Super-Habitability

Photo by Pixabay on Pexels.com

Yesterday I mentioned in passing the concept of super-habitability. I’m happy to say that ‘Handbook For Space Pioneers‘ introduced this concept, although it may have passed unnoticed. In this book, which describes the eight habitable planets available for human settlement in 2376 CETC (Common Era Terrestrial Calendar), the final planet, Athena, 77.6 light years from Earth in the HR 7345 system, is actually more habitable than Earth. The book rates the different planets according to their habitability using the ‘Von Roenstadt Habitability Factor’, with the least habitable, Mammon, having one of 0.79. This is a largely desert planet with a thin atmosphere which was largely settled due to its rare earth metals, which are useful in matter-antimatter reactors. Earth has a factor of 1.0, and Athena one of 1.09. This is because Athena is not only similar to Earth but lacks a polar continent, meaning that more of its land is hospitable to human settlement. Therefore it was this book that came up with the idea. Ahead of its time.

The search for exoplanets tends to be biassed in various ways as I’ve previously mentioned. One of these is that the ideal planet to be detected would be a super-Jupiter orbiting very close to its rather dim star, orbiting parallel to the line of sight. This is indeed a very common type of planet to be found but not at all Earth-like. It also gets a bit depressing after a while because the planets concerned may make their systems unsuitable for more hospitable planets further out. This situation has been somewhat remedied more recently and many somewhat Earth-like planets have now been found.

However, it’s been suggested that we may be setting the bar too low here. I mentioned the Copernican principle yesterday, also known as the principle of mediocrity, that it’s often informative to look at the world with the assumption that there’s nothing special about us as a species, and perhaps more closely, apply the same principle to ourselves as individuals (e.g. “accidents always happen to someone else until they happen to you” – this is not some kind of exaggerated humility and self-effacement). When we look for Earth-like planets, we are in a sense only looking for worlds which are good enough, and also good enough for humans, as opposed to worlds which are fantastic. That is, Earth is all very well, and yes it is precious and rare and all the other stuff, but there could in principle be worlds which are even more hospitable to life than this one. Super-habitable planets, in other words.

I feel a sense of hesitancy here because it’s like insulting my own mother, but the fact is that this planet may be particularly suitable for humans, but it could have, and has been in the past, more comfortable for life than it was when we first evolved as anatomically modern humans. At that point, it was plagued by regular ice ages, had larger deserts and had little in the way of continental shelves, meaning that fishing, for example, would’ve been very difficult without boats in most places. Not that I care, as a vegan, but there is a theory that I accept that we went through an amphibious phase when we depended on sea food, which could be relevant to the development of the our brains and ability to speak. Even now there are issues with this planet regardless of the influence of humans on it. Looking beyond humanity confronts us with the fact that although this planet is really quite a nice place to live, it may not be ideal for other life. There are two aspects to this as well. One is “life as we know it”. That is, life which breathes oxygen, drinks water, uses sunlight to synthesise food, is carbon-based and depends on biochemistry, which may not be the only kind of life. We don’t know that there cannot be other forms of life which are very different, to which Earth would seem a very hostile place. For instance, it’s easy to imagine aliens detecting the high level of corrosive and hyper-reactive free oxygen in our atmosphere and concluding that this is not the best abode for life because they have simply never encountered body chemistry which actually requires that. They might feel the same way about this place as we would about a planet whose atmosphere was high in elemental fluorine or chlorine and had seas of aquæous hydrofluoric or hydrochloric acid. Or, if there were life forms based on plasma, and I strongly suspect this can happen, they might wish to avoid anywhere with even a trace of liquid water in its atmosphere or on its surface and only survive in the very driest deserts here. But the current popular conception of superhabitability is to be biocentric in the sense of looking for the ideal conditions for life to begin, develop and thrive on it. Perhaps surprisingly, Earth is not currently ideal for this, and it isn’t even entirely due to human technological development. Moreover, Earth has been more habitable in the past that it currently is.

Seventy-one percent of Earth’s surface is underwater, and of that most of it is so deeply so that no daylight ever reaches the ocean bed. This doesn’t rule life out at all of course – there is life in the deepest part of the ocean – but it does reduce the energy available and there is less diversity down there than elsewhere. It relies on food raining down from further up, sometimes including dead whales, which provide a huge amount of nutrition for quite some time. The water column above the beds is also rich in life, getting richer the closer to the surface it gets, and there are of course ecosystems around hot water vents at the bottom of the ocean. However, the euphotic zone, where there’s enough light for photosynthesis to take place, is only two hundred metres deep, and that’s where the ocean teems with life. Shallow seas are much richer in life and more diverse for that reason. Hence, withough being disrespectful of the ecosystems of the trenches, abysses and abyssal plains, more than half of the surface of this planet could be said to be “wasted”. Two ways in which things could be different here are for the seas to be shallower. The shallow sea biome is quite rare nowadays on Earth, but in the past has been much more extensive, and would mean that plants could grow on the bottom of the sea and support many other organisms. The same could apply to another possible situation, where the Sun was either brighter or we were closer to it, meaning that although there might still be extensive abyssal plains, the light would penetrate further down. Alternatively, photosynthesis, which currently operates using red light, could possibly be based on shorter wavelengths which penetrate further. A planet with a red photosynthetic pigment, for example, might have seaweed growing deeper. It’s possible that chlorophyll only appeared on this planet because a preceding purple pigment used by another taxon of organisms meant that only red light was available to plants, and if that second stage hadn’t happened, “plants” would now mainly be purple.

Stars are also different colours. From the viewpoint of photosynthesis, this could also have implications for the colour of the pigments. Habitable planets were long thought only to be possible for worlds associated with F-, G- or K-type stars but it’s now thought that red dwarfs may be more suitable (for a summary of spectral types, look here). K-type stars last longer on the Main Sequence and are orange, so I presume a planet orbiting one would be in a constant “rosy-fingered dawn” situation, though much brighter, but this gives life longer to evolve than it does here. Our own planet will be able to support microörganisms for up to 2 800 million years in the future, but these will to some extent resemble the æons when only microbes existed here. Large multicellular life is likely to become extinct only about 800 million years hence when there won’t be enough carbon dioxide in the atmosphere to support photosynthesis, which will happen due to the increasing brightness of the Sun. This is also driven by plate tectonics, as carbonate rocks are forced from the sea bed into the mantle where they react and release carbon dioxide while forming silicates. This means that a fainter, more long-lived star or more active continental drift would make this planet more hospitable to life for longer.

A larger planet would often have a number of advantages for life. Here I’m talking about rocky planets rather than gas giants. This is where the biocentric approach becomes more evident. The definition of a “superhabitable” planet here is to do with how suitable it would be for life of the kind we’re currently familiar with rather than humans, because large, dense planets would have higher gravity than Earth. LHS 1140b, for example, may be superhabitable, but not for us. It’s seven times the mass of Earth and 40% larger in diameter, giving it a surface gravity more than three times ours. This is beyond the capacity of human beings to survive unaided without some form of modification, but its dense atmosphere may provide it with a greenhouse effect which heats it to a temperature compatible with life as found here. Larger rocky planets will take longer to cool, meaning that there will be more active plate tectonics and more carbon dioxide recycling, although there may be a limit here because higher gravity would slow it beyond a certain point due to the weight of the continental plates. Larger planets, particularly fast-rotating ones, would have stronger magnetic fields and therefore be more easily able to hang on to their atmospheres and protect the surface from ionising radiation.

When Earth has been warmer, there has been more biodiversity, although just to comment on anthropogenic climate change that doesn’t work out now because it’s a rapid change and also unstable. Evolution might eventually fill in the gaps of course. This planet has a tendency to edge into colder conditions rather than hotter ones, for instance the current spate of ice ages and the Snowball Earth scenario in the late Cryptozoic Eon, but most of the time it’s been hotter on average than it is today. Consequently we’d’ve done better if we were somewhat closer to the Sun, although it’s not clear how much, at least to me. Another circumstance where there’s been more diodiversity and larger animals has been when oxygen was higher in the atmosphere, although this has a limit above which there would be devastating fires and other oxidative damage. The highest partial pressure of oxygen ever on this planet has been 350 millibars, amounting to 35% of the atmosphere, but in a denser atmosphere this proportion would be smaller because the absolute quantity of oxygen is what matters, not the proportion.

The final helpful criterion is a combination of about the same water cover combined with a larger number of landmasses. Earth currently has six continents, one of which is circumpolar. At other times it’s had as few as one. I’m not sure why this is considered advantageous but I can make a few guesses. It would mean that evolution would take place in isolation on each of the continents, as it has here with Australia, South America and the rest of the non-polar continents taken together, and that arid areas would tend to be smaller, although rain shadow deserts would still exist. Those, however, would be less common as well because there would be fewer mountain ranges due to fewer continents crashing together. There would also be more land near the coast than there currently is here, and more shallow sea areas on continental shelves. I’m reminded of Douglas Adams and his description of Ursa Minor Beta as consisting largely of beaches.

Some of these characteristics are impossible to detect with existing technology. For instance, although I think there is a way of finding continents and mapping them crudely by measuring fluctuations in brightness and colour, only a very few planets have even been imaged as points of light so far and they’re much larger than Earth. There’s probably a way of coördinating and processing telescope images taken in different parts of the Solar System to simulate the effect of an enormously magnifying lens, but I’m just guessing there. Nonetheless, there are certain known planets which do appear to satisfy some of these conditions. One is Kepler-442b. Incidentally, many of these planets have rather boring, monotonous names at present because they were all found by the same project. This planet, also known as KOI-4742.01 orbits its K-type sun at a distance of 61 200 000 kilometres once every 112.3 days, has a mass 2.3 times Earth’s and a diameter of around 17 100 kilometres. This gives it a surface gravity twenty-eight percent higher than ours, which is just about bearable. Without other factors being involved, its surface temperature would be about -40, but it could easily be warmer due to the Greenhouse Effect, low albedo and so forth. This last factor is of course the way in which it isn’t super-habitable, if it’s so.

It’s possible that there are more super-habitable planets than strictly Earth-like ones because there are more orange dwarfs than yellow dwarfs. Nine percent of stars in the Galaxy are of this kind as opposed to seven percent of the Sun’s spectral type, and several of the criteria simply follow from a planet being more massive than Earth. For instance, higher gravity could make the oceans shallower and give the planets more tectonic activity, and as a personal interjection continents on larger planets have more chance of being widely separated and having different evolutionary histories. A planet 1.4 times the diameter of the Earth whose surface is 29% covered in land, i.e. proportionately the same as Earth’s at the moment, has almost twice as much land, which if the average continent size were the same would be represented by a dozen continents. Likewise, we currently have five oceans here but there could be more there, although oceans are not well-defined and in a sense there is only one ocean. Planets with more than fifty percent land coverage could have landlocked oceans, and even worlds with less land due to quirks of geography, but this won’t apply to planets of this kind.

What might such a planet be like? Here I’m going to choose an example which satisfies all the criteria. There will be many others, if they exist at all that is. The average temperature would be somewhat higher than Earth’s and there would be no permanent ice caps at the poles, although snow-covered mountains and glaciers could easily exist. The climate would be warm and humid, with more cloud cover than Earth. Tropical rain forest vegetation would cover much of the land and there would be smaller desert areas. The oceans would be shallower and there would be copious vegetation on the sea beds. Atmospheric oxygen content would be higher in absolute terms but lower in terms of percentage than Earth’s. The denser atmosphere would mean stronger winds and more devastating rotary storms such as tornados and hurricanes. Also, these planets are likely to be more similar to each other than strictly Earth-like planets would be. The general picture is a little similar to the way Earth was at the climax of the age of dinosaurs or during the Carboniferous, although the higher gravity would limit the size of terrestrial megafauna.

These larger planets have a kind of momentum to them, which allows them to continue with fairly stable climatic conditions for many æons. By contrast, Earth-like planets run the risk of becoming permanently ice-covered, tipping into runaway Greenhouse effects and ending up like Venus, losing much of their atmospheres or relying more on large moons to maintain their magnetic fields, and therefore perhaps the ones that don’t have them or something else to raise internal tides only have thin atmospheres and no land life.

However, this does raise another question in my mind. As far as we know, we are the first technological civilisation to arise on this planet, although there’s tantalising evidence that there may have been advanced industrial processes here during the Eocene, maybe not from terrestrial species. If that’s so, it means that the periods of time during which Earth was more hospitable to life than it is today didn’t give rise to tool-using species. Therefore, is it possible that a more hospitable habitat is like the Swiss with their cuckoo clocks? Would stability end up providing little challenge to species and prevent it from evolving humanoid intelligence? Are these planets too comfortable? And there’s another question. Although these planets seem stable, they would be nearer a set of limits for biological habitability. Our planet has issues, but maybe that’s a sign of it being able to endure change. If something happened to one of these planets, like a large asteroid impact or a change in the luminosity of the sun, would this proce too much for life to handle? For instance, on this planet the life could be replenished by that surrounding undersea vents even if it died elsewhere, but I’m not sure whether there’d be many extremophiles – organisms who prefer hostile conditions – on such a world. Also, these planets are superhabitable by the needs of life as we know it in general, but not by human standards. We’d do okay, probably, on a planet which was somewhat larger and warmer than Earth although we’d have to be wary of the storms, but these super-habitable worlds wouldn’t be pleasant places to live for us. There’s a potential second set of hypothetical planets which are super-habitable for us, for instance with the Galactic Association example of Athena, a planet with no polar continent. Some of the characteristics would be similar, such as smaller but more numerous continents, but the set of criteria is not the same.

Taking this the other way is even more speculative because we’re only aware of one example of how life can arise and evolve, which is based on chemistry, organic matter, water and to a lesser extent oxygen for respiration. If there are other ways for life to exist, there could be whole other sets of “habitable” environments – I hesitate to say “planets” here because for all I know this would be happening on the surfaces of neutron stars, in nebulæ or the photospheres of “ordinary” stars. This is rather more difficult to discuss, but if life can exist in different ways it would seem to multiply the probability of life in the Universe, and also of the types of world which could support it. But I can only really leave this as a possibility thus far, or at least without making this post really long.

To conclude then, all this looks rather cheerful as regards the possibility of life as we know it in the Universe, but it also kind of pushes us Earthlings into a corner, as if all of this is true, we’re quite atypical of life in the Universe and our planet’s a bit weird. So who knows?

History of the British Climate Part I

Yesterday I covered the last 400 000 years of British climatological history. Today I’m going to do something like the previous æon, and possibly all the way back to the beginning of the world. In fact, yeah I’ll do that.

4 543 million years ago, the future Solar System was a swirling disc of dust and gas orbiting a newborn Sun. Jupiter had already formed and was gradually pulling the particles whose times to orbit were in harmony with its own slightly towards itself, leading to them drifting slightly out of phase with it and clumping into fairly insubstantial rings of matter. I’m not sure how warm the belt which would become us was at the time, but it was probably well below freezing point, because if it hadn’t been, there would have been no grains of water ice. On the other hand, there were also comets, so maybe not, but the fact remains that the Sun was dimmer and weaker back then and there were no greenhouse gases in a position to warm the dust and gas which would become Earth. It took seventy to a hundred million years for it to form, and at the beginning it would’ve been slightly more massive, have no permanent moon and the atmosphere would have been briefly high in hydrogen and helium. Within ten million years of its formation, a Mars-sized body which has been christened Theia hit us and shattered the outside layers of the planet, causing them to go into orbit around us and fall together into the body I call Cynthia and most other English speakers call “the Moon”. Clearly there was no such place as Britain at this point and the entire surface of the planet was molten rock heated by the mechanical energy of compression and collision along with radioactivity. The atmosphere would have been substantially superheated steam. Shortly after being hit by a planet-sized body, the atmosphere would in fact have been vaporised rock. It’s possible to determine the climate of the entire planet at this point, as it was quite uniform, meaning that although it makes no sense to talk of Britain, it does make sense to describe how conditions were everywhere. This eon lasted about 500 million years, and during this period the vaporised rock atmosphere would have condensed and fallen onto the surface as drops of lava. Towards the end of the Hadean, life was present, which seems to imply that there was liquid water in at least some places.

The next period is referred to as the Eoarchean, when the pressure was probably dozens of times higher than it is today, more like the solid surface of Venus than today’s Earth. Temperatures were between 0 and 40°C and there may have been ice ages. To quote ELO, “the weather’s fine but there may be a meteor shower”, because this was the time of the Late Heavy Bombardment, when for 300 million years asteroid collisions and other large meteors would have rained very often from the sky, although this has recently been questioned. The atmosphere was high in methane and carbon dioxide, which being greenhouse gases may have ensured that this planet was warm enough for life to survive on it given that the sun was 30% weaker than it is now.

All of this is rather vague and applies to the whole world. The earliest known British rocks are found in Na h-Eileanan Siar, also known as the Western Isles, and have been dated at 3 000 million years old. It isn’t clear that anywhere can be meaningfully called Britain before that date, and there’s no trace of anything else. It was likely to have been a small piece of the surface of the planet with unclear neighbours. The rock concerned is gneiss, which is a common component of continental shields, which are bits of Earth’s surface that haven’t been affected much by continental drift, such as mountain formation or rifting. It would be a bit excessive to call the rocks in Na h-Eileanan “continental shield” because they’re quite small, the nearest substantial example of one being most of Finland and Sweden, but they are the original and only rocks in that small area of these isles.

Even long after this, the island of Great Britain would have been in several parts, making it difficult to describe the nature of its climate. It means imposing the current situation on the past when it’s actually quite transient on a geological time scale. Also, in some areas, including this one, Charnwood, sedimentary rocks were laid down at the bottom of the sea or ocean and the idea of this being Britain is almost meaningless. It also changes the significance of climate, and as far as being at the bottom of a really deep ocean is concerned, almost irrelevant.

In the Archean, which lasted fifteen hundred million years, the planet was shrouded in methane clouds and there was practically no free oxygen in the atmosphere. The sedimentary rocks surviving which had been exposed to the atmosphere show no glacial erosion, but they do show evidence of rivers and rain. Therefore it did rain. In fact, presumably there was an enormous rainstorm lasting thousands of years at some point in the late Hadean when the oceans were formed due to the atmosphere and surface getting cool enough for the steam to condense out and persist on the surface, but because the pressure was much higher this would have happened long before the surface temperature dropped below 100°C. It is actually possible to measure the surface temperature by looking at the proportion of oxygen-18 in the rocks. There are two stable isotopes of oxygen: 16 and 18. Because oxygen-18 is heavier, molecules containing it vaporise at a slightly higher temperature. Chert, which is a sedimentary flint-like rock, is silica, i.e. silicon dioxide, containing oxygen, and is present in some Archean deposits, making it possible to measure the temperature where it was laid down. This puts the ocean temperature at 70°C, but this is probably wrong because weathering once it was exposed to the atmosphere would influence this. The degree of weathering which occurred was unaffected by land plants, since there weren’t any – there weren’t any plants in fact – and suggests a surface temperature between 18 and 24°C, so semitropical. The fact that there was neither excessive heat nor excessive cold suggests various things about the planet such as the ratio of methane and carbon dioxide, a relatively transparent atmosphere and only limited land surface, so it seems that not only do we only have bits of Na h-Eileanan available but that may have been partly because there just wasn’t that much land.

The Archean was followed by the Proterozoic, which began around 2 500 million years ago. This was characterised by the evolution of blue-green algæ, which proceeded to release oxygen into the atmosphere and removed carbon dioxide. This may also have reduced the activity of methane-producing organisms, another greenhouse gas, and also oxidised the methane. Incidentally, this hedging language I’m using here is down to my ignorance more than scientists’. Anyway, the consequences of this were that iron began to rust in the ocean, depositing itself in bands of rust on the sea bed, and the temperature of the planet fell, triggering an ice age. It’s theorised that this planet has two relatively stable states climatically, which it switches between: icehouse and hothouse. Icehouse has generally not dominated but can do at certain times and in fact it is at the moment, anthropogenic climate change notwithstanding. The dominant state is hothouse, which is generally warmer than today for millions of years at a stretch. Even so, there does seem to have been an ice age in the early Proterozoic, and at the end of the Proterozoic there was another much more severe one. In between those times the world-wide climate would’ve been warmer than today.

The Cryogenian Period was a crucial time in our planet’s history. It appears that the land was mainly equatorial at the start of this period, which would probably have included the bits of land which were to become these isles. We were situated just south of the Equator, in Laurentia and Baltica, as part of the supercontinent Rodinia, meaning a hot, wet climate, except that we were below sea level, so a very wet climate! The oddity about this time is that glaciers are found at the Equator, i.e. the parts of the supercontinent which were equatorial at the time, and it’s thought that this means that most or all of the planet was covered in ice and as cold as Antarctica. My comment about tropical conditions applies to how things were before this arose. There are a couple of hypotheses about how this happened. One is that Earth may have had an axial tilt as high as 60°, meaning that constant night in the winter and the midnight Sun in the summer would’ve applied to everywhere further from the Equator than today’s Brazil or Israel. Very surprisingly, a snowball Earth can only happen if there’s a lot of equatorial land. Most of the Sun’s heat is absorbed near the Equator, meaning that if there’s a lot of land there the heat would not be absorbed as much, and this would cool down the whole planet.

By Ryan Somma – Life in the Ediacaran SeaUploaded by FunkMonk, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=24277381

The Ediacaran follows the Cryogenian and is for this part of Britain very significant, because it’s from this time, lasting 94 million years from 635 to 541 million years ago, that some of the most famous fossils found in this area date. These can be seen in a local museum and include the feather-like Charnia as seen above, and Bradgatia linfordensis, a lettuce-like organism obviously (to locals) named after Bradgate Park and Newtown Linford, both in Charnwood. Charnodiscus concentricus is another. These are all thought to be “quilted” animals who left no descendants, although some people class them in their own kingdom because they’re quite unlike any animals or plants we’re familiar with. They appeared 600 million years ago and all died out before the Cambrian. They may have had symbiotic algæ in their compartments, meaning that since many of them were also attached to the sea bed, the water must have been sufficiently shallow to allow light to penetrate. Hence Charnwood was still underwater, but the ice must’ve been gone and the water wasn’t particularly deep.

Rodinia was breaking up at this time, so there would’ve been a network of shallow seas, which sounds like the situation as it was here. Rodinia was an unusual supercontinent because it seems to have formed by the landmasses moving all the way round the world and colliding with each other on the opposite side to where they originated, which meant they had a long time to erode and the land surface was quite flat. The network of seas would have increased rainfall on the land, since much more of it would’ve been closer to the sea. This may in fact have been part of what triggered the earlier ice age. The temperature of the Ediacaran was still around 2°C cooler than the average for the Holocene, so it looks like the weather here would’ve been cold, wet and rainy. Plus ça change!

The Cambrian was warmer, around 8°C warmer than the Holocene average, and in fact this set a precedent for the generally warmer temperatures of the Phanerozoic, our current eon. During the next period, the Ordivician, sea levels rose by a hardly believable six hundred metres. This ended as a new supercontinent, Gondwana, reached the South Pole and a new ice age started, lasting twenty million years. A gamma ray burst may then have cause the mass extinction at the end of the period, meaning that it may have rained concentrated nitric acid.

Around 400 million years ago, three mini-continents collided to form the British Isles as we know them today, and it begins to become more meaningful to talk about British climate. These were Laurentia, which is effectively all of Scotland, Avalonia, which is England and Wales, and Armorica, which is Brittany, Devon and Cornwall plus a lot of other land such as Iberia. Glen Mòr, the fault along which Loch Ness is situated, continues into Ireland and therefore I imagine Ireland was also in two halves before this. Avalonia began as a volcanic island chain north of Gondwana. Britain was about 30° south of the Equator then. It drifted gradually north, crossing the Equator about 300 million years ago, and over this time other land collided with the forming Pangæa, meaning that it was increasingly far from the sea. This is about the time the Carboniferous started and the future Britain became covered in the rainforests which would become the coal measures, so Britain was hot and swampy, and the oxygen content of the air was so high that lightning strikes would have ignited wet vegetation, so there would be many forest fires even though conditions were damp. Around 305 million years ago, climate got cooler and drier and sea level fell, leading to retreat of coal forests from higher ground and the emergence of fragmented rain forests, which were no longer able to maintain their genetic diversity and there was a lot of inbreeding, shrinking of the size of, for example, horsetails, to cope with the conditions and a new ice age started in the Southern Hemisphere, although not severe enough to make Britain cold.

By this time, Pangæa was forming, as were the Pennines. Hot dry desert conditions took over from rainforest, with presumably an intermediate phase which today would be like the Serengeti, although with very different flora and fauna the details are not obvious. The late Permian was a peculiar time climatically, as the interior of Pangæa seemed to have extreme temperature variations so that it was both very hot and very cold at different times of year, and it’s been suggested that this was a cause of the Great Dying, where almost all life on Earth became extinct. Britain was now in the northern tropics, and as such was in the same zone as the Sahara is now. The Scottish Highlands at the time would’ve been as high as the Himalayas and formed part of a range which extended southwest into the Little Atlas and Appalachians. There might also have been a rain shadow desert to the east, making it even drier than it would’ve been without them, but the monsoon conditions which prevailed to the southeast might make it heavily forested.

In the Triassic there were salt flats in Cheshire, hence the salt mines which existed there in historical times, and red sandstone forming in what is now the Southwest, hence the very red soils in that area. Towards the end of the Triassic, the sea level began to rise again, converting much of the isles into a subtropical shallow sea and many of the hills and mountains as they existed then into islands, such as the Mendips.

The following photo is taken from this website and will be removed on request:

This is the “Barrow Kipper”, or rather a monument to where it was found in 1851. Barrow-upon-Soar is about an hour’s walk from where I’m sitting and between 200 and 150 million years ago was underwater, over the entire Jurassic Period. This particular plesiosaur was formerly classed as a Rhomaleousaurus but now as an Atychodracon, from the Early Jurassic, looking something like this but with a bigger head:

It used to be thought that plesiosaurs had to climb ashore to lay their eggs, so this suggests that there was land nearby, but fossils have since been found of pregnant ones, and their limbs were arranged in such a way that they would’ve had to have dragged themselves along the shore quite roughly. However, although it isn’t from precisely the same time, a few miles away in Rutland, the largest and most complete dinosaur fossil ever found in Britain was unearthed, a Cetiosaurus, like a mini-“Brontosaurus”, suggesting that this area was an archipelago of smaller islands or just near a beach. There is a famous traditional song called ‘Ashby De La Zouch By The Sea’, which has often made me wonder whether that particular nearby Leicestershire village ever was.

I am of course a Southerner, and as such Leicestershire will always be slightly foreign to me. My mother is from Maidstone, a place sufficiently famous for its Iguanodon finding that the animal is actually on their coat of arms:

These dinosaurs, dating from 157 million years ago, are also found, along with very many others, on the Isle Of Wight. It’s tempting to telescope all these findings into an imaginary scenario where they’re all simultaneous just because they’re all Jurassic, but in reality the Jurassic Period lasted fifty-six million years, almost as long as the time since the non-avian dinosaurs became extinct, and the Isle Of Wight dinosaurs are mainly early Cretaceous. There were, however, coral reefs in Yorkshire. In the Cretaceous, the situation was once again one of rising sea level with lagoons and streams. To the extent that these isles existed at that point, they were substantially united. That is, Ireland and Great Britain formed a single island, which was intermittently joined to the mainland and still steadily drifting north.

The Late Cretaceous climate was warmer than today’s at the same latitude, which was about the same as Madrid and Rome, although it had been cooling for millions of years. When the Chicxulub Impactor hit, the widespread fires would have raised carbon dioxide levels tenfold and caused a greenhouse effect heating the planet by 7.5°C. In the Palæocene the climate was slightly cooler and drier due to dust in the atmosphere reflecting heat into space, but tropical forests then developed all over the world, even in the Arctic, where the water was lukewarm. The Eocene would’ve involved warm swamps in many parts of Britain.

At this point I’ll repeat something I said a few days ago about Europe. Europe over the Cenozoic, that is, since the extinction of the non-avian dinosaurs, has been gradually transitioning from an archipelago to a large peninsula, and the scattered islands of the region have shown a trend of joining together to build a subcontinent, for want of a better word. Looking at Great Britain and Ireland in this way, they are late developers, or outliers which show how the rest of the region used to be. There’s a common, and correct, idea that before the end of the last Ice Age and for several thousand years after that, Ireland and Great Britain formed a peninsula, and this is true, but there has been a kind of seesawing appearance and disappearance of sea around us and the level of the land at the moment has been pushed down by the recent weight of ice and is gradually springing back up. Hence it does make sense to speak of the British Isles, or perhaps an island comprising Ireland and Great Britain plus low-lying land in between, in the earlier Cenozoic, and moreover to see them as the westernmost members of a collection of islands a bit like the Caribbean or Indonesia in arrangement, although that may be a bit of an exaggeration. The North European Plain, though, was underwater for quite some time, Iberia ceased to be an island around the start of the Cenozoic and the Italian-Illyrian region was also separate for a long interval.

In the Neogene, Britain arrived in its present position and is no longer drifting north. Hence the climate began to approach how it is today although it would’ve been somewhat warmer still. Finally, the Pliocene saw a general drying out and the Pleistocene brings me to the start of yesterday’s post.

I can’t completely guarantee that all of this is accurate as I know a little, but some of it is disputed and I’m probably in the Dunning-Kruger trough at this point where I haven’t reached the point of realising how little I really know and how wrong I’m actually being. Nonetheless, it’s nice to imagine how our climate could’ve been more Mediterranean or Caribbean in particular in the geological past, and also, wouldn’t it be nice to holiday at home but do it using a time machine so we could get to the really sunny and warm climates which this part of the world, so to speak, used to experience?

A History Of The British Climate Part II (Part I Tomorrow)

It’s common knowledge that there used to be an Ice Age in this country. Something which is never clear to me is whether people generally realise that this planet has recently, i.e. in the past million years or so, undergone five ice ages, and it’s debated whether anthropogenic climate change will be sufficient to prevent the next one. As I mentioned the other day, up until the 1980s it was considered a toss-up whether the near future would involve global cooling or warming, although looking at the graph of recent global temperatures in 1977, it seemed close to inevitable that it would warm. But there have been people here for hundreds of millennia, back to the Hoxnian about four hundred millennia ago, so I will start with that, work down to the present and then go way up and repeat the process on a grander timescale.

As far as I know, and in fact I suspect I’m wrong, the earliest human remains found in what are currently these isles are the so-called “Swanscombe Man”, a Neanderthal or pre-Neanderthal woman dating from about four hundred millennia BP (before present – in fact before 1950 CE). She was found in a Swanscombe gravel pit, near Dartford in today’s Kent. The Hoxnian Stage was an interglacial lasting from 424 to 374 millennia BP, when it was slightly warmer than today on average. At the time, there were dense forests here, making it difficult for people to penetrate much of the country and they mainly stayed in river valleys, such as the Thames, then a tributary of the Rhine, where the Swanscombe remains were found. Other species sharing that environment included the straight-tusked elephant, hippos and rhinos. This is one of the startling things about British fauna, and in fact fauna in general, up until the start of the last Ice Age: it was actually quite Afrikan. Distinctive European fauna during interglacials didn’t arise until this one, referred to as the Holocene. In fact humans could be seen as an example of that, since we are originally Afrikan.

I grew up calling the Ice Ages of the Pleistocene Donau, Günz, Mindel, Rịẞ and Würm, which are apparently the wrong names for Northern Europe, where they’re called the Hamburger, Elder, Elster, Saale and Weichsel. One of the annoying things about ice ages is that they’re called different things in different parts of the world, which doesn’t generally happen with other geological periods although one of the Cenozoic epochs, can’t remember which, is said to continue in some parts of the world after it had finished in others. Possibly the Oligocene. In the case of ice ages this is to some extent justified, because as far as the Arctic regions are concerned we’ve been in one long ice age since the start of the Pleistocene. Britain, and in particular Scotland, is the northernmost land not actually considered Arctic, so it isn’t surprising that the ice ages operated somewhat differently here than they did further south. The names I mentioned at the beginning of this paragraph are also the names of Alpine rivers, because the Alps were obviously more strongly affected than lower-lying parts of the European peninsula.

When the Ice Age I’m apparently supposed to call the Saale started around 374 millennia BP, glaciers completely covered what would become this archipelago, and of course Doggerland in the German Ocean/North Sea was still completely above sea level, so at this point these isles were not islands at all but a sub-peninsula of Europe. Fauna included lemmings, mammoths, woolly rhinos and musk oxen, but there would’ve been an intermediate cooling period during which horses would have arrived because the forests were thinning out. This came to an end around 130 millennia BP with the gross of centuries or so known as the Eemian or Ipswichian, during which sea level rose to six to nine metres above where it is today. Ice ages during this time are much longer than interglacials, which all seem to last about that long, which also means we’re kind of due for a new ice age, hence Nigel Calder’s fixation which I mentioned here. This is the period during which anatomically modern humans evolved, and our split between Asian and Afrikan populations. During this time there were hippos in the Thames and Rhine, and there were also straight-tusked elephants again in Britain, although we were at the limit of their range by then. They finally became extinct, or perhaps just left, at the start of the next ice age, the Weichsel.

The Weichsel, which is the most recent ice age and the one many probably just think of as the Ice Age, was less severe than the Saale, with the ice sheets only reaching as far south as the Humber and Mid-Wales, and across in Ireland in a line across from Wexford to Galway. South of those would’ve been tundra rather than actual permanent ice cover, and there were reindeer in the Peak District who used to migrate to Lincolnshire to calve. There were also still mammoths, for instance in Shropshire, until 14 000 BP, although they had previously been wiped out here because it was too cold for them. What seems to have been happening here is that local populations of mammoths were dying out and then getting replaced by others moving into the area, in a cycle. There were also bison, woolly rhinos and Irish elks. The last seem to be remembered in Irish legends. They were not closely related to elks but to fallow deer, and their last representatives vanished around 7 700 BP in Russia, at a time when mammoths were still around – they only died out around the time the pyramids were built. Irish elk appear in cave paintings and were hunted by humans.

The Holocene is actually formally defined, kind of by fiat, rather than just being the end of the last ice age. In the 1990s CE, it was proposed that a Holocene calendar be formally designated where years are numbered from the start of the epoch. Hence it started officially in 10 000 BCE or 11 950 BP. This makes it easier to use for geology and archæology, since Bede’s timing for the birth of Jesus is both arbitrary and culturally biassed, and not very useful for these purposes except that it helps us relate to the dates if one has a Christian background. That said, the onset of the Holocene is also the time of the last glacial retreat, and as such dates to around 11 650 years ago, or 9 630 BCE with spurious accuracy. All human recorded history has taken place in this period, and during this time there has been fluctuation in climate, here and elsewhere.

A big factor in the Holocene was the Bond events, which are fluctuations in ice rafting occurring from the Arctic in an approximately ten century cycle. In terms of the Common Era, these nine events took place at the following approximate dates: 9100 BCE, 8300 BCE, 7400 BCE, 6200 BCE, 3900 BCE, 2200 BCE, 800 BCE, 600 CE and 1500 CE. Some of these are associated with particular historical events or trends. What seems to be happening, and this is my interpretation, is that Arctic ice breaks up and spreads out in the North Atlantic, reflecting more heat back into space and cooling the planet globally. Then it refreezes and the planet warms up due to a smaller area being covered by ice.

The events in question sometimes had a major effect here, sometimes either not or not in a discernible way from this distance in time. Before I go on, I’ll talk about Doggerland, the formation of the Irish Sea and the English Channel. Doggerland, as you must surely know but I’ll mention it anyway, is the area now flooded by the North Sea. The Irish Sea used to be a marshy area with some lakes, the English Channel was also above sea level and even after the rest was submerged there was a narrow isthmus across the Pas De Calais until 5000 BCE. All of this was to do with ice melting and sea level rise.

Where the Bond events didn’t directly influence the climate significantly in this country, and in fact they would’ve done although without agriculture or written records the traces are harder to discern without some archæological research such as looking at tree rings, they may still have had a long-term knock on effect from what happened elsewhere. For instance, the 6200 BCE event led to a drier spell in Mesopotamia and therefore may have triggered irrigation efforts which led to the emergence of Sumer and the other cultures in that area, ultimately leading to the arrival of more advanced technology and different peoples here in the characteristic pattern where the East is south of the West. That said, the distribution of the aforementioned elephants also shows a northeast-southwest boundary and the glaciation kind of followed the same “diagonal” line. The 3900 BCE event led to the reformation of the Sahara Desert by four centuries later, whose effects can be seen in rock paintings showing animals usually found in wetter climates in that area. The Bronze Age began a couple of centuries after that. This got to Britain about a millennium later still. A later significant oscillation was the Iron Age Cold Epoch, which started around 800 BCE and coincided with the expansion of Ancient Greece and the foundation of Rome. This was followed by the Roman Warm period from 250 BCE to 400 CE, or 500 to 1150 AUC in the Roman dating system, which seems to have been fairly local, i.e. confined to Europe. Italy at the time was wetter and cooler, and it was the start of the current Subatlantic period. The temperature left to itself is slightly lower in this, current, period, than its predecessors and again this is evidence that we’re due an Ice Age, but human activity seems to be either postponing or preventing this for now. The cooling is thought to have triggered the migration of the Germanic tribes from Scandinavia down into the main part of Europe. There are then a number of named periods: the Late Antique Little Ice Age, Dark Ages Cold Period, Mediæval Warm Period and finally the well-known Little Ice Age.

The first two of these coincide to some extent, with the Late Antique Little Ice Age occurring in the middle of the Dark Ages Cold Period. In other words the former was the peak of the latter. The longer period seems to be precisely dateable to 509-865 CE, and includes for Britain most of the sub-Roman period, Augustine’s arrival and the early years of Alfred’s life until shortly before he became King. The middle of that period seems to have been worsened by volcanic eruptions reducing sunlight. The Annals of Ulster record a crop failure leading to a lack of bread in 536 and those of Innisfallen says this continued until 539. Ice cores from those years show a higher sulphur content than others. The Annales Cambriæ record “great mortality in Britain and Ireland” and also say it was King Arthur’s last battle. In various places it’s said that the Sun shone only weakly for a year and a half. In China it snowed in August 536.

This was eventually followed by the Mediæval Warm Period, lasting from around 950-1250. Sediments in the Sargasso Sea show that it was 1°C warmer than 1996 at this time. It seems that the ice-free seas of the North Atlantic were taken advantage of by the Norse people to colonise Greenland, as they called it, and Afrika was drier. After a bit of a gap, the Little Ice Age began in about 1350 and lasted up until about 1900, and this is something I find puzzling. There was a major famine here in 1315-17 which seems to have set Europe up for the Black Death later in the century because the people who were children at the time of the famine seem to have grown up rather unhealthy, laying them and the communities around them open to the ravages of the plague, if that’s what it was, as adults, and also making them a source of infection for healthier people who might otherwise have escaped. It might be expected that this was due to a series of years with bad weather conditions for growth of wheat in particular because of the climate, but in fact this doesn’t seem to be so. However, it does seem that a five-year long series of eruptions in Aotearoa/New Zealand of Mount Tarawera may have precipitated the event. Some people do extend the Little Ice Age back to 1300.

The following few centuries had such features as white Xmases and frost fairs on the Thames. There are two reasons why white Xmases used to me more frequent. One of them is pretty obvious, but the other, so I hear, is that there tends to be a snowier period shortly before the dates which are now celebrated as Christmas, and the calendar reforms moved it out of this to a less snowy stage of the winter. I’m not sure about that because it seems more likely to snow in early January than mid-December, so it seems to be in the wrong direction.

Frost fairs were held on the Thames in London from the seventh to the nineteenth centuries CE, peaking from the seventeenth century onward when the Little Ice Age was at its most severe. It’s thought that the Thames was more likely to freeze over in any case back then because of the water wheels under London Bridge slowing the flow of the river down and the pollution in the water raising the freezing point. They were in any case quite seldom held, and were much more common elsewhere in Europe. The Thames has frozen over further upstream much more recently, unsurprisingly in winter 1963. I can remember the sea freezing over to a limited extent in the Thames Estuary. It froze over for several weeks in London in the third Christian century, and in 695, the date of the first fair, then there’s a gap until 1608, when it first used name. The biggest was in 1683-4, when the ice was half a metre thick. The last one was in February 1814, when the ice supported an elephant. I don’t want to ignore the cruelty of exploiting a presumably Asian elephant in that way, but note the connection with native British straight-tusked elephants living on the banks of the river in ages past. In 1831, London Bridge was pulled down and the climate was warming, meaning that it ceased to be feasible from that point on.

By Giorgiogp2 – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=8942703

Approaching living memory, there’s the Year Without A Summer, also known as “Eighteen Hundred And Frozen To Death”, a phrase many older people may have heard of. This is 1816. The 1815 eruption of Mount Tambora in today’s Indonesia led to a global fall in temperature of 0.7°C. The summer temperatures were relatively lowest in France and England. There was food price inflation all over Europe and in 1819, there were typhus epidemics in Ireland and Scotland as a result of malnourishment. Mary Shelley wrote ‘Frankenstein’ during the summer of this year because the weather was too bad for them to go outside. Also by this time, sunspots were being observed and the Sun’s surface was unusually “clean” between 1796 and 1820, a period known as the Dalton Minimum, and like other minima it coincided with a spell of colder temperatures. The better-known Maunder Minimum from 1645-1715 had also seen this, and it’s also hypothesised that there’s a rhythm instantiated by these two, meaning that an earlier Spörer Minimum had occurred from 1460-1550.

There are several ways to retrieve the record of climate change in fairly recent times, including ice core samples, tree rings, coral skeletons, cave deposits and foraminiferan skeletons from the sea bed and chalk. One of the things these show is that the industrial revolution, which at the time was fuelled by coal, began to make its presence felt by about 1830, rather surprisingly in the Southern Hemisphere more than the Northern. Antarctica has been protected from much of this by the circulation of water and air currents in the Southern Ocean, but it can be seen in other oceans and landmasses south of the Equator.

This is more or less common knowledge, so I won’t go into much depth, and I’m pretty sure I’ve covered it extensively elsewhere on this blog. Therefore I’ll just mention three events: the winters of 1947 and 1963, and the summer of 1976.

From 23rd January 1947, Britain and the rest of Europe experienced an unusually harsh winter, which incidentally is a major plot point in my novel ‘1934’. I also know someone whose life was basically ruined by it. An anticyclone was stationary over Scandinavia, preventing low pressure areas from moving towards Britain from the Atlantic and allowing winds to blow from the east across the country. The temperature dropped to -21°C, there was pack ice in the Channel and ice floes in the North Sea. Similar, and in some cases more severe, measures were taken as during the War, including lower rations, the suspension of television, the reduction of radio and there were power cuts which even affected Buckingham Palace. Four million people claimed unemployment benefit. Three million sheep died, there were many crops lost or irretrievable from the ground due to frozen soil and there were of course many human casualties. This was followed by serious flooding in March when the snow and ice melted.

The next severe winter occurred sixteen years later, and Sarada can remember this although I wasn’t born. This was known as the Big Freeze of ’63 and was the coldest since 1895. The situation began similarly to 1947 with a stationary high over Scandinavia, but this was then replaced by another over Iceland. Temperatures fell to -19°C in Scotland and the sea froze over at Herne Bay for 1.6 kilometres. January 1963 is the coldest month since January 1814. The difference between the two post-War winters is probably down to the fact that Britain had recovered economically from the War by the second, and there were also some advances in technology and the infrastructure, but that’s just my guess.

Finally for today I want to mention an incident which I can actually remember quite clearly: the summer of 1976. Although this was only the second driest summer since records began, next to 1995, it’s far more memorable for its weather than the later one. You may recall, incidentally, that 1975 was also very hot and dry, and that dryness and mildness continued through the ’75-’76 winter, meaning that more insects survived and continued to reproduce in the next year. Meanwhile the water reserves were already unusually low. The cause of the actual heatwave and drought was, surprisingly, similar to those of the winters of ’47 and ’63, with a high pressure area stuck over Europe, and in fact the whole of Europe was affected, not just Britain. Shade temperatures rose to 34°C in late July. Rivers, lakes and reservoirs dried up, the grass died and there was a plague of ladybirds. It was actually possible to fill shovels with them, and many people, including myself, discovered for the first time that they “sweat” an irritant clear yellow liquid when stressed (incidentally the same thing happened a couple of days ago to me while I was out). This was because ladybirds are predators of other insects, and their plethora had led to a population explosion. There were also standpipes in the street due to a water shortage, and I think hosepipes were banned for the first time. The Archbishop of Canterbury prayed for rain to no avail. Then, bizarrely, the Prime Minister Harold Wilson appointed a minister for drought, Denis Howell, and ordered him to do a rain dance! Then it rained and he became minster for floods. I shall now specifically invite Steve to tell us his tale of ’76.

As for me, my tenth birthday occurred during the drought. I was on holiday in the Isle Of Wight and my brother and I both went down with tonsilitis. My temperature went up to 38.3°C. However, I recovered in time to enjoy the rest of the holiday, and we went to Blackgang Chine where there was a “ride” purporting to be Hell which was very hot inside, except that it wasn’t because of the temperature outside. Two other notable features were that after it had started raining people were still using standpipes and were actually standing in the rain waiting for water, and it was stated that even if it rained every day until the year 2000 there wouldn’t be enough water to replace what there had been in 1974. There was also said to be a problem with the mud getting baked into an impermeable condition, such that the rain would just run off and fail to accumulate. There were forest fires in the South, and everyone was warned to take extreme care. However, these have actually served to replenish heathland in the long run. Deaths went up by twenty percent.

That, then, is the history of climate in this country from the life of Swanscombe Woman four hundred millennia ago into the late twentieth century. Tomorrow I will cover the history of climate here from deep in prehistory up until the advent of the latest spate of Ice Ages.

Ancient Earthians

The Palenque Slab

Far back in the mists of ancient time, yea, e’en before the Great Nova of Gath, I wanted to start a piece of writing with that phrase, which I think is actually a quote from somewhere, so I can’t. But anyway, a long time ago, according to Erich von Däniken, ancient aliens visited this planet, interbred with the hominids here and gave rise to intelligent humans. Their traces are still evident in the markèd differences between us and the other great apes, in ancient myths and legends, and in the art, objects and buildings of ancient civilisations. The word “ancient” has to be used a lot here, with reverence and an air of mystique. None of this happened of course, but the idea has a surprising history.

One of the first people to make this suggestion was none other than Carl Sagan, who later came across very much as a sceptic, although not precisely in the same mould as James Randi or John Sladek because of his claim that the Galaxy is “teeming with life”. In his 1966 book ‘Intelligent Life In The Universe’, cowritten with Iosif Shklovsky, Sagan claimed that scientists should take the possibility that aliens had visited this planet in prehistoric times seriously, although it should be treated as a hypothesis subject to testing as part of the usual scientific process. Their reasoning was that since the Universe was such a big place with so many star systems apparently suitable for life, the chances of intelligent species leaving their worlds and exploring distant stars were very good indeed, particularly over the billions of years this planet has been in existence. He later regretted saying this because he felt responsible for the whole ancient astronaut debacle that ensued, particularly due to Zechariah Sitchin and Erich von Däniken among other less well-known writers, and of course this ultimately led to the interminable History Channel series ‘Ancient Aliens’. Sagan actually used to appear on documentaries in the ’70s trying to undo the damage. He actually wasn’t the first. In 1940, the editor of ‘Astounding’ John W Campbell had Isaac Asimov insert Greek deities as aliens in Asimov’s story ‘Homo sol’, with racist overtones. Asimov, being Jewish, was unsurprisingly not keen on this at all and proceeded to make sure he avoided non-human intelligent life forms in most of his writings after that, thereby inventing the ‘Humans Only Galaxy’ which still shows its influence today, for instance in Rob Grant’s and Doug Naylor’s ‘Red Dwarf’ series, where there are no genuine species not originating ultimately on Earth.

Erich von Däniken is obviously the worst offender here. Some of his work is based on forgeries and outright falsehoods. For instance, he mentions and illustrates stones carved with heart transplant operations which were in fact contemporary engravings which he commissioned personally. I don’t want to go into too much detail about this because even his reputation is old hat nowadays, but just briefly he was found guilty of repeated fraud, embezzlement and forgery in 1968 on unrelated matters connected to loans and went to prison for three years. Luckily for him, ‘Memories Of The Future’, more usually known by its English title ‘Chariots Of The Gods’, had been published by then and he was able to pay off his debts with the royalties. He wrote the second book, ‘Gods From Outer Space’, in prison.

Before I go on, I want to debunk this.

First of all, the really low-hanging fruit is the issue of aliens interbreeding with humans. The definition of a species is a population able to interbreed and produce viable offspring, although this often doesn’t work very well because there are microspecies, asexual organisms and fossils we have no idea about. In one of his attempts to salvage the situation, Carl Sagan once said it would be easier to mate a human with a petunia than with an alien, because petunias are more closely related to us. The only scenario in which this would not be so, given unaltered biology, would be if the aliens were actually completely human. More on that in a bit. However, this is often evoked as an explanation for perceived human exceptionalism, but fails for two reasons even if it worked. Firstly, it attempts to explain something by simply deferring it. Secondly, it makes humans seem more special than we really are. We’re apes, simple as that. Our intelligence differs to some extent from the others but if assessed, inappropriately of course, by human standards all the other species of great ape would have an IQ above thirty, probably higher, and they are also ahead of humans in cognitive development until eighteen months. They also have cognitive abilities we lack, as I mentioned previously.

As far as anyone has been able to discover, all living things on this planet descend from a common ancestor four billion years ago, because our genomes are all fairly similar, and with a few exceptions among the viruses, all use the same DNA or RNA bases. It is possible that there’s a “shadow biosphere”: undetected life forms whose chemistry is somewhat different and therefore undetected. The phenomenon of desert varnish is sometimes explained by this – a coating on rocks in deserts whose mode of formation is unknown. Most scientists involved would say it’s very unlikely that we wouldn’t have detected them by now. Anyway, it would be enormously difficult for visiting aliens not to leave behind a few microörganisms, but there are no traces of those at all, so it’s also unlikely that this planet has ever been visited at all. That said, the Silurian Hypothesis suggests that there may have been a technological civilisation before us on this planet, the best candidate being some time in the Eocene (see the post for details), although that could in theory have been native. Or hypothetically, rather.

The humanoid nature of the aliens might be worth looking into. The general consensus among xenobiologists (the only science without a subject, as it’s been called) is that there won’t be any human-looking aliens. Using a very slapdash approach, if each step in evolution had only two alternatives and every star in the Galaxy had intelligent life on one planet circling it, it would take only thirty-nine steps for every such species to be different. On the other hand, evolution really comprises order imposed on randomness by the constraints of biology and the influence of the environment, and this frequently leads to similar organisms. For instance, a flower-like body plan crops up over and over again in the animal, protist and plant kingdoms, even without similar pressures. As for humans, well, maybe we’re just what intelligent tool-using life forms end up looking like, but I personally doubt it. There are reasons for supposing the opposite though.

The illustration at the start of this post is notoriously interpreted by many as an astronaut at the controls of a spaceship. It’s from Palenque (I’m not sure about the political significance of this spelling incidentally – at school we were taught the spelling “Palenki” and that may be less culturally imperialistic but I’m not sure how Yucatec Maya uses Latin script). This is in fact a bas relief of Pacal (and again I don’t know how to reproduce Mayan glyphs inline), a ruler of the area in question. The Von Dänikenische interpretation of that carving is that the snakes’ heads at the bottom (right) are the bottom of a space capsule, there are flames coming out of them, the thing to Pacal’s left/above Pacal is a control panel and so on. Here’s a link to an illustration of that interpretation in detail.

Glossing over what was happening on the Other Side at the time, which is in fact VASTLY significant to many people, on 26th November 1977, as well as there being a really good episode of ‘Doctor Who’ on BBC1, BBC2 broadcast a Horizon special called ‘The Case Of The Ancient Astronauts’. There must’ve been something in the water on that day, because a nice throwaway tidy-up line at the end of the documentary ended up hugely influencing my thoughts on the matter for years afterwards:

The achievements of the past tell us nothing about spacemen (sic), but a great deal about the intelligence of our ancestors. And if we are ever to find other intelligent life among the stars, it’ll be because we continue to apply that inventiveness and that questioning spirit which the ancient astronaut theory seeks so strongly to deny.

And it’s true of course. The idea of ancient astronauts guiding every great achievement of the human race makes us look as if we’re unable to take the initiative, and also carries with it the suggestion that primitive people were primitive more than they were people. I may be reading too much into this but there seems to be an overtone of colonialism there, in that if a non-Western civilisation comes up with something technologically sophisticated it is automatically explained via alien intervention. The TV series ‘Ancient Aliens’ may be a little better in this regard for all I know, but that’s only because it’s had to keep dredging the bottom of the well for more source material to shoehorn alien intervention into. I don’t know how seriously viewers have taken that programme but if they have, it hasn’t done their critical thinking skills any good. However, I do have a slightly more sympathetic take on this because I think for some people belief in ancient astronaut intervention is a form of religious expression, which is seen elsewhere in for example the Raelians, the Aetherius Society, Scientology and tragically also the Heaven’s Gate cult. Since I am religious, possibly even pathologically so, I can’t help thinking that there’s a widespread instinctive human need for religion and this is an example of a new set of religious beliefs with pseudoscientific trappings. Like some other religious beliefs, it portrays humans as helpless, and this strong statement made at the end of this documentary made quite an impression on me.

Remember first of all that I was only ten at the time. I took on board the idea of human ingenuity and resourcefulness, but didn’t reject the ancient artefacts. As far as I was concerned, there was still a mystery to be resolved vis à vis the likes of the Baghdad Battery, the stainless steel pillar in India, the nuclear war in the ancient Indus Valley and so on. I even attempted to write my own version of ‘Chariots Of The Gods?’ likening snakes to trains and so forth, which was more for fun than anything I took seriously. It was kind of a parody, which ‘The Burkiss Way’ was doing better at the time with their Eric von Kontrick character, who incidentally was a creation of Douglas Adams – his fingerprints are all over the sketch.

These are the odd conclusions I drew at the time, which turned out to be remarkably durable. It’s a good example of my tendency to believe it’s important to be delusional in order to support one’s mental health:

I started with the discovery of fire by Homo erectus. This species was the first whose cranial capacity overlaps that of today’s humans. Two important sets of remains are the Peking and Java Men, the second of which is more like Homo sapiens than the latter. I have to say that although they’re portrayed as another species, since they’re not around today I don’t think there’s any firm evidence that they could not have formed a breeding population with us, the Neanderthals and the Denisovans, and therefore that their physical differences from us may be due to evolution having occurred within our species. I suspect that we are they. Their earlier members had a cranial capacity of 600-800 cm3 but later on it had exceeded a litre, reaching 1250 cm3 . Archaic H. sapiens are actually smaller than that at 1200. I could introduce a lot of stuff that I’ve learnt since then and changes due to scientific findings, but I’m going to stick to this impression as it’s what I based my thoughts on at the time.

This next bit had its first draft in about 1978 when I wrote an essay on it for RE, which I’ve lost.

In order to resolve the problems presented by out of place artefacts without evoking aliens, it’s possible to assume that from the discovery of fire, Homo erectus continued to advance technologically over a period of a few thousand years from about 800 000 BP (=Before Present, present being 1950 here) to develop firstly a global advanced industrial society, then to venture forth into the solar system and then the Galaxy, settling worlds all over the Milky Way and maintaining a Phase Three civilisation for hundreds of thousands of years. At this time, the now lost continents of Atlantis and Mu still existed and were the most heavily developed landmasses on this planet. During the last Ice Age, a catastrophe befell this civilisation and it returned to Stone Age level, before giving rise to civilisation as we know it today.

A little embarrassingly, I held on to this set of beliefs for many years although I can’t place when I stopped believing it was so except that I was definitely adult at the time. I also recognise that it’s somewhat reminiscent of the ‘Battlestar Galactica’ mythos, but I guarantee I wasn’t aware of that at the time because I came up with it in late 1977 and the first episode was broadcast in September 1978. There does, however, seem to be a tendency for ideas to occur to various people at the same time, which I think is due to most of the pieces being in place for them: what Charles Fort calls “steam engine time”.

You might also be wondering how come nobody has found any trace of this civilisation. The answer is that it had been calculated many years before, in the 1920s, that all traces of human civilisation would have disappeared entirely within 50 000 years. However, to my pre-teen mind the presence of fossilised artefacts such as screws, glass jars and hammers would’ve been enough to justify my belief. I think there’s something about that age which makes us very keen to believe in things like the Loch Ness Monster and flying saucers. We want the world to be outlandish, exciting and exotic, and it’s like an outgrowth of our earlier burgeoning curiosity about life with, perhaps, a bit of rebellion mixed in with it.

There’s a danger in using ideas without experience of what other people have done with them. Doris Lessing’s ‘Canopus In Argus’ series is an example of that, as may be Audrey Niffenegger’s ‘The Time Traveler’s Wife’, although I admit that she did something different with it than Kurt Vonnegut did. I’ve seen one Galactica film at the cinema in 1980 and that’s it. I never watched the TV series or the reboot, although I have watched one episode of ‘Caprica’. Therefore I’m quite ignorant of it, which I may in fact already have exposed by writing what I have here, but my impression is that it’s set in prehistoric times and that humans on Earth are in the future relative to the time its set in, although this might have been retconned.

A major flaw in my ideas was that if civilisation had collapsed, it should have left humans all over the Galaxy unaware of their history, which is fine since we don’t know anything about any possible life forms in the rest of the Milky Way except that that then makes the probability of us just happening to be on the planet humans evolved on very low. If it had happened, the chances are we’d be living on a different planet with no fossil record of earlier humans and two distinct sets of life forms, one related to humans (even if only distantly, such as algæ) and another which had completely different genetic code and possibly even biology.

As a world-building idea, it has possibilities. The less plausible one is just to take it as it is: we are living after the end of an interstellar civilisation without knowing it. This is not sustainable in hard science fiction. The more plausible version would involve positing that humans do, in fact, eventually colonise the stars before their civilisation collapses and on various planets recovers and gradually discovers that they are not the first. Andrew Tomas wrote a book with that title in 1972, but I haven’t read it and it seems to confine itself to this planet and the likes of the Ancient Babylonians having electric current or something. I vaguely associate that with a book called ‘On The Shores Of Distant Worlds’, which seems to be imaginary as I can’t find any trace of it.

The remaining question is, what does it say about me that this belief system was so persistent? Does it mean I was immature or psychotic? All I can say is that it’s along the lines of my general belief that it’s important to have some kind of “give” in a rational mind to enable it to persist in being rational under stress. It’s kind of like escapism I suppose. On the other hand, there are people who believe all sorts of strange things throughout their lives, whole communities of them, so maybe I’m not so unusual.