D-Mails (short for DeLorean Mail) are messages that are sent to the past. They can be used to cause the active world line to change by contradicting historical events. To quickly summarise the technology: D-Mails are sent using the Phonewave (name subject to change), an experimental combination of a microwave and a phone that happens to produce mini black holes. A large CRT donates electrons to the black holes, increasing their spin enough for them to become naked singularities. A message passed through the singularity travels to the past, with the microwave timer controlling how far it travels. However, the size of the singularities produced restricts the length of the message that can successfully be sent to 36 bytes, plus metadata.[1]
Most noticeably, D-Mails change which world line the active one is, to one consistent with the arrival of the D-Mail. In practical terms, this can be achieved by selecting an inactive world line which already contains a historical event with similar effects to the D-Mail’s arrival, then overwriting that one cause with the D-Mail’s arrival.[1]
Explanation With an Example[]
Consider the D-Mail Okabe sent himself with the winning LOTO SIX numbers. The initial world line is one where Okabe did not feel like entering LOTO SIX at the time, but there should also exist inactive world lines where he did decide to enter. The D-Mail forces one of these other world lines to become active, but with the inspiration for entering LOTO SIX on that world line changed from being Okabe’s own initiative to a mysterious mail arriving.[1]
Votuko — Mechanics of Steins;Gate[1]
Titor: "Just judging by the phenomenon you described, I would say what you accomplished is indeed changing the past. I suspect that the mail you sent into the past changed the world line’s divergence, if just a little. BRAVO! The instant your mail arrived in the past, I think you were moved from your original world line to an ever-so-slightly different one. In this world line, the world’s supposed past became this: You learned the Loto6 winning numbers from a mail you got from your future self, told your friend the numbers, and your friend mistook a number upon buying the ticket. So the mail probably disappeared from your sent history when the world line changed." — Chapter 3, Steins;Gate
We find ourselves proposing the idea that time travel changes the events on a world line, but only in such a way that the following events are unchanged. This agrees nicely with the TIPS definition of a world line, which states that "no matter how much you change the past along a single world line, the result will converge to the same outcome" . In fact, D-Mails do more than alter the one world line. After two D-Mails are sent, it is generally found that both have arrived on the most recent world line. The implication is that the first D-Mail, when sent, arrived on both the new active world line and at least one inactive world line, which later became active as the result of a different D-Mail. The simplest rule to explain the behaviour is this: Each D-Mail arrives on every inactive world line on which it has no new effect. The one of these world lines most similar to the sender’s world line becomes the new active world line. Inactive world lines are initially independent, but the overwriting of ordinary events with time travel arrivals creates apparent interconnections across the world line structure. In this way, evidence of earlier time travel can accumulate even on inactive world lines, so it is possible for a newly activated world line to already contain time travel events in its past or future.[1]
No Need to Move the Position of the Present[]
Following the above mechanics, there is also no need for a D-Mail to move the position of the Present. The events of the new active world line are already fully determined, without having to repeat a period of history. Multiple lines of evidence support this conclusion:
- First, Suzuha refers to the world’s "supposed past" changing, rather than a new past genuinely being experienced.
- Second, at no point do D-Mails cause new time travel to take place prior to their sending time. If the period of time following their arrival became active, we would expect new D-Mails to sometimes be sent within that period, appearing like a chaining effect to Okabe. This never happens, so it is reasonable to say that this period of time remains inactive.
- Third, Okabe experiences Reading Steiner at the moment of world line reconstruction, and that takes place in the Present, when the D-Mail is sent. There is no record of Reading Steiner ever occurring at the time of a D-Mail being received.[1]
D-RINE[]
On many world lines in the Beta Attractor Field, Itaru Hashida would eventually develop D-RINE, which function similarly to D-Mails but are instead sent via the text messaging app RINE. This would prevent SERN from identifying the messages sent to the past with ECHELON, which would in turn prevent the Attractor Field from changing into an Alpha Attractor Field.
Sent D-Mails and D-RINEs[]
| Date Sent | Date Received | Contents | Original World Line | New World Line | Effects | Notes |
|---|---|---|---|---|---|---|
| July 28, 2010 | July 23, 2010 | Rintaro Okabe notifies Itaru Hashida of Makise Kurisu's death. | 1.130426β | 0.571024α | ||
| August 3, 2010 | Okabe sends lottery numbers to himself. | 0.571024α | 0.571015α | Despite the correct numbers being sent back, a mistake on Luka's part leads to them not winning. | This is to test whether or not the use of D-Mails can actually change the past. | |
| August 4, 2010 | July 31, 2010 | Moeka tells herself the location of the IBN 5100. | 0.571015α | 0.523299α | Leads her to taking the IBN 5100 from Yanabayashi Shrine before Okabe learns of it. | |
| August 6, 2010 | January 1993 | Luka tells his mother to eat more vegetables while pregnant. | 0.523299α | 0.456903α | Changes Luka's gender from male to female. | Sent to Luka's mother's pager. |
| August 7, 2010 | April 3, 2000 | Faris warns her father against boarding the plane. | 0.456903α | 0.409420α | Prevents Yukitaka's death in the plane crash. | |
| August 10, 2010 | August 9, 2010 | Okabe tells himself to pursue Suzuha. | 0.409420α | 0.337187α | Suzuha stays for a few more days. | |
| August 13, 2010 | August 9, 2010 | Okabe warns himself not to stop Suzuha from going to the past. | 0.337187α | 0.409431α | Suzuha is able to go to the past in the undamaged time machine. | |
| August 14, 2010 | April 3, 2000 | Okabe and Faris send a new message that convinces Yukitataka that the previous one was fake. | 0.409431α, | 0.456914α | Yukitaka boards the plane and dies in the crash. | |
| August 15, 2010 | January, 1993 | Okabs sends another D-Mail to Luka's mother in the form of an advertisement. | 0.456914α. | 0.523307α | Luka's mother disregards the first D-Mail and Luka is born male. | Sent to Luka's mother's pager. |
| August 11, 2010 | July 31, 2010 | Okabe attempts sending multiple D-Mails from Moeka's phone. | 0.523307α | No change | None | The D-Mails are unsuccessful because Moeka would only go against FB's orders if FB told her to. |
| August 15, 2010 | July 31, 2010 | Okabe uses FB's phone to tell Moeka to ignore the IBN 5100. | 0.523307α | 0.571046α | Moeka stops her pursuit of the IBN 5100. | |
| January 2, 2011 | August 17, 2010 | Kurisu and Okabe tell past Kurisu not to enter the lab. | 0.571???α | 1.097302β | The D-Mail stalls Kurisu long enough to allow Okabe and Daru to erase the first D-Mail before she can enter. | |
| December 18, 2011 | December 15, 2011 | Okabe receives a D-RINE; "Trick world, Linking each possibility." |
1.055821β | 1.129848β | ||
| August 21, 2025 | August 21, 2010 | Okabe receives a D-Mail telling him to check Dr. Nakabachi's press conference on TV. | 1.097???β | No change | Allows Okabe to know about Nakabachi's attempt to defect to Russia. | |
| August 21, 2025 | July 28,2010 | Okabe tells himself the details of Operation Skuld. | 1.123581β | Unseen | ||
| August 21, 2025 | July 7, 2011 | Daru tells Mayuri & Suzuha the details of Operation Arc-Light. | 1.097302β(Anime) 1.129848β(VN) |
|||
| August 14, 2010 | Okabe and Faris attempt to send a D-Mail that would both save Yukitaka and Mayuri's life. | 0.409431α | -.275349ω | Leads to Faris' ending. |
Trivia[]
- Itaru Hashida was the one who coined the term DeLorean Mail (while in the anime adaptation, it was Mayuri Shiina), naming it after the model of the car equipped with the time traveling machine in the movie trilogy Back to the Future. Rintaro Okabe suggested a number of names for the mail, but it was Kurisu Makise who shortened DeLorean Mail to D-Mail.
- As well as being a reference to Back to the Future, the term D-Mail is also likely a reference to DI-Swords from Chaos;Head.