![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
avvaХаотичность вращения Гипериона, луны Сатурна. (англ.)
Вселенная - прекрасная и удивительная штука.
(для тех, кто не говорит по-английски: там рассказывают, что Гиперион, луна Сатурна, вращается вокруг своего центра столь хаотично, что по сути дела это вращение невозможно вычислить. Если бы вы находились на поверхности Гипериона, то даже самый мощный компьютер не помог бы вам вычислить, когда в следующий раз взойдет Солнце).
Вселенная - прекрасная и удивительная штука.
(для тех, кто не говорит по-английски: там рассказывают, что Гиперион, луна Сатурна, вращается вокруг своего центра столь хаотично, что по сути дела это вращение невозможно вычислить. Если бы вы находились на поверхности Гипериона, то даже самый мощный компьютер не помог бы вам вычислить, когда в следующий раз взойдет Солнце).
![[identity profile]](https://www.dreamwidth.org/img/silk/identity/openid.png){kind=small}
no subject
Date: 2008-10-27 11:10 pm (UTC)no subject
Date: 2008-10-27 11:19 pm (UTC)no subject
Date: 2008-10-27 11:28 pm (UTC)no subject
Date: 2008-10-27 11:39 pm (UTC)no subject
Date: 2008-10-28 12:46 am (UTC)(Some of the comments down there alluding to naive Copenhagen interpretation are just too hilarious...)
no subject
Date: 2008-10-28 12:57 am (UTC)no subject
Date: 2008-10-28 06:32 am (UTC)Now, the chaotic rotation of Hyperion was discovered less than 37 years ago [estimated time for the quantum suppression of classical chaos], but nobody thinks that after the year 2020 astronomers will begin to see quantum effects – specifically the calming of Hyperion’s instability and its replacement by some more moderate multiply periodic motion. And indeed, the predicted quantum suppression of chaos is itself suppressed, and classicality restored, by another quantum effect. This is decoherence. It arises from the fact that Hyperion is not isolated.
no subject
Date: 2008-10-28 07:59 am (UTC)a
Date: 2008-10-28 08:09 am (UTC)First of all, Hyperion is moving chaotically *only because* it is interacting with outside world. Trying to imagine isolated chaotic Hyperion and wonder how its quantum description will diverge from classical is just plain silly - because it's rotation will cease being chaotic the moment it is isolated.
Secondly, external random inputs (such as solar rays) are not as important as internal state of the matter. Simply put, isolated quantum systems "cannot" be chaotic because they can only contain limited number of bits describing their state. This means that any evolution of such systems has to be periodic.
However, with macroscopic objects the amount of information which can be encoded in the internal state of its atoms can quite easily produce periods exceeding lifetime of the Universe - so, for all practical purposes such quantum object may have aperiodic "chaotic" behavior even if completely isolated.
no subject
Date: 2008-10-28 01:49 am (UTC)http://math.ucr.edu/home/baez/week223.html
Sean Carrol is notorious for making a stir-fry out of his thoughts.
His "cosmological origins of entropy" being a major example.
no subject
Date: 2008-10-28 08:11 am (UTC)no subject
Date: 2008-10-28 01:52 am (UTC)no subject
Date: 2008-10-28 07:54 am (UTC)no subject
Date: 2008-10-28 07:57 am (UTC)no subject
Date: 2008-10-28 08:43 am (UTC)