String Theory: Access Parallel Universes with Quantum Tunneling - dummies

String Theory: Access Parallel Universes with Quantum Tunneling

By Andrew Zimmerman Jones, Daniel Robbins

In string theory, one process of getting from one universe to another would be to use the property of quantum tunneling, which is where a particle is allowed to “jump” from one location to another across a barrier.

The uncertainty principle of quantum physics means that particles don’t have a definite location, but instead both the location and momentum of each particle are linked together with a sort of “fuzziness.” The more precisely you determine the location, the more fuzzy the momentum is, and vice versa.

This principle results in a strange phenomenon, known as quantum tunneling and shown in this figure. In this case, there is some sort of barrier (usually a potential energy barrier) that the particle shouldn’t be able to cross normally. But the graph, which represents the probability that the particle is in any given location, extends a bit across the barrier.


In other words, even when there’s an uncrossable barrier, there’s a slight chance — according to quantum mechanics — that a particle that should be on one side of the barrier may end up on the other side of the barrier. This behavior has been confirmed by experiment.

This provides a means that could in theory be used to access a parallel universe. Some cosmologists have suggested that exactly this physical mechanism is what started our own expansion as a universe.

The idea of quantum tunneling is key to the operation of electron-tunneling microscopes, which allow scientists to observe objects in incredibly fine detail.

Particles can only tunnel from a higher energy state into a lower energy state, though, so there are some limits on how this could be used, and the idea of using it to access another universe in a controlled way is way beyond current technology (or even current theory).

But for a sufficiently advanced civilization, one that has a theory that fully explains all aspects of physics and the ability to use vast amounts of energy, this sort of idea may be a possible means of getting to another universe.