I recently watched a scene from the tv sitcom The Big Bang Theory with Sheldon explaining English grammar about time travel (related with the use of have, has, had…), is his explanation even grammatically correct?
Here’s the script
Howard: Something doesn’t make sense. Look. In 2015 Biff steals the Sports Almanac and takes the time machine back to 1955 to give it to his younger self. But as soon as he does that he changes the future, so the 2015 he returns to would be a different 2015. Not the 2015 that Marty and Doc were in.
Leonard: This is Hot Tub Time Machine all over again. Look. If future Biff goes back to 2015 right after he gives young Biff the Almanac, he could get back to the 2015 with Marty and Doc in it. Because it wasn’t until his 21st birthday that 1955 Biff placed his first bet.
Sheldon: But whoa, whoa. Is ‘placed’ right?
Leonard: What do you mean?
Sheldon: Is ‘placed’ the right tense for something that would’ve happened in the future of a past that was affected by something from the future?
Leonard: [thinks] Had will have placed?
Sheldon: That’s my boy.
Leonard: OK. So, it wasn’t until his 21st birthday that Biff had will have placed his first bet and made his millions. That’s when he alters the timeline.
Sheldon: But he had will haven’t placed it.
Sheldon: Unlike Hot Tub Time Machine, this couldn’t be more simple. When Biff gets the Almanac in 1955, the alternate future he creates isn’t the one in which Marty and Doc Brown ever used the time machine to travel to 2015. Therefore, in the new timeline, Marty and Doc never brought the time machine.
Leonard: Wait, wait, wait. Is ‘brought’ right?
Sheldon: [thinks] Marty and Doc never had have had brought?
Leonard: I don’t know, you did it to me.
Sheldon: I’m going with it. Marty and Doc never had have had brought the time machine to 2015. That means 2015 Biff could also not had have had brought the Almanac to 1955 Biff. Therefore, the timeline in which 1955 Biff gets the Almanac is also the timeline in which 1955 Biff never gets the Almanac and not just never gets: never have, never hasn’t, never had have hasn’t.
Here’s the video link
If this isn’t correct, how could the part in bold be written so that a native speaker would understand it to mean what the character intends? Is there a standard construction that people writing about time travel have used?
The notable verb groups under discussion are numbered and shown in bold type:
Leonard: OK. So, it wasn’t until his 21st birthday that Biff (1) had will have placed his first bet and made his millions. That’s when he alters the timeline.
Sheldon: But he (2) had will haven’t placed it.
Sheldon: I’m going with it. Marty and Doc (3) never had have had brought the time machine to 2015. That means 2015 Biff (4) could also not had have had brought the Almanac to 1955 Biff. Therefore, the timeline in which 1955 Biff gets the Almanac is also the timeline in which 1955 Biff never gets the Almanac and not just never gets: never have, never hasn’t, (5) never had have hasn’t.
The simplest — and perhaps the sanest — solution can be had based on the assumption that these speakers are talking about it from the standpoint of your own natural time, which I think they actually are.
Based on this assumption, whenever you’re talking about a different timeline than your own natural timeline, you’re essentially talking about a hypothetical timeline. And in order to describe a hypothetical timeline, you can always use the construction of ‘would/could/might have + past participle‘.
Now, the beauty of this construction is that, as long as you’re talking about a hypothetical timeline, you can always use it, regardless of time relative to your own time of speaking in your own timeline. That is, you can talk about a future time in the hypothetical timeline as well as a present or past time in the hypothetical timeline, relative to your time of speaking.
Of course, you cannot use this construction when talking about a past time before the past event that enables the hypothetical timeline, because at that past time the hypothetical timeline would merge with your own natural timeline. But none of the five verb groups deals with a past time prior to Biff’s taking the time machine back to 1955, so I think the aforementioned construction can be used for all five of them.
Here’s my suggest for the five verb groups, (1)-(5), respectively:
(1′) would have placed
(2′) wouldn’t have placed
(3′) would never have brought or never would have brought
(4′) could not have brought
(5′) would never have had or never would have had
Now, as for the original verb groups, you can never have the auxiliary had followed by the modal will, so (1) and (2) are inherently wrong, regardless of however complicated you want it to be. Also, neither can you have the auxiliary had followed by any infinitive, let alone the auxiliary have in the infinitive form, so (3)-(5) are all inherently wrong, regardless of however complicated you want it to be.