បើកបញ្ជីមេ

ពហុចក្រវាល (រឺ បរមត្ថចក្រវាល) គឺជាសំណុំសម្មតិកម្មនៃចក្រវាលអាចអនន្ត រឺ អន្ត (រួមមានចក្រវាលដែលយើងពាល់ត្រូវជាក់ស្ដែងនេះផង) ដែលរួមផ្សំនូវអ្វីដែលមាន: សារព័ននៃលំហ ពេលវេលា រូបធាតុ និង ថាមពល ដូចគ្នានឹង ច្បាប់ និង លំនឹងរូបវិទ្យាបានបកស្រាយអំពីអង្គផ្សំទាំងនឹង។ ចក្រវាលផ្សេងនៅខាងក្នុងពហុចក្រវាលក៏ត្រូវបានគេហៅថា ចក្រវាលស្របគ្នា រឺ ចក្រវាលឆ្លាស់គ្នា

ការពន្យល់កែប្រែ

រចនាសម្ពន្ធនៃពហុចក្រវាល គឺជាធម្មជាតិនៃចក្រវាលនីមួយៗដែលមាននៅក្នុងវា និងសភាវៈពាក់ព័ន្ធគ្នាក្នុងចំណោមចក្រវាលរួមផ្សំដោយឡែកៗ ផ្អែកលើសម្មតិកម្មពហុចក្រវាលជាក់លាក់ដែលបានយកមកពិចារណា។ ចក្រវាលជាច្រើនត្រូវបានគេឱ្យសម្មតិកម្មនៅខាងក្នុងលោកធាតុវិទ្យា រូបវិទ្យា តារាសាស្ត្រ សាសនា ទស្សនវិជ្ជា ចិត្តវិទ្យាបរិវត្តបុគ្គល និង រឿងប្រឌិត ជាពិសេសរឿងប្រឌិតវិទ្យាសាស្ត្រ និង រឿងស្រមើស្រមៃ។ ក្នុងបរិបទទាំងអស់នេះ ចក្រវាលស្របគ្នាក៏ត្រូវបានគហៅថា "ចក្រវាលឆ្លាស់គ្នា" "ចក្រវាលបមាណតា" "វិមាត្រអន្តវេធការ" "វិមាត្រស្របគ្នា" "ពិភពលោកស្របគ្នា" "តថភាពឆ្លាស់គ្នា" "របាកាលឆ្លាស់គ្នា" "របាបវិមាត្រ" ដែរ ក្នុងចំណោមឈ្មោះដទៃទៀតផ្សេង។ ទស្សនវិទូ និង ចិត្តវិទូជាតិអាមេរិក លោកវិល្លៀម-ចេមស៍បានប្រឌិតបច្ចេកសព្ទ ពហុចក្រវាល នេះឡើងនៅឆ្នាំ១៨៩៥ ប៉ុន្តែនៅក្នុងបរិបទមួយផ្សេងទៀតទៅវិញ។[១]

សហគមន៍រូបវិទ្យាបន្តពិភាក្សតទល់គ្នាយ៉ាងខ្លាំងក្លានូវសម្មតិកម្មពហុចក្រវាល។ រូបវិទូលេចធ្លោមួយចំនួន មិនយល់ស្របថាតើពហុចក្រវាលអាចមានដែររឺទេ ហើយថាវាជាប្រធានបទធម្មានុរូបនៃការរិះរកខាងវិទ្យាសាស្ត្រថែមទៀតផង។[២] ការព្រួយបារម្ភធ្ងន់ធ្ងរត្រូវបានចោទអំពីការព្យាយាមដើម្បីឱ្យពហុចក្រវាលរួចឆ្ងាយចេញពីការផ្ទៀងផ្ទាត់ខាងពិសោធន៍អាចបន្ថយទំនុកចិត្តសាធារណជនខាងវិទ្យាសាស្ត្រ និង ការបំផ្លាញដល់ទីបំផុតនូវធម្មជាតិនៃរូបវិទ្យាមូលដ្ឋាន។[៣] អ្នកខ្លះបានលើកឡើងការចោទពហុចក្រវាលជាទស្សនៈ ជាជាងវិទ្យាសាស្ត្រ ព្រោះតែវាខ្វះមិច្ឆានីយភាព ដែលវាជាលទ្ធភាពបដិសេធទ្រឹស្ដីមួយដោយមធ្យោបាយនៃការពិសោធខាងវិទ្យាសាស្ត្រនានាតែងតែជាផ្នែកនៃក្បួនវិទ្យាសាស្ត្រត្រូវបានគេទទួលស្គាល់។[៤] លោកផូល-ស្តេនហាដថ៍បានលើកទឡ្ហីករណ៍យ៉ាងល្បីល្បាញមួយថាគ្មានការពិសោធណាអាចទាត់ចោលទ្រឹស្ដីបានឡើយ បើសិនជាទ្រឹស្ដីមួយនោះវាអាចផ្ដល់លទ្ធផលដែលអាចទៅរួចអស់ទាំងនោះបានមែន។[៥]

អ្នកគាំទ្រមួយក្នុងចំណោមសម្មតិកម្មពហុចក្រវាលរួមមាន ស្តេផ្វឹន-ហាឃីង [៦] ប្រាយអឹន-ហ្គ្រិន[៧][៨] មែខ្ស-ថិហ្កម៉ាខ [៩] អាឡាន់-ហ្គុថ,[១០] អាន់ដ្រេ-លីនដេ [១១] មីឈិអុ-កាគឹ [១២] ដាវីដ-ឌូច[១៣] លីអូណាដ-ស៊ុស្គីនដ៍,[១៤] រាជកុមារបាថ្រិអ,[១៥] អាឡិច្ស៊ែនដឺរ-វីឡឹនគីន [១៦] ឡរ៉ា-មែរស៊ីនីហោតុន [១៧][១៨] ណេល-ដឺហ្ក្រេស្ស-ទីសុន[១៩] និងសៀន-ខារ្រ៉ុល្ល[២០]

ពួកអ្នកវិទ្យាសាស្ត្រដែលមិនមែនអ្នកគាំទ្រអំពីពហុចក្រវាលរួមមាន: ជ័យលាភីណូបែល ស្ទីវ៉ឹន-វ៉េនបឺហ្ក [២១] ជ័យលាភីណូបែល ដាវីដ-ហ្ក្រុស្ស [២២] ផូល-ស្តេនហាដថ៍[២៣] ណេល-ទូរ៉ូខ[២៤] វីអាតឆេស្លាវ-មូខាណូវ[២៥] ម៉ៃឃល-ថឺណឺរ [២៦] រ៉ចឺរ-ផេនរ៉ូស [២៧] ហ៊្សក-អេល្លីស,[២៨][២៩] ចូ-ស៊ីល្ខ៍ [៣០] អាដាម-ភ្វ្រែង្ខ៍ [៣១] ម៉ាសេឡូ-ហ្ក្លេសឺរ [៣១] ជិម-បាហ្កហ្កុត្ត [៣២] និង ផូល-ដាវីស[៣៣]

នៅឆ្នាំ២០០៧ ស្ទីវ៉ឹន-វ៉េនបឺហ្កបានលើកឡើងថាបើសិនជាពហុចក្រវាលមានពិតមែននោះ "ក្ដីសង្ឃឹមក្នុងការរិះរកខាងសនិទានចំពោះគុណតំលៃត្រឹមត្រូវនៃភារៈរបស់ខ្វាខ និងលំនឹងផ្សេងៗនៃគំរូបមាណីយ ដែលយើងអង្កេតក្នុងប៊ាំងដ៏ធំរបស់យើងត្រូវរលាយអស់មិនខាន ដោយសារគុណតំលៃអស់ទាំងនឹង នឹងនៅត្រឹមតែជាចៃដន្យនៃភាគពិសេសនៃចក្រវាលដែលយើងរស់នៅតែប៉ុណ្ណោះ។" [៣៤]

សម្មតិកម្មចក្រវាលខាងរូបវិទ្យាកែប្រែ

ចំណាត់ថ្នាក់កែប្រែ

មែខ្ស-ថេហ្កម៉ាខ និងប្រាយអ៊ែន-ហ្គ្រិនបានប្រឌិតឡើងនូវគ្រោងចំណាត់ថ្នាក់ដែលចាត់ជាក្រុមពួកប្រភេទពហុចក្រវាលតាមទ្រឹស្ដីផ្សេងៗ រឺ ប្រភេទនានានៃចក្រវាលដែលអាចនឹងផ្សំប្រកបជាប្រជុំពហុចក្រវាលតាមទ្រឹស្ដី។

បួនជាន់របស់មែខ្ស-ថិហ្កម៉ាខកែប្រែ

លោកធាតុវិទូ លោកមែខ្ស-ថេហ្កម៉ាខបានផ្ដល់នូវវគ្គីករណសាស្ត្រមួយអំពីពួកចក្រវាលក្រៅពីចក្រវាលដែលយើងសង្កេតឃើញធ្លាប់ស្គាល់រួចមកហើយ។ ជាន់នានាអាស្រ័យទៅតាមចំណាត់ថ្នាក់របស់ថេហ្កម៉ាខត្រូវរៀបជាជាន់ៗបន្តគ្នាអាចយល់បានដោយគូរជារង្វង់ និង ពាសពីលើជាន់មុនៗគេ ហើយជាន់អស់ទាំងនោះត្រូវបានពណ៌នាដោយខ្លីៗខាងក្រោម។[៣៥][៣៦]

ជាន់ទី១: ឯនាយដែនលោកធាតុរបស់យើងកែប្រែ

ការព្យាករណ៍តាមពួកនៃរំប៉ោងកលិយុគគឺជាចក្រវាលព្រឹត្តាសទភាព ដែលជាសភាពអនន្ត ត្រូវតែមានមាឌហាប៊លជាច្រើនដែលដឹងលក្ខណៈដើមទាំងអស់។

ដោយហេតុនោះហើយ ចក្រវាលអនន្តមួយនឹងមានចំនួនមាឌហាប៊លអនន្តមួយដែរ ទាំងអស់នឹងមានច្បាប់រូបវិទ្យា និង លំនឹងរូបវិទ្យាដូចគ្នា។ In regard to configurations such as the distribution of matter, almost all will differ from our Hubble volume. However, because there are infinitely many, far beyond the cosmological horizon, there will eventually be Hubble volumes with similar, and even identical, configurations. Tegmark estimates that an identical volume to ours should be about 1010115 meters away from us.[៩] Given infinite space, there would, in fact, be an infinite number of Hubble volumes identical to ours in the Universe.[៣៧] This follows directly from the cosmological principle, wherein it is assumed our Hubble volume is not special or unique.

ជាន់ទី២: ពួកចក្រវាលដែលមានលំនឹងរូបវិទ្យាផ្សេងគ្នាកែប្រែ
 
"Bubble universes": every disk is a bubble universe (Universe 1 to Universe 6 are different bubbles; they have physical constants that are different from our universe); our universe is just one of the bubbles.

In the chaotic inflation theory, a variant of the cosmic inflation theory, the multiverse as a whole is stretching and will continue doing so forever,[៣៨] but some regions of space stop stretching and form distinct bubbles, like gas pockets in a loaf of rising bread. Such bubbles are embryonic level I multiverses. Linde and Vanchurin calculated the number of these universes to be on the scale of 101010,000,000.[៣៩]

Different bubbles may experience different spontaneous symmetry breaking resulting in different properties such as different physical constants.[៣៧]

This level also includes John Archibald Wheeler's oscillatory universe theory and Lee Smolin's fecund universes theory.

ជាន់ទី៣ : បំណកស្រាយពហុ-លោកនៃយន្តសាស្ត្របមាណតាកែប្រែ

Hugh Everett's many-worlds interpretation (MWI) is one of several mainstream interpretations of quantum mechanics. In brief, one aspect of quantum mechanics is that certain observations cannot be predicted absolutely. Instead, there is a range of possible observations, each with a different probability. According to the MWI, each of these possible observations corresponds to a different universe. Suppose a six-sided ទំព័រគំរូ:Dice is thrown and that the result of the throw corresponds to a quantum mechanics observable. All six possible ways the die can fall correspond to six different universes.

Tegmark argues that a level III multiverse does not contain more possibilities in the Hubble volume than a level I-II multiverse. In effect, all the different "worlds" created by "splits" in a level III multiverse with the same physical constants can be found in some Hubble volume in a level I multiverse. Tegmark writes that "The only difference between Level I and Level III is where your doppelgängers reside. In Level I they live elsewhere in good old three-dimensional space. In Level III they live on another quantum branch in infinite-dimensional Hilbert space." Similarly, all level II bubble universes with different physical constants can in effect be found as "worlds" created by "splits" at the moment of spontaneous symmetry breaking in a level III multiverse.[៣៧] According to Yasunori Nomura[៤០] and Raphael Bousso and Leonard Susskind,[១៤] this is because global spacetime appearing in the (eternally) inflating multiverse is a redundant concept. This implies that the multiverses of Level I, II, and III are, in fact, the same thing. This hypothesis is referred to as "Multiverse = Quantum Many Worlds".

Related to the many-worlds idea are Richard Feynman's multiple histories interpretation and H. Dieter Zeh's many-minds interpretation.

ជានទី៤: សរុបអវសានកែប្រែ

The ultimate ensemble or mathematical universe hypothesis is the hypothesis of Tegmark himself.[៤១] This level considers equally real all universes that can be described by different mathematical structures. Tegmark writes that "abstract mathematics is so general that any Theory Of Everything (TOE) that is definable in purely formal terms (independent of vague human terminology) is also a mathematical structure. For instance, a TOE involving a set of different types of entities (denoted by words, say) and relations between them (denoted by additional words) is nothing but what mathematicians call a set-theoretical model, and one can generally find a formal system that it is a model of." He argues this "implies that any conceivable parallel universe theory can be described at Level IV" and "subsumes all other ensembles, therefore brings closure to the hierarchy of multiverses, and there cannot be say a Level V."[៩]

Jürgen Schmidhuber, however, says the "set of mathematical structures" is not even well-defined, and admits only universe representations describable by constructive mathematics, that is, computer programs. He explicitly includes universe representations describable by non-halting programs whose output bits converge after finite time, although the convergence time itself may not be predictable by a halting program, due to Kurt Gödel's limitations.[៤២][៤៣][៤៤] He also explicitly discusses the more restricted ensemble of quickly computable universes.[៤៥]

Brian Greene's nine typesកែប្រែ

American theoretical physicist and string theorist Brian Greene discussed nine types of parallel universes:[៤៦]

Quilted
The quilted multiverse works only in an infinite universe. With an infinite amount of space, every possible event will occur an infinite number of times. However, the speed of light prevents us from being aware of these other identical areas.
Inflationary
The inflationary multiverse is composed of various pockets where inflation fields collapse and form new universes.
Brane
The brane multiverse follows from M-theory and states that our universe is a 3-dimensional brane that exists with many others on a higher-dimensional brane or "bulk". Particles are bound to their respective branes except for gravity.
Cyclic
The cyclic multiverse (via the ekpyrotic scenario) has multiple branes (each a universe) that collided, causing Big Bangs. The universes bounce back and pass through time, until they are pulled back together and again collide, destroying the old contents and creating them anew.
Landscape
The landscape multiverse relies on string theory's Calabi–Yau shapes. Quantum fluctuations drop the shapes to a lower energy level, creating a pocket with a different set of laws from the surrounding space.
Quantum
The quantum multiverse creates a new universe when a diversion in events occurs, as in the many-worlds interpretation of quantum mechanics.
Holographic
The holographic multiverse is derived from the theory that the surface area of a space can simulate the volume of the region.
Simulated
The simulated multiverse exists on complex computer systems that simulate entire universes.
Ultimate
The ultimate multiverse contains every mathematically possible universe under different laws of physics.
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