# A “time capsule” that can last for trillions of years?

The universe is dying because it has exhausted nearly all of its resources. Humans became the last species in the universe because of their resilience and sheer willpower.

And yet, humanity still doesn’t want to die. Relying on the Big Bounce Theory, scientists developed a sort of “time capsule”. It was designed to hold up to 200 people, plant seeds, and animal dna. The people, seeds and animal dna would probably have to be frozen for trillions and trillions of years until another Big Bang was to happen.

Requirements for the “time capsule”

1. It would most likely need to be incredibly heat proof (the sheer light emanating from the big bang would probably melt most metals)
2. It needs to be airtight, at least until it could land on a habitable planet.
3. Regarding #2, it needs to be corrosion-proof as well.
4. None of the above would be possible if they placed the time capsule right on top of, or very near the epicenter of the Big Bang.
5. A predictor system, before the Big Bang 2.0 Electric Boogaloo happens, the time capsule needs to predict where a habitable planet will pop up in the new universe and crash land there while still in the old universe.

How is it possible that a universe that literally has no more materials respawn???

1 word, magic. Universe 2.0 now has magic, aka Mana. We all know how magic breaks all known laws of physics from the fictions we read. Who knew that it could save the laws of physics from nothingness?

But that’s besides the point, the most important question; how do I design, build and finally, “pilot” such a thing?

Ps: this is a crudely drawn representation of what I think may happen:

• you might want to get rid of the science-based tag, the universe and processes you describe are really not based on current science Mar 4 '20 at 9:19
• The main problem is that the big bang happens everywhere and includes all space as far as we can tell. So its not some sort of explosion that happens somewhere in a preexisting space. The best bet would be to have access to some form of hyperspace, but then then question is dependant on the properties of that hyperspace. Mar 4 '20 at 9:40
• It's unclear to me what you want. We cannot possibly predict every single thing such a capsule has to endure. On those time scales, there is no corrosion proof or air tight. Gases are quite small and can enter and exit basically any material. Could you share with us your research so far? What events do you account for specifically? Mar 4 '20 at 9:42
• "magic" is right. there are numerous problems with this, starting with the fact that there is nowhere this capsule could be except as part of the singularity, as space does not exist anymore. the BB is not like a supernova, expanding into surrounding space. it's space itself explosively expanding.
– ths
Mar 4 '20 at 10:18
• Your point 1 is a hard stop: the early universe would destroy literally everything, not just "most metals". Similarly with 4: literally everywhere is the epicentre of the big bang. Mar 4 '20 at 23:03

Instead of trying to freeze something for that long and have it remain viable, I would suggest that you could consider hiding away under the event horizon of a rotating massive black hole.

There are a lot of interesting things you can potentially do with black holes that I won't go into here, but there are a few important things.

• The event horizon of a very large black hole is a surprisingly benign thing... you can cross over it without being mangled by tidal forces as you would in a much smaller black hole.
• Black holes are exceedingly long lived... there's no danger of even massing as little as our sun evaporating within your trillion-year limit.
• The enormous mass of a black hole causes relativistic time dilation, so if you were close enough (and, of course, well within the event horizon) those trillions of years could pass outside without you really noticing.
• There's a possibility that black holes could persist through a new big bang: Persistence of black holes through a cosmological bounce.

In our universe, it would appear that once you've crossed an event horizon that's where you'll stay until you get reduced to a spray of radiation by the eventual collapse of the black hole in the far, far future.

In your Universe 2.0 though, magic exists, and that means there's scope for travel through an event horizon. You tweak that particular bit of handwavium to prevent time travel, but (possibly limited) FTL would be just fine, and so the contents of your black hole can simply pop out when it seems like a good idea.

Discovery of the news laws of physics can be made by the "time capsule" spaceship inside the event horizon, which can then cross the event horizon and investigate the new universe. If nothing interesting is immediately available, they can return to the highly time-dilated orbit they survived the end of the last universe in and allow large amounts of time to pass outside until the local environment becomes sufficiently benign or interesting to make it worth leaving for longer periods of time.

• I like this answer. Just a few questions, How long could a massive black hole hope to last and could it fit within my timeframe? Mar 4 '20 at 10:33
• @Inthenameofthestory there's an equation on the wikipedia page for hawking radiation if you wanted specific figures, but a solar mass black hole will last for approximately 10^64 years (and remember that a trillion is 10^12) and massive black holes will last for much, much longer than that. Mar 4 '20 at 11:08
• David Brin's short story The Crystal Spheres has a series of alien communities doing just this in order to have someone to talk to. Mar 4 '20 at 16:27
• This is extremely speculative, but as long we are not very science-based, that a +1 from me. Mar 4 '20 at 18:25
• @Peter-ReinstateMonica with a very large black hole, the tidal forces as you cross the event horizon are surprisingly mild. You could fly across it without noticing. The same is definitely not true for a much smaller one, however. Mar 5 '20 at 10:37

A Pocket Dimension

Scientists learn how to create pocket universes. Being a separate universe even if somewhat compact, it's time flows differently to the main universe and can be controlled. This means the inhabitants can be effectively frozen in time and sample the main universe once for a fraction of a second every billion years or so time is effectively sped up passing a trillion years every minute or so.

Once a new universe forms, time can altered down while searching for a new planet or materials to create a new human habitat.

Pocket universes are a common trope in many scifi and fantasy series from Doctor Who to Dungeon and Dragons.

• Pocket universes need a lot of power, don’t they? Mar 4 '20 at 10:47
• @Inthenameofthestory might explain how all the resources of the entire universe got "used up" in your backstory... Mar 4 '20 at 11:10
• If OP has a story involving a Big Crunch, then there's no other possibilities, since the Universe will collapse in a single point, you have to be outside "normal spacetime" to avoid being dragged. Mar 4 '20 at 12:39
• In the final book of the series The Three Body Problem, The Dark Forest, and The End of Death, there is a pocket universe. The mass that cosmically-many species had removed from the universe to live in pocket dimensions had decreased the mass of the regular universe enough to turn it from closed to open. Mar 4 '20 at 14:40
• I believe some physicists have suggested that a black hole is a pocket universe, since nothing can get out of it. So all you need to do is design something strong enough to withstand the tidal forces of crossing an event horizon, and voila! Instant Pocket Universe! Mar 4 '20 at 18:46

You're already talking about Human society existing towards the end of the universe. This is an excessively long time by any standards to even think that current technology has any real meaning. So a major handwave in the style of any technology sufficiently advanced is indistinguishable from magic is probably acceptable.

Examples of such handwaves from existing fiction are;

1. Tau Zero - Go faster. You don't need to store that much oxygen or worry about corrosion if in your frame of reference very little time is passing. Whizzing around the emptying universe at very close to light speed will do that for you.
2. Across Realtime - Stasis bubbles called "Bobbles" are for all intents and purposes single use force fields that last as long as you need them. Jump in, switch it on, an bingo you're there.
3. Flood - Pocket Universe. While being mostly an aside to the main story, Arc3 in Flood leaves a flooding earth behind by tucking itself into a pocket universe and heading out across the stars. Nudge the effects a little and your pocket universe can actually become the seed of the next one.
• I haven't read Tau Zero, but a similar effort would be to orbit a super massive black hole just outside the event horizon as close to the speed of light as you can get. Mar 4 '20 at 19:03
• Accelerating your entire star system (and maybe some nearby ones) to close to the speed of light would let you enjoy nice baryonic matter even after all the stars have gone out and you are simply waiting for everything to decay. There was a I think Phoul Anderson story like this - not sure if it was Tau Zero where a star creature accidentally did this as a distraction to eliminate its rivals and eventually the star system returns to its original position after everything has decayed. Mar 4 '20 at 21:20
• @MichaelRichardson Interesting. I always thought that the tidal forces would be too strong close to the event horizon but apparently they aren't for supermassive black holes. Mar 4 '20 at 21:51
• @MichaelRichardson You can't orbit arbitrarily close to the horizon. The innermost stable orbit is still some distance out, which is the closest orbit in which an object can stay without constant acceleration. Unsure how much time dilation you get in this orbit, but it probably won't be enough to pass trillions of years quickly enough.
– Hene
Mar 5 '20 at 9:45

Don't try to pass any physical objects forward into the next universe. Instead, use the new universe as a machine to make them for you.

Humanity creates a device which predicts (or causes) a new universe. The device perturbs the state of the early new universe just ever so slightly and perfectly to ensure a habitable planet forms around a habitable star upon which evolves humans, plants, and animals.

The calculations required are outrageous, but if humanity (or whatever counts as humanity) has survived the $$10^{40}+$$ years into the Black Hole Era their technological advancements and computing power would be equally outrageous.

A similar idea is used in Greg Egan's Diaspora where...

humanity has been fully digitized. After learning all they can about our universe, they decide to "travel" to neighboring universes by injecting, particle-by-particle, a machine which can make a machine which can make copies of themselves.

Alternatively, humanity perturbs the new universe to leave the plans for itself in the Cosmic Background Radiation in the hopes that a future advanced civilization will find those plans and recreate humanity.

If they're really good and really specific, they could recreate an exact duplicate of people at the moment of their encoding including all their memories; presumably with some tweaks to survive in the new universe's physics. In effect, humans would "go to sleep" in their old universe and "wake up" in the new universe. Like the philosophical Swampman which is an exact duplicate of, but has no continuity with, the original person.