Kurzgesagt – In a Nutshell
Sources - Alien Empire Ocean
We are grateful to Dr. Caleb Scharf (NASA Ames Research Center) for his critical reading of the script and input.
This script is mainly based on the following publication that he coauthored:
#Jonathan Carroll-Nellenback, Adam Frank, Jason Wright and Caleb Scharf. The Fermi Paradox and the Aurora Effect: Exo-civilization Settlement, Expansion, and Steady States. 2019.
https://iopscience.iop.org/article/10.3847/1538-3881/ab31a3/pdf
– While the milky way is ancient and gigantic, even traveling at 10% the speed of light any civilizations could take over the whole galaxy within a million years.
Traveling at one tenth of the speed of light across the galaxy, it would take ten times longer to cross its diameter of 100,000 light years, 10 x 100,000 = 1,000,000 light years.
#Goddard Space Flight Center. The Milky Way Galaxy. Retrieved Jan 2024.
https://imagine.gsfc.nasa.gov/science/featured_science/milkyway/
Quote: “The Milky Way is approximately 100,000 light-years in diameter.”
– But we haven’t seen anybody yet. So it would seem that we are alone in the milky way. But this idea is built on a lot of assumptions. Usually when scientists speculate where all the alien civilizations are, they assume technology will progress to a point where colonizing all of space becomes kind of easy.
In this video, we explore another solution to the Fermi Paradox, to the famous question that if there are many potentially habitable planets and therefore a high chance of life flourishing elsewhere in the universe, then why haven't we seen them or any of their traces. Undoubtedly, the question has been around way longer than that, but since its conception in the 50s, it intrigued many scientists. This scientific curiosity led to more formal explorations of the problem and more scientific speculations. The first formal description was laid out by Hart in his 1975 paper and there he went through the alternative explanations for our seemingly eerie loneliness in the universe:
#Micheal Hart. An Explanation for the Absence of Extraterrestrials on Earth. 1975.
https://articles.adsabs.harvard.edu/pdf/1975QJRAS..16..128H
Quote: “We observe that no intelligent beings from outer space are now present on Earth. It is suggested that this fact can best be explained by the hypothesis that there are no other advanced civilizations in our Galaxy. Reasons are given for rejecting all alternative explanations of the absence of extraterrestrials from Earth.”
And not everyone was satisfied with the conclusion that the absence of extraterrestrial intelligence is because of their inexistence. Since then many different explanations came by, which are also neatly summarized in the Introduction section of the main paper we used for this script. It is cited at the top of the document.
We have tackled this topic a few times before with different approaches. If you want to get a more fun reminder on the basics of the Fermi Paradox though, you can refer to the following videos:
Kurzgesagt Fermi Paradox I
https://www.youtube.com/watch?v=sNhhvQGsMEc
Kurzgesagt Fermi Paradox II
https://www.youtube.com/watch?v=1fQkVqno-uI
– Oceania is a region with tens of thousands of islands scattered across millions of square kilometers, separated by an unforgiving, deadly sea. Kind of like a galaxy.
#Britannica. Oceania. 2023.
https://www.britannica.com/place/Oceania-region-Pacific-Ocean
Quote: “Oceania, collective name for the islands scattered throughout most of the Pacific Ocean. The term, in its widest sense, embraces the entire insular region between Asia and the Americas. A more common definition excludes the Ryukyu, Kuril, and Aleutian islands and the Japan archipelago. The most popular usage delimits Oceania further by eliminating Indonesia, Taiwan, and the Philippines, because the peoples and cultures of those islands are more closely related historically to the Asian mainland. Oceania then, in its most restricted meaning, includes more than 10,000 islands, with a total land area (excluding Australia, but including Papua New Guinea and New Zealand) of approximately 317,700 square miles (822,800 square km).
Oceania has traditionally been divided into four parts: Australasia (Australia and New Zealand), Melanesia, Micronesia, and Polynesia. As recently as 33,000 years ago no human beings lived in the region, except in Australasia. Although disagreeing on details, scientists generally support a theory that calls for a Southeast Asian origin of island peoples.”
– Some 5000 years ago the first people set out to colonize oceania.
The settlement of the pacific islands is a topic on its own and there are still many unknowns regarding the exact timing of the human dispersal and settlement in the region. Since we have very limited archeological evidence, scientists turned to genomic studies to figure out the pattern of human movements in the region. There are competing hypotheses but we stick to the following paper that the East Asian ancestors of pacific populations started out of Taiwan 5000 years ago.
#Peter J. Sheppard. Lapita Colonization across the Near/Remote Oceania Boundary. 2011.
https://www.jstor.org/stable/10.1086/662201
Quote: “Linguistic data indicate that speakers of Proto-Austronesian originated in East or Southeast Asia, perhaps some 5,000– 6,000 years ago (Pawley and Ross 1993). Most recently, Gray, Drummond, and Greenhill (2009), using a phylogenetic approach, have replicated the standard historical linguistic model and placed the origin of Austronesian in Taiwan circa 5230 BP. It is argued that the spread of Austronesian, by either migration of speakers or language shift, was fueled by development of agriculture and Neolithic technology (Bellwood 1991; Diamond and Bellwood 2003), although this association
has been challenged, most recently by Donohue and Denham (2010). ”
#Choin, J., Mendoza-Revilla, J., Arauna, L.R. et al. Genomic insights into population history and biological adaptation in Oceania. 2021.
https://www.nature.com/articles/s41586-021-03236-5
Quote: “The Pacific region is of major importance for addressing questions regarding human dispersals, interactions with archaic hominins and natural selection processes1. However, the demographic and adaptive history of Oceanian populations remains largely uncharacterized. Here we report high-coverage genomes of 317 individuals from 20 populations from the Pacific region. We find that the ancestors of Papuan-related (‘Near Oceanian’) groups underwent a strong bottleneck before the settlement of the region, and separated around 20,000–40,000 years ago. We infer that the East Asian ancestors of Pacific populations may have diverged from Taiwanese Indigenous peoples before the Neolithic expansion, which is thought to have started from Taiwan around 5,000 years ago2,3,4. Additionally, this dispersal was not followed by an immediate, single admixture event with Near Oceanian populations, but involved recurrent episodes of genetic interactions.”
#Skoglund et al. Ancient Genomics and the Peopling of the Southwest Pacific. 2016.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5515717/pdf/nihms862743.pdf
Quote: “Pacific islanders today derive from a mixture of two highly divergent ancestral populations3 . One arrived in island southeast Asia more than 40,000 years before present (BP), and contributed to the ancestry of both indigenous Australians and Papuans, and hence to other Pacific islanders4.
The second ancestral population is more closely related to mainland East Asians4, and is not found in unadmixed form today. The first humans to reach Remote Oceania—a term we use to refer to the region unoccupied prior to ~3,000 BP beyond the main Solomon Islands and in this case excluding Micronesia—were associated with the Lapita culture that spans 3,450-3,250 to 2,700-2,500 BP. These people spread into Remote Oceania using the first boats capable of long-distance sea travel, introduced new domesticated animals and plants, and their successors reached the most isolated islands of the eastern and southern Pacific by 1,000-700 BP6.”
#Anderson and O'Connor. Indo-Pacific Migration and Colonization Introduction. 2008.
Quote: “UNDERSTANDING OF INDO-PACIFIC PREHISTORY during the late Holocene is changing continually and no more so than in thinking about issues of migration and colonization. These can be regarded as the mobile and relatively sessile phases
respectively of initial or later human settlement in oceanic landscapes. The IndoPacific region comprises Island Southeast Asia (ISEA), Australia, and the Oceanic islands, to which are added the remote outlier ofMadagascar. In Indo-Pacific prehistory, especially within the last 5000 years, the movement of populations by voyaging, coastally and across sea-gaps of up to several thousand kilometers, is perhaps the most notable feature and the most influential in shaping the geography of human prehistory. The repeated creation and development of new societies and interactive networks, the introduction of plants, animals, and productive systems, the advent of new technologies, and the anthropogenic impact upon island environments are integrally related consequences of maritime colonization.”
– Especially the Polynesians achieved mind blowing feats. Without any modern technology they set out into the vast nothingness hoping to find a new island to claim or like, die far from home.
The islands across Polynesia were settled through a series of extraordinary travels on an ocean spanning almost one third of the Earth. Even though there are competing hypotheses on the origins of Polynesians and the exact timings of their settlements across the sequence of islands, the feats they achieved are uncontested. They reached out to the last habitable places on our planet without tools like compass, or big ships.
#Ioannidis AG et al. Paths and timings of the peopling of Polynesia inferred from genomic networks. 2021.
Quote: “The Polynesians are predominantly descended from Austronesian-speaking voyagers17 who trace their linguistic origins to Taiwan;9 their ancestral expansion is thought to have proceeded into Island Southeast Asia and eventually out into the Pacific19. The Austronesian-speaking settlers of the western Pacific (Fiji, Tonga and Samoa) went on to people the widely dispersed islands in the vast ocean to their east through extraordinary voyages of exploration and settlement2,20. Historians believe that family groups of 30–200 individuals sailed in double-hulled canoes across thousands of kilometres of open ocean to inhabit each new Polynesian island group21,22. The first arrivals to these isolated island groups are thought to have experienced rapid initial growth, driven by the abundant resources of unfished reefs, huge seabird colonies and flightless birds (that soon became extinct) unhabituated to humans2,7,22–25. These rapidly expanding island populations then initiated new voyages of exploration in search of— according to some theories—further untapped resources26, a model supported by early oral histories27. Geological analyses of Polynesian trade goods, particularly adzes, indicate that the remote Polynesian islands remained in trade contact with one another for several centuries26,28,29. However, these contacts were necessarily limited in frequency by the vast distances between island groups and limited in size by the capacities of the double-hulled sailing canoes21.”
#Exploratorium. What is Polynesia? Retrieved January 2024.
https://www.exploratorium.edu/never-lost/origins/what-polynesia
Quote: “Polynesia—from the Greek for "many islands"—is a collection of over 1,000 islands strewn over a broad region of the Pacific Ocean known as the Polynesian triangle.
Bounded by (and including) Hawai'i to the north, Easter Island to the southeast, and New Zealand to the southwest, the vast Polynesian triangle covers an area equivalent to North and South America combined. The land mass of Polynesia is puny by comparison: all the Polynesian islands stuck together would cover an area only about a third the size of New York state.
[...]
Polynesia was first populated some 3,000 years ago, when a people known as the Lapita journeyed eastward from New Guinea, arriving first in Tonga and Samoa. There, in what's known as the "Cradle of Polynesia," a distinctly Polynesian culture developed over the course of a thousand years. Roughly 2,000 years ago, these Polynesians journeyed across thousands of miles of deep ocean to populate the Cook Islands, the Marquesas Islands, French Polynesia, Hawai'i, Easter Island, and finally, New Zealand.
Early Polynesians probably journeyed all the way across the Pacific to South America. That's the only ready explanation for the presence all across Polynesia of sweet potatoes, which hail from South America. Further evidence: Throughout Polynesia the word used for sweet potato is kumara—the same word used by the Peruvian Indians in South America.”
#World Regional Geography. Pacific Islands. Retrieved January 2024.
https://open.lib.umn.edu/worldgeography/chapter/13-1-the-pacific-islands/
Quote: “The largest region of the Pacific is Polynesia, a land of many island groups with large distances between them. The root word poly means “many.” Numerous groups of islands have come together under separate political arrangements. The region includes the Hawaiian Islands in the north and the Pitcairn Islands and Easter Island to the east. New Zealand is now studied as a part of the Austral realm, but the Maori living there are originally from Polynesia. Polynesia has a mixture of island types ranging from the high mountains of Hawaii, which are more than 13,800 feet, to low-lying coral atolls that are only a few feet above sea level. Islands that have enough elevation to condense moisture from the clouds receive adequate precipitation, but many islands with low elevations have a shortage of fresh water, making habitation or human development difficult.”
Apart from cultural and linguistic comparisons across the islands and debated archeological findings, one way to trace the voyages of Polynesians is to track the DNA samples they left behind. Recently there have been genomic studies trying to figure out the origins of Polynesians as well as the timing sequence of their settlement. Findings point to a start in west Pacific in Samoa, onto Cook Islands in the 9th century, the Society Islands by 11th century ad Tuha’a Pae Islands and Tuamotu Archipelago in the 12th century. Though their settlement probably was not a linear process, hopping from one island onto the other, leaving all behind. There had been interisland connections in East Polynesia. OR they passed by some islands on the way to further east but didn’t settle them until centuries later.
#Ioannidis AG et al. Paths and timings of the peopling of Polynesia inferred from genomic networks. 2021.
Quote: “Our reconstruction of the branching Polynesian migration sequence reveals a serial founder expansion, characterized by directional loss of variants, that originated in Samoa and spread first through the Cook Islands (Rarotonga), then to the Society (Tōtaiete mā) Islands (11th century), the western Austral (Tuha’a Pae) Islands and Tuāmotu Archipelago (12th century), and finally to the widely separated, but genetically connected, megalithic statue-building cultures of the Marquesas (Te Henua ‘Enana) Islands in the north, Raivavae in the south, and Easter Island (Rapa Nui), the easternmost of the Polynesian islands, settled in approximately 1200 via Mangareva.”
They were traveling by double hulled canoes characteristic to Polynesia, probably in small groups of a few dozen people at a time.
#Museum of New Zealand The Papa Tongarewa. Pacific canoes. Retrieved January 2024.
https://collections.tepapa.govt.nz/topic/2354
Quote: “To explore the Pacific, early voyagers needed canoes that were strong and seaworthy. Today these are called vaka, va‘a, waka, or wa‘a – depending on where in Polynesia you are.
The first Europeans who ventured into the Pacific marvelled at the skill with which these canoes were made.
The range of designs and building methods was vast. In double-hulled canoes, the two hulls were joined together by booms and a decking. Outriggers had just one hull and a float attached to it by two or more booms. Some canoes had hulls built from planks, while others had ‘dugout’ hulls made from hollowed-out tree trunks.
The earliest Polynesian canoes were ‘tacking canoes’. Like modern yachts, they had a specific bow (front) and stern (back). But later, probably influenced by Micronesian boat builders, some Polynesians made ‘shunting canoes’, where either end could be the bow.”
The earliest archeological findings of the canoes date back to the 14th century, the Anaweka waka (canoe) . From the bits they could find, researchers reconstructed how it might have looked like.
#Johns et al. An early sophisticated East Polynesian voyaging canoe discovered on New Zealand's coast. 2014.
https://www.pnas.org/doi/full/10.1073/pnas.1408491111
Quote: “The colonization of the islands of East Polynesia was a remarkable episode in the history of human migration and seafaring. We report on an ocean-sailing canoe dating from close to that time. A large section of a complex composite canoe was discovered recently at Anaweka on the New Zealand coast. The canoe dates to approximately A.D. 1400 and was contemporary with continuing interisland voyaging. It was built in New Zealand as an early adaptation to a new environment, and a sea turtle carved on its hull makes symbolic connections with wider Polynesian culture and art. We describe the find and identify and radiocarbon date the construction materials. We present a reconstruction of the whole canoe and compare it to another early canoe previously discovered in the Society Islands.”
– But most of the pacific islands are merely a few wet rocks or corrals, maybe some palm trees and if you are lucky, birds making a pit stop. Others with more vegetation are often hostile, lacking the resources to really sustain a lot of people and remain uninhabited even today.
There are 25,000 islands scattered on the Pacific. There are high islands (also known as volcanic islands), which emerged due accumulation of material from volcanic eruptions over time, like Hawaiin group of islands. High islands can be as tiny as a square km but in total they account for almost 40 percent of the islands in pacific. Melanesia has a lot of these islands since it is sitting on the Ring of Fire. There are low islands (also known as coral islands), barely above sea level and surrounded by a lagoon. Whe low islands encircle a lagoon, then it is called an atoll. For example, Kiribati has 32 atolls and a raised coral island, Banaba. Polynesia and Micronesia have a lot of these low islands. And there are also continental islands like Australia and Zealandia, that were attached to continents once but sea-level changes and tectonic activity isolated them.
High islands tend to have more fertile land, material to make tools, fresh water but they are mostly mountainous with different levels of elevation which makes it difficult to settle. Also, there can still be volcanic activity on the island, or harsh weather conditions like hurricanes or sea level changes can hinder long term settlement.
#A DigitalNZ Story by National Library Services to Schools. Geography And Geology Of The Pacific. Retrieved Jan 2024.
https://digitalnz.org/stories/5e5c3fc5220a7a00097daf0f
Quote: “Mostly below the Equator, there are more than 25,000 islands in the Pacific region. This story looks at the geography and geology of these landforms as well as the ocean they are part of.”
In the following you can find brief information about individual conditions and challenges for each type of island with examples.
#Museum of New Zealand. Tokelau: three low coral atolls. Retrieved Jan 2024.
https://collections.tepapa.govt.nz/topic/2352
Quote: “What is a low coral atoll?
A low coral atoll is formed from a coral reef that has grown on top of a submerged volcano. The actual land rises only a few metres above sea level. This land consists of sand and coral that has built up on the surface of the reef. The three main islands of Tokelau all sit on extinct volcanic peaks.
Food and water on Tokelau
Low coral atolls like Tokelau have no surface fresh water. The people had to dig wells to a lens-shaped natural reservoir of fresh water trapped beneath the sand. This precious resource is replenished by rain.
For food, Tokelauans in earlier times depended on the native pandanus and coconut trees, as well as introduced plants such as swamp taro (which they grew in ponds dug down to the freshwater level) and breadfruit. Marine resources were also vital.”
#Museum of New Zealand. Samoa: a group of high volcanic islands. Retrieved Jan 2024.
https://collections.tepapa.govt.nz/topic/2353
“What is a high volcanic island?
A high volcanic island is rugged and mountainous – formed by volcanic activity. Samoa is made up of volcanic islands that have formed over the last two million years. Some of its volcanoes are still active. The last eruption was on Savai‘i in 1911.
Food and water on Samoa
Samoa has fertile soils, plenty of fresh water, and good marine resources. Earlier inhabitants depended on food crops that their ancestors had introduced. These included taro, breadfruit, bananas, and yams. All grew well in the Samoan soil.
Toolmaking in Samoa
Samoa is rich in high-quality basalt, a volcanic rock excellent for making tools. Samoan tools were prized in many parts of the Pacific, and have been found as far away as the Cook Islands, the Solomon Islands, and the Caroline Islands.”
#Museum of New Zealand. Niue: a raised coral atoll. Retrieved Jan 2024.
https://collections.tepapa.govt.nz/topic/2351
Quote: ”What is a raised coral atoll?
A raised coral atoll forms when a coral reef grows on an underwater volcanic peak, which is then raised above sea level. This can happen from both earth movements and falls in sea level. Niue consists of coral limestone – old, dead coral that now makes up both the central bedrock and the coastal cliffs. The volcano on which Niue is formed is extinct.
Food and water on Niue
Compared with other types of islands, a raised coral atoll is not well suited to human habitation.
There isn’t much fresh water on Niue. In former times, the inhabitants had to find it in caves or dig wells for it. Niue also has very little fertile soil. There is only a thin layer in most places. However, Niueans made the most of the soil they had, and cultivated introduced plants – especially taro, bananas, and coconuts. Niue’s marine resources are good, but access to the sea is difficult because of the rugged coastal cliffs.”
– And then there are the good islands. The Polyneisians colonised them, spreading their culture and society to dozens of remote islands of all sizes. Some united in kingdoms spanning many islands, others were independent, many home to competing and belligerent tribes. And although thousands of kilometers apart, even the most remote islands were connected with at least some trade and exchange. A microcosm of humanity.
For an island to be habitable, there needs to be a supply of fresh water, suitable soil to grow crops, plentiful marine resources for protein and raw materials for making tools. And back then, not all islands checked all boxes. There are unfortunately not a lot of archeological findings that we can reconstruct the details of life in the region back then but we at least know that there was trade running in between islands and they were not isolated from each other.
#Britannica. Traditional Polynesia. Retrieved Jan 2024.
https://www.britannica.com/place/Polynesia/Traditional-Polynesia
Quote: “Linguistic evidence suggests that western Polynesia was first settled some 3,000 years ago, by people of the Lapita culture. It has proved harder to establish when eastern Polynesia was settled. It is possible that some islands were occupied soon after the arrival of Lapita colonists in western Polynesia. However, while the Lapita are best known for their distinctive pottery, eastern Polynesia’s archaeological sites lack ceramics of any kind. Nonetheless, it is clear that the various island groups in Polynesia interacted frequently with one another during the early period of settlement, exchanging luxury goods such as basalt adzes, pearl shell, and red feathers.”
Quote: “Violence was an ever-present element of Polynesian cultures. This is reflected in the oral literature and in all aspects of traditional life. Various customs controlled and repressed the direct physical expression of aggression within the kin group and the tribe up to a point, but there were definite boundaries of behaviour beyond which only violence could restore status or assuage injured pride. Punishments for transgressing ritual prohibitions and social rules often incorporated ritual sacrifice or even the death of the transgressor. Intertribal warfare was extremely common, particularly when populations began to outgrow available resources.”
#Louise Furey and Emma Ash. Old Stones for Cash’. The Acquisition History of the Pitcairn Stone Tool Collection in Auckland Museum. 2020.
https://www.aucklandmuseum.com/getmedia/6ade8826-c58e-4ee9-bc96-f50782566fee/ram_2020_furey_ash
Quote: “Little archaeological research has been carried out on Pitcairn and the history of Polynesian settlement is poorly understood. The island was abandoned prior
to the 18th century, but settlement probably occurred around the 12th century, at the same time as island groups in the wider south east Pacific region (Molle and Hermann 2008; Sear et. al. 2020). Basalt, obsidian and oven stones were exported from Pitcairn and materials including coral and pearl shell imported through regional voyaging networks (Weisler 1997; Weisler et. al. 2004). These local networks, encompassing Henderson, Pitcairn and Mangareva, broke down around the mid-1400s (Molle and Hermann 2008; Weisler 1997:
167). Wider distribution of stone materials is evidenced by the presence of Pitcairn obsidian in the 14th century site of Atiahara on Tubuai in the Australs Group, and basalt in the Tuamotu group (Molle and Hermann 2008).”
#Stephen M. Younger. Conditions and Mechanisms for Peace in Precontact Polynesia. 2008.
https://www.journals.uchicago.edu/doi/abs/10.1086/591276
Quote: “Polynesia provides an excellent data set for the study of violence across a range of demographic and environmental variables. Populations of islands or island clusters ranged from a few hundred (just sufficient to maintain a viable gene pool) to tens of thousands (adequate for the formation of polities with many of the qualities of a nation state). Environments ranged from small isolated atolls to large volcanic archipelagos. The levels of violence varied from Kapingamarangi, which had no weapons at the time of contact (Ray 1917), to the Marquesas, where violence was a way of life (Handy 1923).”
– But it didn’t always work out. The extremely isolated Pitcairn islands were settled for hundreds of years and relied on trade with each other and bigger islands hundreds of kilometers away. And then the local population vanished. We don’t know why – maybe because the islanders did the human thing and ravaged the natural resources until they became unsustainable. Maybe the decline on distant bigger islands severed important connections. We only know their culture declined and they left or died out.
The Pitcairn Islands are made up of four islands (Pitcairn, Henderson, Oeno and Ducie) more than 100 km away from each.
#Furey and Ash. ‘Old Stones for Cash’. The Acquisition History of the Pitcairn Stone Tool Collection in Auckland Museum. 2020.
https://www.aucklandmuseum.com/getmedia/6ade8826-c58e-4ee9-bc96-f50782566fee/ram_2020_furey_ash
Quote: “Pitcairn Island is situated 25 deg south of the Equator and is the southernmost of the four islands making up the isolated Pitcairn Group. Other islands are Henderson, a raised limestone island, and Oeno and Ducie which are coral atolls. Pitcairn is a young volcanic island approximately 5 sq. km in area, and is the better resourced with fresh water, good quality fertile soils suitable for gardening and basaltic geology highly suitable for tool production. Henderson, the only other island in the group with evidence of Polynesian occupation (Weisler 1995), is approximately 170 km to the north east of Pitcairn. Nearest neighbours outside the Pitcairn Group are Mangareva (400 km) and Rapanui Easter Island (1600 km). The nearest islands in the Society Island Group, and the Marquesas Group, are 1980 km and 2310 km respectively.”
To the surprise of the mutineers of the famous HMS Bounty, they found the island stranded when they set foot in 1790. However, archeological findings tell us that it was inhabited on and off, though with a patchy record, across centuries, though when and why Polynesians stopped inhabiting the island is not known still today.
#Furey and Ash. ‘Old Stones for Cash’. The Acquisition History of the Pitcairn Stone Tool Collection in Auckland Museum. 2020.
https://www.aucklandmuseum.com/getmedia/6ade8826-c58e-4ee9-bc96-f50782566fee/ram_2020_furey_ash
Quote: “The remote Pitcairn Island is well known as the final destination of the mutineers from HMS Bounty. It was unoccupied in 1790 when the mutineers arrived, accompanied by Tahitian women and men, although there was evidence of former Polynesian occupation such as marae, standing tiki figures, rock carvings, adzes, cooking stones and plants such as taro, ti, and breadfruit that Polynesians transported during voyages of settlement (Erskine 2004: 37). Like other islands in the wider south eastern Pacific, the island was occupied by Polynesians by the 12th–13th century (Molle and Hermann 2008). When the island was abandoned by Polynesians is unknown, but it is believed that the small land area and limited resources, coupled with remoteness, meant that occupation could not be sustained long-term after interisland sailing networks broke down (Weisler 1996).”
There are also conflicting views as to why the islands discontinued to be inhabited. One example is Easter Island. Some experts say that it was the devastation of natural resources by humans while some suggest that the change in the climate rendered the islands inaccessible. Though it is beyond the scope of this script, we left a few publications below for the interested viewers.
#Rolett and Diamond. Environmental predictors of pre-European deforestation on Pacific islands. 2004.
https://www.nature.com/articles/nature02801
Quote: “Some Pacific island societies, such as those of Easter Island and Mangareva, inadvertently contributed to their own collapse by causing massive deforestation1,2,3,4,5,6,7. Others retained forest cover and survived3,8,9. How can those fateful differences be explained? Although the answers undoubtedly involve both different cultural responses of peoples and different susceptibilities of environments, how can one determine which environmental factors predispose towards deforestation and which towards replacement of native trees with useful introduced tree species? Here we code European-contact conditions and nine environmental variables for 81 sites on 69 Pacific islands from Yap in the west to Easter in the east, and from Hawaii in the north to New Zealand in the south. We thereby detect statistical decreases in deforestation and/or forest replacement with island rainfall, elevation, area, volcanic ash fallout, Asian dust transport and makatea terrain (uplifted reef), and increases with latitude, age and isolation. Comparative analyses of deforestation therefore lend themselves to much more detailed interpretations than previously possible. These results might be relevant to similar deforestation-associated collapses (for example, Fertile Crescent, Maya and Anasazi) or the lack thereof (Japan and highland New Guinea) elsewhere in the world.”
#DiNapoli et al. A model-based approach to the tempo of “collapse”: The case of Rapa Nui (Easter Island). 2020.
https://www.sciencedirect.com/science/article/abs/pii/S0305440320300182?via%3Dihub
Quote: “Rapa Nui (Easter Island, Chile) presents a quintessential case where the tempo of investment in monumentality is central to debates regarding societal collapse, with the common narrative positing that statue platform (ahu) construction ceased sometime around AD 1600 following an ecological, cultural, and demographic catastrophe. This narrative remains especially popular in fields outside archaeology that treat collapse as historical fact and use Rapa Nui as a model for collapse more generally. Resolving the tempo of “collapse” events, however, is often fraught with ambiguity given a lack of formal modeling, uncritical use of radiocarbon estimates, and inattention to information embedded in stratigraphic features. Here, we use a Bayesian model-based approach to examine the tempo of events associated with arguments about collapse on Rapa Nui. We integrate radiocarbon dates, relative architectural stratigraphy, and ethnohistoric accounts to quantify the onset, rate, and end of monument construction as a means of testing the collapse hypothesis. We demonstrate that ahu construction began soon after colonization and increased rapidly, sometime between the early-14th and mid-15th centuries AD, with a steady rate of construction events that continued beyond European contact in 1722. Our results demonstrate a lack of evidence for a pre-contact ‘collapse’ and instead offer strong support for a new emerging model of resilient communities that continued their long-term traditions despite the impacts of European arrival. Methodologically, our model-based approach to testing hypotheses regarding the chronology of collapse can be extended to other case studies around the world where similar debates remain difficult to resolve.”
– The milky way has around 200 billion star systems and it seems that almost all of them have planets. Estimates vary, but there may be some 300 million to tens of billions of rocky, earth-like planets, in the habitable zone around a star, where water can be liquid. Amazing!
#Maggie Masetti. How Many Stars in the Milky Way? 2015
https://asd.gsfc.nasa.gov/blueshift/index.php/2015/07/22/how-many-stars-in-the-milky-way/
Quote: “There are different models for estimating the number of stars in the Milky Way and the answers they give differ depending on what is used as the average mass of a star. The most common answer seems to be that there are 100 billion stars in the Milky Way on the low-end and 400 billion on the high end. But I’ve seen even higher numbers thrown around.”
#Caleb Scharf. Alone in a Crowded Milky Way. 2020.
https://www.scientificamerican.com/article/alone-in-a-crowded-milky-way/
Quote: “In the Milky Way galaxy, there are perhaps as many as 300 billion stars. The best estimates from exoplanet-hunting efforts, such as those undertaken with NASA’s Kepler space telescope, suggest that within this ocean of stellar bodies there may be more than 10 billion small, rocky worlds in orbital configurations conducive to temperate surface conditions. Like the islands of Earth, these exoplanetary specks might both generate and support living systems and could provide a network of waypoints for any species determined to migrate across interstellar space. And that is where things get really interesting.”
#John P. Millis. How Many Habitable Planets are Out There? 2020
https://www.thoughtco.com/counting-habitable-planets-3072596
Quote: “As additional data is accumulated and analyzed, the number of candidates will increase. Extrapolating out to the rest of the galaxy, scientists estimate that the Milky Way could contain upwards of 50 billion planets, 500 million of which could be in their stars' habitable zones. That's a lot of planets to discover!”
#University of Florida. One-third of galaxy's most common planets could be in habitable zone. 2023
https://phys.org/news/2023-05-one-third-galaxy-common-planets-habitable.html
Quote: “Sagear and Ballard found that stars with multiple planets were the most likely to have the kind of circular orbits that allow them to retain liquid water. Stars with only one planet were the most likely to see tidal extremes that would sterilize the surface.
Since one-third of the planets in this small sample had gentle enough orbits to potentially host liquid water, that likely means that the Milky Way has hundreds of millions of promising targets to probe for signs of life outside our solar system.”
#Charles Q. Choi. How Many Planets Can Fit Inside a Star's Habitable Zone? 2016
https://www.space.com/34555-how-many-planets-fit-inside-one-habitable-zone.html
Quote: “Van Laerhoven and her colleagues focused on K and M type stars, also known as red dwarfs. These stars are small, cold and about one-fifth the sun's mass and up to 50 times fainter. Red dwarfs constitute up to 70 percent of the stars in the universe, and NASA's Kepler spacecraft has discovered that at least half of these stars host rocky planets that are one-half to four times the mass of Earth.
[...]
The gravitational influence that the rocky planets exerted on each other limited how many planets could cram into a region around the star; the scientists calculated that, at most, a red dwarf could host less than a half-dozen Earth-size planets in its habitable zone.”
#Frank Tavares. About Half of Sun-Like Stars Could Host Rocky, Potentially Habitable Planets. 2020.
Quote: “Now, we’re one step closer to finding an answer. According to new research using data from NASA’s retired planet-hunting mission, the Kepler space telescope, about half the stars similar in temperature to our Sun could have a rocky planet capable of supporting liquid water on its surface.
Our galaxy holds at least an estimated 300 million of these potentially habitable worlds, based on even the most conservative interpretation of the results in a study released today and to be published in The Astronomical Journal. Some of these exoplanets could even be our interstellar neighbors, with at least four potentially within 30 light-years of our Sun and the closest likely to be at most about 20 light-years from us. These are the minimum numbers of such planets based on the most conservative estimate that 7% of Sun-like stars host such worlds. However, at the average expected rate of 50%, there could be many more.”
– Except that most of them are terrible. Hells of lava, dead frozen worlds, bare rocks sterile from radiation, blanked by toxic atmospheres. It is easy to forget, but Venus and Mars are “earth-like”, too.
We do not have enough qualitative data to safely extrapolate this assumption into the depths of the universe and have a definite conclusion here. However, when we hear news about a new potentially habitable planet, researchers reach that conclusion generally through stitching three pieces of information together: mass of the planet, size of the planet, distance of the planet to its star. Mass and size of the planet tell if it is rocky and there is some floor to set foot on or if it is a gas giant where there is no hope to land. How far it is from the star on the other hand hints at the existence of liquid water. This is mostly what we can know, any additional information is mostly true disappointment. Take our Solar System as an example, Venus and Mars are rocky planets at a somewhat fair distance from the Sun, but they are not very welcoming as our Earth. So a very simple calculation tells us that two thirds of the planets seemingly satisfying the conditions for habitability are in reality inhabitable. Then there are planets around dwarf stars, which are by far the dominant types of stars in our galaxy by number. And even though their planets might be at the right distance for liquid water, they also experience stellar eruptions or flares bathing the planet in radiation. Therefore, based on what we observed so far, Earth still looks like the best option.
– Mars is the next human frontier and fairly exciting – but Mars dust is poison and deadly radiation and low gravity will make you sick. Mars is the worst. Except Venus is even worse, crushing you to death, burning and dissolving you in acid.
Martian soil contains perchlorates in toxic levels to humans. But it is probably only one of the many others that are dangerous for us.
#M. H. Hecht et al. Detection of Perchlorate and the Soluble Chemistry of Martian Soil at the Phoenix Lander Site. 2009.
https://www.science.org/doi/10.1126/science.1172466
Quote: “Several microorganisms on Earth are known to harvest energy by anaerobic reduction of the perchlorate molecule (36, 37). Under martian conditions, perchlorate does not readily oxidize organics (although the presence of perchlorate salts may indicate a vigorous oxidant-forming chemistry in the martian atmosphere or on the surface), but the low water activity associated with such a strongly desiccating substance may inhibit many forms of life. The high-temperature oxidizing properties of perchlorate will, however, promote combustion of organics in pyrolytic experiments, compromising the ability of Phoenix’s TEGA experiment to readily detect organics (38) and possibly affecting the Viking mass spectrometer experiments (39).”
Since Mars has no magnetosphere unlike Earth, it can not protect us from radiation coming from the sun or cosmic rays.
#Sarah Frazier. NASA’s Goddard Space Flight Center, Real Martians: How to Protect Astronauts from Space Radiation on Mars. 2015
Quote: “A human mission to Mars means sending astronauts into interplanetary space for a minimum of a year, even with a very short stay on the Red Planet. Nearly all of that time, they will be outside the magnetosphere, exposed to the harsh radiation environment of space. Mars has no global magnetic field to deflect energetic particles, and its atmosphere is much thinner than Earth’s, so they’ll get only minimal protection even on the surface of Mars.”
Mars has a round a third of Earth’s gravity, which can make you sick beyond merely nauseated.
#Kathryn Powley. Getting Sick In Space On The Way To Mars. 2017.
https://pursuit.unimelb.edu.au/articles/getting-sick-in-space-on-the-way-to-mars
Quote: “There is no gravity on the International Space Station, and Mars only has about a third of Earth’s gravity. This instantly plays havoc with the human body.
Astronaut’s faces grow puffy and round, and they constantly feel like they have the flu with blocked sinuses.
“Your body has developed to push fluid up to your brain against gravity. In space, too much fluid gets pushed up to the top half of your body so it then tries to get rid of fluid by making you urinate more, and you end up dehydrated,” says Dr Jurblum.”
#Kate Howells. What would it be like to stand on the surface of Venus? 2023.
https://www.planetary.org/articles/what-would-it-be-like-to-stand-on-the-surface-of-venus
Quote: “When learning about the fascinating planets and moons of our Solar System, it’s natural to imagine seeing the place for yourself, perhaps exploring the lava tubes of the Moon or hiking the mountains of Mars. But when it comes to Venus, the more you learn about its surface conditions, the less you’d want to picture yourself there. With extreme heat and crushing atmospheric pressure, the surface of Venus is one of the most deadly environments in the Solar System.”
#Fraser Cain. Why is Venus so horrible? 2014.
https://phys.org/news/2014-12-venus-horrible.html
Quote: “Venus sucks. Seriously, it's the worst. The global temperature is as hot as an oven, the atmospheric pressure is 90 times Earth, and it rains sulfuric acid. Every part of the surface of Venus would kill you dead in moments.”
– Of course both could be terraformed, we talked about it in detail in other videos. If humanity was really motivated, built a dyson swarm and space industries for unlimited energy we could do it within maybe a thousand years. But the thing is, we have a planet already that is pretty great. So currently humanity's motivation is not very intense.
We talked about these in our previous videos:
#How To Terraform Venus (Quickly)
https://www.youtube.com/watch?v=G-WO-z-QuWI
#How To Terraform Mars - WITH LASERS
https://www.youtube.com/watch?v=HpcTJW4ur54
– Every star moves in its own orbit through the galaxy and most stellar neighbourhoods are only temporary. At any given time, in some regions there will be more good islands than in others. While simply because of bad luck, other regions will be pretty isolated.
If you were to watch the stars within a few hundred light-years around the sun, they may seem to be moving in random directions. In the scales of thousands of light-years however, you would notice the bigger picture: the orbital motion that drives stars around their galaxy. The closer to the galactic center they are, the less time it takes to complete their travel. This effectively creates dynamic neighborhoods, that in a matter of ten thousand years, you might get new neighbors.
#Caleb Scharf. Alone in a Crowded Milky Way. 2020.
https://www.scientificamerican.com/article/alone-in-a-crowded-milky-way/
Quote: “What this means is that for a civilization looking around itself for target stars to explore, what is closest and what will be closest in the future vary significantly over time. A good illustration of this is our own solar system. Right now our nearest star, Proxima Centauri, is 4.24 light-years away, but in about 10,000 years it will be only 3.5 light-years distant—a significant savings in interstellar travel time. If we were to wait until about 37,000 years from today, our nearest neighbor would for a time be a small red dwarf star called Ross 248, which would then be a mere three light-years from us.”
Scientists actually ran a computer simulation of this scenario. It is nicely explained in the excerpt below but in short, they simulated the dispersion of a spacefaring civilization in a 3D box of a shifting stellar backdrop, kind of bringing a small portion of the galaxy to virtual life. The simulation has of course many parameters, like life span of civilizations and a certain waiting period before launching on another settlement. And researchers actually found that it is not that unlikely that a settlement front can propagate through interstellar space. So they found that it is actually possible!
#Caleb Scharf. Alone in a Crowded Milky Way. 2020.
https://www.scientificamerican.com/article/alone-in-a-crowded-milky-way/
Quote: “What we find is both simple and subtle. First, the natural, gaslike motion of stars in the galaxy means that even the slowest interstellar probes, moving at some 30 kilometers per second (nearly twice as fast as Voyager 1’s current speed of 17 kilometers per second in its outbound motion from our sun), would ensure that a settlement front would cross the galaxy in much less than a billion years. If we factor in other stellar motions, from galactic rotation or halo stars, this time span only shrinks. In other words, just as Fermi saw, it is not hard to fill the galaxy with life. But it is also the case that exactly how “filled” the galaxy becomes depends on both the number of genuinely settleable worlds out there—what we have dubbed the Aurora effect in homage to Kim Stanley Robinson’s epic 2015 science-fiction novel Aurora—and the length of the period civilizations are able to endure on a world.”
– Earth might currently be in one of these backwaters, surrounded by really bad islands for dozens of light years in all directions. We may be Pitcairn island, so isolated that nobody knows we are here, or cares for establishing a colony so remote.
#Caleb Scharf. Alone in a Crowded Milky Way. 2020.
https://www.scientificamerican.com/article/alone-in-a-crowded-milky-way/
Quote: “Can this “galactic archipelago” scenario explain our situation on Earth? Remarkably, it may. For example, if typical planetary civilizations can last for a million years and if only 3 percent of star systems are actually settleable, there is a roughly 10 percent probability that a planet like Earth has not been visited in at least the past million years. In other words, it is not terribly unlikely that we would find ourselves on the lonely side of the equation.”
– First of all, most great neighbourhoods would dissolve over time and connected islands would turn remote.
#Jonathan Carroll-Nellenback, Adam Frank, Jason Wright and Caleb Scharf. The Fermi Paradox and the Aurora Effect: Exo-civilization Settlement, Expansion, and Steady States. 2019.
https://iopscience.iop.org/article/10.3847/1538-3881/ab31a3/pdf
Quote: “Our steady-state calculations in the low density limit further imply that
successful settlements are hard to achieve. The lack of settlement success could come for many reasons ranging from failure of interstellar vessels capable of establishing persistent
settlements to the inability to develop viable progeny civilizations on new worlds.”
[...]
Quote: “In particular, the assumption that the Earth’s life-sustaining resources make it a particularly good target for extraterrestrial settlement projects could be a naive projection onto exocivilizations of a particular set of human attitudes that conflate expansion and exploration with conquest of (or at least indifference toward) native populations (Wright & OmanReagan 2018). One might just as plausibly posit that any extremely long-lived civilization would appreciate the importance of leaving native life and its near-space environment undisturbed.”
– Also space is just a different ballpark. The enormous distances between stars make it hard to keep a consistent civilization – just think about how many cultures we have on earth alone. Imagine if sending a message between continents took decades to arrive.
Unless interstellar travel is easy, civilizations might not be willing to invest further in the settlements that can not be reached and maintained.
#Jonathan Carroll-Nellenback, Adam Frank, Jason Wright and Caleb Scharf. The Fermi Paradox and the Aurora Effect: Exo-civilization Settlement, Expansion, and Steady States. 2019.
https://iopscience.iop.org/article/10.3847/1538-3881/ab31a3/pdf
Quote: “For our present results these factors indicate that it is possible that developing the requirements for interstellar settlement may be expensive enough to be universally
prohibitive. In addition, if establishment of viable settlements proves difficult, meaning the success rate of world ships is low, then civilizations may be unwilling to continue investing in
them over time. This is particularly true if one considers that the long travel and communication times may make it difficult to establish an interstellar civilization. Unless the individuals in the species driving the settlement have very long lifetimes (>100 yr) it is difficult to see how a galactic scale culture can arise (i.e., commerce, etc.; Krugman 2010). Thus each settlement may, in practice, be relatively isolated culturally, which may limit the effort civilizations are willing to put into long-term programs of expansion.”
– Would colonies care what the home world wants from them, if it can neither help nor really enforce its will on them. This also would make interstellar war, except the genocidal kind, completely uneconomic. Would you go to war with someone because their great grandfather killed yours? At these distances, it's not like anyone could easily sneak up on each other anyway.
And on a much more fundamental level, if island empires don’t exchange relevant amounts of genetic information – if there are no hook ups between worlds –, sooner or later these populations will develop in different directions and eventually become different species. Making it less likely that they’ll want to be under a common rule.
We speculate here, but there have been researchers who wrote about how distance can be a limiting factor on the probability of interstellar war. We cite one example below in case you are interested:
#Janne M. Korhonen. MAD with aliens? Interstellar deterrence and its implications. 2013.
https://www.sciencedirect.com/science/article/abs/pii/S0094576513000283
We also partly covered this topic in a previous video:
#Interstellar War