@Starswirl  
Same here.

@Meanlucario  
That, I have no in-depth knowledge of. Somepony with greater insight than I would need to explain.

@Starswirl  
How does it work in the Doctor Who series? Seeing that we’re using their idea here, than it should be using its logic as well.

@Meanlucario  
Well, ruins are already there. The future isn’t. So, more like ruins that will be in a place where there’s a forest right now, only you don’t know they’ll be built.

@Starswirl  
So like ruins that no one appreciates until the civilization is long dead? Also, Twilight and Spike will notice it, since they’ll be there.

@Meanlucario  

 
It’s not because we want it to, it’s because to a lot of ponies, this resolution makes little sense. Or rather, in the way it makes sense to them, what happened lacked meaningful impact.
 
They saved a future—which only has any impact for the ponies there if that future is still ongoing, as its own separate thing.
 
If it’s not its own separate thing, meaning this will all happen again to these same characters, they’re going to step into the same traps, make the same mistakes, everything, because they can’t remember how they solved the problems the first time around. Heck, if it’s the same timeline, then saving it the first time has no impact because it hasn’t happened yet.
 
So, either it’s a different timeline like the Crystal War one, or it’s the same, in which case what we got was to see in advance what’ll happen later and not much else.

How knows…good and bad…they balance each other…i guess that’s why they don’t last forever?

@zippysqrl  
I think this is Doctor Who’s version of time travel.

@zippysqrl
 
In some settings many forms of time travel exist depending how what was used to achieve to do the time travel. So with one magic or technology you can do the time loop and then another one actually lets you change time (and another one created alternate timelines instead).

@Meanlucario  
i prefer the idea of creating new branches in the timeline every time you enter/leave, so that you can do things like go to a point just before you arrived already on another occasion to create a new timeline so the old you joins the old timeline and not the current one, so you get to enjoy that dinner as many times as you want.  
_{also allows you to do things like produce infinite versions of yourself or anyone you want or infinite money/any resource by taking from other timelines and discarding them}

@zippysqrl  
I mean arriving at the same time you left. It’s like someone saying they don’t want to travel through time because they don’t want to miss dinner.

@Meanlucario  
“you don’t know how time travel works”  
>implying  
As much as I love to think about which methods of time travel would work if it were real, that statement right there is loaded, regardless of who says it.  
There’s no singular way that time travel can be theorised to behave _{(if it were possible)}.  
There is one model where by travelling to the future, they’re creating a future where they up and vanished, yes, but there’s also a model where the future they travelled to includes the eventual part where they travel back, in an unchangeable pre-defined linear-sense.

@Background Pony #816E  
No. You don’t know how time-travel works, and they left Twi because they died, not because they traveled through time once.

didn’t the whole future happen because they vanished from twilight’s point of view in the past?
 
They went in the Tardis to the future and as far as twilight knew they just up and disappeared.

@Background Pony #2228  
No, just their memories. Why would the timeline be wiped if they fulfilled the prophecy? Their memories were wiped so the timeline would remain.

@Meanlucario  
Really? I thought the timeline was wiped, hence those people they saved don’t even exist anymore. Unless I interpreted this wrong? 🤷

@Background Pony #2228  
And? They still saved everyone. That’s like saying that a cruel dictator’s death is meaningless because it wasn’t prevented.

@Xidphel  
They saved it, but have no way to prevent it happening. That and they also forgot how they saved it, so years later, once the future occurs, this whole mess would occur, with no way to stop it from happening. They might as well just wait it out since it’s “destined” that it will be fixed. 🙂

@Qev  
So the fact that they saved the future is meaningless. Got it.

@Qev  
How? They still saved Twi in ger final hours, and what they did isn’t null because they don’t remember what they did. It’s like you guys want all this to be pointless.

Yay everything is meaningless because predestination.

@Xidphel
 
Oh yeah, I can’t believe I made that error (although I got it right later on). Time Masters are from Legends of Tomorrow.

@Background Pony #CA95
 
Time lords.
 
@Background Pony #2228
 
Same thing with the 50th anniversary of Doctor Who:  
Every iteration of the doctor from 1 to 13 helped save Galifrey from the Time War. Everyone except 12 and possibly 13 forgot it ever happened.
 
One special later and that becomes a plotpoint.

@Meanlucario
 
I liked it when The Doctor declared that without the Time Masters around, he could do whatever he wanted and was planning to no longer care about preserving the original timeline.
 
The Time Lord Victorious would have been great but he gave up on those plans so easily.

Because if bad things never happened, you would never appreciate the good.