[ExI] On a more extropian note...

[Adrian Tymes]

The paper is less than the article seems.

To be short and only somewhat imprecise, it's a better proof than
previously existed that, if you assume no Grandfather Paradox, then you get
no Grandfather Paradox (and specifically, that physics and causality work
in the absence of such paradoxes).

On Sun, Sep 27, 2020 at 8:56 PM Dylan Distasio via extropy-chat <
extropy-chat at lists.extropy.org> wrote:

> Apparently, life may imitate the movie 12 Monkeys!  Curious if John or
> anyone else has any comments on the underlying paper:
>
> A Physicist Has Come Up With Math That Makes 'Paradox-Free' Time Travel
> Plausible
> DAVID NIELD
> 26 SEPTEMBER 2020
> No one has yet managed to travel through time – at least to our knowledge
> – but the question of whether or not such a feat would be theoretically
> possible continues to fascinate scientists.
>
> As movies such as The Terminator, Donnie Darko, Back to the Future and
> many others show, moving around in time creates a lot of problems for the
> fundamental rules of the Universe: if you go back in time and stop your
> parents from meeting, for instance, how can you possibly exist in order to
> go back in time in the first place?
> It's a monumental head-scratcher known as the 'grandfather paradox', but
> now a physics student Germain Tobar, from the University of Queensland in
> Australia, says he has worked out how to "square the numbers" to make time
> travel viable without the paradoxes.
> "Classical dynamics says if you know the state of a system at a particular
> time, this can tell us the entire history of the system," says Tobar.
> "However, Einstein's theory of general relativity predicts the existence
> of time loops or time travel – where an event can be both in the past and
> future of itself – theoretically turning the study of dynamics on its head."
> What the calculations show is that space-time can potentially adapt itself
> to avoid paradoxes.
>
> To use a topical example, imagine a time traveller journeying into the
> past to stop a disease from spreading – if the mission was successful, the
> time traveller would have no disease to go back in time to defeat.
> Tobar's work suggests that the disease would still escape some other way,
> through a different route or by a different method, removing the paradox.
> Whatever the time traveller did, the disease wouldn't be stopped.
> Tobar's work isn't easy for non-mathematicians to dig into, but it looks
> at the influence of deterministic processes (without any randomness) on an
> arbitrary number of regions in the space-time continuum, and demonstrates
> how both closed timelike curves (as predicted by Einstein) can fit in with
> the rules of free will and classical physics.
> "The maths checks out – and the results are the stuff of science fiction,"
> says physicist Fabio Costa from the University of Queensland, who
> supervised the research.
>
>
> https://www.sciencealert.com/a-physicist-has-come-up-with-the-maths-to-make-time-travel-plausible
> _______________________________________________
> extropy-chat mailing list
> extropy-chat at lists.extropy.org
> http://lists.extropy.org/mailman/listinfo.cgi/extropy-chat
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.extropy.org/pipermail/extropy-chat/attachments/20200927/c2e05ca3/attachment.htm>