Are there multiple universes

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Support science journalism. Knowledge awaits. During this period of inflation , there were quantum fluctuations which caused separate bubble universes to pop into existence and themselves start inflating and blowing bubbles. Russian physicist Andrei Linde came up with this concept, which suggests an infinity of universes no longer in any causal connection with one another — so free to develop in different ways.

Cosmic space is big — perhaps infinitely so. String theory , which is a notoriously theoretical explanation of reality, predicts a frankly meaninglessly large number of universes, maybe 10 to the or more, all with slightly different physical parameters.

The idea of the multiverse, and specifically of parallel universes that were identical to our own until those critical decisions, offers us the hope that our past decisions are not as immutable as we currently believe.

Even if inflation has been ongoing for an infinite amount of time, whatever occurs in the other universes that exist are in no way related to what is occurring or has occurred in our universe. Our past is fundamentally written. There are no opportunities arising in any multiverse scenario either to rewrite the past or to import, from another universe, an outcome that turned out differently.

The multiverse may be inevitable and parallel universes may be possible, but they do not affect our universe is any measurable or observable way. Beyond the limits of science, all we have is speculation. Until the evidence catches up, no further definitive statements can be made. Skip to content The multiverse idea states that there are large, possibly infinite numbers of Universes like our own, and large, possibly infinite numbers of universes with differences.

It all depends on the duration that inflation persisted for prior to the onset of our hot Big Bang. Ethan Siegel. Share Could there be a parallel universe identical to our own? If we presume that: the hot Big Bang, which gave rise to the observable universe as we know it, was preceded by cosmic inflation all of the particles and fields within the universe are fundamentally quantum in nature Then it follows that the existence of a multiverse is all but inevitable.

Galaxies give way to large-scale structure and the hot, dense plasma of the Big Bang at the outskirts. Credit: Chris Blake and Sam Moorfield Typically, we like to visualize inflation as a simple field: it has certain properties that affect the space over which the field is present.

Inflation ends top when a ball rolls into the valley. But the inflationary field is a quantum one middle , spreading out over time. While many regions of space purple, red and cyan will see inflation end, many more green, blue will see inflation continue, potentially for eternity bottom.

Credit: E. Siegel This sets up a fascinating scenario to consider. From a preexisting state, inflation predicts that a series of universes will be spawned as inflation continues, with each one being completely disconnected from every other one, separated by more inflating space.

Credit: Nicolle Rager Fuller Are these universes related? Our universe is immense by itself. How could there be more than one? How can scientists come to believe in more than one universe?

What's more, multiple universes can be generated by radically different mechanisms. But what's a 'universe' anyway? The whole vast ensemble of universes is now called a 'multiverse'. View the discussion thread. Skip to main content. Closer to Truth Closer to Truth. Home Topics Cosmos.