Do We Exist in a Multiverse?

As for we presently know, there is a solitary expanding blob of spacetime speckled with trillions of galaxies – that is our Universe. If there are others, forming a multiverse, we have no riveting evidence for their existence.

Theories of cosmology, quantum physics, and the very philosophy of science have some issues that could be solved if our blob of ‘everything’ was not, well, everything.

That does not mean other universes must exist. However, what happens if they do?

What is a universe?

This should be a simple question to answer. However, different areas of science will have slightly different perspectives on what a universe is.

Cosmologists might claim it describes the total mass of stuff (and the space in between) that has actually been gradually expanding from an extremely concentrated volume over the last 13.77 billion years, becoming significantly disordered with age.

It currently stretches 93 billion light-years from edge to edge, at least based on all of the visible (and invisible) things we can identify in some way. Over that limit, there are either things we can not see, an infinite expanse of nothingness, or– in the improbable scenario that every one of space bends back around on itself– a round-trip back to the start across a hyperspherical universe.

If we’re speaking quantum physics, however, a universe could describe all fields as well as their particles, and their joined influences over one another. As a rule of thumb, a universe (like ours, at least) is a closed system, meaning it can not unexpectedly lose or obtain a considerable sum of energy.

Philosophically speaking, a universe may be a distinct collection of fundamental laws that control the behavior of everything we observe. A universe would be characterized by its own rules that set its distinct speed for light, dictate particles how to push or pull, or space exactly how it should expand.

What is a multiverse in cosmology?

A century of astronomical observations has informed us a lot about the age, size, and evolution of galaxies, stars, matter, and the four dimensions we summarize as spacetime.

We know with great confidence that all we see currently is expanding at an expediting rate. This rationally suggests the Universe, at the very least the one we inhabit, used to be a lot smaller.

We can, in theory, squeeze all of the matter of the Universe down to a point where the concentration of energy cuts down atoms to a soup of simpler particles and forces combine till we cannot tell them apart. Any kind of smaller than that? Big shrugs.

If we go along with what is called a cyclic model of cosmology, the parent universe preceded ours in some way. It could also be similar to this one, only running in reverse compared with ours, diminishing over time right into a concentrated point only to bounce back out for one reason or another. Played out for eternity, we may picture the respective universes bounce back and forth in an infinite yo-yo effect of expanding and collapsing.

Alternatively, suppose we choose what is referred to as a conformal cyclic model. In that case, universes expand over trillions upon trillions of years up until their cold, point-like particles are so extended for all mathematical purposes everything looks and acts like a brand new universe.

If you do not like those, there is a likelihood our Universe is a white hole– the hypothetical back end of a black hole from another universe. Which, logically, just may mean the black holes in our Universe can all be parents, pinching off brand-new universes like cosmic amoebae.

What is a multiverse in quantum physics?

Early 20th century, physicists found theories that described matter as little objects only informed half of the story. The other half was that matter behaved as if it additionally had attributes of a wave.

Specifically, what this dual nature of reality suggests is still a matter of debate, yet from a mathematical viewpoint, that wave describes the rise and fall of a game of chance. Probability, you see, is developed into the very machinery that makes up the gears of a universe like ours.

Naturally, this is not our daily experience as substantial collections of atoms. When we send a vessel of molecules called a rocket to the Moon as it zooms past 300,000 kilometers away, we are not rolling dice. Classical old physics is as trustworthy as tomorrow’s sunrise.

However, the closer we zoom in on a region of space or time, the more we must consider the possible range of measurements we might locate.

This randomness is not the result of points we do not know– it is because the Universe itself is yet to make a decision. There is nothing in quantum mechanics describing this transition either, leaving us to imagine what all of it means.

In his 1957 doctoral dissertation, American physicist Hugh Everett suggested the variety of possibilities are all as legitimate as one another, representing actual realities– separate universes, if you prefer– similar to the one we are all familiar with.

What makes any one universe in this numerous worlds interpretation distinctive is just how each wave associates with a certain measurement taken of other waves, a phenomenon we refer to as entanglement.

Furthermore, what ‘we’ means and why ‘we’ experience one entangled set over waves over an additional is not clear and, in some ways, introduces an even larger problem to resolve.

What is a multiverse in philosophy?

One of science’s most fundamental starting assumptions is that you are not special despite what your mother tells you. Neither is any other human, or our planet, or– by extension– our Universe.

While rare events take place every so often, we do not answer The Big Questions with ‘it simply happened that way.’ 

Then why does our Universe seem to have simply the right tug-of-war of forces that permit not just particles to appear but to congeal for sufficiently long periods into atoms that can undergo complex chemistry to generate thinking minds like ours?

Philosophically speaking, the anthropic principle (or principles, given that there are many different ways to spin the idea) indicates we may have it backward. Without these conditions, no minds would have emerged to consider the amazing turn of events.

If simply a single universe ‘just took place that way’ early one spring morning, it would certainly be one huge coincidence. Too large, really.

However, if there were infinite universes, with infinite blends of forces pushing and pulling, some would certainly generate minds that simply might ask, ‘are we part of a multiverse?’

Will we ever discover other universes?

Given that the very definition of a universe depends on some physical fence keeping influencing factors apart, it is tough to think of ways we might ever observe the existence of a sibling for our Universe. Suppose we did; we might as well see it as an extension of our own Universe anyway.

That stated, there could be some cheats that could offer us a glance.

Any kind of experiment to locate one would have to depend on that ‘fence’ having some holes in it that enable particles or energy to leak throughout, either right into ours or far from it, alternatively, in the case of universes existing in our past. These huge events left enough of a scar that not even a rebirth can erase.

In the meantime, we still have no good reason to assume our blob of everything is anything but unique. Considering we are still finding out exactly how our own Universe works, the existing gaps in physics might yet be plugged with no need to imagine a reality besides ours.

In countless other versions of this article spread across the multiverse, however, the question of whether we are alone simply could have a different answer.

Read the original article on Science Alert.

Related “Researchers State That the Laws of Physics Might Be Changing”