15 July 2015

Great Filters: the Limits of Future Life

The concept of the Great Filter was introduced by Robin Hanson. According to it, the Fermi-paradox can be explained by the existence of a barrier that usually prevents the dead matter to become living and/or intelligent and albeit we were able to overcome it, the other candidates for either life or thinking wasn’t lucky/smart enough to get over it. In short: there are some factors that work against the living/intelligent beings.
Of course, it is only a theory and there are other, possible explanations for the “Great Silence” (=our missing “companion intelligences” in the Universe). For example: a low probability of life; or our inability to detect their signs; or we are the first intelligent races so it is not a surprise not to observe other intelligences in our light cone.
But we could adapt this Great Filter hypothesis for the future. Fred C. Adams (Long-term astrophysical processes, in: Global Catastrophic Risks, 2008) draws up our Universe’s very distant future up to 10^100 ears and regarding the survival of life, there are some fundamental turning points in the distant future of the Universe.
The first one is about the survuval of the earthly life. Our planet will be uninhabitable for an intelligent being within a 0.9 – 1.5 billion year and the biosphere will be “essentially sterilized in about 5.5 billion years” by the Sun. Notice that our environment in the Planetary System is not too life-friendly: a smaller start with 10% mass of the Sun would shine for trillion years (p. 44–46.). Regarding our actual knowledge about the pace of our human races’ technological developments, it seems to be possible to circumvent these problems–e.g. by migrating to another star.
The second barrier is more problematic. About 10^40 years later, because of the proton decay the matter in its traditional form will disappear and it means the “life as we know it”. (p. 47.)
It seems to be a serious “Great Filter” regarding the future of life and it would be a real challenge to find a solution which would be able to guarantee the survival of the life in this radically different physical environment. Of course, 10^40 year seem to be an unimaginably long time–but notice that it is not the end of the history of our Universe. The remains of the earlier era: the last black holes will be evaporated within a 10^100 years and only after it begins that epoch when “predictions of the physical universe begin to lose focus”. (p. 49.)
In other worlds: the living period (its end will be caused by the baryon decay) is like a phenomenon disappearing after the first trillionth – trillionth – trillionth… second of the Big Bang.  A 10^40 years are simply negligible to the remaining period of time.
So it isn’t evident to argue that the “aim” of our whole Universe is that momentary phenomenon of life. However, the final conclusion of the Strong Anthropic Principle is that the appearance of life is a necessity. But why not, for example, the black holes?
So we have two choices. We can either refuse the Strong Anthropic Principle as a ridiculous and flawed theory (and I tend to do it) or we can ask how it would be possible for the future life to survive these two Great Filters: the baryon and the black hole barriers–and it is a really exciting question.

10 July 2015

To Destroy Literally Everything

According to Evgeny Morozov, there are two kinds of walls: stone walls and virtual firewalls (The Net Delusion, 2011, p. 45.). Regarding the previous one, it is hard to build, but relatively easy to destroy. A house of cards is an extreme example of it: difficult to create and easy to ruin. Opposite to it, it is relatively simple to build (to write) a firewall, but it is impossible (or, at least, almost impossible) to destroy if you don’t have a physical access to the computer which runs it. This is because both the stone wall builder and invader act on the same level: on the level where the wall itself exist. Opposite to it, a firewall attacker has to work on the level of the actual system, while the programmer creator constructs the firewall from a “higher level” or, if you prefer, from an external point. Notice that some there are “harder to ruin than to build” systems can exist in the physical reality, as well: e.g. the pro WWII French Maginot Line of a concrete fortification system is such a construction. But the two level nature of firewalls is more important from our point of view, so it shall be used as a metaphor. Applying this wall approach to our Universe, it is obvious that a house of cards world unsuitable either for life or intelligence since it is too sensitive to any disturbance: We can imagine a multiverse with continuously appearing and promptly disappearing cosmoi. This multiverse differs from ours: Edward Teller was afraid during the WWII that an exploding hydrogen bomb, because of the extremely high temperatures, would destroy the whole Earth, but we don’t have neither weapons to ruin our planet, nor our Universe even today (opposite to the alarm bells in connection with the possible dangers of the CERN’s supposed miniature, artificial black holes). Namely, the physical system of our world seems to be both intelligence and technology proof (and at least to a certain level seem to be even foolproof). It can be imaginable a universe which is vulnerable even to a relative low level technology. It was a popular belief in the cold war era that the answer for the Fermi paradox was that every alien civilization perished because of the nuclear weapons. This scenario is adaptable in a slightly modified form for a cosmic level supposing that the stability of the physics of different universes are different. Traditionally the end of a universe is interpreted as a “matter of fact” question, but from our point of view it, can be interpreted as a version of Anthropic Principle where the level of technical development is correlated with the physical laws’ strength to determine the whole universe’s fate. Of course, it is not known whether our world’s relative long existence is a result of only a stone wall style stability and it wouldn’t be too difficult to ruin this using a near-future technology. Or, we live in a firewall style world where we can act only under the level of physics. In this case we can destroy the physically existing Universe at most: Writing about Global Catastrophic Risks, Nick Bostrom and Milan Cirkovic discuss “only” the possibility of a disaster destroying “the potential of our future light cone of universe to produce intelligent… beings" (2008, p. 2–3.).
It would be even more fatal to create a super bomb–e.g. an artificial black hole–which can destroy everything but keeps intact the laws of physics. But this not the end of the possibilieties since it is imaginable that we could destroy somehow not only the physically existing Universe but the physical laws themselves too.

02 July 2015

Existing, non-existing and other universes

“According to modal realism, possible worlds really exist” writes Jennifer Fisher in his book On Philosophy of Logic (p. 91.). This approach is based on modal logic that interprets true and false statements in relation to possible worlds: E.g. necessity means that the statement “is true in all possible words” (Ibid, p. 75.) and our actual world is nothing more than a world which was chosen from the set of other, existing ones. I don’t accept modal realism’s logic (after all, possibility isn’t equal to existence), but it is interesting from our point of view that the logic of modal worlds is similar to the logic of classic multiverse hypothesis that assumes the existence infinitely many words and this similarity shall lead us to a strange type of imaginable universes.
Max Tegmark interprets the multiverse as the manifestation of every mathematically possible world. It is a form of mathematical Platonism, and the main thesis is that on the one hand, anything is possible mathematically exists in reality. On the other hand, everything is governed by the rules of mathematics. “Mathematical” means in this case that every combination of different sets of physical laws and constants, or even different equations exist. In other words: according to Tegmark, all words can be described by mathematics and every imaginable combination is manifested in a really existing world. The core of Tegmark’s concept is that mathematics is equal to physics in a certain sense, since it describes the world ruled by physical laws.
But it is not sure that even our universe can be described perfectly by mathematics and perhaps only our belief suggests that every natural phenomenon is controlled by either deterministic, or probability or evolutionary laws. Inter alia, it is possible that the Great Unified Theory (GUT) doesn’t exist, since there is no mathematics to describe every connection. It is perhaps only about our inability to give a coherent description about reality, since our tools (including our minds, mathematics and logic) aren’t appropriate for it.
Or, it is imaginable that there are universes that cannot be described by mathematics at all: after all, mathematics is based on the presumption of the conservation of some rules. Thus, it is not necessarily well-founded to state that every universe is mathematical in nature. So we can imagine whole universes (albeit they wouldn’t be biofil) without mathematically interpretable natural laws. In other words: although they exist, they cannot be described by one or other mathematical form of physical laws.
Traditionally, we distinguish existing and non-existing worlds and the main sin of modal realism is that it intermixes these two categories. Now we can introduce a third kind of universes which differ from both the “existing” and “non-existing” ones and since per definitionem it is impossible to give a scientific description about their features, they don’t belong to the realm of physics.