Hey everyone,
I just finished reading Dr. Stone, and the ending with the time machine totally blew my mind. After thinking about it, there is a wild theory that connects this machine, Senku's origins, and the mystery of Byakuya in a way that actually makes mechanical and scientific sense.
The Starting Mystery: The Byakuya Anomaly
As we all know, one of the most surprising details of the manga is that Senku and Byakuya share no blood relation. Byakuya was simply the best friend of Senku's biological father.
Yet, look at them: they share the same insane determination, the same absolute love for science, the same facial expressions, and even a gravity-defying hairstyle. Why did Inagaki insist on this adoption? What if the answer was hidden on the very last page of the manga?
The Grandfather Paradox
At the end of the series, Senku wants to build a time machine to save the billions of humans who died or were destroyed during the 3,700 years of petrification.
But Senku is a man of science. He knows perfectly well that if he cancels the petrification in the past, he creates a massive Grandfather Paradox:
If the Why-Man is stopped, Earth is never petrified.
If Earth is never petrified, Senku never wakes up in the Stone World.
If he never wakes up, he never meets Chrome, Kohaku, Gen, and the others. Ishigami Village doesn't exist.
Therefore, the Kingdom of Science is never founded, the time machine is never built, and we are back to square one.
Senku would never sacrifice Chrome, Suika, and Byakuya's legacy. He has to use the Many-Worlds Interpretation. He doesn't create one timeline, but two.
The Plan
Here is how the Kingdom of Science pulls this off to create a closed causal loop:
Step 1: Securing Timeline A
The Kingdom of Science realizes that for their present to exist, the events of the past must happen exactly as they experienced them. Ishigami Village must be founded, and Senku must be adopted. Among the descendants of the new Stone World, they find a brilliant teenager, obsessed with space, who shares Senku's exact genetic lineage. His name is Byakuya.
Step 2: The First Time Travel
They send this young Byakuya back in time to the late 20th century. The teenager grows up in our era, pursues astronomy, becomes best friends with Senku's dad, and eventually adopts baby Senku. This neatly explains the ISS alibi: when the petrification strikes, Byakuya is already in space as an adult of our time, having lived a completely normal life up to that point.
Byakuya's Blind Faith Was a Roadmap
This brings us to the biggest piece of evidence. There is a detail that bothers a lot of readers: Byakuya's absolute, almost prophetic certainty.
In every flashback, he repeats tirelessly that Senku will wake up and save humanity. But let's be real for a second: how can someone leave a capsule filled with platinum, the exact rare catalyst Senku will need for nitric acid, on a remote island, being absolutely certain that 3,700 years later the descendants will still be there, the capsule will survive, and Senku will find it at the exact moment he needs it? Fatherly faith alone doesn't cover that level of statistical insanity.
Unless Byakuya already knew.
If Byakuya comes from the future Kingdom of Science, he didn't just have blind faith. He had a mission.
The future Kingdom of Science would have given him a strict roadmap of historical milestones:
Adopt a child named Senku.
Found a village and name it Ishigami.
Create the hundred tales to transmit vital survival messages.
Gather platinum and seal it in the Soyuz because it is the only way to create the miracle fluid in the Stone Age.
This changes how we view Byakuya. When he cries looking at the stars or exhausts himself panning for gold and platinum in rivers for decades, it is not just the crazy hope of a father. It is the heavy burden of a man executing humanity's survival plan to the letter, knowing that a single mistake on his part erases everything. He knows Senku will succeed because he was told before leaving that this is exactly how it happened.
Step 3: Creating Timeline B
Once they secure their own existence by sending Byakuya to lay the groundwork, the Kingdom of Science can finally achieve its ultimate goal. They use the machine a second time to send a signal or an AI to disable the Why-Man right before the strike, creating a second timeline where humanity was never petrified.
Conclusion
If this theory holds true, it gives a whole new dimension to the story: Byakuya is actually Senku's descendant, traveling to the past to adopt his own ancestor and dying on an isolated island to ensure humanity survives. The Kingdom of Science becomes the architect of its own history, orchestrating the petrification to lead to a scientific renaissance.
Dr. Stone's optimism remains intact: with science and time, humanity can conquer destiny, save everyone, and honor those who paved the way.
TL;DR: The time machine at the end is used to create two timelines. To avoid erasing Ishigami Village and his friends, Senku sends a teenager from their future into the past. That teen grows up in the 21st century, adopts Senku, and goes to the ISS. That teen is Byakuya, who is actually Senku's descendant. Byakuya's crazy foresight with the platinum and the tales wasn't just faith, it was a roadmap given by the future Kingdom of Science. Once their timeline is secure, they create a second timeline where they cancel the petrification to save everyone without causing a paradox.
What do you think about it?