An alternative is to conjecture that, while time travel is possible, it never leads to paradoxes ; this is the Novikov self-consistency principle.

It was shown by Pyotr Novikov in 1955 that there exists a finitely generated ( in fact, a finitely presented ) group G such that the word problem for G is undecidable.

The Novikov self-consistency principle, also known as the Novikov self-consistency conjecture, is a principle developed by Russian physicist Igor Dmitriyevich Novikov in the mid-1980s to solve the problem of paradoxes in time travel, which is theoretically permitted in certain solutions of general relativity ( solutions containing what are known as closed timelike curves ).

Stated simply, the Novikov consistency principle asserts that if an event exists that would give rise to a paradox, or to any " change " to the past whatsoever, then the probability of that event is zero.

This could mean that the Novikov self-consistency principle does not actually place any constraints on systems outside of the region of spacetime where time travel is possible, only inside it.

The Novikov Principle is able to circumvent most commonly-cited temporal paradoxes which are often alleged to exist should time travel be possible ( and are often claimed to make it impossible ).

The Novikov consistency principle assumes certain conditions about what sort of time travel is possible.

However, the Novikov self-consistency principle is intended to go beyond just the statement that history must be consistent, making the additional nontrivial assumption that the universe obeys the same local laws of physics in situations involving time travel that it does in regions of spacetime that lack closed timelike curves.

Time loop logic, coined by the roboticist and futurist Hans Moravec, is the name of a hypothetical system of computation that exploits the Novikov self-consistency principle to compute answers much faster than possible with the standard model of computational complexity using Turing machines.

* Novikov is alluded to by name in the comic Nth Man: The Ultimate Ninja.

* In Season 4 episode 2 of the TV series Eureka The Novikov Self Consistency Principle is explicitly mentioned to justify the many similarities between the " alternative timeline " experienced by the protagonists and their " original timeline ".

However, some philosophers and scientists believe that time travel into the past need not be logically impossible provided that there is no possibility of changing the past, as suggested, for example, by the Novikov self-consistency principle.

Igor Dmitriyevich Novikov () ( born November 10, 1935 in Moscow ) is a Russian ( and former Soviet ) theoretical astrophysicist and cosmologist.

Novikov is married to Eleonora Kotok and has two children, Elena and Dmitry.

It was only in 1992 that Sergei Vasilievich Ivanov was able to prove an analogue of Novikov – Adian theorem: for any m > 1 and an even n ≥ 2 < sup > 48 </ sup >, n divisible by 2 < sup > 9 </ sup >, the group B ( m, n ) is infinite.

Extending this result, Pyotr Novikov and William Boone showed independently in the 1950s that the word problem for groups is not effectively solvable: there is no effective procedure that, given a word in a finitely presented group, will decide whether the element represented by the word is the identity element of the group.

In Miami, Florida, a national multi-divisional championship known as The Novikov Invitational is held for anybody within a certain level of expertise, regardless of how they obtained it.

By reversing this construction, John Milnor and Sergei Novikov ( among many others ) were able to answer questions about the existence and uniqueness of high-dimensional manifolds: this is now known as surgery theory.

The Red Army Choir became known as a propagator of Soviet songs, performing original compositions by composers such as Vasily Solovyov-Sedoy, Anatoli Novikov, Matvey Blanter and Boris Mokrousov.

The Novikov Principle does not allow a time traveller to change the past in any way at all, but it does allow them to affect past events in a way that produces no inconsistencies — for example, a time traveller could rescue people from a disaster, and replace them with realistic corpses if history recorded that bodies of victims had been found.

* 1964-A. G. Doroshkevich and Igor Dmitrievich Novikov write an unnoticed paper suggesting microwave searches for the black-body radiation predicted by Gamow, Alpher, and Herman.

In 1968, Pyotr Novikov and Sergei Adian's supplied a negative solution to the bounded exponent problem for all odd exponents larger than 4381.

1955: Pyotr Novikov showed that there exists a finitely presented group G such that the word problem for G is undecidable.

When changing to a different coordinate system ( for example Lemaitre coordinates, Eddington-Finkelstein coordinates, Kruskal-Szekeres coordinates, Novikov coordinates, or Gullstrand – Painlevé coordinates ) the metric becomes regular at r = r < sub > s </ sub > and can extend the external patch to values of r smaller than r < sub > s </ sub >.

Or that the time-traveler's personal knowledge of history already includes their future travels to their own experience of the past ( for the Novikov self-consistency principle ).

Other proposals which allow for backwards time travel but prevent time paradoxes, such as the Novikov self-consistency principle which would ensure the timeline stays consistent, or the idea that a time traveler is taken to a parallel universe while his original timeline remains intact, do not qualify as " chronology protection ".

1978 saw a public statement made by Soviet psychiatrist Yuri Novikov, who was the head of a section of the Serbsky Institute for six years and first secretary of the Association of Soviet Psychiatrists until he left the Soviet Union in June 1977.

This theme is represented, in particular, by considerable progress on the Novikov conjecture and the Baum-Connes conjecture and the development and study of related group-theoretic notions such as topological amenability, asymptotic dimension, uniform embeddability into Hilbert spaces, rapid decay property, and so on ( see, for example ,).

This Novikov self-consistency principle says that anything a time traveler does in the past must have been part of history all along, so although the time traveler can have a causal influence on events in the past, it is impossible for anything the time traveler does to " change " history.

Corneliu Coposu, who had friendly contacts with Pătrăşcanu at the time, attested that the latter had been selected by the Soviets as representative of the Communists ( during negotiations in Cairo, Nikolai Novikov, the Soviet ambassador to Egypt, had reportedly first mentioned Pătrăşcanu's name to Barbu Ştirbey for further contacts ).

* Pyotr Novikov ( 1957, mathematics, for proving the undecidability of the word problem for groups )

There exists a similar famous and difficult result establishing topological invariance for rational Pontryagin classes, due to Sergei Novikov.

Novikov used his influence for various noble purposes, such as a large-scale project of promoting Shakespeare to Russian public.

The above condition of semi-positive and the compactness of symplectic manifold M is required for us to obtain Novikov ring and for the definition of both Floer homology and quantum cohomology.

A quarter century later a 1975 paper by E. A. Novikov and a 1979 paper by H. Aref on chaotic advection finally brought this important earlier work to light.

Some years ago one of us ( Novikov < sup > 10 </ sup >) briefly considered the possibility that CTCs might exist and argued that they cannot entail this type of causality violation: Events on a CTC are already guaranteed to be self-consistent, Novikov argued ; they influence each other around a closed curve in a self-adjusted, cyclical, self-consistent way.

* From wormhole to time machine: Comments on Hawking's Chronology Protection Conjecture, which also addresses the Novikov self-consistency principle

The Novikov self-consistency principle and Kip S. Thorne expresses one view on how backwards time travel could be possible without a danger of paradoxes.

Both Novikov – Adian and Ivanov established considerably more precise results on the structure of the free Burnside groups.

Novikov published his results on the topological invariance of the rational Pontrjagin classes on smooth manifolds.

Novikov ( 1987 ) found a central extension of the Lie algebra of meromorphic vector fields on a higher genus compact Riemann surface that are holomorphic except at two fixed points, and M. Schlichenmaier ( 1993 ) extended this to the case of more than two points.

In 1990, commenting on the Novikov self-consistency principle ( in relation to sending objects or people through a traversable wormhole into the past, and the time paradoxes that could result ), Polchinski raised a potentially paradoxical situation involving a billiard ball sent through a wormhole which sends it back in time.

He was born in Novorossiysk, on the Black Sea, and in the early 1980s moved to Leningrad, where he met and became friends with leaders of the art scene there, such as the painter Timur Novikov and musician Boris Grebenshchikov.

Prince Mikhailo Mikhailovich Shcherbatov (, July 22, 1733 – December 12, 1790 ) was a leading ideologue and exponent of the Russian Enlightenment, on the par with Mikhail Lomonosov and Nikolay Novikov.