles. you can make a bunch of waves going around faster then light.

Then the universe will just expand and cool down.

And then stars and galaxies will form.

and maybe the black holes can be created too.

You don't have to use that many particles.

Just enough to look good.

happy

Added (05.07.2015, 08:24)
---------------------------------------------

Quote Scruffygamer ()
Okay. Maybe you can make a Big Bang in SpaceEngine

It won't take a CRAP load of particles. you can make a bunch of waves going around faster then light.

Then the universe will just expand and cool down.

And then stars and galaxies will form.

and maybe the black holes can be created too.

You don't have to use that many particles.

Just enough to look good.


And when you said you can't view the Big Bang from the outside in Space Engine,

then how come you can leave the universe in Space Engine? Maybe we can do it.
 
WatsisnameDate: Sunday, 05.07.2015, 13:46 | Message # 5
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Quote Scruffygamer ()
It won't take a CRAP load of particles. you can make a bunch of waves going around faster then light.


I don't understand how that makes any sense, either physically or as a computational aid.

The observable universe contains trillions of galaxies. If you want to simulate the evolution of the universe, even on only the largest scales, then you need to allow for the dynamical motion of trillions of particles... one for each galaxy. The motions are governed by gravity, so this means you have to do, for each time-step, a calculation of the acceleration of each galaxy due to the force from each other galaxy. The physics is very simple, but the computational expense is insane. Look into N-body dynamics to learn about it. This is why these simulations you see require supercomputers. And even then they are not rendering in anything remotely close to real time! It can take hours just to produce a few seconds worth of frames.

Now, I suppose you could try to shortcut this by mapping the galaxy distribution to fractal noise (what SE already does), and then have that fractal noise be a function of time in such a way that it mimics how the cosmic web forms and evolves. However, this would not show how the individual galaxies move within clusters, or how clusters move along filaments. You have to simulate gravity to show that. So you're back to calculating gravitational attraction between a lot of particles. Computational dead end.

Quote Scruffygamer ()
And then stars and galaxies will form. And maybe the black holes can be created too.


Then you have to simulate how that happens! That's an extra level of complexity, with additional physics, and more particles on a finer scale. Now you've gone from "impossible" to "beyond impossible" (with current technology, maybe once when we have fully developed quantum computing).

I wish this wasn't the case, but, well, it is. If it was as easy as you're making it out to be, then we would already have a beautiful simulation which simultaneously shows everything from the formation of the cosmic web to stars and planets. I guarantee there is no such thing.

Quote Scruffygamer ()
And when you said you can't view the Big Bang from the outside in Space Engine, then how come you can leave the universe in Space Engine? Maybe we can do it.


In the real universe, there is no meaningful sense of an "outside" perspective. The universe is also homogeneous and isotropic, meaning it looks the same in all directions and from all points in space (assuming a sufficiently large viewing distance). This is true at all times, whether it be now or at the Big Bang. So, viewing the Big Bang as an explosion of stuff out of a point is physically wrong. It contradicts both of these principles. Instead, what the Big Bang looks like is a uniform space which expands from every point.

In Space Engine, we see the universe at a specific instance of time (how it appears at the present, roughly), and we only see a finite part of it which is roughly the size of the real observable universe. Beyond that, you are free to fly, but nothing is generated there. This is one way in which the Space Engine universe does not fully correctly represent the real universe. In Space Engine, the universe is not isotropic or homogenous beyond the boundaries of its generated cube.

In a future version of SE, perhaps this will be improved. Perhaps it may use a closed model where if you fly off one edge, you seamlessly appear on the other.

I hope this is a bit clearer. smile





 
ScruffygamerDate: Sunday, 05.07.2015, 21:42 | Message # 6
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Quote Watsisname ()
In the real universe, there is no meaningful sense of an "outside" perspective. The universe is also homogeneous and isotropic, meaning it looks the same in all directions and from all points in space (assuming a sufficiently large viewing distance). This is true at all times, whether it be now or at the Big Bang. So, viewing the Big Bang as an explosion of stuff out of a point is physically wrong. It contradicts both of these principles. Instead, what the Big Bang looks like is a uniform space which expands from every point.

In Space Engine, we see the universe at a specific instance of time (how it appears at the present, roughly), and we only see a finite part of it which is roughly the size of the real observable universe. Beyond that, you are free to fly, but nothing is generated there. This is one way in which the Space Engine universe does not fully correctly represent the real universe. In Space Engine, the universe is not isotropic or homogenous beyond the boundaries of its generated cube.

In a future version of SE, perhaps this will be improved. Perhaps it may use a closed model where if you fly off one edge, you seamlessly appear on the other.

I hope this is a bit clearer.


Okay I apoligize for not making any sense.

Can you atleast make a reset button?

Like I edited a planet. And I want a reset button for the edited planet to turn back to before it was edited.
 
HarbingerDawnDate: Wednesday, 15.07.2015, 00:17 | Message # 7
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Quote Scruffygamer ()
And I want a reset button for the edited planet to turn back to before it was edited.

This is already in the planet editor.





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