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Forum » SpaceEngine » Feedback and Suggestions » Further away objects are younger (Depiction of the universe as we currently see it)
Further away objects are younger
wtg62Date: Sunday, 23.03.2014, 23:35 | Message # 16
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Quote HarbingerDawn ()

Yeah it would. But I think that's beyond what will be possible for this program.


Yeah, procedural generation of all points in time for an object would be hard to successfully pull off.

The OP does have a good point that cataloged objects are recorded as how we see them now instead of how they actually are in the current point of time.


Edited by wtg62 - Sunday, 23.03.2014, 23:36
 
HarbingerDawnDate: Monday, 24.03.2014, 00:00 | Message # 17
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Quote wtg62 ()
The OP does have a good point that cataloged objects are recorded as how we see them now instead of how they actually are in the current point of time.

This is a matter of necessity, obviously, and also a good thing for those using this for astronomy education. But there's no reason that the entire universe should be restricted around that one fact.





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IngolifsDate: Saturday, 29.03.2014, 07:37 | Message # 18
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Quote
But there's no reason that the entire universe should be restricted around that one fact.


I'm not sure why you find the idea 'restricting', considering that at present there is probably several quadrillion times as much content in the game than anyone can access in their lifetime, all of it representing a current view of the universe. I don't see why having at least some of that content represent the earlier universe (and for the really noticeable differences it would have to be the very early universe) would be such a restricting thing. I would say that limiting astronomical objects to the present day is more restrictive. Early-universe objects are just as interesting as present day ones, I think.

Also, you claim that quasar formation is still possible in the modern universe. Considering that there are zero quasars in the volume of radius of 2.3 billion light years (a big volume), this is demonstrably false. The conditions required for quasar formation no longer exist in the universe.
 
HarbingerDawnDate: Saturday, 29.03.2014, 10:09 | Message # 19
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Quote Ingolifs ()
I'm not sure why you find the idea 'restricting'

The goal is to portray the universe as it is. You want to portray the universe as it is observed to be from one very specific point in the cosmos. That is very clearly restricting.

Quote Ingolifs ()
I don't see why having at least some of that content represent the earlier universe

If some does and some doesn't, then that would be inconsistent. Also, programming it to represent things in the earlier universe would be MUCH more challenging and time-consuming than you seem to realize. A huge amount of work would have to go into it. I'm not saying your idea doesn't have merit, but I am saying that it is inconsistent with what SE has been developed to be, and that it would require much more work to implement than it's worth right now. Maybe in the future another version can be made with these things, but for the foreseeable future it simply cannot happen.

Quote Ingolifs ()
you claim that quasar formation is still possible in the modern universe. Considering that there are zero quasars in the volume of radius of 2.3 billion light years (a big volume), this is demonstrably false

Maybe you missed these points that I raised, which contest your claim:

Quote HarbingerDawn ()
the nearest quasar known to have existed in the modern universe is only 730 million light-years away, which ceased its quasar activity only within the last 70,000 years
Quote HarbingerDawn ()
quasars are simply the most dramatic examples of AGNs, which are ubiquitous throughout the cosmos. They will be quite plentiful even in an SE with a modern universe.

Quote HarbingerDawn ()
Even if they were just as probable at all ages of the universe, you would still expect to find increasing numbers of them with increasing distance simply because of the rapidly increasing sample size at larger distances

So please tell me, if the nearest quasar to us is 2.3 billion light years away, how far away from THAT quasar is the nearest quasar to it? Are there any places we have yet observed in the universe where the density of quasars is a large amount per billion light year radius, which would be expected if quasars really were substantially more likely in the older universe? I'm not debating whether they were more common, of course they were, but I am saying that your logic deserves closer examination here.

Quote Ingolifs ()
The conditions required for quasar formation no longer exist in the universe.

Please explain to me exactly what those conditions are and why they are impossible in the universe today.





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DinoflyDate: Monday, 16.06.2014, 03:01 | Message # 20
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He has a point!
When we click a very far object it should not say what's now, but what was billion years ago biggrin
But this will be just a minor finish, before there a lot of things to do and fix.
 
WatsisnameDate: Monday, 16.06.2014, 07:52 | Message # 21
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The OP's suggestion is for SE to simulate cosmological light-travel delay, so that objects appear younger with respect to their distance. This in itself would be fine, but the issue that Harbinger has, and which I share as well, is that Ingolifs wants it to be calculated with respect to the Milky Way / Earth, and fixed that way. I.e. if you look at a distant galaxy, and then travel to it, it still appears young. This is not a good idea, and to explain why I will condense the reasoning down into two basic principles:

The real universe is:
homogenous - everywhere looks the same. Valid over sufficiently large (cosmological) distances.
isotropic - looks the same in all directions, again valid over sufficiently large distances.

Space Engine, within the limitations of its 10x10x10 Gpc simulated cube, is both homogenous and isotropic, so it conforms to the real universe well in this respect. (A closed model, so that there are no boundaries, would make it perfect, but that's another topic.) It doest matter where you go in it, the large scale structure looks the same everywhere and in all directions. But, if we introduce cosmological light-travel delay, fixed with respect to the Earth, then both conditions would fail. There would everywhere be a preferred direction (which points toward Earth) in which objects look younger, and this breaks isotropy. And if we forbid young structures from existing far from Earth, or old structures from existing nearby, then we also break homogeneity.

The logical course of action is to implement light-travel delay but have it dynamically update for the observer's present position in the universe. In other words, no matter where you go, farther away objects seem younger, and if you look far enough, you'll see the CMB. This is how the real universe works, and hopefully SE will someday show it properly.





 
SalvoDate: Monday, 16.06.2014, 11:27 | Message # 22
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Quote Watsisname ()
hopefully SE will someday show it properly

Dynamic light-travel delay isn't impossible to code, nothing is impossible to code, but SE would need a model for Galaxies and Stars evolution.



In any case this wouldn't be very userful for galaxies, since SE don't have procedural models, if you zoom to a galaxy very far away (if you use a very little FOV that allows that), you would see the same identical model. Changing it to a default one would cause distant galaxies to change suddenly shape, more you approaching them, and this wouldn't be so good.

But I admit that I would like this on stars, because you can travel to a catalogue star that you know and see if it actually changed or not. The only problem would be, on loading, changing catalogue stars' parameters to actually make this thing work.





The universe is not required to be in perfect harmony with human ambition.

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Forum » SpaceEngine » Feedback and Suggestions » Further away objects are younger (Depiction of the universe as we currently see it)
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