I live in a town called Toptown. It's called that because it's very nearly at the top of the world. Mummy says the world doesn't really have a top, but everyone knows it does really.
My Mummy is a Scientist. My Daddy says he's a Scientist too, but Mummy says he's really an Explorer, and that that's why he's away from home so much.
Our teacher told us that the stars you can see in the sky in winter are really very big, they only look little because they're a very, very long way away. She told us that they're just like the Sun, except that some of them are a bit bigger than the Sun, and some of them are a bit smaller. She said that maybe some of them have worlds like ours spinning around them, just like our world spins around the Sun.
She told us to imagine that there might be little children just like us on one of those worlds that there might be spinning around one of those stars. She told us that we couldn't possibly send a letter to them, and they couldn't possibly send a letter to us but she said we had to imagine that we could send letters to them, and get letters from them.
She said that their world was probably very different from ours. Maybe it was much hotter, or much colder, or it had more land and less sea than our world, or more sea and less land, or maybe it didn't have any sea at all. Maybe it rained all the time, or maybe it didn't rain at all. If it didn't rain at all, they wouldn't even know what rain was!
I think our teacher must have been talking to my Mummy, because my Mummy talks like that, too. Other people's Mummies don't talk like that at all at all.
Our teacher told us we had to write about our world as though we were writing for one of those children who might be on one of those worlds there might be spinning around one of those stars. "And remember, they don't know anything about our world yet."
So this is what I've written.
Our world is mainly sea. People can live on the sea in boats, but most people spend most of their time living on land. The land we live on is the biggest island. There's a lot of other islands near ours, some quite big and some small. Beyond that, there's lots and lots of sea, then further away there are some more little islands. Then a long, long way away there are more big islands even bigger than our island but they're funny islands. I'll tell you more about them later.
Long, long ago, people didn't know the world was round, and they didn't know about the faraway islands they only knew about our island, and the others nearby. They had little boats to get from island to island, and to go fishing. They used to go quite a long way out to sea for fishing, but never so far that they couldn't see the land. They didn't want to get lost.
Oh, that's another thing Mummy told me about. You know how in Winter the sky's black, and when it's not cloudy you can see stars; and in Summer the sky's blue when it's not cloudy, and the Sun goes round and round the sky; and in the middle of Spring and Autumn the Sun comes and goes for a week or two, without it ever really getting dark? Well it's not like that everywhere. Mummy says that the further away from Toptown you go, the more the Sun goes up and down. If you go far enough she says you've got to go right out to sea to really see this the Sun comes up for a little while every day even in the middle of Winter, and goes down for a little while every night even in the middle of Summer. She calls it The Land of the Midwinter Sun, which is silly, because it's out at sea.
Well, as time went by, people built bigger boats to go fishing in, and they caught more fish. If you've got a bigger boat, you can have a taller mast, and with a little girl or boy at the top of the mast, you can see further, so you can go further away from the land without losing sight of it. But you still can't go very far away from the land, and you're sure there are more fish further out, and you want to get them. So somebody worked out how you could find your way back home even when you'd gone out of sight of the land. Then people started going further and further away from home, looking for more and more fish.
And they found more islands! That was a surprise. Even more surprisingly, there were already people living on some of those islands funny people, who couldn't talk. Well, they could talk to each other, but they couldn't talk properly, and although they could understand each other, no-one else could understand them, and they couldn't understand anybody else. And they lived very rough lives, and wore very rough clothes and lived in very rough houses and had very simple boats, and no bicycles and no schools and no books or pencils and only a few very simple tools made from wood, bone or stone. No metal.
But that's a very long time ago, and all those people have learnt how to talk and how to live, and life on those islands is very like life on our island now, except that they're a long way away. Oh, and they are The Lands of the Midwinter Sun.
Now I've got to explain The Land of the Midwinter Sun to my star-circling friend. I'll worry about that later!
Most of those other islands are very little and they're a very long way from everywhere else, but Mummy says some people like living there anyway.
Then further away still, there are more islands, and some of them are very big you remember I told you about them, and said I'd tell you more about them later. Well, now is later. There were people living on some of those bigger, further away islands, too but not actually very many, because although the islands are very big, only a little bit of some of them is any good to live on, and even those little bits aren't very good to live on really. Very unhealthy and uncomfortable.
The livable bits are very hot and steamy, and there are lots of strange insects and strange animals. Some of the insects are very big and scary, and some of them little ones as well as big ones have really nasty bites, like a mosquito bite only much, much worse. You can get very ill, or even die, from an insect bite down there in The Land of the Midwinter Sun! Some of the animals can bite you to death, too, Daddy says. I don't know why he wants to go there.
Mummy says he's really more interested in the places beyond the livable bits.
Beyond the livable bits it gets hotter and hotter, and the Sun comes and goes more and more, until you get to the fattest bit of the world. Daddy says that at the fattest bit of the world, the Sun goes up and down like crazy. Every night, even in the middle of Summer, you can see the stars; and every day, even in the middle of winter, the Sun goes right across the middle of the sky! And it's ever so ever so hot. You can't go outside the ship for very long at all or you'd be cooked, Daddy says. It's only since they invented cooling systems like a big fridge for a whole ship, only not really cold, just cooler than outside that they've been able to go so far.
And those big islands really are big they stretch all the way to the fattest bit of the world and beyond. But they're just bare rock and sand, mile after mile after mile. People have got out of the ships and gone and climbed on the rocks and walked on the sand, but not for long. It's too hot.
Then after the fattest bit of the world, it starts cooling down again. It's still horribly, horribly hot for a long, long way, but eventually it gets down to temperatures where you can go outside for a while, and then cooler still and almost reasonable. And then finally the land isn't bare rock and sand any more, and there are forests on the land, a bit like the hot and steamy forests on our end of the big islands.
By this time, Daddy is thousands and thousands of miles away from Toptown getting near to Bottomtown, in fact. Except that there isn't any Bottomtown, because there aren't any islands at the bottom of the world, it's all sea.
And down there at the bottom of the world, the temperature's nice again, and the Sun goes round and round the sky properly just like it does here, except that when it's winter here it's summer there, and Daddy's never been to the bottom of the world when it's winter there and summer here.
And then there's the biggest surprise of all. It's all sea right at the bottom of the world, but there's lots of land not so very far from the bottom of the world, close enough to the bottom of the world that it's not too terribly hot, and there are people there, too. Quite a lot of them. And they can't talk, either well, they can talk to each other, but Daddy and his friends can't understand them, and they can't understand Daddy. That's just like the people that were found on the islands not so very far away from home, but in other ways they're not like those people. They've got good tools, and books that Daddy can't read, and roads and carts and things, and altogether quite an advanced society. And Daddy says there's lots we can learn from them, and lots they can learn from us once they work out how they can talk to each other.
But I should tell you a bit about Daddy's main interest. Daddy's a geologist. He looks at rocks, and tries to work out how they got to be the way they are. There's lots of geologists, and between them they've worked out an awful lot. They've worked out that the world is ever so, ever so old.
Which I think is funny. Surely the world just IS? Hasn't it always been here? How can the world have had a beginning? How can the world have an age, like a little girl, or even a grown-up? But never mind about that. I'll tell my star-circling friend about what Daddy thinks, not what I think.
They've found fossils of creatures that lived long, long ago, that were completely different from anything that lives nowadays. Some of them were amazing! That was millions of years ago, they reckon.
But one of the most amazing things is that much more recently, only thousands of years ago...
Only thousands of years ago? My Daddy is funny sometimes. Thousands of years is a long, long time.
...they think that the world was much colder than it is nowadays, and that Toptown was buried in ice. Ice miles deep. Can you imagine that? The world like a great big fridge. Rain falling from the sky frozen solid! Even maybe the sea frozen solid. Nobody could possibly have lived anywhere near Toptown. But people lived in a lot of those places that are too hot nowadays, Daddy reckons. Well, lots of Daddy's friends reckon that much, too.
They've found bits and pieces of things that they think those people long ago must have done, here and there on the coasts all the way to the fattest bit of the world, and a long way beyond. They reckon those people long ago did some pretty fantastic things, but most of the things they've found are pretty hard to understand. Daddy says thousands of years can mess things around rather a lot, and it's quite hard to work out what the things they've found must have been like before they got messed around.
They're pretty sure that there'd be a lot more things to find if they could explore further inland in the bare rock and sand places. Or if they could dig deep under the sand, there'd probably be interesting things there, too, because the sand gets blown about by the wind and buries things, and in thousands of years things can get buried very deep. But they can't get far away from the sea, into the middle of the land, and they can't dig deep, because it's so very, very hot there.
But what Daddy is thinking, he says, and what he's trying to get his friends to think about too, is that because of all that ice on Toptown, and another lot of ice he says there must have been on some of the islands down near where Bottomtown isn't, sea level must have been much, much lower than it is now. And lots of those people long, long ago would have lived on land that's under the sea now, and maybe there were a great lot of them.
He says that quite a few mysteries might be explained if there were billions of people for a few generations, all that time ago. Just imagine billions. Hundreds of times as many people as there are now thousands of times as many as there were just a few generations ago. He thinks that when the world was colder, all those big islands that are now too hot to live on, and mostly bare rock and sand, must have been good places to live. There'd have been plenty of room for lots more people billions, even.
Only Daddy doesn't call them people, he calls them proto-humans. He says people must have evolved from a few of them who survived some kind of big disaster something that heated the world up a great lot. I like the world how it is now, but they must have thought it was quite a disaster all those thousands of years ago.
Now from her Daddy's point of view...
“I must admit that’s what it looks like to me, too. But we can’t publish anything based on such flimsy evidence. Looked at objectively, it’s little more than wild speculation.”
“Can’t we? Lots of groups publish stuff that’s no more solid than this – less solid in some cases, if you ask me.”
“We’ve got our reputation to think of. Some people certainly do seem to get away with publishing things like this, but I can think of a quite a few groups who’ve damaged their careers beyond repair like that. It’s not a risk I’d take lightly.”
“But if we don’t publish, we’ll continue to be the only group looking at it; and with the evidence being so thinly and randomly scattered, the odds are that working on our own we’ll never find enough.”
“It seems randomly scattered, but perhaps it’s not really random. Perhaps we can think of a way to predict where we can locate it. We ought to put some effort into that. I understand very well what you’re getting at, but I don’t want to risk our reputation unless we really have to.”
“So. What do we have? Let’s tabulate it and put our thinking caps on for a while. Start with what we actually know for sure.”
“That’s actually less than we might think. Some important pieces of the jigsaw are the work of other groups, whose conclusions might be less securely founded than we’d like.”
“You’re both being risk averse. Don’t just think about the groups who’ve ruined their careers by publishing something speculative that turned out to be wrong. Think about the groups who’ve succeeded big time by publishing something speculative that turned out to be right. More to the point, think about the vast majority who slave away and never get anywhere because they don’t publish anything until after someone else has already published.”
“But no-one else is working on this, so that won’t happen to us.”
“Can we be sure of that? The big error the groups who spoil their reputations make isn’t publishing too soon, it’s clinging to their ideas after they’re disproved. If you’re open from the outset about how speculative the idea is, and you’re ready to abandon it if it turns out to be wrong, where’s the risk?”
“It’s not as simple as that. There’s psychology to think about. People are naturally sceptical of other people’s ideas, and they’ll regard an idea as untenable even if you don’t; they’ll think you’re clinging to a disproven idea long before you’re ready to abandon it. You don’t succeed big time by publishing something speculative that is actually correct and then abandoning it as soon as anyone pooh-poohs it. On the other hand, you don’t save your reputation by not abandoning an idea that turns out to be wrong until years after everyone else has ridiculed it. That’s not simply a difficult balancing act. There isn’t actually any space between the two problems at all. They overlap. It’s always, inevitably, a gamble.”
“And if you don’t gamble, you can’t win. It’s just a matter of making sure the odds are as good as we can make them. Okay.”
Unconformities are some of the most interesting things in geology. They form a gap in the geological record for the location, because rather than deposition occurring at that location, the surface was being eroded – meaning that not only is some old record being destroyed, but also no new record is being created for a period. But the state of the erosional surface itself at the time of the change back to deposition gets recorded – and that can be especially interesting.
In general, most deposition occurs under the sea, and land surfaces are mostly being eroded. Deposition on land does occur, particularly by water in the lower reaches of valleys, and by wind in deserts – but we think such deposits are often short-lived, and deposition and erosion occur in cycles over long periods. Thus many unconformities represent the state of the land at a time of sea level rise.
According to our theory, sea level is pretty much at an all time high at present, so that almost all the unconformities we can find – without trying to engage in underwater geology! – are in rocks that have been uplifted. These are all very old unconformities, and while they’re interesting, they’re not the most interesting of all. There are a relatively large number of them, and the erosional surfaces they represent have been widely examined. The interpretation of these surfaces is relatively secure.
The unconformities we have been investigating are those very few newer ones, formed above sea level since the beginning of the current period of high sea level, which had been tentatively dated to about 12,000 years ago. The deposits above the unconformities are mostly unconsolidated sediments, either river-borne or windblown, or, in a few places, volcanic ash or lava flows.
A couple of months later, we decided we were ready to go public and take the chance. It fell to me to present our ideas at the conference.
“Several lines of evidence suggest to us that about 12,700 years ago, a species of creatures very similar to ourselves – indeed, most probably a species from whose survivors we have evolved – underwent a population explosion, followed unsurprisingly by a population crash. At their peak, they may have numbered half a billion, possibly even more. We believe that a wide range of previously unexplained mineral aggregations with interesting chemical characteristics and sometimes with odd geometry on a variety of scales may be the remains of their extraordinary activities.”
“Much of the world’s surface has been remodelled by natural forces since that time. Much has been eroded away, and most of the rest is buried under more recent sediment. Only in a few places are these interesting aggregations at the surface, but presumably many more have been lost to erosion or are beneath sediment elsewhere. And of course that species, even with a population of half a billion, didn’t cover the whole surface of the Earth with the remains of its activities anyway, so the majority of locations even where the surface is of the appropriate age are devoid of them. In particular, for reasons that will become clear, they may mostly have lived in areas of the world not now inhabited.”
“You’re doubtless familiar with Peterson’s idea that, at some point in the past, the Earth was for some unknown reason considerably colder than it is today; that sea level was approximately seventy metres lower than it is today because the water was tied up in a great depth of ice on land at high latitudes; and that land at lower latitudes was cool, wet, and forested. We know many of you see difficulties with this interpretation of the evidence. However, we believe Peterson’s suggestions to be broadly correct.”
“One of the main lines of evidence for this is the existence in many places around the world’s coasts, of an approximately level platform seventy metres below sea level, which is remarkably similar to the wavecut platform at low tide sea level today. We would like to see more depth soundings around coasts in areas of the world where they are currently sparse or absent, to confirm or deny the existence of this platform elsewhere.”
“We suspect that deposits similar to those we have been investigating may be present more frequently under the sands of tropical deserts or under the sea, in most places under many metres of mud at the bottom of tens of metres of water.”
“We have reason to believe that, whatever the reason for the change in temperature of the Earth, it was approximately contemporaneous with the rise and fall of that species. Further investigations are required to determine whether the temperature change occurred just before the population explosion, presumably causing it, or just after it. So far the evidence points to the latter, suggesting, difficult as this might be to believe, that the temperature change may have been a result of the population explosion.”
I was challenged on several points by speakers from the floor, most of which were issues our group had already considered and where necessary investigated, and which I was therefore able to answer reasonably well.
The question of the variability of the exact depth of the seventy metre platform was raised, and of course we didn’t really have a good explanation of that. Peterson’s suggestion is that the bedrock may have moved vertically in response to the changes in ice and seawater loading. We are fairly sure that bedrock does move vertically, during mountain building for example, but it’s hard to believe that such movement has occurred significantly in a period of only 12,700 years.
One young woman had a very interesting contribution to make.
“This ties in well with something our group has been working on. Lake sediments in several places in the world show clear annual variations in particle size and composition, enabling us to date the layers precisely. In addition, they show a complicated but consistent pattern of variation from year to year. Several trace elements and compounds show a clear peak at about the same time everywhere, tailing off exponentially thereafter at different rates. We don’t currently have any site anywhere in the world that covers the whole period, but by matching up partial records from different lakes or fossil lakes we have managed to make a pretty convincing montage of worldwide particulate deposition from the atmosphere. We had quite independently arrived at that 12,700 year figure for the peak.”
She went on, “Recent variations from year to year can be clearly associated with particular volcanic eruptions, and most of the older variations seem to be of a similar character and we tentatively associate them with earlier, undocumented eruptions. The 12,700 year peak is of a markedly different character, involving a radically different spectrum of elements, and in particular several organic molecules that as far as we can ascertain are found nowhere else in nature. The length of the recognizable tail is much longer, due to the greater residence time in the atmosphere of some of the materials involved.”
We are still waiting to see whether we will be proved right or wrong, or whether, even if we are right, anyone will believe us. Extensive excavations under hot desert sands haven’t proved feasible, and it’s difficult to persuade sailors to measure the depth of the sea in locations where they have little interest in the information themselves. Evidence is mounting, however, and it now seems likely that the peak population of these proto-humans may have been as high as ten billion, and that they may have inhabited a substantial percentage of the world’s land area, far more than is habitable today.
The Land of the Midwinter Sun ©Clive K Semmens 2009, Wild Speculation ©Clive K Semmens 2013