For some, the idea of time travel is about fantasy. For others it's science. But for Ronald Mallett, it was love -- a son's love for his father.
You might even call it his lifelong mission.
"I thought if I could build a time machine to save my father's life and see him again," said Mallett, whose father died when he was just 10.
"My father was someone who was the center of my life -- I was the oldest of four children and we grew up in the Bronx. And my father was a television repairman," Mallet said.
"He was terrific at his job, as a matter of fact. He really spent a lot of time with me, gave me little scientific toys like gyroscopes and crystal radio sets. I just I just worshipped him."
Mallet said he kept his plan a secret.
"I was astute enough to realize that people were worried about me already and if I told them that wanted to build a time machine I might not want to deal with the consequences," Mallett said.
People might think he was crazy, even though he has worked his way to a job as a tenured physicist at the University of Connecticut.
But it's not a secret anymore, because of something really crazy. He said he thinks he has come up with a way to do it.
It's complicated, but not crazy, according to some other scientists who have studied Mallett's idea.
Albert Einstein theorized that space and time are linked, and that gravity can bend time just like it bends space.
Mallett said he believes that if he can create a gravitational swirl -- a whirpool -- he can actually twist space and time.
"So if I'm twisting space violently enough, ultimately what will happen is that that timeline will get twisted into a loop," Mallet said.
Think of the loop like a time tunnel. Where Mallett thinks maybe we might be able to move back and forth. He said he will use criss-crossing lasers to try to create his time tunnel.
But even if Mallet builds his time machine, and proves his theory, which would be an epic breakthrough, there is still one major limitation.
"It only works from the moment the machine turns on," Mallet said.
That means you couldn't go back to a time earlier than the time when the machine begins to work. So Mallett could never go back to 1955 to see his father. But still, he said, he is certain his father would be proud.