Time Travel Via Wormhole Breaks the Rules of Quantum Mechanics. Science has done it again everybody!
Brace yourselves for this groundbreaking news, freshly determined by physicists: Time travel, if it exists, may have some weird consequences. Gosh, who’d have thunk it? But no, seriously, a recent article suggests that a certain kind of theoretically possible time machine would wreak minor havoc with a firm principle of quantum mechanics, the often-weird science of the smallest bits of the universe. You know what this means: We get to explore the science of time travel!
Time Travel: No, Really Let’s get this out of the way first: Obviously time travel exists, because it’s already the third week of 2014. The “useful” kind of time travel, though, for sci-fi authors and dreamers alike, is into the past, Back to the Future style. Okay, so a wormhole-based time machine might actually be possible, if not necessarily very likely.
2011. Time travel. Time travel is the concept of moving between different points in time in a manner analogous to moving between different points in space, generally using a theoretical invention, namely a time machine.
It has a commonly recognized place in philosophy and fiction, but has a very limited application in real world physics, such as in quantum mechanics or wormholes. Although the 1895 novel The Time Machine by H. G. Wells was instrumental in moving the concept of time travel to the forefront of the public imagination, The Clock That Went Backward by Edward Page Mitchell was published in 1881 and involves a clock that allows a person to travel backwards in time.[1] Non-technological forms of time travel had appeared in a number of earlier stories such as Charles Dickens' A Christmas Carol.
Historically, the concept dates back to the early mythologies of Hinduism (such as the Mahabharata), Buddhism, and Islam through ancient folk tales. Quantum mechanics of time travel. Until recently, most studies on time travel are based upon classical general relativity.
Coming up with a quantum version of time travel requires us to figure out the time evolution equations for density states in the presence of closed timelike curves (CTC). Novikov[1] had conjectured that once quantum mechanics is taken into account, self-consistent solutions always exist for all time machine configurations, and initial conditions. However, it has been noted such solutions are not unique in general, in violation of determinism, unitarity and linearity.
The application of self-consistency to quantum mechanical time machines has taken two main routes. Novikov's rule applied to the density matrix itself gives the Deutsch prescription. Deutsch's prescription[edit] In 1991, David Deutsch[2] came up with a proposal for the time evolution equations, with special note as to how it resolves the grandfather paradox and nondeterminism. He showed that such fixed points always exist. . And . . . If. Quantum Time Machine Lets You Travel to the Past Without Fear of Grandfather Paradox. Looking to build a time machine but nervous about the classic grandfather paradox, aka the Marty McFly conundrum, aka the idea that you might unwittingly do something that causes you to never exist in the first place?
An MIT professor and a few of his quantum quoting buddies have published a theory that allows for time travel while circumventing the grandfather paradox. All you need is a quantum teleportation device and a precise understanding of the idea of postselection--Flux Capacitor optional. Postselection is one of the notions that makes quantum computing simultaneously so exciting and perplexing; the idea that for a super-complex problem riddled with variables, you solve by letting the variables take any value at random and postselect for the one combination that makes the problem true.
This form of theoretical time travel solves two major problems associated with the feat. Quantum Time Machine Solves Grandfather Paradox. Of all the weird consequences of quantum mechanics, one of the strangest is the notion of postselection: the ability to trigger a computation that automatically disregards certain results.
Here’s an example: suppose you have a long, tortuous expression in which there are a frighteningly large number of variables. The question you want answering is which combination of variables makes the expression logically true. And the conventional way to solve it is by brute force: try every combination of variable until you find one that works.
That’s hard. Postselection, however, makes the solution easy to find. Postselection is controversial because it leads to all kinds of fantastical predictions about the power of quantum computers. Now postselection gets even weirder thanks to some new ideas put forward by Seth Lloyd at the Massachusetts Institute of Technology and a few buddies. Before we look at how this idea works, a quick reminder about quantum teleportation. Fire up the Delorean.