Inflationary Multiverse and Eternal Chaotic Inflation
Perhaps the most far-reaching prediction made by Linde was related to what is now called the theory of inflationary multiverse, or string theory landscape. In 1982-1983, Steinhardt, Linde and Vilenkin realized that exponential expansion in the new inflation scenario, once it begins, continues without end in some parts of the universe. On the basis of this scenario, Linde proposed a model of a self-reproducing inflationary universe consisting of different parts. These parts are exponentially large and uniform, because of inflation. Therefore for all practical purposes each of these parts looks like a separate mini-universe, or pocket universe, independent of what happens in other parts of the world.
Inhabitants of each of these parts might think that the universe everywhere looks the same, and masses of elementary particles, as well as the laws of their interactions, must be the same all over the world. However, in the context of inflationary cosmology, different pocket universes may have different laws of low-energy physics operating in each of them. Thus our world, instead of being a single spherically symmetric expanding balloon, becomes a huge fractal, an inflationary multiverse consisting of many different pocket universes with different properties. This provided a simple scientific interpretation of the cosmological anthropic principle: Our world may consist of different parts, but we can live only in those parts of the multiverse which can support life as we know it.
These ideas did not attract much attention at that time, in part because the anthropic principle was very unpopular, in part because the new inflationary scenario did not quite work and was replaced by the chaotic inflation scenario. However, in 1986 Linde found that in many versions of the chaotic inflation scenario, the process of exponential expansion of the universe also continues forever in some parts of the universe. Linde called this process eternal inflation. Quantum fluctuations produced during eternal chaotic inflation are so large that they can easily push different parts of the universe from one vacuum state to another, and even change the effective dimensionality of space-time. This provided a very powerful realization of the theory of the multiverse.
Read more about this topic: Andrei Linde
Famous quotes containing the words inflationary, eternal and/or chaotic:
“An alliance is like a chain. It is not made stronger by adding weak links to it. A great power like the United States gains no advantage and it loses prestige by offering, indeed peddling, its alliances to all and sundry. An alliance should be hard diplomatic currency, valuable and hard to get, and not inflationary paper from the mimeograph machine in the State Department.”
—Walter Lippmann (1889–1974)
“In Arms not worse, in foresight much advanc’t,
We may with more successful hope resolve
To wage by force or guile eternal Warr
Irreconcileable, to our grand Foe,”
—John Milton (1608–1674)
“The attitude that nature is chaotic and that the artist puts order into it is a very absurd point of view, I think. All that we can hope for is to put some order into ourselves.”
—Willem De Kooning (b. 1904)