If you traveled back in time and met your parents when they were young, you would not be able to separate them and prevent your birth - even if you wanted to, claims a new model in quantum mechanics
Researchers speculate that time travel may occur in a kind of situation where movement back in time is possible, but only in a way that is "complementary" to the present. In other words, you can jump back and check what happened in the past, but you won't be able to do anything to change the present you left behind. The new model, based on the laws of quantum mechanics, gets rid of the famous paradoxes surrounding time travel.
Explanation of the paradox
Although the laws of physics seem to allow doing stunts in time, the idea is loaded with distressing contradictions. The main problem stems from the idea that if you traveled back in time, you could, theoretically, do something that would change the present. This possibility pretty much destroys the idea of time travel.
There is no doubt that the present does not undergo changes due to malicious time travelers, since people do not evaporate to them due to a repeated running of events that prevented their birth - we know that for sure. If so, the options before us are that time travel is not possible or that something prevents time travel from changing the present.
To most of us, the first option seems more likely, but Einstein's theory of general relativity leads some physicists to suspect the correctness of the second option.
According to Einstein, the space-time warp has the ability to curve back on itself, which theoretically allows time travelers to meet younger versions of themselves.
Now a team of physicists from the United States and Austria claims that the above scenario is only possible to the extent that there are physical restrictions, which act to protect the present from changes in the past.
Bizarre rules
The researchers say that these restrictions exist in the strange laws of quantum mechanics, although originally they were not talking about moving backwards in time.
Quantum behavior is governed by probabilities. Before anything is measured, there are several options regarding its state. However, at the moment of measurement whether these benefits are reduced to one - the uncertainty disappears.
That is, if you know what the present is, you cannot change it. If, for example, you know that your father is alive today, the laws of the quantum world dictate that there is no possibility of him being killed in the past.
You can look at it as if, in some strange way, the present takes into account all the possibilities that involve time travel, and since your father is definitely alive, none of those possibilities can lead to his death.
"Quantum mechanics distinguishes between something that might happen and something that actually happened," said Professor Dan Greenberger (Greenberger) from New York University in the US to the BBC news website.
"If you're not sure your father is alive right now — if there's only a 90 percent chance he's alive right now, you might go back in time and kill him."
“However, if you know for sure that he is alive, you cannot kill.”
In other words, even if you travel back in time with the clear intention of killing your father, as long as you know he was sitting safely on the throne when you left him in the present, you can be sure that nothing will stop you from murdering him in the past. Just like it already happened.
"You go back in time to kill your father, but come after he's left the room, you won't find him or you'll change your mind," Professor Greenberger said. "You will not be able to kill him, because the very fact that he is alive today will conspire against you so that there will be no situation in which you will kill him."
Greenberger and his colleague Carl Svozil present their quantum model of time travel on the Arxiv service.
One response
So there is actually no time travel!
Because everything done in the past can change the future - it's called the butterfly effect!