Past resembles distance; our view there becomes unreliable und loses itself, if not history and chronology had set up beacons, torches at the most obscure places; but despite those lights of written tradition, going back several centuries, which uncertainties concerning the facts, which errors about the causes of events and which profound obscurity does not surround the times before that Tradition!
Georges-Louis Leclerc de Buffon (Learn more)
The photograph contrasts the lifetime of a human – depicted in passport photos of the author of this text made over a period of a few decades – with the time that is available to the Earth, represented by rocks of different ages, whose evolution takes millions of years. During the time when a human ages and traces of this process become visible, the rocks remain unchanged. Their evolution takes place on a time scale for which the term "deep time" was coined. (Learn more)
The contrast shown in the photograph between different time scales – the human timescale and the time scale on which the 'life' of rocks takes place – serves as a prelude to the topic of this text. In a multi-part series, I would like to approach, step-by-step, an understanding of the different time scales on which, at one end, human life, and, at the other end, the history of Earth takes place.
In this blog post, I first provide a brief philosophical classification of the topic. In the second blog post, we deal with landscape changes in prehistoric and historical times. In the third blog post, we get to know lakes in the Black Forest and the Vosges as geological archives.
On June 19, 2026, there was a lecture at the Atelier Klausenpfad in Heidelberg (in German; covering the content of the first three blog posts).
Hans Blumenberg’s 'Weltmißbefinden'
Our life inevitably takes place in time. We think, speak, feel, move – indeed, we exist in this „medium“ like a fish in water. We cannot take ourselves out of time.
And yet, as mortal beings, we 'have' only a limited amount of time.
The German philosopher Hans Blumenberg (1920 – 1996) has expressed this in a smarter way (Learn more):
Time is the most ours, but the least available.
Hans Blumenberg talks about a mental state 'Weltmißbefinden' – which can be translated to world-discontent – when he tries to grasp the following primordial human experience („Ur-Erfahrung“):
Within a single human life, only a tiny part of what the world as a whole has to offer can be experienced. When we are born, the world exists already and many things have already happened without our participation. When we die, the world continues to exist and those living after us will have experiences that are denied to us.
According to Blumenberg, since the Fall of Man – the realization of our mortality – a gap yawns between the 'Lebenszeit' (lifetime) – the limited span of a human life – and the 'Weltzeit' (world time) – the time that is available to the world as a whole. (Learn more)
Horizons of memory
With our personal memory, we explore the area within the horizon of our lifetime. Memory takes us back to some more or less clear impressions from our childhood, which are placed like „beacons“ at the edge of a darkness, in the depths of which our birth must have occurred somewhere. But the more we try to focus on an event far in the past, the more that picture – which had started to become apparent – blurs.
For example, I think of a day during my childhood when we were on vacation in the mountains. We hiked to a nearby village. Maybe I was 4 years old or so. I see the silhouettes of farmhouses with their big roofs. And I realize a wooden stick I used to scratch a line into the gravel walk. Only this detail has been preserved. The image does not become any clearer. My personal memory reaches a limit here.
When parents talk with their children about experiences far in the past, the collective remembering creates a story of what supposedly happened once. This story is told – and changed – again and again. Personal and collective memory complement each other; the boundaries sometimes blur. Documents like old letters and photographs can act as reference points that help to fix this narrative.
An interesting perspective arises from the time span during which a single human can be connected with other humans through direct generational succession. The Icelandic writer Andri Snær Magnason presents this perspective powerfully in his book On Time and Water. The author’s daughter can still have a personal connection to her great-grandmother and (possibly later in her own life) to her great-grandchildren – a time span of about 260 years. This means that for a single human being, the time span of a quarter millennium is tangible. (Learn more)
The historical memory covers a significant larger period. A possible point of reference is the invention of writing. Cuneiform, which developed from pictorial signs, is first attested for the 4th millennium BC. The alphabet script emerged around 1700 BC on the Sinai Peninsula.
Human knowledge was also carried on from generation to generation by oral tradition. Already thousands of years ago, sailors in the Pacific used sophisticated navigational techniques to travel securely between the widely separated islands of Micronesia and Polynesia. These techniques were based on the knowledge of the rising and setting of bright stars on the horizon and also included the observation of the behavior of birds, ocean waves, and wind patterns. These skills were handed down orally from generation to generation, though it is unknown exactly when this tradition began. (Learn more)
Archaeological finds provide evidence of much earlier epochs of humanity. However, what early humans thought or felt can hardly be derived from these artifacts – if at all.
Like personal memory, humanity’s collective memory trails away in a darkness, and our gaze would disappear completely – as Buffon expressed so nicely – 'if not history and chronology had set up beacons, torches at the most obscure places'.
Time of Earth – the abyss of time
This means, also for humanity there’s a time 'before' and a time 'after'.
There was a time in Earth’s past when humans as a species did not yet exist, and, possibly, there will be a time when humans have disappeared from Earth's surface.
Geological processes happen on those time scales that come into view here. Mountains form and are eroded away again, continents change their position. But these changes take place on time scales beyond our human time horizon – outside the range that is accessible to our personal, familial, or even our historical memory.
Although we, as abstract-thinking beings, can deal with the parameter of time in scientific equations as a matter of course, it is hard for us to translate such slow processes as the rise and erosion of mountains into our everyday understanding, or to build a relationship with this knowledge.
I can observe that every time during a rainfall a little bit of soil eroded from a slope or how during an extreme weather event a street is spilled by an earthslide. I can try to imagine what happens when such events repeat themselves over millennia. Nevertheless, long-term processes such as the transformation of a landscape relief elude a deeper understanding. They can be accessed neither through perception, memory, nor through tradition. They belong to the 'profound obscurity' of which Buffon spoke.
He used – like other natural philosophers of the Enlightenment – metaphors from the historical sciences to describe the evolution of Earth, the history of Earth. In his theory, he divided this history into seven epochs. In the last epoch, man appears.
Buffon formulated his ideas at a time when large parts of society assumed that the age of the Earth was about 6000 years – a number that was given by biblical chronologies. However, many natural philosophers of the time who dealt with strata or fossils assumed that there must be geological processes that take significantly longer than just a few millennia – so did Buffon.
He developed a theory according to which the Earth was initially a hot, molten sphere. With the equations of early thermodynamics he calculated how long it took until Earth had cooled down to today’s temperatures. On his estate in Montbard, Burgundy, France, he made experiments with heated metal spheres in order to determine cooling rates for solid bodies. (Learn more) Based on these considerations and experiments, he estimated the age of the Earth at about 75 000 years.
It is interesting to note that Buffon was among the first to assume that humans are able to cause a change in the Earth's climate. Since in his model the Earth was inexorably cooling down, from his perspective it was – unlike the consensus today – considered desirable that humans did everything in their power to counteract the cooling – for example, by burning coal. (Learn more)
The dicovery of radioactive decay end of the 19th century made it possible to develop modern dating methods. With their help, in the 1950s, the age of the Earth was estimated at 4.54 billion years. (Learn more) That is 60 000 times longer than Buffon had estimated.
With this knowledge, we rate ourselves superior to the natural philosophers of earlier centuries. However, the pure number with 10 digits doesn't help us grasp this immense span of time. We find ourselves, in the truest sense, face to face with an abyss of time which should make one humble.
To emphasize the challenges posed to us by such long geological time spans, the term deep time was established. The determiner 'deep' holds a poetical dimension and refers to a domain that is detracted from human comprehension.
The palaeontologist Stephen Jay Gould asserts that we can comprehend deep time only as a metaphor (Learn more):
An abstract, intellectual understanding of deep time comes easily enough – I know how many zeroes to place after the 10 when I mean billions. Getting it into the gut is quite another matter.
Deep time is so alien that we can really only comprehend it as metaphor.
Approaching deep time – the retrospective narrative mode
With this text, I’d like to approach an understanding of deep time step-by-step.
It seems obvious, when writing a popular science text that deals with cosmology or Earth history, to start from a presumed initial point – typically, the Big Bang – and to work one's way forward from there through the past up to the present. This narrative mode suggests an omniscient narrator who surveys those immense periods that this „world narrative“ is about.
I instead adopt a more modest perspective by using a retrospective narrative mode: starting from the human time perspective familiar to us, the reader is guided step-by-step deeper into the past, toward ever larger time scales and ever more unfamiliar terrain. (Learn more)
From this perspective, initial – comparatively rapid – geological changes soon become perceptible: changes in vegetation, shifting of river courses, and the development of lakes. These processes happen slowly from a human perspective – they cannot be perceived even on the time scale of several human generations. However, they produce visible changes already within historical time spans. In a next step, we compress the time scale step-by-step so that long-term processes like mountain building or continental drift become visible.
The natural monument known as the 'Balzer Herrgott'. A long time ago, a stone statue of Christ was placed against a tree in the Southern Black Forest, forgotten there, and gradually engulfed by the expanding trunk over the years. The tree continues growing inexorably and will finally enclose the statue – a change in the vegetation that happens slowly but can be perceived within the time span of a human life. Human artwork, however, persists over centuries or even millennia, outlasting historical periods. But if we expand the time scale and try to envision a depth of time reaching millions of years into the future, then this stone testimony to human presence will also have disappeared.
A historical-literary reference – the Mummelsee episode in the works of Grimmelshausen
To begin discussing changes to Earth’s surface that occur relatively quickly compared to geological time scales, I’d like to tell you the story of a few small lakes in the Black Forest and the Vosges – mountain ranges in Germany and France. These lakes formed at the end of the last ice age in depressions created by retreating glaciers. These terrain formations are called cirques. Consequently, the lakes are referred to as cirque lakes.
One of these cirque lakes is even referenced in world literature.
In the picaresque novel The adventurous Simplicissimus, written by Hans Jakob Christoffel von Grimmelshausen (1622 – 1676) and published in 1668, the protagonist undertakes an excursion to this remote location, that was accessible in the 17th century exclusively by a lengthy march.
Let’s begin our journey into the depths of Earth’s past within the realm of historical memory. To do so, let’s mentally transport ourselves to the 17th century – to a time that seems foreign to us today in many ways. We will read a short excerpt from the novel. (Learn more)
So together we set off over hill and dale and came to the Mummelsee; and that before we had gone six hours, for my dad was as lively as a cricket and as good a traveller as any young man. And there we consumed what meat and drink we had brought with us, for the long journey and the high mountain on which the lake lieth had made us both hungry and thirsty. So having refreshed ourselves I did inspect the lake, and found lying in it certain hewn timbers which my dad and I took to be the remains of the Würtemberg raft : and I by geometry took or estimated the length and breadth of the water (for 'twas far too wearisome to go round the lake and measure it by paces or feet), and entered the dimensions, by means of the scale of reduction, in my tablets. And having done this, the sky being completely clear and the air windless and calm, I must needs try what truth was in the legend that a storm would arise if any should throw a stone into the lake; having already found those stories I had heard, how the lake would suffer no trout to live in it, to be true, by reason of the mineral taste of the waters.
The text contains some interesting details, for example, 'the remains of the Würtemberg raft', which point to the fact that this lake was not as isolated from human activity as it might seem at first glance.
The photograph shows the Mummelsee in the year 2006. Today, the lake lies on the busy Black Forest High Road, with a hotel on its shore.
The Mummelsee in the year 2006.
Mummelsee is perhaps the most popular glacier cirque lake in the Black Forest. However, there are others: the Black Forest and the Vosges together have about 30 such lakes. (Learn more)
In the next blogpost, we visit these lakes and learn about their history.
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Translation into English: Thomas Knorra, scientific advice: Ingrid Schindler.
Original text in French:
Le passé est comme la distance; notre vue y décroît, & s’y perdroit de même, si l’Histoire & la Chronologie n’eussent placé des fanaux, des flambeaux aux points les plus obscurs; mais malgré ces lumières de la tradition écrite, si l’on remonte à quelques siècles, que d’incertitudes dans les faits! que d’erreurs sur les causes des événemens! & quelle obscurité profonde n’environne pas les tems antérieurs à cette tradition!
Cf. Leclerc, Georges-Louis and Buffon, Le Comte de (1780): Les Époques de la Nature, Volume 1, L’Imprimerie Royale, Paris, p. 2
Zeit ist das am meisten Unsrige und doch am wenigsten Verfügbare.
Cf. Blumenberg, Hans (2020): Lebenszeit und Weltzeit, Suhrkamp, Frankfurt am Main, 6. Auflage, p. 74.
×Cf. Blumenberg, Hans (2020): Lebenszeit und Weltzeit, Suhrkamp, Frankfurt am Main, 6. Auflage, p. 77.
According to Blumenberg, the gap between lifetime („Lebenszeit“) and world time („Weltzeit“) gives rise to a discontent with the world ('Weltmißbefinden'), that is, an awareness of the 'deficit' of missed opportunities for living. This discomfort can – according to Blumenberg – knock over into a compulsion, to enforce the convergence of lifetime and world time – thereby facilitating pathological developments, including susceptibility to false promises of redemption and to fascism.
I do not think it is too far-fetched to see in these prescient reflections from the 1980s an anticipation of developments such as the rise and increasing influence of the Make America Great Again (MAGA) movement in the United States, as well as the apparent disregard shown by some technology billionaires for the finite lifetime of present and near-future generations.
Most concisely, Blumenberg might have formulated this pathological relationship to time in the following statement where he refers to the the Apocalypse of John (12, 12), p. 71:
Narrowness of time is the root of evil.
German original text (translated by me):
Enge der Zeit ist die Wurzel des Bösen.
An alternative approach has been offered by Pope Franziskus in his writing Evangelii Gaudium from 2013, where he formulates the following principle:
Time is greater than space.
One of the faults which we occasionally observe in sociopolitical activity is that spaces and power are preferred to time and processes. Giving priority to space means madly attempting to keep everything together in the present, trying to possess all the spaces of power and of self-assertion; it is to crystallize processes and presume to hold them back. Giving priority to time means being concerned about initiating processes rather than possessing spaces.
Why do I insist on these social and political implications?
In the course of this essay, I will argue that an unclear relationship to deep time carries the risk of setting in motion developments that may steer our societies into turbulent waters. In particular, I have in mind certain offshoots of longtermist and transhumanist philosophy, as well as the visions of some billionaires, which already seem to have the planet's very distant future in view and to envisage the colonization of Mars, but which appear to lack any empathy for people living today or in the near future. I will return to this in a later section.
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Cf.
[Magnason, Andri Snær (2025): On Time and Water](https://andrimagnason.com/books/on-time-and-water/)
The theme of this book is that global warming is already happening so rapidly that extensive and long-lasting changes, such as the melting of Iceland’s glaciers, are already perceptible within the span of a single human lifetime – or within a span of 260 years that people can directly relate to.
×To find out to what extend this tradition has survived until nowadays, the circumnavigator and adventurer David Lewis (1917 – 2002) visited a couple of archipelagos in the Pacific and made contact with local people. He interviewed those who were skilled in navigation, learned traditional techniques from them, and embarked on longer voyages at sea.
Cf. Lewis, David (1994): We, the Navigators: The Ancient Art of Landfinding in the Pacific, University of Hawaii Press, Honolulu, 2. Auflage.
It is difficult to determine exactly how far back these oral traditions date. However, archaeological finds suggest that remote islands in the Pacific were already settled thounsands of years ago – which implies that advanced navigational techniques must have existed at that time.
Cf.
×For an overview, cf. Dalrymple, G. Brent (1991): The Age of the Earth, 2nd Edition, Stanford University Press, Stanford, p. 29.
×The term was popularizes in the 1990s by John McPhee. For the citation from Stephen Jay Gould, cf.
Gould, Stephen Jay (1987): Time's Arrow, Time's Cycle: Myth and Metaphor in the Discovery of Geological Time, Harvard University Press, Cambridge, Massachusetts and London, England, p. 3.
The discovery of deep time can be considered as a further metaphysical humiliation. As generally known, the following three discoveries have set into question the self-perception of man such extensively that the term 'humiliation' is used, a term coined by neurologist and founder of psychoanalysis Siegmund Freud (1856 – 1939).
The cosmological humiliation followed the work of Nicolaus Kopernikus (1473 – 1543) which shattered the certainty that Earth was the center of the universe. The biological humiliation arose from Charles Darwin`s (1809 – 1882) theory of evolution, which revealed that humans had evolved from the animal kingdom. Finally, the psychological humiliation came with Siegmund Freud, whose theory posited that a significant part of our mental life remains inaccessible to conscious awareness, and that the 'ego' has only limited mastery 'in its own house'.
×I adopted this narrative technique from the biologist Richard Dawkins who has used it in the following book:
Cf. Dawkins, Richard (2016): The Ancestor’s Tale: Pilgrimage to the Dawn of Life, Houghton Mifflin (US) Weidenfeld & Nicolson, 2nd Edition.
In his book, Dawkins tells the stor yof the evolution of life on Earth in retrospective order: starting with humans. From this point, he moves backward to the point where the last common ancestor of hominides and great apes lived, about 6 million years ago. Then it traces back to the next branch in the tree, and so on, until it finally reaches the first cell. In this way, it avoids a narrative that ends with humans as the supposed 'goal' of evolution.
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German original text (early new high German):
Also wanderten wir miteinander über Berg und Thal / und kamen zu dem Mummelsee / ehe wir 6 Stund gegangen hatten / denn mein Petter war noch so käfermäßig und so wohl zu Fuß als ein Junger; Wir verzehrten daselbst was wir von Speiß und Trank mit uns genommen / dann der weite Weg und die Höhe des Bergs / auf welchem der See ligt / hatte uns hungrig und hellig gemacht; Nachdem wir sich aber erquickt / beschauete ich den See / und fand gleich etliche gezimmerte Höltzer darinn ligen / die ich und mein Knan for rudera deß Würtenbergischen Flosses hielten; ich nahm oder masse die Länge und Breite deß Wassers vermittelst der Geometriae, weil gar beschwerlich war umb den See zu gehen / und denselben mit Schritten oder Schuhen zu messen / und brachte seine Beschaffenheit vermittelst deß verjüngten Maßstabs in mein Schreibtäfelein / und als ich damit fertig / zumaln der Himmel durchauß hell / und die Luft gantz windstill / und wol temperirt war / wolte ich auch probiren was Wahrheit an der Sagmehr wäre / daß ein Ungewitter entstehe / wann man einen Stein in den See werffe; sintemal ich albereit die Hörsag / daß der See keine Forellen leide / am Mineralischen Geschmack deß Wassers wahr zu seyn befunden.
cf.
von Grimmelshausen, Hans Jacob Christoffel (2024): Simplicissimus Teutsch, Herausgegeben von Dieter Breuer, Deutscher Klassiker Verlag, Frankfurt am Main, 6. Auflage (erste Auflage 2005). Diese Ausgabe entspricht Band I/1 der Edition Hans Jakob Christoffel von Grimmelshausen, Werke in drei Bänden, herausgegeben von Dieter Breuer, Frankfurt am Main 1989, p. 490.
The protagonist of this novel, Melchior Sternfels von Fuchshaim – or simply: Simplicius Simplicissimus – is kidnapped as a child by soldiers during the Thirty Years' War. He subsequently pursues a military career. After a partly colorful life journey, during which he experiences and also commits many cruelties, Simplicius eventually turns away from the „earthly world“.
English translation:
Cf.
Grimmelshausen, Hans Jakob Christoph (1912): The adventurous Simplicissimus : being the description of the life of a strange vagabond named Melchior Sternfels von Fechshaim, London, p. 379
×Uranium-lead dating, which relies on the uranium-lead decay chains, played a crucial role. The geochemist Clair Cameron Patterson (1922 – 1995) applied this method to samples from the iron meteorite Canyon Diablo iron meteorite, whose impact formed the Barringer crater in Arizona 50.000 years ago. The meteorite originated from an asteroid with a diameter of 60 kilometres.
Using this approach, Patterson derived an age of the Earth of $4.55 \pm 0.07$ billion years.
Cf. Dalrymple, G. Brent (1991): The Age of the Earth, 2nd Edition, Stanford University Press, Stanford, p. 321.
Through his work, Patterson gained extensive knowledge about the element lead and became deeply engaged in studying atmospheric lead concentrations. He investigated how lead levels in the atmosphere changed over time and discovered that, before 1923, the atmosphere contained almost no lead. However, after this point, concentrations rose sharply, reaching levels harmful to human health. This increase correlated with the year tetramethyllead began to be added to gasoline.
His work and advocacy ultimately led to the Clean Air Act of 1970, which introduced stricter emission regulations, and in 1986, the sale of leaded gasoline was banned.
The Tyler Prize for Environmental Achievement—which Patterson received in 1995—recognizes his contributions on its website as follows:
The chain of lead contamination that Dr. Patterson traced from the gas pump and other sources to the human blood stream has resulted in revolutionary changes in public policy. His findings gave rise to a political effort that resulted in a phased end to the sale of leaded gasoline in the Clean Air Act of 1970.
×
For this counting, I refer to the following work:
Woldstedt, Paul and Schwarzbach, Martin (Hrsg.). (1967): Eiszeitalter und Gegenwart: Jahrbuch der Deutschen Quartärvereinigung, Volume 18, Hohenlohe'sche Buchhandlung Ferd. Rau, Öhringen, Württemberg, p. 53.
https://egqsj.copernicus.org/articles/egqsj-volume18.pdf
The authors to a large extend lean on the following study, but supplement his information:
Fezer, Fritz (1957): Eiszeitliche Erscheinungen im nördlichen Schwarzwald, Selbstverlag der Bundesanstalt für Landeskunde
According to these sources, the northern Vosges (north-west of the Bruche Valley) contain one cirque lake (Lac de la Maix). The southern Vosges contain 12 cirque lakes (including the well-known Lac Vert and Lac Blanc). The southern Black Forest contains one cirque lake (the Feldsee on the slope of the highest mountain, the Feldberg), and the northern Black Forest contains eight such lakes (including the Mummelsee). Strictly speaking, two of the lakes in the northern Black Forest still exist only because they were dammed by humans in historical times. We will return to this topic in the next section.
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The upper half of the image shows the development of a human – using the example of passport photographs from different periods of his life arranged in chronological order. To contrast the relevant time scale of about a few decades with the time scales on which Earth develops, the lower half of the image shows rocks representing different rock types and originating from very different geological periods, arranged from left to right in order of increasing age.
There, at right, a pumice (rock class: magmatic) from the French Auvergne region (Puy de la Vache); it originated very like from a volcanic eruption about 8000 years ago. The second rock from left is a piece red sandstone from the northern Black Forest (from sediments of the lower Trias that were sedimented about 247 million years ago). The third rock from left is a piece of granite from the Günterfels in the Black Forest. As part of the Triberger Granit series, this rock formed about 325 to 330 million years ago in the Karbon period during the Variscan orogenesis; about 65 million years ago, this rock was laid bare by erosion. The fiurth rock from left is a piece metamorphic rock from the Silvretta massive in the Austrian Alps; the last significant metamorphis took place presumably during the Variscan orogenesis (when the supercontinent Pangaea formed), but maybe also later during the development of the Alps. The rock at the extreme right contains a fossil oif a creature that lived in the middle Devonian about 385 million years ago and that was „eternized“ in sediment rock (limestone).
The rocks shown in the image have changed little over the course of a human lifetime. Yet each reveals its own unique history when the timescale of Earth history is compressed and we journey ever deeper into the depths of geological time.
×
Cf.
Wyse Jackson, Patrick N. (2006), The Chronologers' Quest: The Search for the Age of the Earth, Cambridge University Press, p. 112
