When I read the question from today's consultation I thought “Why are you asking it that way instead of asking if it's possible to travel to the past?” But I like it that way. What occurred to me is that the reader who asked this question must think that in order to teleport we are a complex organism, and therefore, you would not risk your life, because on the other side you would have to rebuild. However, the message, if you send it digitally, 0 and 1, might make time travel easier.
There is a very fascinating paradox about the transmission of messages through time, which is widely used in the field of quantum information. This paradox is the following: Someone wrote a book in the past that solved all the problems of humanity: Goodbye wars, goodbye diseases… And in the future you read the book and say to yourself, “This person is my role model.” I'm going to travel back in time to meet her.” You travel back in time and meet this person, but when you find him he says to you: “I haven't written any book.” You show it to them and insist: “Yes, yes, look, this is the book you're going to write.” Then you give him the book and he publishes it. This information was transmitted into the past and was received by this person. But where did that information come from? Where was it created? In the past or in the future?
This is the wording of the question. To answer your question, I will explain why we cannot send information to the past. I start from the idea that we can send information into the future, for example, by writing a book. But not to the past. Firstly because we don't have a time machine, at least not yet. Secondly, can you build a time machine? On a theoretical level, yes. Mathematically, yes, it is possible. In theory, wormholes would allow such a machine to be built.
A wormhole is a hypothetical tube-shaped structure whose open ends are at two different points in space-time. Moving through the hole will allow you to move from one of those points to another, and therefore, also theoretically, it will allow you to travel through time. However, at the moment, no evidence has been found that spacetime actually contains these structures, so it is a theoretical possibility.
This is the theoretical area that I've worked in, and I've made my case, specifically, with wormholes. Such a wormhole acting as a time machine is a theoretical possibility that could be built within the laws of physics. But in reality, this is not possible, because, on the one hand, all constructs of time travel require something completely alien, or alien matter, or alien space. By strange, I mean that it is not something we know of in our physical world like matter, energy, or any of the systems we know. I mean, you could think, theoretically, that maybe you could build that machine with negative energy, but in our universe we've never seen anything with negative energy or mass. Also, if you had a time machine and you tried to put something in it, what would happen? Even if you could build that machine because you got the exotic materials needed, how you put something in one of those machines so that it comes out through… the other sideI will definitely end up destroying that information.
In short: The paradox is easily solved, because even though I have a wormhole that acts as a time machine, when I bring that information closer to that wormhole it is as if there is a wall destroying the message I want to send. .
So building these time machines would be very difficult due to the difficulty of obtaining the necessary alien matter, but even if you did build them, they have horizons and forces acting at their entrance that prevent anything from getting in and out unharmed. So, even if it could be built theoretically, it wouldn't be effective because it couldn't be used for anything.
Ana Alonso Serrano She is a researcher at the Humboldt University of Berlin and the Max Planck Institute for Gravitational Physics in Potsdam (Germany).
The question was sent via email by Pedro Santangelo.
Formatting and writing:Victoria Toro.
Dice is a weekly science consultation, sponsored by the Dr. Anthony Esteve Foundation and the L'Oréal-UNESCO “For Women in Science” programme, which answers readers' questions about science and technology. They are scientists and technologists, members of AMIT (Association of Women Researchers and Technologists), who answer these questions. Send your questions to [email protected] Or by X #werespond.
“Creator. Devoted pop culture specialist. Certified web fanatic. Unapologetic coffee lover.”