In Vancouver, at a conference on quantum gravity, we caught up with Kip Thorne, Nobel laureate in physics and scientific advisor to the film Interstellaralong with Philip Stamp, a professor in the Department of Physics and Astronomy at the University of British Columbia (UBC), to discuss the possibility of such journeys through time.
Here are five concepts to better understand the scientific theories behind time travel.
1- The essential ingredient: wormholes
One of the theories raised by the physicist Kip Thorne would be that of using tunnels in space-time, called wormholes. They would connect two distinct regions of space-time. This theory was made popular by the movie Interstellar, of which he is one of the executive producers.
Can they exist naturally in our universe? Probably not. Can they be made by an infinitely more evolved civilization? It’s conceivablesays the theoretical physicist.
Wormholes are an inevitable consequence of Einstein’s theory explains Philip Stamp, a professor at UBC.
A lot of people say it’s science fiction, but the theory [de la relativité générale] was developed a long time ago, has been verified in great detail and has predicted black holes.
Did you say “general relativity”?
Albert Einstein’s theory of general relativity states that gravitational fields are caused by distortions or curvatures in the web of time and space.
It remains to be seen, however, whether it is possible to travel through these cosmic tunnels.
2- A machine not yet perfected
People think I invented the time machine, but I didn’t., Kip Thorne said with a big smile. Some would be too optimistic about this possibility, but others
think it’s totally impossible, but we know that’s not true eitherhe explains.
To travel in time, a device must allow space travel and return before departure, says the physicist.
You can’t sit here and time travel like you do in the movie. tenet for example.
Unfortunately, a lot of evidence suggests that any time machine will self-destruct upon powering up, according to the Nobel Prize winner. This discovery, during his research work, surprised him a lot.
However, even if science could prove that time travel is possible,
technology is so late that it wouldn’t happen in my granddaughter’s lifetimehe said.
Many questions remain unanswered, in particular because of the incompatibility between the two dominant theories that explain the functioning of our Universe: quantum mechanics and Einstein’s theory of general relativity.
3- A door to a “new world”
The answers would therefore be found in a theory of quantum gravity which would unify the theories of general relativity and quantum mechanics, and whose discovery has not yet been made. It is this quest that has brought the world’s greatest physicists to meet in Vancouver for a conference.
According to Philip Stamp, one of the organizers of the event, the discovery of quantum mechanics which was made very quickly by a small institute
had an incalculable effect on our future and one could imagine it happening again. I think that’s one of the goals of the Quantum Gravity Society.
This discovery could change the future, but could it change the past?
4- The grandfather paradox
This paradox takes the example of a time traveler who returns to the past to eliminate his own grandfather before he had children, destroying the very possibility of his existence.
Thinking you can change the past is a misconception, says Professor Philip Stamp.
The choice of what you do in the past is determined by what happened in the future, so even if you think you are making a choice, in fact the choice has already been determined.
5- Bring science further
Time travel seems far from attainable, but it has nevertheless inspired, through numerous books and films, several generations of physicists.
When we think about and analyze the technology needed to create a time machine, even if it is very far from human capacities, we wonder about the laws of physics and what they say of such a time machine. So we have learned a lot from the laws of physics themselvesconcludes Kip Thorne.
These laws which govern the mysteries of the Universe are the real source of motivation for the theoretical physicist.