How Does Sans Knows About The Time Line

[James]

how does sans knows that you have reset

[fushigi friend]

He ate a Jelly Sandwhich and then the Jelly gods gave him super powers.

[MetalSlime]

Haven't you read up on the latest theories? He is a time lord and uses a magic toilet to travel through time and space.

[Terra]

He used to be the Royal Scientist. Evidence of this is (obviously) his knowledge of Timelines AND the machine in his lab/basement.

[RinneItachi]

To TerraGamer22. There is also the badge in the secret room.

[(Edgy) Asriel Dreemurr]

There's no canonically established answer as to how Sans knows how timelines work.
However, some bits of dialogue from Sans and other characters, and details in Sans' secret workshop suggests that Sans, and possibly Papyrus, is actually from a parallel universe.

My own sort of headcanon is that W.D. Gaster, a character only mentioned in very rare circumstances, unless you hack the game, was experimenting with travel between universes. The idea is that Sans, Papyrus, and W.D. are all "Dr. Gaster", but from 3 separate universes. Sans and Papyrus were accidentally brought to W.D.'s universe during his experiments. The trio explored the multiverse for research purposes, as Sans states "according to our reports" and then goes on to describe the events of the player resetting and destroying the timeline when you fight him. I speculate that the ENTRY NUMBER 17: "Dark Darker Yet Darker" is about the trio of Gaster(s) discovering the aftermath of the genocide run.

The broken machine in Sans' Workshop is possibly the device they used to travel between universes, and its destruction is also what caused W.D. Gaster's life to be cut short.

As for evidence as to how I came up with this. . .

A lot of the evidence about Sans and Papyrus being from another universe, was brought up by MatPat in his "Sans is Ness" theory. While I don't believe that either Sans is Ness or that Papyrus is a Starman, I do think that idea that they are not from the world presented in Undertale, or at least this version of it, still stands. Though, I will say that I did come up with my conclusions of this before MatPat released that video. So it's not that I'm copying him, we just came to some of the same conclusions. . . while he thought that they came from Earthbound, I thought that where they came from would be explored in a potential spin-off game which may or may not happen.

[Goblin]

Originally posted by MetalSlime:

Haven't you read up on the latest theories? He is a time lord and uses a magic toilet to travel through time and space.

This.

[Zeox]

Gaster tells him through skype

[Volcanic163]

Originally posted by (Edgy) Asriel Dreemurr:

There's no canonically established answer as to how Sans knows how timelines work.
However, some bits of dialogue from Sans and other characters, and details in Sans' secret workshop suggests that Sans, and possibly Papyrus, is actually from a parallel universe.

My own sort of headcanon is that W.D. Gaster, a character only mentioned in very rare circumstances, unless you hack the game, was experimenting with travel between universes. The idea is that Sans, Papyrus, and W.D. are all "Dr. Gaster", but from 3 separate universes. Sans and Papyrus were accidentally brought to W.D.'s universe during his experiments. The trio explored the multiverse for research purposes, as Sans states "according to our reports" and then goes on to describe the events of the player resetting and destroying the timeline when you fight him. I speculate that the ENTRY NUMBER 17: "Dark Darker Yet Darker" is about the trio of Gaster(s) discovering the aftermath of the genocide run.

The broken machine in Sans' Workshop is possibly the device they used to travel between universes, and its destruction is also what caused W.D. Gaster's life to be cut short.

As for evidence as to how I came up with this. . .

A lot of the evidence about Sans and Papyrus being from another universe, was brought up by MatPat in his "Sans is Ness" theory. While I don't believe that either Sans is Ness or that Papyrus is a Starman, I do think that idea that they are not from the world presented in Undertale, or at least this version of it, still stands. Though, I will say that I did come up with my conclusions of this before MatPat released that video. So it's not that I'm copying him, we just came to some of the same conclusions. . . while he thought that they came from Earthbound, I thought that where they came from would be explored in a potential spin-off game which may or may not happen.

That actually sounds plausible!

[JabberwockTheLemur]

Sans only knows that timelines exist. He doesn't actually know what goes down in them.

[Alexander]

Because he's Ness because he is short ad=nd has a badge! And Pappiroos iz starzmeen cuzz hee standz lik onne OMG soo muuh evidenssece