How to Survive the End of the Universe

TL;DR: If we find a way to sur­vive the end of the uni­verse, we could cre­ate much more happy minds in the fu­ture. The de­ci­sion about the need to fight the end of the uni­verse should be made now as we could start an ir­re­versible wave of space colon­i­sa­tion soon.

perma­l­ink: https://​​philpa­pers.org/​​rec/​​TURHTS-2

Ab­stract. The prob­lem of sur­viv­ing the end of the ob­serv­able uni­verse may seem very re­mote, but there are sev­eral rea­sons it may be im­por­tant now: a) we may need to define soon the fi­nal goals of run­away space coloniza­tion and of su­per­in­tel­li­gent AI, b) the pos­si­bil­ity of the solu­tion will prove the plau­si­bil­ity of in­definite life ex­ten­sion, and с) the un­der­stand­ing of risks of the uni­verse’s end will help us to es­cape dan­gers like ar­tifi­cial false vac­uum de­cay. A pos­si­ble solu­tion de­pends on the type of the uni­verse’s end­ing that may be ex­pected: very slow heat death or some abrupt end, like a Big Rip or Big Crunch. We have re­viewed the liter­a­ture and iden­ti­fied sev­eral pos­si­ble ways of sur­vival the end of the uni­verse, and also sug­gest sev­eral new ones. There are seven main ap­proaches to es­cape the end of the uni­verse: use the en­ergy of the catas­trophic pro­cess for com­pu­ta­tions, move to a par­allel world, pre­vent the end, sur­vive the end, ma­nipu­late time, avoid the prob­lem en­tirely or find some meta-level solu­tion.

1. Introduction

Based on some op­ti­mistic mod­els, we could start a wave of coloniza­tion of the uni­verse us­ing von Neu­mann probes mov­ing at near-light speed a few hun­dred years from now (Stu­art Arm­strong & Sand­berg, 2013), lev­er­ag­ing tech­nol­ogy such as nan­otech repli­ca­tors con­nected to laser-pow­ered sails. Com­mu­ni­ca­tion and co­or­di­na­tion be­tween differ­ent parts of such a wave would be difficult. But to pre­vent some sce­nar­ios of the end of the uni­verse, a form of large-scale co­or­di­na­tion may be needed. This may take, for ex­am­ple, the form of an ag­gre­ga­tion of large masses of mat­ter to build mas­sive as­tro­eng­ineer­ing struc­tures, as de­scribed by (Hooper, 2018), who sug­gested that an ad­vanced civ­i­liza­tion will send stars to its cen­tral re­gion and in­crease mass of available mat­ter af­ter ex­pan­sion of the uni­verse will make these stars in­ac­cessible. (Hooper ex­pected that it may help to in­crease the available mass by 1000 x, but Loeb wrote that it may be cheaper to mi­grate to a dense cluster of galax­ies (Loeb, 2018)).

Bostrom sug­gested the idea of as­tro­nom­i­cal waste (Bostrom, 2003), a huge op­por­tu­nity cost which could come into play if we de­lay our ex­plo­ra­tion of the uni­verse—as many new stars be­come per­ma­nently in­ac­cessible ev­ery day be­cause of the ex­pan­sion of the uni­verse. He also states that hu­man en­dow­ment could be to reach all our op­por­tu­ni­ties and be­come ev­ery­thing which we could be. This as­sumes that we should use re­main­ing time and mat­ter of the uni­verse in the most effec­tive way to get as much hu­man-val­ues-re­lated util­ity as pos­si­ble. How­ever, there is an­other al­ter­na­tive: use all the time and mat­ter available to use to find the ways to sur­vive the end of the uni­verse, as the pos­si­ble prize could be very large: in other words, this en­ter­prise is a form of Pas­cal’s wa­ger.

More­over, be­fore the de­ci­sion about how to fight the end of the uni­verse is made (or at least be­fore we know how much time we ac­tu­ally have left), we need a perfect knowl­edge of high-en­ergy physics—as we need to know for sure how and when the uni­verse will end and what can be done to pre­vent it. Gain­ing such knowl­edge may re­quire cre­ation of large-scale par­ti­cle ac­cel­er­a­tors or long-term ob­ser­va­tions of changes in dark en­ergy. Sabina Hossen­felder has said that new physics be­come ap­par­ent only by study­ing en­er­gies many or­ders of mag­ni­tude higher than those achiev­able on Cern’s Large Hadron Col­lider (LHC), and for ex­am­ple, to study quan­tum grav­ity, an ac­cel­er­a­tor the size of the Milky Way Galaxy is needed (Hossen­felder, 2019).

Sev­eral au­thors have ex­plored the pos­si­bil­ity of reach­ing im­mor­tal­ity and sur­viv­ing “the end of the uni­verse.” Ti­pler sug­gested that we will use the en­ergy of the col­laps­ing uni­verse to perform an in­finite num­ber of com­pu­ta­tions in Omega point (Ti­pler, 1997), but this idea was crit­i­cized by (Ellis & Coule, 1994). Many pre­dic­tions made by Ti­pler now seem to be ob­so­lete: for ex­am­ple, the mass of the Higgs bo­son turned to be differ­ent than that re­quired by Ti­pler’s Omega the­ory, as well as Hub­ble’s con­stant. Notably, Ti­pler wrote his book The physics of Im­mor­tal­ity be­fore the dis­cov­ery of dark en­ergy.

Egan sug­gested—in fic­tional form—mi­gra­tion into an eter­nal math­e­mat­i­cal uni­verse as the ul­ti­mate form of es­cape in his novel Per­mu­ta­tion City (Egan, 2010). Dvorsky ex­plored sev­eral ideas about sur­viv­ing the end of the uni­verse (Dvorsky, 2015). Cirn­cov­ich and Bostrom sug­gested the pos­si­bil­ity that a mind could travel be­tween old and new uni­verses via sin­gu­lar­i­ties (Ćirković & Bostrom, 2000).

There have also been sug­ges­tions about how to ex­tend our ex­is­tence as long as pos­si­ble in the case of a Big Freeze. For ex­am­ple, Sand­berg et al. sug­gested an “aes­ti­va­tion hy­poth­e­sis” (Sand­berg, Arm­strong, & Cirkovic, 2017), in which civ­i­liza­tions might wait un­til very cold times to perform com­pu­ta­tions more effec­tively. How­ever, such “civ­i­liza­tional life ex­ten­sion” is not a form of true im­mor­tal­ity. Along similar lines, Free­man Dyson ex­plored how to sur­vive for a very long time in a slowly freez­ing uni­verse (Dyson, 1979).

Prevent­ing the end of the uni­verse could be also re­garded as a cause pri­ori­ti­za­tion area for effec­tive al­tru­ism, be­cause if we pre­vent (or sur­vive) some short-term forms of the end of the uni­verse, like false vac­uum de­cay or a Big Rip soon, we could in­crease amount of good we can cre­ate by many or­ders of mag­ni­tude. We could also act effec­tively in this di­rec­tion by pre­vent­ing col­lider ac­ci­dents (Kent, 2004) or other po­ten­tially dan­ger­ous ex­per­i­ments, and by in­clud­ing the goal of sur­viv­ing the end of the uni­verse in the goal sys­tem of fu­ture su­per­in­tel­li­gent AI (Bostrom, 2014). By ex­plor­ing sur­vival strate­gies for the uni­verse, we may help es­tab­lish ex­is­ten­tial op­ti­mism for peo­ple who are liv­ing now, sup­port life ex­ten­sion re­search, and gain more in­for­ma­tion from fun­da­men­tal stud­ies of physics.

Another pur­pose of the dis­cus­sion about sur­viv­ing the end of the uni­verse is to show that ac­tual im­mor­tal­ity is pos­si­ble: that we have the op­por­tu­nity to live not just billions and trillions of years, but for an un­limited du­ra­tion. My hope is that rec­og­niz­ing the pos­si­bil­ity to sur­vive the end of the uni­verse will en­courage us to in­vest more in life ex­ten­sion and pre­ven­tion of global catas­trophic risks. Our life could be eter­nal and thus have mean­ing for­ever. The end of the ob­serv­able uni­verse is not an ab­solute end: it’s just one more prob­lem the fu­ture hu­man race will be able to ad­dress. And even at the limited level of knowl­edge about the uni­verse that we have to­day, we are still able to offer sev­eral dozen more ideas on how to pre­vent its end. In the dis­tant fu­ture, we can find more ideas, choose the best, val­i­date them, and pre­pare for their im­ple­men­ta­tion.

2. How will our uni­verse end, and what does it mean for us?

2.1. The end of the uni­verse is not the end of the mul­ti­verse or of existence

When we say, “the end of the uni­verse,” we mean the end of the three-di­men­sional man­i­fold with one-di­men­sional time with or­di­nary mat­ter in it, which al­lows or­dered causal con­nec­tion be­tween states of mat­ter, and thus, un­in­ter­rupt­able com­pu­ta­tion. This does not mean the “end of ex­is­tence,” but only some form of trans­for­ma­tion of the ob­serv­able world, one in which com­pu­ta­tions and mem­ory about pre­vi­ous states be­come im­pos­si­ble. For ex­am­ple, in the case of the Big Crunch, the uni­verse will col­lapse into a sin­gu­lar­ity, even­tu­ally fol­lowed by a new Big Bang. In that case, all, or al­most all in­for­ma­tion about the pre­vi­ous state of the uni­verse will be de­stroyed in the mo­ment of sin­gu­lar­ity.

Thus, the end of the ob­serv­able uni­verse is not the end of the mul­ti­verse, which is ev­ery­thing which ac­tu­ally ex­ists. This dis­tinc­tion al­lows the­o­ret­i­cal routes to sur­vive the end of the ob­serv­able uni­verse by send­ing data to other parts of the mul­ti­verse.

The mul­ti­verse could be much larger than the ob­serv­able uni­verse. The­o­ret­i­cal mod­els of the mul­ti­verse in­clude differ­ent ap­proaches which all as­sume the ex­is­tence of an in­finitely large uni­verse which in­cludes all pos­si­ble things: chaotic in­fla­tion, a string land­scape with 11 di­men­sions, math­e­mat­i­cal uni­verses, a chain of Big Bang–Big Squeeze. In these mod­els, mul­ti­verse con­sists of many “blobs” of space-time which a rel­a­tively sta­ble and causally con­nected, and in which life could ap­pear.

In this sec­tion, we will provide an overview of ex­ist­ing ideas about the ways in which the uni­verse could end. There are two main sci­en­tific views on the ex­pected end of the uni­verse: the slow end, some­times called a “Heat death” or “Big Freeze”, and sev­eral ideas about abrupt ends of the uni­verse.

2.2. Sur­viv­ing the end of the uni­verse is not im­mor­tal­ity, but it is one step closer

If we—defined here as hu­man-origi­nated in­tel­li­gence which has at least some of our val­ues—sur­vive the end of the ob­serv­able uni­verse, we will pass just one of the many ob­sta­cles to the in­finite ex­is­tence. This is analo­gous to the way in which we will have to find ways to leave the Earth be­fore the Sun en­gulfs it. In other words, the new world which we might reach af­ter break­ing out of this uni­verse could still be finite, and there could be other ob­sta­cles to our in­finite ex­is­tence.

2.3. A slow end, or heat death

Heat death is not the end of the uni­verse per se, but rather the end of the mat­ter and pro­cesses in it. If there is no abrupt end, and the ex­pan­sion of the uni­verse con­tinues at its cur­rent speed, all or­di­nary mat­ter will de­cay, black holes will even­tu­ally evap­o­rate, and all pro­cesses will stop be­tween 10100 or 10200 years from now.

2.4. Abrupt end

The choice be­tween these sce­nar­ios de­pends on the ge­om­e­try of the uni­verse, which is de­ter­mined by gen­eral rel­a­tivity and—above all—the be­hav­ior of an al­most un­known pa­ram­e­ter: dark en­ergy.

Big Crunch: grav­ity over­whelms the rate of ex­pan­sion of the uni­verse and it col­lapses into a sin­gu­lar­ity.

Big Rip: if dark en­ergy is ac­cel­er­at­ing not ex­po­nen­tially, but quicker, it will reach an ex­pan­sion speed reach­ing in­finity in a finite time. In one model, this will hap­pen 20 billion years from now, a rel­a­tively short time, only around five times longer than time in which life has ex­isted on Earth (Cald­well, Kamionkowski, & Wein­berg, 2003).

False vac­uum de­cay: If our vac­uum is not true vac­uum, it could col­lapse into the state with lower en­ergy, start­ing from one point, from where a bible of new vac­uum will ex­pand with the light speed de­stroy­ing ev­ery phys­i­cal ob­ject (Krauss & Dent, 2008). This the­o­ret­i­cally could hap­pen in any mo­ment, but Bostrom showed that the prob­a­bil­ity of it (or any other cos­molog­i­cal catas­tro­phe) is less than 1 per cent in the next 1 billion years based on our rel­a­tively late lo­ca­tion on the his­tory of the uni­verse.

Big Freeze: the growth of phan­tom en­ergy stops any move­ment of par­ti­cles in the finite time. The idea is ex­plored in the ar­ti­cle “Worse than a Big Rip?” (Bouh­madi-López, González-Díaz, & Martín-Moruno, 2008).

The end of existence

Unex­is­tence: It seems that the uni­verse popped into ex­is­tence dur­ing the Big Bang; in that mo­ment the causal chain of events started. Thus, there is some mechanism in na­ture which al­lows the cre­ation of some­thing from noth­ing. Unex­is­tence is a hy­po­thet­i­cal mechanism by which the uni­verse com­pletely stops ex­ist­ing. It seems rea­son­able to as­sume that if there is a mechanism of ap­pear­ing from noth­ing, there should be a sym­met­ri­cal mechanism of dis­ap­pear­ing, which I term un­ex­is­tence. Hope­fully, this can’t hap­pen just in a ran­dom mo­ment, as the uni­verse ap­peared not in a ran­dom mo­ment, but in the mo­ment of Big Bang’s sin­gu­lar­ity or shortly af­ter, dur­ing in­fla­tion. Thus, the ap­pear­ance of a new sin­gu­lar­ity may trig­ger un­ex­is­tence.

Another way to (maybe ac­ci­den­tally) cause un­ex­is­tence is to cre­ate an un­re­solv­able vi­o­la­tion of the laws of causal­ity, be­cause the Big Bang is also a vi­o­la­tion of causal­ity (some­thing ap­peared from noth­ing). Log­i­cal para­doxes, time travel, or at­tempts to learn the fi­nal the­ory of ev­ery­thing (or more likely some­thing uni­mag­in­able) could cause such causal­ity vi­o­la­tions.

Si­mu­la­tion ter­mi­na­tion: We may live in a simu­la­tion, and such a simu­la­tion could be ter­mi­nated by its own­ers. I ex­plored this hy­poth­e­sis and simu­la­tion ter­mi­na­tion risks in an­other ar­ti­cle (Greene, 2018; Turchin, Yam­polskiy, Denken­berger, & Batin, 2019). In this work, we as­sume that we live in a “real”, un­si­mu­lated world.

Fluc­tu­a­tion ends: I am a Boltz­mann brain and will dis­ap­pear in the next mo­ment. If BBs are pos­si­ble, chains of BB-ob­server-mo­ments seems plau­si­ble, and in that case, the end of one BB is, seam­lessly, the be­gin­ning of an­other. The prob­lems of be­ing a BB and ter­mi­na­tion risks are ex­plored in an­other ar­ti­cle (Turchin & Yam­polskiy, 2019).

2.5. Other limits of existence

Finite com­pu­ta­tions: In the same way, finite ex­is­tence in time al­lows in­finite com­pu­ta­tions in the Omega Point the­ory, in­finite ex­is­tence in time may not al­low in­finite com­pu­ta­tions, if, for ex­am­ple, the speed of com­pu­ta­tions con­stantly be­comes slower.

Finite reach­able space and ob­serv­able space: Liv­ing in an ac­cel­er­at­ing uni­verse means that there are fun­da­men­tal limits on reach­able space.

Finite available mat­ter: The ex­pan­sion of the uni­verse means that the to­tal amount of mat­ter which we will be able to reach is limited, and thus the amount of any com­pu­ta­tions (or the num­ber of be­ings which could ex­ist si­mul­ta­neously—or the to­tal size of mem­ory available) is also limited.

Growth of en­tropy: Even if we have ac­cess to un­limited en­ergy and mat­ter, we also need a tem­per­a­ture differ­ence to pro­duce use­ful com­pu­ta­tion.

Growth of “com­pu­ta­tional en­tropy”: ac­cu­mu­la­tion of er­rors, loops, etc. Some­thing similar to age-re­lated changes in the hu­man brain, when it be­comes more repet­i­tive and even­tu­ally for­get­ful and de­mented.

Eter­nal bore­dom: There are sev­eral philo­soph­i­cal ar­ti­cles about how to fight such bore­dom (Bor­tolotti & Na­ga­sawa, 2009).

Many of the ideas dis­cussed be­low may also help to solve these prob­lems.

3. Overview of ideas about sur­viv­ing the end of the universe

There are sev­eral gen­eral ap­proaches to solve the end of the uni­verse prob­lem; each of them in­cludes many sub­types, which will be dis­cussed:

1. Surf the Wave: Utilize the na­ture of the pro­cess which is end­ing the uni­verse for com­pu­ta­tions. The most well-known solu­tion of this type is Ti­pler’s Omega Point, where the uni­verse’s en­ergy col­lapse is lev­er­aged to perform in­finite calcu­la­tions.

2. Go to a par­allel world.

3. Prevent the end of the uni­verse.

4. Sur­vive the end of the uni­verse.

5. Ma­nipu­late time, thus dilut­ing the idea of the “end”.

6. Dis­solve the prob­lem (that is, re­frame the prob­lem and its ba­sic no­tion in the way where the prob­lem no more ex­ists.)

7. Meta-level solu­tions.

Now we will com­bine differ­ent gen­eral ap­proaches with differ­ent ideas how the uni­verse will end and will see which con­crete ideas go into this clas­sifi­ca­tion.

3.1. Surf the wave: use the pro­cess of the uni­verse’s de­struc­tion for computation

For an abrupt end

Ti­pler’s Omega Point: Use the en­ergy of the os­cilla­tions dur­ing the Big Crunch near the sin­gu­lar­ity point to make in­finite calcu­la­tions. Cur­rently, this seems an un­likely out­come, as it re­quires very fine-tun­ing of some cos­molog­i­cal pa­ram­e­ters, which could be ex­plained only by the fi­nal an­thropic prin­ci­ple, that is, that the uni­verse is cre­ated in a way that en­sures the in­finite ex­is­tence of in­tel­li­gent life. Many of Ti­pler’s pre­dic­tions about cos­molog­i­cal con­stants have been shown to be wrong. Also, most col­lap­sars don’t show os­cilla­tions be­tween pre­dom­i­nant con­trac­tion di­rec­tions (which is a source of en­ergy for Ti­pler’s Omega), as they have ro­ta­tion, which sta­bi­lizes most of the mat­ter in one plane, like galax­ies. (We can see here how the best ideas about sur­viv­ing the end of the uni­verse can be­come ob­so­lete just in 20 years).

The Omega Space: the same as Ti­pler’s Omega point, but in case of the Big Rip sce­nario. Here, dark en­ergy is used for calcu­la­tions dur­ing the late stages of the Big Rip.

Eter­nal re­turn: af­ter the Big Crunch, a new uni­verse will ap­pear, and our civ­i­liza­tion will ex­ist again in it (as was sug­gested by Niet­zsche, (Bergström, 2012; Niet­zsche, 1883)) or maybe with some vari­a­tions, in which case it turns out in some form of quan­tum or big-world im­mor­tal­ity.

Create new uni­verses from cos­molog­i­cal in­fla­tion foam: Use the en­ergy cre­ated by the de­struc­tion of our uni­verse to cre­ate new uni­verses with pre­de­ter­mined prop­er­ties. For ex­am­ple, new sin­gu­lar­i­ties or new bub­bles with eter­nal in­fla­tion. Higher con­cen­tra­tions of en­ergy dur­ing the Big Rip or Big Crunch could help make such ex­per­i­ments pos­si­ble.

For heat death

Boltz­mann brains chains: use a chain of com­ple­men­tary BBs for in­finite calcu­la­tions (Loew, 2017; Muel­ler, 2017). The empty uni­verse will be not com­pletely empty: it will be filled with ran­dom ghosts of quan­tum fluc­tu­a­tion, which could cre­ate ob­server mo­ments (OM). For any OM there is at least one next pos­si­ble OM, so there could be illu­sion­ary chains of OM, which would sub­jec­tively ap­pear con­tin­u­ous, and could be in­finite.

• Use sur­viv­ing par­ti­cles for in­creas­ingly slow calcu­la­tions (with trillions of light-years be­tween them). Lower back­ground ra­di­a­tion means that the en­ergy re­quired for com­pu­ta­tions could be even lower than now, so para­dox­i­cally, a colder uni­verse could be more effec­tive for com­pu­ta­tion, as de­scribed by (Sand­berg et al., 2017).

The re­main­ing mat­ter in the uni­verse could be used to perform ever-slower com­pu­ta­tion. For ex­am­ple, there will be a pe­riod where only atoms of positro­n­ium with a size larger than the cur­rent size of the uni­verse are pre­sent—struc­tures con­sist­ing of such atoms will still be ca­pa­ble of perform­ing com­pu­ta­tions. The main ques­tion here is if the to­tal amount of com­pu­ta­tion will be finite or not af­ter in­te­gra­tion over all time un­til in­finity (tak­ing into the ac­count higher effi­ciency of com­pu­ta­tions in the ever-colder uni­verse).

Boltz­mann simu­la­tions: vac­uum fluc­tu­a­tion in an empty uni­verse may cre­ate a su­per­com­puter which simu­lates our re­al­ity for a long time from the sub­jec­tive per­spec­tive of its in­hab­itants (Arm­strong, 2018).

Ran­dom quan­tum fluc­tu­a­tions or quan­tum tun­nel­ling: may pro­duce an­other Big Bang, in which our civ­i­liza­tion will ap­pear again, with small, but pos­si­bly sub­stan­tial differ­ences. This is similar to the idea of a Big Bounce and eter­nal re­turn, but small differ­ences will make the re­turn not iden­ti­cal, and could be used to “ex­plore” differ­ent op­tions. This, how­ever, will even­tu­ally look like a form of quan­tum im­mor­tal­ity (Turchin, 2018b).

• Start ar­tifi­cial false vac­uum de­cay and use its en­ergy for calcu­la­tions. In a case of false vac­uum de­cay, enor­mous amounts of en­ergy will ap­pear on its do­main walls. Re­cent re­search on the Higgs bo­son in­di­cates that smaller black holes could cat­alyze false vac­uum de­cay (Burda, Gre­gory, & Moss, 2015). If there is no more en­ergy in our uni­verse use­ful for com­pu­ta­tions, false vac­uum de­cay may be started ar­tifi­cially—and the en­ergy of the de­cay some­how used for com­pu­ta­tions in­side the do­main walls. While this ap­proach is very spec­u­la­tive, it is no more spec­u­la­tive than the Omega Point.

• Try to reach bor­ders of the Uni­verse or re­gions with other phys­i­cal laws. The end of our uni­verse will fol­low from its phys­i­cal laws, but why they should these laws be the same ev­ery­where? Per­haps there are re­gions of the uni­verse with differ­ent phys­i­cal con­stants, and thus, a differ­ent fate? Start­ing near-light speed probes could help “us” to reach re­mote parts of the ob­serv­able uni­verse, but this is an in­finitely small por­tion of the whole in­fla­tion­ary vol­ume of the uni­verse, so it is un­likely that there will be sig­nifi­cantly differ­ent sets of phys­i­cal con­stants within that range.

• A re­lated idea is to over­come the sec­ond law of ther­mo­dy­nam­ics, maybe by us­ing open sys­tems or Maxwell demons, which would al­low in­finitely long com­pu­ta­tions with­out loss of en­ergy or growth of en­tropy. Rev­ersible com­put­ing (com­pu­ta­tions which don’t in­crease en­tropy) is an­other idea in this di­rec­tion.

• Merge with the uni­verse. The uni­verse it­self is re­garded by some, like (John A. Wheeler, 1990) and (Wolfram, 2002), as a com­pu­ta­tional pro­cess. While the ob­serv­able, sta­ble uni­verse could end in a vi­o­lent or a slow death, from an­other point of view, it is just a form of com­pu­ta­tion. The idea is to ex­ploit the com­pu­ta­tional na­ture of the uni­verse to perform use­ful com­pu­ta­tions. This is a rather gen­eral idea, and it could be im­ple­mented in sev­eral ways.

One of such ideas to merge with the uni­verse is the ul­ti­mate mi­ni­a­tur­iza­tion and reach­ing the level of small­est par­ti­cles which ex­ist. One of them is small­est pieces space-time which are known as “quan­tum foam”. Quan­tum foam is the idea that at the low­est scale the space it­self be­comes quan­tum and is in the state of con­stant fluc­tu­a­tions (it is also similar to the ideas of quan­tum loop grav­ity). Another idea is not to merge with the “small­est par­ti­cles”, but with the laws of physics them­selves. As phys­i­cal laws gov­ern the uni­verse and all “com­pu­ta­tions” in in, then be­com­ing such a law is equal in some sense to be­com­ing an eter­nal com­puter pro­gram

3.2. Go to a par­allel world

Go to a math­e­mat­i­cal uni­verse (like in Egan’s “Per­mu­ta­tion City”): If the ul­ti­mate re­al­ity is math­e­mat­i­cal, as as­sumed by (Teg­mark, 2014), cre­at­ing an ev­er­last­ing com­puter, which runs simu­la­tions of minds would rep­re­sent a way to mi­grate. In this sce­nario, a phys­i­cal copy of such a com­puter is cre­ated and then turned off, but in the math­e­mat­i­cal uni­verse, an in­finite chain of the next states of such a com­puter will be pos­si­ble, and thus ac­tu­ally ex­ist.

Use quan­tum im­mor­tal­ity: In other branches, the death of the uni­verse will come later, so our civ­i­liza­tion will always sur­vive (Turchin, 2018b). Another type of trav­el­ling to par­allel wor­lds could be jump­ing be­tween Everettian branches (Deutsch, 2002). Some of the branches could ex­ist longer than an­other, while all will have even­tu­ally similar ends. More­over, at least some very im­prob­a­ble branches will always sur­vive, and if an idea like quan­tum im­mor­tal­ity is true, there is no need to jump to other Everettian branches; we will (even­tu­ally) find our­selves only in those branches which con­tinue to sur­vive, no mat­ter how im­prob­a­ble that sur­vival may be. There is noth­ing prob­le­matic in sur­viv­ing in im­prob­a­ble situ­a­tions: think about the very small chance of life aris­ing on Earth or of your birth.

• Use other quan­tum prop­er­ties: i.e. use non-lo­cal­ity (Ein­stein, Podolsky, & Rosen, 1935) or quan­tum branches in­ter­ac­tion (in­terfer­ence) for com­pu­ta­tions.

Create new uni­verses (maybe in black holes or col­liders): mi­grate to them or define their prop­er­ties, so our copies are likely to ap­pear in them. This is the idea be­hind the evo-devo fe­cund uni­verses de­scribed by Lee Smolin, that our uni­verse is op­ti­mized via a pro­cess similar to nat­u­ral se­lec­tion to cre­ate new uni­verses via black holes (Smolin, 1992). As our uni­verse is also op­ti­mized to cre­ate in­tel­li­gent life, we could as­sume that civ­i­liza­tions are needed to fine-tune this pro­cess, per­haps via the ac­ci­den­tal (and deadly) cre­ation of black holes in col­liders.

Find that we already live in a de­signed uni­verse: Grib­bin sug­gests that we could cre­ate small uni­verses even now in our col­liders, as they are just in­te­ri­ors of small black holes (Grib­bin, 2010), but in the fu­ture, we could reg­u­late their laws, or even send data in­side them. In other words, there are cre­ators of the uni­verse, who more hu­man than gods (and the uni­verse is not a simu­la­tion). Lem wrote a short story, “New Cos­mogony”, where changes in phys­i­cal con­stants could be ex­plained by the wars of in­visi­ble civ­i­liza­tions (Lem, 1999).

Go to a higher di­men­sional re­al­ity (if our world has 5 or more di­men­sions as string the­ory sug­gests): If the uni­verse has more di­men­sions than the three spa­tial ones we ob­serve, then travel be­tween di­men­sions is con­ceiv­able. The string the­ory land­scape and M-the­ory as­sume that there are 11 di­men­sions, but other di­men­sions are hid­den. In the string land­scape, there are could be 10500 or even 10272000 pos­si­ble types of the uni­verse (Susskind, 2003), and many of uni­verses that ac­tu­ally ex­ist could be close to each other in the many-di­men­sional space. While most of the uni­verses may be not suit­able for the ori­gin of in­tel­li­gent life, as they could have differ­ent phys­i­cal laws, they could sup­port ex­ist­ing “tech­no­life”, pro­vid­ing it with new sources of en­ergy and com­pu­ta­tional me­dia. Each par­allel uni­verse could have its own end even­tu­ally, but some may have a much longer ex­is­tence than our uni­verse; trav­el­ling be­tween uni­verses could help us to find one that will con­tinue to ex­ist af­ter ours ends. The law of con­ser­va­tion of en­ergy seems to be ev­i­dence against the pos­si­bil­ity of travel be­tween uni­verses be­cause if one sends some mat­ter to an­other uni­verse, it would con­tra­dict lo­cal laws of con­ser­va­tion. How­ever, we may not need to send mat­ter (in the form of large star­ships), but only data. Even send­ing an equiv­a­lent of a nanobot or SETI mes­sage (Turchin, 2018c) to a par­allel uni­verse could be enough to pre­serve our civ­i­liza­tion.

· Go to an­other brane (if many 3-di­men­sional branes float in higher di­men­sional space, like in Egan’s “Di­as­pora” (Egan, 1997)): This might be ac­com­plished by us­ing worm­holes to send data (Mac­cone, 2000).

Lev­er­age acausal con­nec­tion with other uni­verses: In some sense, this is an analogue of quan­tum im­mor­tal­ity; copies of us may ex­ist in other uni­verses (which are not causally con­nected) in which the Big Rip will not hap­pen. We could de­liber­ately cre­ate var­i­ants of our­selves smaller and more ig­no­rant about our fate, which will them­selves have more copies in differ­ent wor­lds. The sim­pler the mind, and the more ig­no­rant it is about its lo­ca­tion, the more ex­act copies of it may ex­ist in the uni­verse.

Con­tact “aliens” from the par­allel wor­lds and send them in­for­ma­tion about us, as ex­plored in Asi­mov’s novel The Gods Them­selves (Asi­mov, 1972): Even send­ing a rel­a­tively small amount of in­for­ma­tion, like hu­man DNA, could be the equiv­a­lent of sur­vival for Homo sapi­ens.

Use in­ter­ac­tions be­tween differ­ent uni­verses for com­pu­ta­tion. It was as­sumed that grav­i­ta­tion could leak from uni­verse into an­other, which could ex­plain dark mat­ter ob­ser­va­tions. While each uni­verse could be finite in time, their in­ter­ac­tions could be in­finite (or at least much longer).

3.3. Prevent the end of the universe

Prevent a quick end to the universe

Choose a differ­ent way of the end of the Uni­verse. If the end is in­evitable, maybe we could choose the most prefer­able one. Maybe we could start false vac­uum de­cay if we have an idea of how to use its en­ergy for com­pu­ta­tion—or we could mimic Ti­pler’s Omega Point by jump­ing in­side a black hole. (Ac­tu­ally, we can’t jump in­side already ex­ist­ing black holes as we would for­ever be stuck on the hori­zon; how­ever, we if ag­gre­gate a large amount of mat­ter around our­selves and it starts col­laps­ing, we will find our­selves in­side a black hole.)

Con­trol mat­ter and dark en­ergy and change the fate of the uni­verse: The fate of the uni­verse mostly de­pends on the fu­ture evolu­tion of the cos­molog­i­cal con­stant or dark en­ergy. If we could ma­nipu­late this, as we can ma­nipu­late all other types of mat­ter we have found (atoms, fields), we may gain con­trol over the fu­ture of the uni­verse. The sim­plest form of such ma­nipu­la­tion is ma­nipu­la­tion of den­sity and cur­va­ture of the uni­verse by mov­ing large amounts of grav­i­ta­tional mass.

Con­trol over laws of physics (us­ing cal­ibrat­ing fields): One the­ory claims that the laws of physics, or at least some im­por­tant con­stants, were fixed shortly af­ter the Big Bang via the ran­dom break­down of some ini­tial quan­tum fields, called “cal­ibra­tion fields”. Now, it seems that this the­ory is be­ing re­placed by spon­ta­neous sym­me­try break­down in string M-the­ory (Susskind, 2003). Con­trol over such fields would provide con­trol over the ob­served phys­i­cal laws, and thus, the laws of na­ture.

Ex­ploit the na­ture of “ac­tu­al­ity”: Deter­mine the differ­ence be­tween ex­is­tence and non-ex­is­tence (Men­zel, 2017). Is modal re­al­ism true? What is the differ­ence be­tween ex­is­tence and pure pos­si­bil­ity?

Ex­ploit qualia and their in­de­struc­tibil­ity: Even if the ma­te­rial world is doomed, some “im­ma­te­rial” el­e­ments of it, such as qualia (and num­bers), are still in­de­struc­tible: the green color won’t stop be­ing green, even if ev­ery­thing stops ex­ist­ing.

Prevent de­liber­ate de­struc­tion of the uni­verse: Some form of an ul­ti­mate Dooms­day weapon (Kahn, 1959) is con­ceiv­able: a party cre­ates a “False Vacuum breaker” and uses it to black­mail all other par­ties in the uni­verse. While cre­at­ing such a “Death Star” weapon may be difficult, it is more prob­a­ble than the ran­dom cre­ation of false vac­uum de­cay (if our vac­uum is not very frag­ile). The logic of Dooms­day weapons is such that if more than one is cre­ated, they could be locked into some­thing like mu­tu­ally as­sured de­struc­tion (MAD), which makes their firing al­most in­evitable.

The ob­vi­ous con­di­tion for pre­vent­ing the end of the uni­verse is co­op­er­a­tion be­tween all sides: space wars (Tor­res, 2018), or just differ­ent ap­proaches to the sur­viv­ing the uni­verse, could make it less pos­si­ble, es­pe­cially if it re­quires mov­ing large masses, but not es­cap­ing into small black holes.

Prevent the heat death of the universe

Learn how to cre­ate en­ergy and mat­ter from vac­uum: The law of en­ergy con­ser­va­tion seems to be fun­da­men­tal, but there are still some con­tro­ver­sial ideas about gen­er­at­ing en­ergy from vac­uum, or other ways to vi­o­late this law.

Study and use the phys­i­cal prop­er­ties of vac­uum: Even if all mat­ter dis­solves, vac­uum will still ex­ist. It has non-zero en­ergy, all pos­si­ble things ap­pear as fluc­tu­a­tions, and there could be quan­tum space-time foam on the Planck level, as well as hid­den di­men­sions of space-time.

Rev­ersible com­pu­ta­tion and eter­nal com­put­ing us­ing eter­nal par­ti­cles: If some par­ti­cles could ex­ist for­ever, and if re­versible com­put­ing turns out to be pos­si­ble and use­ful, eter­nal com­pu­ta­tion could be pos­si­ble. How­ever, there are doubts that such com­pu­ta­tion will ac­tu­ally be use­ful, as it could be locked into in­escapable pat­terns. This is a start­ing point of the plot of Bax­ter’s novel “Man­i­fold: Time”; in that story, a civ­i­liza­tion reaches in­finite ex­is­tence in a re­versible com­puter at the end of times but is suffer­ing from the lack of new in­for­ma­tional in­puts.

“Geo­met­ric com­put­ers” which are us­ing the cur­va­ture of space-time for calcu­la­tions. In other words, they are us­ing grav­i­ta­tional waves in­ter­ac­tions to perform com­pu­ta­tion. Another idea in this style is that space-time it­self is a quan­tum cor­rect­ing code.

Un­der­stand­ing of the laws of physics as com­put­ing pro­cesses: Could take place in cer­tain en­vi­ron­ments (per­haps as cel­lu­lar au­tomata (Wolfram, 2002)) and in­volve elimi­na­tion of the bound­aries be­tween com­put­ers and phys­i­cal phe­nom­ena, as is as­sumed by the field of digi­tal physics (Wheeler, 2015).

Use of “naked sin­gu­lar­i­ties” as Omega points: ei­ther for com­pu­ta­tion, as bunkers against the de­struc­tion of the uni­verses, or as gates to new uni­verses.

• Change the ge­om­e­try of the Uni­verse and its cur­va­ture. The fu­ture of the uni­verse de­pends on its cur­va­ture, which is defined by the den­sity of mass in it ac­cord­ing to gen­eral rel­a­tivity. By mov­ing masses, we could change such den­sity at least in some re­gion of the uni­verse.

• Jump to eter­nal chaotic in­fla­tion level of (Linde, 1983), which, by defi­ni­tion, ex­ist for an in­finitely long time. This would in­volve sur­fing the wave of the in­fla­tion­ary field for eter­nal ex­is­tence.

3.4. Sur­vive the end of the Universe

Ex­treme mi­ni­a­tur­iza­tion: go to the Planck level (fem­totech­nol­ogy) via cre­ation smaller and smaller com­put­ers, on which hu­man minds will be up­loaded. The small­est ob­jects may be not af­fected by events at higher lev­els.

Ex­ploit the prop­er­ties of black holes (maybe they can sur­vive the end of the Uni­verse). There is a the­ory that some cur­rent black holes ap­peared be­fore the Big Bang dur­ing pre­vi­ous Big Crunch.

Create a new uni­verse with pre­defined prop­er­ties us­ing an ar­tifi­cial black hole, as was sug­gested by (Smolin, 1992). There should be a way to send a large amount of data to a new uni­verse (at least on the or­der of ter­abytes, the size nec­es­sary to trans­fer in­for­ma­tion about this civ­i­liza­tion’s ex­pe­riences). If there is a way to send such data to a new uni­verse, our uni­verse is un­likely to be the first, and we could find such data from pre­vi­ous uni­verses. One way to code the data is in the nu­mer­i­cal val­ues of di­men­sion­less con­stants or in the fluc­tu­a­tion of cos­mic back­ground noise. Find­ing such noise will be similar to find­ing a SETI sig­nal (which also in­cludes the cor­re­spond­ing risks of AI-virus at­tack, or at least the effects of a so­phis­ti­cated alien cul­ture on our naïve cul­ture (Turchin, 2018c)). To start an­other fe­cund uni­verse, in­stru­ments other than black holes may be more suit­able, like con­trol over cos­mic in­fla­tion and/​or ini­ti­at­ing false vac­uum de­cay.

Send in­for­ma­tion into the next uni­verse (in the cyclic model of the uni­verse) (Stein­hardt & Turok, 2002).

Create in­de­struc­tible par­ti­cles as com­po­nents for com­put­ers: Some par­ti­cles do not seem to have a half-life, like elec­trons, and thus could ex­ist for an in­finitely long time, at least un­til it in­ter­acts with its an­tipar­ti­cle.

Create a re­fuge in a bub­ble of curved space (per­haps in­side or near a black hole).

Travel at speeds above light speed. This will help us to reach re­mote re­gions of the uni­verse where more mat­ter could sur­vive or the end is not so nigh; al­ter­na­tively, the rel­a­tivis­tic slow­down of time in the star­ship may help some ob­jects sur­vive rel­a­tively longer, or could even re­sult in travel back in time.

There is no ex­act end date in the heat death sce­nario, so “sur­vival” is not ap­pli­ca­ble to that sce­nario.

3.5. Ma­nipu­late time

The end of the uni­verse is an in­evitable event in the fu­ture. Thus, es­cap­ing the fu­ture, by, say, trav­el­ling in or ma­nipu­lat­ing time, may help us to es­cape the event.

Time travel to the past to es­cape the end of the uni­verse: Per­haps via a sys­tem of worm­holes, one of which is mov­ing at near-light speed. Note that there is no need to send ac­tual star­ships or hu­man be­ings through the worm­hole: a small nanobot or “fem­to­bot” could be enough, or even an in­for­ma­tion pack­age. For ex­am­ple, if our cur­rent civ­i­liza­tion ob­serves that a re­mote “black hole” pro­duces re­peated flashes of light (like Morse code), we could down­load the mes­sage. Kar­da­shev spoke about this pos­si­bil­ity at the “SETI sem­i­nar” in Moscow in 2019 (Kar­da­shev, 2019).

A smaller size for this pack­age means much less en­ergy is needed to cre­ate the worm­hole, and such a probe would be much more re­silient than a larger one. Send­ing data to the past could cause a “grand­father para­dox” (a change in the past which makes a given fu­ture im­pos­si­ble), but if the probe is re­ally small, it could have a very small “foot­print”. It could be sent to the ear­lier uni­verse, closer to the Big Bang, where con­di­tions are more fa­vor­able for the cre­ation of worm­holes, but af­ter it will re­main in the “aes­ti­va­tion” to avoid caus­ing a grand­father para­dox.

Alter­na­tively, the probe’s goal could be to in­ten­tion­ally cause a grand­father para­dox, thus cre­at­ing an al­ter­na­tive branch of the uni­verse. This could be done again and again, ar­bi­trar­ily in­creas­ing the “sub­jec­tive time” of ex­is­tence. An ob­server would live many times from the be­gin­ning of the uni­verse to its end in some kind of loop (or “time-like curve”).

Go back in time (as de­scribed in Bax­ter’s novel “Man­i­fold: time” (Bax­ter, 2003)) and change the way we cope with the uni­verse’s end: Time travel could help us bet­ter pre­pare to the uni­verse’s end, as we could start prepar­ing from the be­gin­ning and know what to do. Even send­ing a small amount of in­for­ma­tion about the type of the end and the best pre­ven­tion strat­egy will be very helpful if it is sent far enough back in time.

Maybe it is easy to send data not to the pre­sent time, but into some ear­lier uni­verse, like shortly af­ter Big Bang. In that case, the data would need to be pre­served un­til “now” in a way that avoids the grand­father para­dox, via some form of aes­ti­va­tion. For ex­am­ple, time-trav­el­ling nanorobots from the fu­ture could have been pre­sent since the dawn of the uni­verse with­out demon­strat­ing their ex­is­tence, as that would pre­clude the for­ma­tion of life as we know it on Earth. When we are ready, they will show them­selves.

• Closed time-like curves: or use time loops for eter­nal ex­is­tence, ei­ther via time ma­chine or near a black hole’s event hori­zon.

Per­pen­dicu­lar time ar­row and other types of di­men­sions: There are phys­i­cal the­o­ries which as­sume the ex­is­tence of two-di­men­sional time (Bars, Tern­ing, & Nekoogar, 2010). A real-world ex­am­ple of two-di­men­sional time is the evolu­tion of a novel from one re­vi­sion to an­other by its au­thor. In that case, the in­ter­nal time of the nar­ra­tive is per­pen­dicu­lar to the time in which the writer makes changes. For ex­am­ple, “Anna Karen­ina” had 4 re­vi­sions by Tols­toy; in each, Anna changes (by be­com­ing a more beau­tiful woman). As the end of the uni­verse is an event in lin­ear time, mov­ing side­ways in the per­pen­dicu­lar time could help to es­cape it, or at least to “dis­solve” the event of “end­ing” (that is, de­scribe it on an­other lan­guage, where it is not the end). If there are other types of di­men­sions be­yond space and time, they could be also used to es­cape.

Move from “in­finity” to “eter­nity”: “un­time”. Un­time, or ex­is­tence with­out change, in­cludes such phe­nom­ena as a math­e­mat­i­cal uni­verse or pure qualia. As un­time is un­chang­ing, it can’t end, but it is very re­mote from what we could call hu­man life, if we don’t as­sume some illu­sion of change within it.

• A non­lin­ear ap­proach to time and ex­pe­rience: Ti­pler’s Omega point is an ex­am­ple of this ap­proach when an in­finite amount of ex­pe­rience is gen­er­ated dur­ing a finite time. Some peo­ple ex­per­i­ment­ing with psychedelics claim to be able to ex­pe­rience time di­la­tion or even a stop­page of time, which, of course, would not save them from the end of the uni­verse (or even per­sonal death), but could be an “in­tu­ition pump”—show­ing how an in­crease in the wide­ness and in­ten­sity of ex­pe­rience could al­low a higher net amount of ex­pe­rience to hap­pen in a finite time.

The non­lin­ear­ity of time may lead to time loops, in­ter­nal clock breaks, illu­sions of time­less­ness, and trav­els to per­pen­dicu­lar time.

Re­v­erse the ar­row of time: The fi­nal an­thropic prin­ci­ple, sug­gested by Ti­pler, states that the uni­verse is fine-tuned for hu­man ex­is­tence, as hu­mans are needed to sur­vive the end of the uni­verse. This as­sumes some form of retro­causal­ity, where the need to cre­ate Omega back-prop­a­gates to the past and en­sures hu­man ex­is­tence. This may seem out­landish, but the “or­di­nary” an­thropic prin­ci­ple looks ex­actly like this: the uni­verse is fine-tuned for our ex­is­tence and also it is fine-tuned to gen­er­ate hu­man ca­pa­bil­ity to think about an­thropic now (we could ob­serve only those uni­verses where we could think about an­thropic).

Another the­o­ret­i­cal ap­proach to re­vers­ing the ar­row of time is to cre­ate a state of mat­ter that performs com­pu­ta­tions not in the fu­ture, but in the past (es­pe­cially if the “past” is not un­equiv­o­cally defined). This seems to be pos­si­ble based on the time-sym­me­try of ba­sic quan­tum laws, but as the na­ture of the ar­row of time is not known, this ap­proach is still just hy­po­thet­i­cal.

Turn the ar­row of time back­wards: Be­sides a com­puter that runs back­wards in time, as dis­cussed above, more ad­vanced ideas may be re­lated to find­ing par­ti­cles, e.g. tachyons, which move back in time. If we could move back in time, we could post­pone en­coun­ters with catas­tro­phe.

Be­come ac­cel­er­ated up­loads that ex­pe­rience a tremen­dous (pos­si­bly in­finite) amount of ex­pe­riences in a finite time. Nat­u­ral “ac­cel­er­a­tion of time”—in the sense of the num­ber of events per time unit—is prob­a­bly hap­pen­ing around sin­gu­lar­i­ties in col­laps­ing black holes, and is as­sumed in Ti­pler’s Omega in the col­laps­ing uni­verse.

3.6. Dis­solv­ing the problem

Solve the prob­lem of the ori­gin of the uni­verse: learn how some­thing can arise from noth­ing and im­ple­ment this knowl­edge to cre­ate new uni­verses with de­signed prop­er­ties.

Prac­ti­cally prove the ex­is­tence of a benev­olent and eter­nal God: and/​or af­ter­life (or that we live in a com­puter simu­la­tion cre­ated by an ad­vanced civ­i­liza­tion).

Merge with the uni­verse: Reach some form of “prac­ti­cal pan­the­ism” where there are no bor­ders be­tween Self and the out­side world.

Find that the uni­verse is already im­mor­tal: Per­haps as a re­sult of alien ac­tivity.

Dis­cover we live in a simu­la­tion and find a way to per­suade its hosts not to dis­able it: Or make use of an eter­nal Ma­tryoshka simu­la­tion: an in­finite num­ber of hosts upon hosts. In an in­finite nested simu­la­tion, there is always an up­per level of ex­is­tence (Tor­res, 2014).

Real­ize hu­man po­ten­tial: Ex­pe­rience all pos­si­ble ex­pe­riences be­fore the end of the Uni­verse, as was sug­gested by Bostrom (Bostrom, 2003).

· Mo­dal re­al­ism: if ev­ery­thing pos­si­ble ac­tu­ally ex­ists, there is no “end”.

· Solve on­tol­ogy: neu­tral monism. Find some level of ex­is­tence where there is no differ­ence be­tween ob­jec­tive and sub­jec­tive. This is prob­a­bly the level of qualia.

· “The restau­rant at the end of the uni­verse” (Adams, 1978): ac­cept and cel­e­brate the end.

3.7. Meta-level solutions

Th­ese are solu­tions that do not spec­ify ways to sur­vive the end of the uni­verse but offer a cred­ible path to find­ing the solu­tion.

• Find new laws of physics. The end of the world—as well as new ways to pre­vent it—fol­lows from the known laws of physics.

• Create su­per­in­tel­li­gent AI and give it the task of find­ing a way to sur­vive the end of the uni­verse.

• Prevent col­lider ac­ci­dents which could cre­ate false vac­uum de­cay.

• Prove that we are in a simu­la­tion, pre­vent its ter­mi­na­tion, and move to the base re­al­ity level.

• Prove that the end is in ev­ery next sec­ond, and en­joy it. If I am a Boltz­mann brain (BB), I will dis­ap­pear in the next mo­ment, but the same situ­a­tion has hap­pened in all pre­vi­ous mo­ments I have an illu­sion of re­mem­ber­ing, and this is “ok” (Turchin & Yam­polskiy, 2019). There will be a next BB some­where that will have mem­o­ries of me now.

The rad­i­cal Dooms­day ar­gu­ment sug­gests the end is in the next mo­ment. It is as fol­lows:

As­sump­tion 1. If the Everettian mul­ti­verse ex­ists in the sense of the many-wor­lds in­ter­pre­ta­tion, the num­ber of sep­a­rate branches is grow­ing ex­po­nen­tially ev­ery sec­ond, pro­por­tional to the num­ber of ran­dom quan­tum events in the ob­serv­able uni­verse. As there are around 1080 el­e­men­tal par­ti­cles in the uni­verse, this means that the num­ber of branches is also grow­ing many or­ders of mag­ni­tude ev­ery sec­ond. Even if we count only differ­ent pos­si­ble next ex­pe­riences of an ob­server, the num­ber will be as­tro­nom­i­cal, as each differ­ent pixel in the vi­sual field could be counted as a sep­a­rate ob­server.

As­sump­tion 2. The prob­a­bil­ity of be­ing an ob­server de­pends only on the num­ber of ob­servers, but not of the mea­sure of an ob­server.

Con­clu­sion: In that case, a ran­dom ob­server will most likely find her­self near some cut-off mo­ment which is most likely to be the end of the uni­verse. For ex­am­ple, if the mul­ti­verse branches 1020 times ev­ery sec­ond, there will be 1020 of my copies in the last mo­ment of my ex­is­tence com­pared to just one a sec­ond ago. How­ever, if the end of the uni­verse, like false vac­uum de­cay, is it­self a prob­a­bil­is­tic pro­cess, even a high prob­a­bil­ity of it will be un­ob­serv­able: there could be some form of fine-tun­ing in which branch­ing and false vac­uum de­cay com­pletely com­pen­sate for each other. In other words, if there are 1020 braches ev­ery sec­ond, but the prob­a­bil­ity of the false vac­uum de­cay is 1020 to 1 ev­ery sec­ond, the to­tal num­ber of ob­servers will not change. More­over, the biggest num­ber of ob­servers in the uni­verse could be lo­cated in such fine-tun­ing re­gions, as the ap­pear­ance of a large num­ber of ob­servers ev­ery sec­ond will not ob­vi­ate the pos­si­bil­ity that a large num­ber will ap­pear in the next sec­ond. In such a case, all will even­tu­ally “add up to nor­mal­ity” as Yud­sowsky said.

Post­pone the end. Even if the end is in­evitable, maybe we could trade one type of end for an­other; for ex­am­ple, by ma­nipu­lat­ing dark en­ergy to es­cape the Big Rip and in­stead reach a heat death sce­nario, get­ting, say, 100 trillion years in­stead of 20 billion. Dur­ing these trillions of years, we could find new ways to post­pone the end, maybe us­ing en­ergy or the re­main­ing black holes to power our think­ing. So, we never ac­tu­ally solve the prob­lem, but just find ways to live longer; this is how things of­ten hap­pen in day-to-day life. Post­pon­ing the end might also give us time to find a per­ma­nent solu­tion.

• Alter­na­tive the­o­ries of re­al­ity, like a holo­graphic uni­verse (where the uni­verse could be com­pletely de­scribed by its bound­ary), can offer al­ter­na­tive ways to avoid the death of the uni­verse. A deeper study of fun­da­men­tal physics could help us to find new types of “ends” and new sur­vival strate­gies.

4. Prepar­ing for in­finite survival

4.1. Prevent­ing hu­man ex­tinc­tion be­fore the end of the universe

It seems rather triv­ial but worth men­tion­ing: if hu­man­ity (or our de­scen­dants in the form of up­loads and AI) goes ex­tinct be­fore the end of the uni­verse, we will not need ways to avoid such an end. How­ever, if su­per­in­tel­li­gent AI and nan­otech ap­pear, and hu­man­ity sur­vives most early risks con­nected with them, there will be rather ob­vi­ous ways of sur­vival for billions of years (e.g. Dyson spheres, von Neu­mann probes and space travel) (Bostrom, 2002). Space wars or some now-uni­mag­in­able catas­tro­phes could end hu­man­ity, even at such ad­vanced stages, but it seems less likely, as the size of the space it­self will pro­tect us (bar­ring situ­a­tions such as an ab­solute Dooms­day weapon, as dis­cussed above).

4.2. Choos­ing be­tween long and very long futures

There is an im­por­tant choice we must make be­fore the start of space coloniza­tion: what are our val­ues and what do we want to do with the uni­verse? If we send von Neu­mann probes (vNPs) in op­po­site di­rec­tions with near-light speed, it will be difficult to re­pro­gram them if our un­der­stand­ing about our goals changes. Thus, we need a bet­ter un­der­stand­ing of the fate of the uni­verse and our at­ti­tude to­ward it be­fore we start ir­re­versible coloniza­tion of its outer reaches.

This in­cludes an im­por­tant de­ci­sion: should we try to get most of the value from the ob­serv­able uni­verse and ac­cept its nat­u­ral end—or should we spent most of our re­sources on a risky bet with a very high pay­off: try to find the ways to sur­vive the end of the uni­verse.

4.3. Fight­ing cos­molog­i­cal uncertainty

To make this choice, we must solve “cos­molog­i­cal un­cer­tainty”, that is, learn with high cre­dence what will be the ac­tual end of the uni­verse, how much com­pu­ta­tion and star travel we can do be­fore it hap­pens, and what our best op­tions and chances to sur­vive it are. In a Wikipe­dia ar­ti­cle about un­solved prob­lems in physics, sev­eral dozen high-level ques­tions are posted, like why we have the ar­row of time, and what the cor­rect in­ter­pre­ta­tion of quan­tum me­chan­ics might be. It seems that most of these ques­tions will need to be an­swered be­fore we can know for sure which is the most prob­a­ble end of the uni­verse.

How long it will take to solve cos­molog­i­cal un­cer­tainty is not clear. Maybe su­per­in­tel­li­gent AI will ap­pear on a rel­a­tively short time scale of around 100 years and will be able to guess ev­ery­thing it needs to know from already available col­lider and space ob­ser­va­tion data, or quickly build in­stru­ments to gather data and de­velop an an­swer. In that case, the fi­nal fate of the uni­verse will be known in a few mil­len­nia.

Another pos­si­ble view is that we can’t learn much from lo­cal lev­els of en­ergy and will need very high-en­ergy ex­per­i­ments with Galac­tic-size ac­cel­er­a­tors or black holes. The rele­vant in­for­ma­tion about the type of the end is, per­haps, just not available here, and we will need to wait billions of years be­fore we can ob­serve small differ­ences in dark en­ergy changes. In that case, fight­ing cos­molog­i­cal un­cer­tainty will have a sig­nifi­cant op­por­tu­nity cost, as the later we start ir­re­versible space ex­plo­ra­tion, the smaller the area of the ob­serv­able uni­verse that will be un­der our con­trol. This would limit our abil­ity to cre­ate as­tro-en­g­ineer­ing con­struc­tions to fight the end.

The closer we are to the end of the uni­verse, the more cer­tain we will be re­gard­ing its na­ture and timing, but the less time we will have to pre­pare.

Also, para­dox­i­cally, to fight cos­molog­i­cal un­cer­tainty, we need larger and more so­phis­ti­cated phys­i­cal ex­per­i­ments, which, in turn, in­creases chances of false vac­uum de­cay or other types of catas­tro­phe.

4.5. Get­ting con­trol over large masses and energy

Some ideas about how to pre­vent the end of the uni­verse as­sume the need to move large amounts of mat­ter. For ex­am­ple, a large con­cen­tra­tion of mat­ter could change lo­cal cur­va­ture of space. There are some ideas about how to use Dyson spheres to ac­cel­er­ate stars, but this would be a very slow pro­cess (Loeb, 2018).

There is only a limited part of the ob­serv­able uni­verse which we could ever reach. There is an even smaller part within which effec­tive com­mu­ni­ca­tion with Earth is pos­si­ble (i.e. send­ing and re­ceiv­ing data a few times).

4.6. Prevent ac­ci­den­tal uni­verse destruction

There is a very small prob­a­bil­ity that we could de­stroy uni­verse even now by start­ing false vac­uum de­cay. Small black holes could be nu­cle­ation points of new vac­uum, and such small black holes could the­o­ret­i­cally ap­pear dur­ing ex­per­i­ments in a hadron col­lider. The re­cently dis­cov­ered Higgs bo­son’s mass range ren­ders the vac­uum de­cay hy­poth­e­sis more prob­a­ble; also, true vac­uum will not be like or­di­nary vac­uum, but will it­self grav­i­ta­tion­ally col­lapse (Elias-Miro et al., 2012; Mack, 2015). Ob­jec­tions of­ten re­fer to the fact that much more in­ten­sive col­li­sions are hap­pen­ing in the uni­verse all the time; how­ever, there are small differ­ences be­tween col­lider ex­per­i­ments and nat­u­ral col­li­sions: the prod­ucts of LHC col­li­sions have a small rel­a­tive speed to the Earth as op­po­site beams col­lide (Kent, 2004). As a re­sult, it is pos­si­ble small black holes could have the op­por­tu­nity to catch sur­round­ing atoms be­fore evap­o­rat­ing via Hawk­ing ra­di­a­tion and could start to grow.

Such a grow­ing black hole would even­tu­ally con­sume the Earth (as in David Brin’s novel Earth), but not im­me­di­ately, as the ac­cre­tion rate ini­tially could be very slow on the early stages. It may take years be­fore any ob­serv­able effects be­came ob­vi­ous (as the ac­cre­tion rate could be­come sta­ble on some lower level and the whole black hole will be just the size of a few atoms, sur­rounded by a pocket of hot gas and sit­ting some­where in the cen­ter of the Earth).

How­ever, such a small black hole could ex­ist long enough to make the ran­dom event of the false vac­uum de­cay more prob­a­ble (or maybe two such small black holes would need to col­lide) (Burda et al., 2015; Villa­toro, 2015).

5. Sur­vival strate­gies in re­la­tion to other ideas

5.1. Order of implementation

Prevent­ing the end of the uni­verse should con­cen­trate on differ­ent risks at differ­ent times.

1. False vac­uum. We need to min­imise the risk of false vac­uum de­cay, while si­mul­ta­neously get­ting more in­for­ma­tion about the na­ture of the uni­verse and re­duc­ing our cos­molog­i­cal un­cer­tainty. We should con­duct ex­per­i­ments about the na­ture of the uni­verse care­fully, as they them­selves may trig­ger false vac­uum de­cay or have other un­in­tended con­se­quences. Also, if ev­ery­thing pos­si­ble ac­tu­ally ex­ists, false vac­uum de­cay may be ex­actly com­pen­sated for by quan­tum im­mor­tal­ity, and thus will be an un­ob­serv­able and in­con­se­quen­tial event.

How­ever, if the speed of the false vac­uum bub­ble is a lit­tle bit be­low the speed of light, we could ob­serve the in­com­ing bub­ble. For ex­am­ple, if the bub­ble origi­nates 1 billion light-years from us and has the speed of 99.9 per cent of the speed of light, we would ob­serve and may be even be de­stroyed by the ra­di­a­tion of its do­main walls.

Bostrom and Teg­mark es­ti­mated that such type of catas­tro­phes has a prob­a­bil­ity be­low one per cent in a billion years based on some ob­ser­va­tion se­lec­tion effects: if they oc­curred more of­ten, we should find our­selves ear­lier in the timeline of our uni­verse (Teg­mark & Bostrom, 2005).

2. Big Rip. This risk could arise rel­a­tively soon, but not very soon: even in the case of very im­plau­si­ble val­ues of dark en­ergy, it is still 20 billion years from now.

3. Heat death is the most re­mote risk, and we have plenty of time to pre­pare for it.

5.2. Sur­viv­ing the end of the uni­verse and the mul­ti­ver­sal Fermi paradox

If there is a way to es­cape our uni­verse and to travel be­tween uni­verses, other civ­i­liza­tions from other uni­verses would be also ca­pa­ble of reach­ing our world—but where are they? Typ­i­cal ex­pla­na­tions of the Fermi para­dox do not work here, as mul­ti­verse (as much as we can guess any­thing about it) is al­most in­finite, ex­ist al­most for­ever, and thus the “rare Earth” or “uni­ver­sal ex­tinc­tion” hy­pothe­ses do not work here. This lack of the “in­ter­di­men­sional trav­el­lers” in the mul­ti­verse could be dubbed a mul­ti­ver­sal Fermi para­dox, more in (Turchin, 2018a).

Conclusion

In this ar­ti­cle, we pro­vided an overview of sev­eral dozens of ways to over­come pos­si­ble end­ings of the ob­serv­able uni­verse and the cor­re­spond­ing demise of our fu­ture civ­i­liza­tion. Differ­ent ideas are ap­pli­ca­ble to differ­ent types of pos­si­ble end­ings; how­ever, these ideas can be cat­e­go­rized into seven main groups: surf the wave, go to a par­allel world, pre­vent the end of the uni­verse, sur­vive the end of the uni­verse, ma­nipu­late time, dis­solve the prob­lem, meta-level solu­tions.

The fact that we could iden­tify so many ideas de­spite our early stage of un­der­stand­ing of the na­ture of the uni­verse may be cause for cau­tious op­ti­mism about the pos­si­bil­ity of such sur­vival.

More­over, if we will make ir­re­versible pivotal acts soon, which will define the shape of our civ­i­liza­tion, like start­ing space coloniza­tion by von Neu­mann Probes or defin­ing goal sys­tem of su­per­in­tel­li­gent AI-Sin­gle­ton, we should take into ac­count the need to sur­vive the end of the uni­verse and in­sert it into the goal sys­tem of such AI.

Liter­a­ture:

Adams, D. (1978). The Hitch­hiker’s Guide to the Galaxy. (Vol. 6). Pan Macmil­lan.

Arm­strong, S. (2018). Are you in a Boltz­mann simu­la­tion? - LessWrong 2.0. Retrieved Fe­bru­ary 4, 2019, from LessWrong web­site: https://​​www.less­wrong.com/​​posts/​​ygELzNSAF5nzLXD7j/​​are-you-in-a-boltz­mann-simulation

Arm­strong, Stu­art, & Sand­berg, A. (2013). Eter­nity in six hours: in­ter­galac­tic spread­ing of in­tel­li­gent life and sharp­en­ing the Fermi para­dox. Acta Astro­nau­tica, 89, 1–13.

Asi­mov, I. (1972). The Gods Them­selves. Spec­tra.

Bars, I., Tern­ing, J., & Nekoogar, F. (2010). Ex­tra di­men­sions in space and time. Springer.

Bax­ter, S. (2003). Man­i­fold: time (Vol. 1). Del Rey.

Bergström, L. (2012). Death and eter­nal re­cur­rence. The Oxford Hand­book of Philos­o­phy of Death.

Bor­tolotti, L., & Na­ga­sawa, Y. (2009). Im­mor­tal­ity Without Bore­dom. Ra­tio, 22(3), 261–277.

Bostrom, N. (2002). Ex­is­ten­tial risks: An­a­lyz­ing Hu­man Ex­tinc­tion Sce­nar­ios and Re­lated Hazards. Jour­nal of Evolu­tion and Tech­nol­ogy, Vol. 9, No. 1 (2002).

Bostrom, N. (2003). Astro­nom­i­cal waste: The op­por­tu­nity cost of de­layed tech­nolog­i­cal de­vel­op­ment. Utili­tas, 15(3), 308–314.

Bostrom, N. (2014). Su­per­in­tel­li­gence. Oxford: Oxford Univer­sity Press.

Bouh­madi-López, M., González-Díaz, P. F., & Martín-Moruno, P. (2008). Worse than a big rip? Physics Let­ters B, 659(1), 1–5. https://​​doi.org/​​10.1016/​​j.physletb.2007.10.079

Burda, P., Gre­gory, R., & Moss, I. (2015). Vacuum metasta­bil­ity with black holes. Jour­nal of High En­ergy Physics, 2015(8), 114. https://​​doi.org/​​10.1007/​​JHEP08(2015)114

Cald­well, R. R., Kamionkowski, M., & Wein­berg, N. N. (2003). Phan­tom En­ergy: Dark En­ergy with w < − 1 Causes a Cos­mic Dooms­day. Phys­i­cal Re­view Let­ters, 91(7), 713011–713014.

Ćirković, M. M., & Bostrom, N. (2000). Cos­molog­i­cal con­stant and the fi­nal an­thropic hy­poth­e­sis. Astro­physics and Space Science, 274(4), 675–687.

Deutsch, D. (2002). The struc­ture of the mul­ti­verse. Pro­ceed­ings of the Royal So­ciety of Lon­don A: Math­e­mat­i­cal, Phys­i­cal and Eng­ineer­ing Sciences, 458(2028), 2911–2923. https://​​doi.org/​​10.1098/​​rspa.2002.1015

Dvorsky, G. (2015). Will Our Descen­dants Sur­vive the Destruc­tion of the Uni­verse? Retrieved from https://​​io9.giz­modo.com/​​will-our-de­scen­dants-sur­vive-the-de­struc­tion-of-the-uni-1744169933

Dyson, F. J. (1979). Time with­out end: Physics and biol­ogy in an open uni­verse. Re­views of Modern Physics, 51(3), 447.

Egan, G. (1997). Di­as­pora. Le Bélial.

Egan, G. (2010). Per­mu­ta­tion city. Hachette UK.

Ein­stein, A., Podolsky, B., & Rosen, N. (1935). Can quan­tum-me­chan­i­cal de­scrip­tion of phys­i­cal re­al­ity be con­sid­ered com­plete? Phys­i­cal Re­view, 47(10), 777.

Elias-Miro, J., Espinosa, J. R., Giu­dice, G. F., Isi­dori, G., Riotto, A., & Stru­mia, A. (2012). Higgs mass im­pli­ca­tions on the sta­bil­ity of the elec­troweak vac­uum. Physics Let­ters B, 709(3), 222–228. https://​​doi.org/​​10.1016/​​j.physletb.2012.02.013

Ellis, G. F. R., & Coule, D. H. (1994). Life at the end of the uni­verse? Gen­eral Rel­a­tivity and Grav­i­ta­tion, 26(7), 731–739. https://​​doi.org/​​10.1007/​​BF02116959

Greene, P. (2018). The Ter­mi­na­tion Risks of Si­mu­la­tion Science. Erken­nt­nis, 1–21.

Grib­bin, J. (2010, Au­gust 31). Are we liv­ing in a de­signer uni­verse? Retrieved from https://​​www.tele­graph.co.uk/​​news/​​sci­ence/​​space/​​7972538/​​Are-we-liv­ing-in-a-de­signer-uni­verse.html

Hooper, D. (2018). Life Ver­sus Dark En­ergy: How An Ad­vanced Civ­i­liza­tion Could Re­sist the Ac­cel­er­at­ing Ex­pan­sion of the Uni­verse. ArXiv:1806.05203 [Astro-Ph, Physics:Physics]. Retrieved from http://​​arxiv.org/​​abs/​​1806.05203

Hossen­felder, S. (2019, Fe­bru­ary 13). Sabine Hossen­felder: Back­re­ac­tion: When grav­ity breaks down. Retrieved July 19, 2019, from Back­re­ac­tion web­site: https://​​back­re­ac­tion.blogspot.com/​​2019/​​02/​​when-grav­ity-breaks-down.html

Kahn, H. (1959). On ther­monu­clear war. Prince­ton Univer­sity Press.

Kar­da­shev, N. (2019). Kar­da­shev, 88, about Fermi para­dox in mul­ti­verse and worm­holes—YouTube. Retrieved from https://​​www.youtube.com/​​watch?v=Fj0QLW026yA&t=12s

Kent, A. (2004). A crit­i­cal look at risk as­sess­ments for global catas­tro­phes. Risk Anal­y­sis, 24(1), 157–68.

Krauss, L. M., & Dent, J. (2008). The Late Time Be­hav­ior of False Vacuum De­cay: Pos­si­ble Im­pli­ca­tions for Cos­mol­ogy and Me­tastable In­flat­ing States. Phys­i­cal Re­view Let­ters, 100(17). https://​​doi.org/​​10.1103/​​PhysRevLett.100.171301

Lem, S. (1999). A perfect vac­uum. North­west­ern Univer­sity Press.

Linde, A. D. (1983). Chaotic in­fla­tion. Physics Let­ters B, 129(3–4), 177–181.

Loeb, A. (2018). Se­cur­ing Fuel for Our Frigid Cos­mic Fu­ture. ArXiv Preprint ArXiv:1806.07170.

Loew, C. (2017). Boltz­man­nian Im­mor­tal­ity. Erken­nt­nis, 82(4), 761–776.

Mac­cone, C. (2000). SETI via worm­holes. Acta Astro­nau­tica, 46(10–12), 633–639.

Mack, K. (2015). Vacuum de­cay: the ul­ti­mate catas­tro­phe. Cos­mos Magaz­ine. Retrieved from https://​​cos­mos­magaz­ine.com/​​physics/​​vac­uum-de­cay-ul­ti­mate-catastrophe

Men­zel, C. (2017). Ac­tu­al­ism. In E. N. Zalta (Ed.), The Stan­ford En­cy­clo­pe­dia of Philos­o­phy (2014th ed.). Retrieved from https://​​plato.stan­ford.edu/​​archives/​​win2017/​​en­tries/​​ac­tu­al­ism/​​

Muel­ler, M. P. (2017). Law with­out law: from ob­server states to physics via al­gorith­mic in­for­ma­tion the­ory. ArXiv:1712.01826 [Physics, Physics:Quant-Ph]. Retrieved from http://​​arxiv.org/​​abs/​​1712.01826

Niet­zsche, F. (1883). Thus spoke zarathus­tra. Jester House Pub­lish­ing.

Sand­berg, A., Arm­strong, S., & Cirkovic, M. M. (2017). That is not dead which can eter­nal lie: the aes­ti­va­tion hy­poth­e­sis for re­solv­ing Fermi’s para­dox. ArXiv Preprint ArXiv:1705.03394.

Smolin, L. (1992). Did the uni­verse evolve? Clas­si­cal and Quan­tum Grav­ity, 9(1), 173.

Stein­hardt, P. J., & Turok, N. (2002). Cos­mic evolu­tion in a cyclic uni­verse. Phys­i­cal Re­view D, 65(12), 126003.

Susskind, L. (2003). The An­thropic Land­scape of String The­ory. ArXiv:Hep-Th/​0302219. Retrieved from http://​​arxiv.org/​​abs/​​hep-th/​​0302219

Teg­mark, M. (2014). Our Math­e­mat­i­cal Uni­verse: My Quest for the Ul­ti­mate Na­ture of Real­ity (1st edi­tion). New York: Knopf.

Teg­mark, Max, & Bostrom, N. (2005). How un­likely is a dooms­day catas­tro­phe? (Vol. 438). Retrieved from https://​​arxiv.org/​​abs/​​as­tro-ph/​​0512204

Ti­pler, F. J. (1997). The physics of im­mor­tal­ity: Modern cos­mol­ogy, God, and the re­s­ur­rec­tion.

Tor­res, P. (2014). Why Run­ning Si­mu­la­tions May Mean the End is Near. Retrieved from https://​​ieet.org/​​in­dex.php/​​IEET2/​​more/​​tor­res20141103

Tor­res, Phil. (2018). Space Coloniza­tion and Suffer­ing Risks: Re­assess­ing the “Max­ipok Rule.” Fu­tures.

Turchin, A. (2018a). “Cheat­ing Death in Da­m­as­cus” Solu­tion to the Fermi Para­dox. Retrieved Au­gust 19, 2018, from LessWrong web­site: https://​​www.less­wrong.com/​​posts/​​R9javXN9BN5nXWHZx/​​cheat­ing-death-in-dam­as­cus-solu­tion-to-the-fermi-paradox

Turchin, A. (2018b). For­ever and Again: Ne­c­es­sary Con­di­tions for the “Quan­tum Im­mor­tal­ity” and its Prac­ti­cal Im­pli­ca­tions.

Turchin, A. (2018c). The Risks Con­nected with Pos­si­bil­ity of Find­ing Alien AI Code Dur­ing SETI. Jour­nal of Bri­tish In­ter­plane­tary So­ciety, 70.

Turchin, A., & Yam­polskiy, R. (2019). Types of Boltz­mann brains. Retrieved from https://​​philpa­pers.org/​​rec/​​TURTOB-2

Turchin, A., Yam­polskiy, R., Denken­berger, D., & Batin, M. (2019). Si­mu­la­tion Ty­pol­ogy and Ter­mi­na­tion Risks.

Villa­toro, F. (2015, Septem­ber 23). Micro black holes are seeds of vac­uum in­sta­bil­ity. Retrieved July 22, 2019, from Map­ping Ig­no­rance web­site: https://​​map­pingig­no­rance.org/​​2015/​​09/​​23/​​micro-black-holes-are-seeds-of-vac­uum-in­sta­bil­ity/​​

Wheeler, J.A. (2015). It From Bit or Bit From It?: On Physics and In­for­ma­tion (2015 edi­tion; A. Aguirre, B. Foster, & Z. Mer­ali, Eds.). New York, NY: Springer.

Wheeler, John A. (1990). In­for­ma­tion, physics, quan­tum: The search for links. Com­plex­ity, En­tropy, and the Physics of In­for­ma­tion, 8.

Wolfram, S. (2002). A New Kind of Science. May, 14.