Forget space — time travel could be the next infinite frontier. Like Bill and Ted’s Excellent Adventure, living history would replace the museum with exhibits of epic proportions. Multiple dimensions could answer every historian’s questions of “what if?”

Although often disregarded as impossible, time travel exists in the physicists’ and philosophers’ world as a definite possibility — but today it only exists in numbers.

“I think time travel is possible,” John Blondin, professor of physics, said. “But I don’t think it will happen in my lifetime.”

Scientists’ theories such as Einstein’s relativity and string theory mock up mathematical worlds where linear and multidimensional time travel are a reality.

Relativity offers a one-dimensional pathway for time travel. Regular physics classes teach the possibility of slowing time down at high speeds, but the theory actually offers much more possibility than fast forwarding to the future. Einstein’s relativity theory defines time as the fourth dimension, so space and time can be folded back on themselves — similar to folding a piece of paper.

“According to Einstein, an example of that is a wormhole, folding it so much you end in the past,” Blondin said.

String theory is an attempt to bring quantum physics and relativity together, according to Blondin. String theory supports the view that the universe is made of multiple dimensions and opening a porthole between these dimensions could cross time barriers.

Blondin pointed out the movie Contact as a good example.

“The premise in Contact is they created this doorway with a huge amount of energy, and it looked like she just fell through, but to her it was as though she went somewhere else,” he said.

Beyond the physical aspects of time travel are the philosophical problems that could arise if people went back to the future. There are two main paradoxes John Carroll, professor of philosophy, covers in his class on time travel: the “grandfather paradox” and the “self-visitation paradox.”

The grandfather paradox examines what would happen if someone went back in time and killed his or her grandfather before his or her father was born — the problem then arising, how could the killer be born?

The self-visitation paradox plays the mind game that if someone went back in a time machine he could visit himself.

“If I went back in time and I was sitting down, but I do not sit down, I watch standing — then at the same time I am both sitting and standing — and that is impossible, right?” Carroll said.

These examples focus mainly on a one-dimensional travel experience, meaning a person can only travel forward and backward in one pathway. But with the introduction of string theory became the possibility of a multidimensional universe and multidimensional time travel.

Samuel Harward, a senior in mechanical engineering, is working on an honors independent study on multidimensional time travel.

“It is branching,” he said. “Every option that could occur does occur, so whatever path you take is what you are experiencing.”

This possibility of a “multi-verse” can lead to an identity paradox — the problem that if infinite world options of a person exist, which option is actually the person? Where does his or her identity exist?

Harward also finds time travel as a way to explore the idea of free will.

“Time travel is a good tool for free will scenarios — if this will happen would this happen and so forth,” he said.

Common misconceptions about time travel derive from science-fiction literature and movies where people drive in a car and flash out of sight. People see the commercialization and automatically think the science is impossible, but there are respected scientists around the country working on time travel.

“Most of my students are thinking Back to the Future or Bill and Ted’s ,” Carroll said. “And they are surprised to see that physicists take it seriously now. There is a professor [Ronald Mallet] at the University of Connecticut who is claiming to be building a machine to go backward.”

There are still many hurdles in science and the philosophy to keep experts busy, especially as the possibility of time travel becomes closer to reality.

“This is where science and philosophy collide,” Blondin said.