# Will this super flying brick meet his identical copy in another universe?

I’m writing a superhero story. The protagonist is a normal human transformed (long story) into a super-powered entity. The protagonist is unique in all of creation, according to my plot. The only super-powered individual on earth as well. Ergo, no exact, identical copies exist. He is similar to Superman in that he has flight, superstrength, superspeed, and is invulnerable, however, all to an insanely powerful degree. In one chapter he wants to fly to his supposed identical copy, which is 10^(10^29) meters distant (he read about that in a Max Tegmark article).

Our observable universe is in the "local domain”, which has all the physical constants, etc., to support life, planets, stars, and galaxies. There are j = 4→7→3→3 (Conway arrow chain, far larger than Graham's number) domains like ours throughout the "local bubble", surrounded by other domains that have different constants and are therefore empty (they are about the same size, ~10^50 meters in extent). There are 2→3→2→2→2→2→2 (= k) of these empty domains, with the “j” domains scattered more or less evenly among the k's. All domains, empty or full, are enclosed in a local bubble. His flight powers are insanely powerful, and he is able to travel throughout the vast “domain” and even more vast “local bubble” quickly.

My question is: since the exact copies are as far apart as Tegmark says, would super guy ever come across his near identical clone in the numerous j domains that contain galaxies, stars, life; even though they are individually too small? Or could it be, since there are so many of these domains, there are googolplexes upon googolplexes of identical copies of superguy throughout the vast expanse of the "Local Bubble"? Probably the Tegmark calculation is imperative, and I don’t know how he came by the result. My high school math education is not up to the task.

• @RobertRapplean Of course they can predict the probability. As author and therefore god, they can decide exactly how far apart are the two superdudes, and how long they take to meet, Dec 30, 2022 at 14:06
• @Daron, that's not predicting the probability, thats dictating events via the anthropic principal. Probability tells you how believable your dictated events are. Dec 30, 2022 at 23:08
• @RobertRapplean The author can do either. Jan 1 at 15:34

# No

The simplest way to try to understand the idea of identical copies throughout the universe is probably by making a comparison to Minecraft world seeds. In Minecraft, when you create a new world the game first chooses a random number for its seed. Then, as the game generates the world, it uses that seed as the basis for every single choice it makes.

If you had an arbitrarily large number of people playing Minecraft, there are only so many random numbers that can be chosen so there must be duplicates. So some of those people must be playing in a world that is an exact copy of the world someone else is playing.

For the observable universe, there are a very large yet finite number of possible arrangements of the matter within it. You could say that it's similar to how there are a finite number of possible Minecraft seeds, and therefore a finite number of possible Minecraft worlds.

So if the universe is infinite, every single sphere with a radius of ~14 billion light years is effectively a universe independent from all of the others. The paper you reference is basically calculating how many possible seeds there are for a universe, and then based on that number calculating how far away the nearest universe with the same seeds as ours is likely to be.

It is important to understand that 10^(10^29) meters is not a distance, but a radius! If you measured out a sphere with that radius centered on Earth, then it is likely that you will find an exact copy of Earth somewhere in that radius.

With the superpowers you have given your hero, there is no way for him to find a copy of himself. He can't just travel 10^(10^29) meters and expect to find a copy - he has to check every universe from his start to that distance, and in each universe has to check each galaxy to see if it's a copy of the milky way, so he can check if the Earth in that galaxy is a copy of his Earth.

However your hero doesn't have super vision. In order to see a universe he has to be in it. In order to see a galaxy he has to be reasonably near it. The human eye isn't strong enough on its own to see far away galaxies, let alone make out any details about them. He's going to have to jump around a ridiculous number of times to find a universe, then adequately check that universe.

Your hero also doesn't have a super intellect. 10^(10^29) is too large. There are trillions of galaxies in each universe, and they're not aligned to any grid. As he has searches a single universe, he's going to make a number of maneuvers that are not humanly possible to remember. There will not be a straight line from the previous universe through the current universe and to the next universe he will search. Your hero will be hopelessly lost, forever.

It is also not humanly possible for him to remember any significant details about the universes he has already searched. By the time he has searched through a hundred universes, he has seen so many galaxies that the shear amount of information he has seen will have wiped out any previous knowledge he once had. Even if he stumbled across a copy of our universe, he would no longer remember the details of our universe well enough to be able to find the milky way or Earth.

The real nail in the coffin is that without super senses, he can't even reasonably search a single universe. Light takes time to enter the eye, and it has to enter at a normal speed for it to be focused correctly by the cornea. Even if he can effectively instantly travel to wherever he wants to go, he has to stop for the light to reach him and enter his eyes. With more than a trillion galaxies to search and multiple stops to make for each galaxy, he has no hope of ever being able to search enough universes to have a reasonable chance of finding a clone.

• @catsteevens no, I mean it takes time for light to enter his eye. At intergalactic distances it would take a significant fraction of a second for enough light to enter his eye for his human-level vision to register it. Dec 29, 2022 at 19:22
• The Minecraft analogy is really helpful, and makes it clearer why other answers that focus exclusively on practical problems were not satisfying to OP. Well done!
– Tom
Dec 30, 2022 at 1:58
• Wouldn't there be an exact copy of you somewhere along a "line" from you in any direction? Therefore, he could just zip off about 10^(10^29) meters in any direction and run into his copy that way. Jan 10 at 14:13
• @catsteevens not in 10^(10^29) meters. I think in a 10^(3*10^29) meter line you could expect to intersect a copy of your home observable universe, but the line would have to be significantly longer to expect it to intersect a copy of the milky way and longer still to expect it to intersect a copy of Earth. The line would also contain a large number of near misses - galaxies that are almost but not quite like the milky way, and planets that are almost but not quite like Earth. The hero would still need super senses and a super intellect. Jan 10 at 17:45
• @RobWatts I got that idea from a physics forum. A couple of posters claimed that was all the super had to do. I don't understand... the super needs to zip a thousand times more distant just to get to his observable universe? Also, his eyes are not human, he is neither a biological or artificial being, so he doesn't have a delay for the light to reach into his eye. Am I missing something... why does he have to memorize all those details? He only has to memorize the Milky Way and its environs--M31, the Magellanic Clouds, a few more. Jan 10 at 23:02

You cannot hope to ever comprehend the magnitude of a number like 4→7→3→3 or 2→3→2→2→2→2→2; you cannot even hope to ever comprehend how much larger the latter is than the former.

Let's just ignore the sizes of your bubbles and the distances between them, and focus on the sheer quantity of them. Suppose your superhero explores these bubbles until he finds one containing his duplicate. The proportion of bubbles containing a duplicate of him is 0% to more decimal places than you can imagine imagining. Even if your superhero takes only a Planck time to check one bubble and move onto the next, and he lives until the heat death of the universe, he will have time to check 0% of the bubbles. He will not find one of the bubbles he is looking for.

Or suppose he knows the exact location of such a bubble, and he has a magical device which shows the correct direction to fly in to reach it, and he can accurately see which direction this device is pointing at on a Planck-length scale and fly in exactly that direction. Suppose it takes him only one Planck time to look at this device and correct his trajectory accordingly, and he will continue his journey until the heat death of the universe. The number of different bubbles he can reach in his lifetime based on how many different sequences of turns the device might tell him to make, is 0% of the number of bubbles. So there is not enough time in the world for him to make enough corrections to his trajectory to reach his destination even if he knows where it is.

The only way your hero can meet his clone is if you accept that it's impossible and write it anyway. As a writer, you have that power.

## No

Trivially, the answer is "yes" on a long-enough timeline. But within the expected lifetime of your hero, or the universe itself, the answer is absolutely no.

Let's assume your hero can travel at the speed of light (which is impossible) and can travel in a straight line directly towards his/her twin without having to deviate for black holes, or stop for lunch or pee breaks. How long would it take to travel 101029 meters at the speed of light?

I don't know, because Wolfram Alpha says "cannot be determined by current methods."

Let's ballpark it and say it would take "merely" one thousand years of travel (which is certainly wrong by thousands of orders of magnitude). If your hero steps out for two thousand years to go on this journey, they will effectively remove themselves from all the events they might care to influence.

By the time they return, everybody they cared about will be dead, all their projects and schemes will be irrelevant, the society they were part of will be completely remade, and indeed the human species itself will be changed. It is overwhelmingly likely your hero wouldn't even be able to understand the language used by these people from 2000 years in the future.

But, as I said, these numbers are wrong by a huge amount. The more likely truth is that your hero would die of old age before traveling even 1% of the distance to their twin. And by the time they would theoretically return, the Earth's sun would have reached its end of life and destroyed the Earth.

• I was liking the part about no pee breaks. Probably he can just let it go in space because he flies naked. But then it was a big bummer. He does not find love, only people who speak foreign languages and have their sun burnt out. Dec 28, 2022 at 21:57
• $10^{10^{29}}$ metres is $10^{10^{29} - 16} \approx 10^{10^{29}}$ light years - the number is so big that a factor of $10^{16}$ doesn't make any practical difference. So it will take $10^{10^{29}}$ years to get there. Not only will everyone be dead but the sun will have burnt out long ago and the universe will be well on the way to its heat death. Dec 30, 2022 at 2:15
• @N.Virgo I prefer the term "heat nap."
– Tom
Dec 30, 2022 at 17:33

## No

Aside from the issues mentioned by Tom and kaya3, if the copies are truly identical, then your protagonist will never meet an identical copy, because that identical copy will have gotten the same identical idea of flying to its copy, and so on. All copies will just shift one local bubble.

Superdude punched through the void between local bubbles and found the nearest bubble to his own. After finding his galaxy, and his star in that galaxy, and landing on his planet, he decided to immediately visit his own home. “Boy, will my copy be surprised when he sees me!“ he thought. He entered his copy's home, but nobody was there. There was a note on the kitchen counter though saying: “Out visiting neighboring local bubble. Be back before lunch.” “Darn,” he thought, “that's exactly the same as the note I left in my kitchen!”

• > Then, famished from his journey, Superdude opened his copy's refrigerator to forage. Inside he discovered a wedge of flaky spanakopita nestled next to a glistening mound of olive salad, seemingly identical to the treats he had procured from the Greek joint down the block from his own apartment in anticipation of his return. He hesitated only a moment before greedily hauling them out. "If the shoe fits..." he thought, and dug in.
– Tom
Dec 30, 2022 at 17:50
• > He thought about waiting for his copy to return, but quickly realized the folly of that. He then decided to go home, but was suddenly struck by the realization: if everything was identical in this local bubble to his own, would going back even matter? But then, he would know he was not in his own bubble, so he would feel like an imposter. He decided to go home after all, but upon returning he didn't feel any better. Depressed, he sat down in his couch and started watching some Rick & Morty. Dec 30, 2022 at 18:49

Nah

SuperDude wants to meet SuperLady. This is easy peasy if he knows SuperLady is exactly $$10^{10^{29}}$$ miles away. He can just use his physics-breaking speed to fly $$10^{10^{29}}$$ miles in a second.

And his physics-breaking invulnerability to prevent existence failure due the laws of physics in other bubbles causing the atoms in his body to collapse.

Unfortunately, he does not know the exact distance. All he knows is Superlady is somewhere between zero and $$10^{10^{29}}$$ miles away (maybe?). That means every lightyear or so -- this is VERY generous -- he has to stop and look around to see if SuperLady is nearby. Let's say (GENEROUSLY) this takes one second each time. He needs to live $$10^{10^{29}}$$ seconds to find her.

For comparison the universe is only $$10^{18}$$ seconds old. . . .

• @catsteevens It will take much longer if you want another Milky way and not just another Superdude. Dec 29, 2022 at 19:05
• @catsteevens Oh, in that case the answer is easy: "Will this super flying brick meet his identical copy in another universe?" No he won't. Dec 29, 2022 at 19:26

## Yes, if his super sight is powerful enough

To move that fast he would need inhumanly good senses. As such, if he has sight that can see much faster than FTL, he could find his copy across the multiverse and fly there at some absurd FTL speed to fight him.

If you have arbitrarily large numbers, you can just counter them with other arbitrarily large numbers.

• If he lacks super senses he won't be able to examine even a single universe in his lifetime. Dec 29, 2022 at 15:57
• If he's looking for a copy of himself, even with perfect visual resolution, then he'd only be able to see back his own age in light-years. He'd need a sense that could detect things for which the light hadn't reached him. Jan 1 at 18:31

Yes

Since all these "local bubbles" are generated probabilistically, you are free to declare that Superdude finds SuperLady much closer than the $$10^{10^{29}}$$ miles you cite.

Or perhaps there is some local bubble with two Superdudes relatively nearby. The story takes place in this bubble and not in any of the other bubbles where the Superdudes are far apart.

• @catsteevens Perhaps I meant domain instead of bubble. It makes no difference, since you have not bothered to explain what either of these things are. Dec 29, 2022 at 19:01
• @catsteevens I did not understand. I only say a link to an article and some bewildering pictures that raise more questions than they answer. Dec 29, 2022 at 19:25

Since the local domain (below), while huge, is nowhere big enough, the protag's clone would not exist. If it was infinitely large, as Tegmark posits, yes, but not in my story's cosmology.