What happened before the Big Bang?


When the two physicists tried to combine Einstein’s equations of relativity with quantum physics, they came up with a surprise. Both sets of laws independently featured time as a variable against which events evolved. But when the theories were combined into one, the time variable was literally cancelled out of the mathematical equation. The duo had derived a new equation for how the universe behaved, yet there was no longer a quantity in their mathematical description that could be used to mark out change or the passage of time. “The Wheeler-DeWitt equation says that the universe is stationary and that nothing evolves,” says Genovese. “But, of course, we all experience time and change.”


Page and Wooters decided to apply the controversial concept that the universe as a whole could be treated as a giant quantum object—subject to the same physical laws as electrons, protons, and other tiny particles of the subatomic world. They imagined splicing the contents of the cosmos into two pieces. Because quantum laws prevailed, the pieces would be entangled. Scientists have found that two entangled particles measured in the lab can have equal but opposite values. If one is spinning clockwise, for instance, the other will be spinning counter-clockwise so that, when summed together, the properties cancel each other out. Page and Wooters argued that in similar fashion, each section of their divided cosmos could independently evolve, but because they were entangled, the changes in one would be counter-balanced by the changes in the other. To someone inside one of the sections, time would appear to pass. But to the outside observer, the overall universe would appear static. While Page and Wooters had offered a theoretical sketch, based on quantum entanglement, for how the cosmos might appear to be stationary to someone peering in from the outside, there seemed to be no way to confirm or rule out their idea. But, in 2013, Genovese and his colleagues performed an experiment to test whether—at least in the lab—it is possible to create a model of the universe in miniature, with just two particles of light, or photons, generated from a laser. The aim of the experiment was to prove that it is possible to create a situation in which a quantum system, when viewed from outside, appeared unchanging, but when observed from within appeared to evolve.


“What we are seeing is that at the start of the universe, the notion of time ceases to make sense.”


However, Genovese still had to confirm the second part of the hypothesis: that when the entire entangled system was monitored as a whole, from the outside, it would appear static. In this part of the experiment, the team took the point of view of a “super observer” standing outside the universe. This external watcher could never look at the individual state of either photon because by doing so he would become entangled with them, becoming an internal observer. Instead, the observer could only measure the joint state of the pair of photons. The team ran the test many times, stopping at different points. They looked at the two photons as a combined whole and measured their joint polarization. Each time, they ascertained that the two entangled photons were polarized in equal but opposite ways. No matter how much time passed, the two photons were always poised in exactly the same “embrace.” The mini-universe appeared to be static from the outside and completely unchanged. It turns out the so-called “problem of time,” discovered by Wheeler and DeWitt, can be resolved if time is an artifact of quantum entanglement.


Before the discovery of string theory, physicists ran into trouble whenever they tried to combine the equations of general relativity with those of quantum mechanics. The combined mathematics appeared to tell them that infinitely small points in space all around us should contain infinitely large amounts of energy—essentially predicting that we are surrounded by black holes everywhere we turn, which is not true. String theory sidestepped this problem, however, by positing that nothing can be smaller than the size of a string. That meant that its equations never had to worry about regions of space that were smaller than this fundamental limit, eliminating the messy math with its predictions of infinite energies and other impossible results. With string theory, the physics of the very large and the very small appeared as if they could coexist—at least once string theory was finessed. Yet string size raised new questions about the reality of space, and, in turn, of time itself. This is because string theory says that no experiment, no matter how elaborate, will ever be able to show us what happens at distances smaller than the size of a single string. “What happens at short distances,” explains IAS string theorist Nathan Seiberg, “is an ill-defined concept—maybe space exists, but we can’t measure it, or perhaps there is nothing there to measure at all.” That meant that space may simply not exist below a certain limit. Since Einstein had already shown with his theory of relativity that time is just another dimension, like space, then “if space becomes ambiguous, time must do so too,” says Seiberg. “People often ask: ‘What happened before the Big Bang?’ But what we are seeing is that at the start of the universe, the notion of time ceases to make sense.”

When it comes to cosmic ingredients, quantum entanglement is more fundamental than space and time.


By Zeeya Merali

Любопытно, что подобная картина — спейстайм, если смотреть извне, остается очень маленьким, а внутри может быть бесконечным, — получается и без квантовой запутанности. Достаточно теории инфляции, пишет Брайан Грин.

Подобного рода двойственности-тройственности в теоретической физике возникают и в теории мультиверса: мультиверсов очень много, как о том свидетельствуют разные теории; попытку синтезировать различные мультиверсы предпринял Макс Тегмарк в своей известной книжке (которую физики ругают за болтологичность).

Вполне возможно, впрочем, поскольку it’s all relative, что извне спейстайм можно попросту не зафиксировать: он не будет коррелировать со спейстаймом наблюдателя.

Теоретическая физика последних двадцати-тридцати лет может дать фору любой метафизике, пишет Кэрролл.

Я, впрочем, не могу не вспоминать об индуистском и буддийском учении о множественности миров, когда читаю о мультиверсе.

Очень сложно, думая о черных дырах, отделаться от мыслей об аде и прочих христианских реминисценций (черные дыры извне конечны, благодаря радиации Хокинга, а внутри, скорее всего, вечны: it’s all relative).

Да, но самое важное, конечно, заключается в том, что всё, что становится светом, — по большому счету, любым электромагнитным излучением, — лишено времени.

Еще очень сложно представить эту систему как нечто возникшее само по себе. Дело в том, что культура и сложные часовые механизмы не возникают в результате перебора вариантов. Всё это нужно строить долго. И, ей-богу, ничего не вижу страшного в креационизме (представьте, что субъект этого дела — суперпуперкомпьютер, и вам сразу станет легче, если что). Среди сторонников неодеизма — математики, физики, философы-трансхьюманисты, не говоря о всякого рода сингулярщиках (1, 2, 3, 4).

По законам физики, скорее всего, вмешаться в происходящее в универсе-мультиверсе невозможно (это обмен информацией). Такова основная теодиция.

Может ли информация-смысл, что-то ставшее и обособленное, ускользнуть из системы куда-нибудь подальше, вовне?

Это, с одной стороны, интересный вопрос (попробуйте медитацию :), а с другой — встречный. А надо ли?

Если по условиям это невозможно, то, может быть, стоит принять систему as is? И воспринимать ее как вечный (сумасшедший) дом.

Инфляция, кстати говоря, судя по всему не прекращается, то есть миры будут создаваться вечно, некоторая информация, судя по всему, умеет не теряться, чем не рай.


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