How could two alternate realities "blend" at a single point in space time?

Question

From:

https://en.wikipedia.org/wiki/Multiverse

The multiverse (or meta-universe) is a hypothetical set of various possible universes including the universe which we live in. Together, these universes comprise everything that exists: the entirety of space, time, matter, energy and the physical laws and constants that describe them. The miscellaneous distinct universes within the multiverse are called the “parallel universes,” “other universes” or “alternative universes.”

And from:

https://en.wikipedia.org/wiki/Many-worlds_interpretation

Many-worlds implies that all possible alternate histories and futures are real, each representing an actual “world” (or “universe”). In layman's terms, the hypothesis states there is a very large, perhaps infinite, number of universes, and everything that could possibly have happened in our past, but did not, has occurred in the past of some other universe or universes.

I’m using those definitions/explanations here because they put into words my thoughts better than I could right now.

So, let’s say we take the above described concepts as real, with those as a jumping off point I am trying to create a place, some point in space/time, where two of the universes from that infinite bunch (ours and another) are blending into one another without either being destroyed. Imagine these two realities are caught in the same space/time but instead of annihilating one another they are “blending”, mixing, and creating something new, something that is a little of both.

My sci-fi explanation of this is that an alien race with the tech to warp space time was conducting an experiment that they hoped would take them to one of those other realities. Instead it mistakenly brought another reality closer to ours, but not fully, so there’s “blending” going on at this point of space/time.

I want my space explorer characters to achieve some kind of understanding of what might cause this to be possible. Any thoughts?

I realize that some hand waving will come into play, but I want to give readers something that at least sounds plausible. Maybe something that scientists are really theorizing(?).

EDIT: Just adding some food for thought:

A) Dark Matter cannot be observed except we know its there because of its gravitational effects. So isn't that kind've like another dimension existing right here within ours without any annihilation?

B) Neutrinos can pass through matter because they have little mass and no charge. Couldn't something similar apply here?

Answer 1

Fundamentally, you're not going to get into the subatomic physics of the blend. In fact, it's almost certain that if you tried, you'd get the physics wrong (since there is no physical version of this).

Thus, what you need is something that feels right and is useful to the story. Bonus points for physics based and slightly unintuitive.

My recommendation would actually be to look at supercritical fluids. Add heat to a liquid, you can boil it into a gas. Refrigerate a gas, and you can turn it into a liquid. Increase the pressure, and this effect happens at a higher temperature. We can draw what is known as a phase transition curve showing this effect at different places.

Here we can see a phase diagram. You can see that, at reasonable temperatures and pressures, if you have a liquid and increase it's temperature, you can make it a gas. But what about that funny point marked "critical point?" This is where something funny happens. If you heat a liquid past this point, its molecules have so much energy that the structure assumptions we get to make about how bonds form in liquids just don't work. It's not a liquid. However, it's still too dense and there's too much intermolecular interactions to be treated as a gas.

At this point, we have a "supercritical fluid." It's a phase of matter all its own. It's not a liquid. It's not a gas. It's something else with some hybrid behaviors from both. Weird behaviors. Ever wonder how they make decaffeinated coffee? They raise the pressure on some CO2 until it goes supercritical, then pass it through the beans. I mean that: through. Supercritical CO2 can pass right through the solid coffee beans. It then acts as a solvent to pick up all the caffeine molecules, and passes right out.

You can add whatever quantum verbage you like. You can talk about resonance or interference, but if you really get into it, those concepts are hard for a reader to grasp. They're hard enough for a writer to grasp. However, the nature of supercritical fluids, and how they aren't just a summation of liquids and gases, is much easier to grasp.

It also creates room for a natural drama. As the temperature and pressure fall towards the critical point, the material is going to act more liquid like or more gas like, depending on how they fall. There's a natural winner-takes-all feel to this process that is easy to take and weave into some plot. While this supercritical quantum flux foam might be supporting both realities now, as it cools, it may begin to take on aspects of one reality or the other. That should be terrifying.

Answer 2

It seems like you're trying to bend the rules on causality, or rather you're trying to blend two points that have no common cause into one.

Paraphrasing the definition of causality: an effect cannot occur from a cause not in it's past light cone, and cannot cause an effect outside it's future light cone. A light cone is essentially the cone of all possible paths that a photon can take through spacetime. In other words, a light cone represents all possible effects that a cause can have, because the effect cannot reach outside of the cone without traveling faster than the photon/faster than light.

I don't have enough physics doctorates to go into the math on why what you want is physically possible or impossible. However, I can roughly describe what would need to be possible for what you want to happen:

Imagine you are looking at the light cone of an event coming toward you, i.e. you are looking at the base of the cone which looks like a circle. If the event that made that cone could have produced a different effect, i.e. created a different universe, and was also coming at you, then the two cones would look like a Venn diagram.

The common parts of each universe are in the overlapping center of the two cones and are already 'blended' because they came from the same event. The edges, however, are the differences between the two universes and are what you want to blend together in your weird non-causality world. Therefore, the sci-fi alien hand-waving-the-non-fun physics explanation for blending two universes is simply blending two non-overlapping light cones into one, thus bending the rules of causality. Essentially, things just need to happen without any event causing them to happen.

Answer 3

Note: Quantum anything is odd. Don't take my word as law. Look to the comments and to other answers for reasons why this is impossible. I'm simply here to describe a possible course of action.

Let's look at the base idea: Two universes diverge at a single point, and the differences ripple out at the speed of light.

Suddenly, these two universes are literally overlapping. The base volumes of space randomly flips between the two universes as they merge. For most of the observable universe, nothing would be wrong. Since each universe has the same contents, randomly flipping between them shows no difference.

The issue comes in when you're less than $c*\Delta t$ from the event. In this case, you're inside the light cone, and are affected by the merger.

Suddenly, the basic units of matter are flitting in and out of existence. Affected by the diverging causalities, atoms that would have been in one place are in another place, leaving gross problems occurring all across the light cone. These interactions effect more change, leading to a slurry of the two universes that is completely uninhabitable by standard physics.

You can't outrun the growing bubble of problems. You don't even know it exists. It is literally the fastest growing bubble of death that could possibly exist. By the time you know it exists, it is upon you. The only recourse is FTL, with its own host of problems.

Inside the problems bubble, though, things begin to settle out. It's still a slurry of probabilities, but with the two universes interacting at the level of the basic forces acting on matter, they eventually resonate into alignment, becoming effectively one universe again.

Unfortunately, there's still a giant front of death expanding across the universe as the two universes reconcile their differences.

Now, this isn't even remotely possible. We have no real systems that could 'un-collapse' a quantum waveform, and the base tenets of many worlds exclude this scenario.

Answer 4

I don't really understand causality. Jakob Lovern seems to be suggesting that when it blends, the same matter can't be in two different places possibly causing massive damage(who really knows and I'm not sure I understood his point). Giter seems to suggest that you just need to focuse on differences because the things that are the same can already be considered blended, how you blend the differences, having both, part-n-part or only one is up to you.

I wanted suggest a different route where the nothing is blended, everything becomes duplicated (kinda) instead .

You can consider this idea is that many universe share the same space and are only seperated by a fragile glass that prevents them from affecting each other. Once the aliens make a hole in the glass, the matter of the two universes start to affect each other through gravity, this puts even more stress on it until the cracks go from the epicenter to all throughout the universe(This could happen fast or slow and the barrier near the center is probably long gone by the time the cracks reaches the edge). This would probably destroy the structures in the majority of the universe but there is possible that some galaxies might not be too affected as they werent aligned with anything on the otherside.

Ofcourse as the only survivors would probably be in the places nothing interesting was happening, it might not be the best story setting but I still had to say it. Another reason I like this idea is that it could show that the big bang could have expanded into to each dimension at the same time and not that it existed in both dimension, which could show that the big crunch is only likely to happen if more dimmensional barriers are broken, as one dimension will have more mass.

Answer 5

The multiple universes are just different simulations. A programming error, or CPU overload could break down the separation

memory leak or space leak: https://en.wikipedia.org/wiki/Memory_leak

Also, it allows use of exploits that would allow travel to other universes

Answer 6

I'd suggest dropping multiverse and accomplishing your task through another mechanism entirely.

The interactions between particles are governed by the fundamental forces. (Gravity, EM, Weak, and Strong are to our knowledge what's going on at room temperature.) The influence of the fundamental forces is goverened by coupling constants, like the electron's charge. Without the coupling, the forces don't do anything.

So, let's say that all along there has been an entire other universe (overlayed on the same space), with an extra set of forces, and an orthogonal set of charges. Their positive and negative would look neutral to our electromagnetic force, and our positive and negative would look neutral to theirs (extend this to the other forces). We'd be like a ghost to them, and they a ghost to us. Something happens that causes the charges to start changing: suddenly, a block of matter from our universe acquires their kind of charge and looses our kind of charge. Somewhere else, it happens in the other direction. A naive observer would think that the chunks were "teleporting," between realities, but they wouldn't have to move at all.

Extra work: what happens if the matter ends up with both universe's associated charges? Neither?

(If neither, it would all fly apart as the bits and pieces would have thermal and degenerate energy, but wouldn't exert confining forces on each other any longer!)

Answer 7

Large wormhole?

People use think of wormholes as giant doors, but in general relativity, there more like a place that two points in the universe, or even two different separate universes, are "glued" together.

In fact, if a wormhole was large enough, you may not even notice is it there (besides all the exotic matter in it, but there will probably be exotic matter outside it as well).

So, if you are near the wormhole, some directions naturally "lead" into the other universe. This might lead to blending if someone has blenders in the wormhole.

If you just want to connect to different points in time, any Closed timelike curve (of which wormholes are just one variety), would work. They allow the future to be near the past in a wide variety of ways.

Answer 8

Imagine multiple more-or-less parallel tunnels in a cave system, or through a mountain.  The tunnels aren’t perfectly straight; they meander enough that sometimes two of them come very close together.

• If the wall between them gets down to 1 cm in thickness, it may be possible for the occupants of one tunnel to hear sounds from the other.
• If quartz and/or other transparent / translucent rock are present, it may be possible for the occupants of one tunnel to see events in the other.
• There could be a hole in wall, allowing matter to move between the tunnels.

Do this in a handwavium mine, and you’ve got parallel universes.

You should look at the “Apprentice Adept” series by Piers Anthony.  It takes place in two parallel universes that have limited points of contact / overlap.  He doesn’t explain how this came to be;

• it’s treated as a feature of the multiverse that has always existed.
• magic works in one of the universes, so there’s not a lot of technical exposition.

But he does explore the concept of inter-universe contact.

Answer 9

Imagine the universe as Einstein's trampoline, with each universe being its own trampoline.

Go to a point on your trampoline where it's just like the trampoline of your target destination - probably (but not always) a really long way from a gravity well, where both trampolines are almost flat. If there were two identical solar systems, you might be able to do it in a gravity well.

Blast off a shitload of energy. Like, infinite heat levels of energy, where the rules of physics start to get really weird. You can punch a hole through your trampoline and their trampoline. You can even cauterizing the edges to keep it open.

Now you can travel between universes.

Answer 10

Mirror matter: https://en.wikipedia.org/wiki/Mirror_matter

This is NOT anti-matter. But another set of particles that effectively only interact gravitationally with our visible universe. One of the serious proposals for the missing mass problem.

See also John Cramer's novel "Twistor"
https://www.amazon.ca/Twister-John-Cramer/dp/0450551172
It's only a ho-hum novel, and will remind you of the pulps of the 40's. But Cramer is a working physicist.

Finally getting back to the parallel universe, take a gander at 'renormalization' in particular. Start here:

https://4gravitons.wordpress.com/2013/01/11/whats-so-hard-about-quantum-field-theory-anyway/

The idea is that for any given quantum interaction there are a multitude of "it could have happened this way" and the actual outcome is the superposition of all the other possibilities.

So your parallel universes are constantly in the process of spliting and merging. The length of time it takes to merge is a matter of both balance and scale.

This has some explaining power: The car keys that are on the kitchen counter but weren't there 10 minutes ago are the merge of two universes. Some of the times that your memory of an event is totally different from someone else's memory is the result of merging.

It also gives you a neat response to one problem of multi-universes: If everything is possible, what is the point of making a good choice? Yes, you need more hand-wavium to make it work.