“I wrote the book that I would have liked to learn from.” 
A. Zee and Steve Weinberg
South Kenya near Maasai Mara ; a few minutes after six. The sun has set and it is dark. Tonight four Maasai warriors – distant family of Narrator – keep guard at the edge of the camp. The campfire burns. Carla has set up her tent for the night: the sleeping bag lies rolled up on the camp bed, so a snake does not have a chance to crawl into it. Now she looks at the flames and waits for the others.
Man comes first; he has finished his daily medical check.
“Everything fine?”, asks Carla.
“Ferdinand says so. I'm tired soon and during day time I still have to get used to the heat”, says Man.
“Fortunately in August the difference in temperature between home and Kenya is less. This month is excellent for visiting the parks. Take care of yourself. When it is necessary, we can split ourselves from the rest of the group and stay in a luxury hotel until the others return from northern Kenya.
I hope that we can meet Narrator's brother and sisters in two weeks in this area via his cousin: I am curious about the stories of their youth”, says Carla.
“I think I can manage. It's nice that we have met Narrator's nephews last night. Shall we go to our cook to see his progress with the supper? Maybe he still needs some help”, says Man.
Carla and Man go to the cooking tent where the cook prepares supper. They help him with the meal. When the food is ready, the others – who now have set their sleeping place – come to the cooking tent. After washing the dishes, they sit around the campfire.
“The campfire is beautiful, but in fact we should look at the starry sky. Thus, we can – in my view – look all the way to the origin of our universe”, says Man.
“We see the origin of the universe everywhere . A classic book on astronomy states:
“All places are alike: this cosmological principle declares
that apart from local irregularities the universe is the same everywhere.”
Everywhere we see the consequences of the Big Bang that according to today's standard model shapes the beginning of the universe we can observe tonight in our human form. What has happened before the Big Bang and what is happening outside our perception beyond the Big Bang, we cannot see”, says Carla.
“What do you think has been before the Big Bang?”, asks Man.
“Before I will give my ideas about this question, I will explain – with omission of many, many details – the contemporary standard model for the Big Bang with its different variants. In this standard model, very small and very large meet in one and the same calculation. It is presumed that the universe – that we can perceive – has arisen at one single point, because from astronomical observations it appears that the universe is extremely uniform on mainlines, and it has expanded uniformly everywhere. Where we look, the expansion is completely even and uniform: this means that the middle and the edges of our universe expand evenly whereby the distant parts of our universe move faster away than the nearby parts. This also means that according to the standard model our universe has originated in a flash at one very tiny point from an extremely large amount of energy. The enormous energy of a supernova star – released during the explosion at the end of its life – is just a tiny fraction of the energy that caused the creation of our universe and its expansion.
Until about 25 years ago, the calculation of atomic physics and quantum mechanics (the tiny minimum) were incompatible with the calculation of astronomy and the theory of general relativity for modelling our contemporary – vast and expanding – universe: the combination of both calculation always resulted in "indefinite endless", because this is the result of dividing by zero.
Calculation models in theoretical physics should be mathematical sound. In case a calculation model in physics does not meet the formal language of mathematics, then – most likely – a calculation error is made; or worse: there is a fallacy.
Classical mathematics can easily handle ordinary numbers or fractures of numbers. Later, the concept of infinity – or innumerable – has joined and rather late the concept zero appeared. Recently, mathematicians started calculating with imaginary numbers and – in topology  – specific shapes.
Until now, dividing by zero is not possible in mathematics; usually an approximation of the calculation is made by dividing by a very small positive (and / or negative) number . This approach approximates the outcome of the division: the outcome of this approach is – from either side – either positive infinite or negative infinite depending from which side the approach is made.
As I said before, the calculator model for the Big Bang includes an extremely large number – based on astronomy – divided by virtually zero – viewed from quantum mechanics – and the outcome is steadily plus and / or minus infinite. This infinite outcome does not fit into the cosmology we perceive, because – according to our observations in astronomy – the universe is estimated to exist about 14 million years, and we can observe the edges of our universe with precision instruments.
From 1970, theoretical physicists have used for their calculations extremely tiny mathematical strings, and later manifolds – with different degrees of success – that are finite; much smaller than all we may observed in atomic physics, but significantly larger than zero.
With this string theory , the most amazing mathematical models are made sound: mathematically, other universa may easily exist parallel to our universe; particles may originate and disappear continuously from the void, that still contains a lot of energy”, says Carla
“Sorry for interrupting you. In my daily life, I am a professor in physics at a high school. Half a year ago, I was studying in quantum mechanics in my own time. I have always wondered where the Big Bang had originated from. What's your idea about that?”, says Peter.
“According to theoretical physics, the standard model for the big bang presupposes at the creation of our universe a very tiny spot that is many times smaller than an atom; from this tiny spot a number of dimensions of a manifold have been formed or – better – unfolded. This unfolding is comparable to the opening of flower from a button.
The number of dimensions that have expanded within our universe – similar to blossom leaves, are at least the known four dimensions of space time: length, width, height and time. But most of the time the models take into account 10 or 11 dimensions, because it is the smallest number of dimensions, that give pretty conclusive results.
There are several models for the origin of the unimaginable energy during the big bang. One model assumes that the full energy within our universe has been arisen and expanded fully simultaneously with the unfolding of the dimensions. Within this model, I think it interesting to note that the photons at the extreme edge of the big bang have not gained any understanding of time and change, because no information about change – and thus time – can reach these photons anymore. These photons have not grown older after their birth at the big bang, because these have not received any change and new information afterwards.
A second model presupposes that the dimensions have first been unfolded and expanded to create a void wherein the full energy is arisen and expanded afterwards from one tiny spot”, says Carla.
“With this second model, I am reminded of the 19th century physics framework of thought, that had presupposed a medium – or an ether – for conveying light rays, just like waves propagating in water and sound waves propagating through the sky. At the beginning of the 20th century, Michelson and Morley  have demonstrated with an interferometry for the first time, that this medium or ether is not present. I wonder whether or not medium or void is necessary for the creation of our universe”, says Peter.
“Probably there is also a third model wherein the void already exists before the dimensions and the energy originate and unfold at the same time or after each other.
I personally think that the empty space – that actually contains a lot of energy according to the standard model – has developed together with the unfolding of the dimensions. But it is quite possible that a form of emptiness has already existed or has even been always present. How this void looks like, is outside our universe and this emptiness is by definition beyond our reach. In case this void is uniform and completely empty, this emptiness has the highest order and thus the lowest imaginable entropy ; and this void corresponds to "being-whole"  according to Martin Heidegger's view; or this void may well be the original "All-encompassing One". Even without this original emptiness, the origin of our universe – wherefrom the universe has expanded from one point – has the highest order and thus the lowest conceivable entropy: it is –as far as we know – “being-whole" or the original "All-encompassing One".
Is "being-whole" or the original " All-encompassing One" in the form of empty space the medium or not? I do not know. I do not think there is an original ether present; I cannot prove it: it is an intuition. But I think that during the big bang wherefrom our universe has originated, the medium and the universe have unfolded together; I cannot prove this either.
The question why only a limited number of dimensions unfolded at the big bang, has not yet been answered unambiguously. It is true that the calculations with 10 or 11-dimensions show some sound results, and we assume a universe that matches with sound mathematical calculations. All in all, we assume an "elegant universe" .
When considering these 10 or 11 dimensions, I wonder about many questions, such as:
- Hasn’t there been enough energy available to allow more dimensions to unfold from the tiny spot at origin of our universe?
- Are more dimensions expanded from the origin of our universe than we know, because we cannot perceive these other dimensions?
- Have similar or other universes expanded from points outside the origin of our universe? If so, are these arisen at the same time and if so, how many other universa are there outside our universe? Mathematics allows this easily by extending the necessary dimension in the calculation model.
These questions are easily forwarded, but we cannot retrieve the unambiguous answer in our manifestation as human being”, says Carla.
“Your description – of the standard model for the creation of our universe – closely resembles the Story Creation in the beginning of the book Genesis in the Bible. It seems that humanity has only a limited numbers of myths for its creation and worldview [16a]. If I understand it correctly, everything within our universe has originated in an identical way from a tiny origin, that may well be empty; nothing is privileged and everything is equivalent and uniform from the beginning. Then the question remains how the galaxy systems, our solar system, the stars and the planets have originated from this tiny point?”, asks Man to Carla.
“You are right: I think there are only a limited number of myths in the imagination of humanity. For the explanation of the origin of our universe, we must with our imagination go beyond the existing myths.
The physicist Richard Feynman  has said that:
Our imagination is stretched to the utmost,
not – as in fiction – to imagine things that are not really there,
but just to comprehend those things that are there. 
As I have said before, our universe is uniformly expanded everywhere from an absolutely minimal point. Wherever we look at the starry sky: everywhere the universe expands at the same speed. This means that everything has arisen equally and evenly from this original spot. Or, as you said: "Nothing is in any way privileged above anything else". This is perfectly correct when we look from a distance at our universe; everything is uniformly distributed on the scale that is significantly larger than a galaxy. But when we zoom into a galaxy, or certainly to star systems and planetary systems, the uniformity of matter and radiation decreased further with every step: ever-increasing differences arise.
Where do these differences come from? In fact, we do not know, but the standard model – or the standard myth – assumes that our universe has started approximately 13.8 billion years ago at a minimum point of approximately zero. The temperature was more than 1.5 x 10¹² K., and all matter, energy and radiation were unimaginably homogeneous. After 0.1 second the temperature has fallen to 10¹¹ K. . Not much later, due to quantum mechanical fluctuations, the first very small irregularity arose in this homogeneity.
There is a variant of the standard model that assumes that matter and antimatter are created together. In matter and antimatter, the electrical charges of the particles are each other's opposites, and according to the Feynman diagrams  (co-developed by Richard Feynman) antimatter does not go forward in time, but goes backward in time . The matter and the antimatter have merged in an unimaginable amount of energy – or, more specifically, converted into energy – but due to a small irregularity, there was a little matter than antimatter . From this matter our universe has come into being and the energy of the merger is the major engine for the uniform and even expansion.
It is also possible that the matter of our universe has evolved along the positive axis of time, while the antimatter has unfolded along the negative axis of time: hereby, matter and antimatter – both arisen during the big bang – did not encounter each other, so that neither could have annihilated in energy after the big bang.
Around one second after the big bang, our universe has cooled to 10¹° K and the first particles have appeared within the – still homogeneous – whole. After about 15 seconds the temperature has dropped to 10? K – that is 70 times the temperature of our sun – and the first chemical elements such as hydrogen and helium appear.
The next 700,000 years atoms appear and our universe expands further. The small quantum mechanical irregularities that have previously occurred within homogeneity, cause that matter cluster in galaxies and stars under influence of gravity. In a metaphor: the homogeneous whipped cream slowly shifts into clots and empty transparent liquid.
After about 10 million years, the first living creatures arise in our universe .
At this moment our universe is still expanding, whereby the entire universe cools further. Of course, the temperature will increase locally at the rise of new stars and during a super nova, but the total energy will be distributed over a larger space.
Depending on the total amount of mass in our universe, three scenarios are possible according to the standard model:
- There is insufficient mass to shrink our universe again. This means that our universe continues to expend further and everything will continue to cool down. This ultimately results in a cold universe with potential a local temporary increases of energy, perhaps even periodically as in John Conway’s “Game of Life” ;
- There is just enough mass to stop the expansion of our universe at some point without any further expansion or contraction;
- There is enough mass to stop the expansion of our universe and then this mass will cause that eventually our universe shrinks to one point again .
This third scenario has two variants. The first variant: after the shrinkage, our universe will return to its point of origin to annihilate (for example, by colliding with antimatter) and disappear. And the second variant: our universe comes back to the origin to start a new big bang in a next cycle of expansion and shrinkage . These last cycles can be repeated unimaginable many times. I always think of a Möbius ring, whereby the outbound journey is the same as the return journey, with the difference that the outbound journey takes place at one side of the surface and the return journey at the other side of the surface .
The latest estimations of the mass present in our universe, indicate:
- a lasting expansion with finally a cold universe or
- just no permanent expansion, whereafter our universe will start to shrink again”, says Carla.
“A difference in temperature from 1.5 x 10¹² K to 10?K from the origin of our universe to the third second of existence seems small, but it is 1500° C or the difference between molten steel and steel at room temperature. This is the temperature interval wherein earthly life takes place. There are a number of scientists – often with a Christian background – who are convinced that the exact alignment of our universe is not a coincidence: it is clear to them that the universe is exactly organised to enable our human life on earth. Human life on earth can, according to the evolutionary theory of Darwin, have been acquired by "trial and error" and "survival of the fittest. But this does not apply for our universe; our universe has arisen from one big bang: it should have meet exactly the conditions to make human life possible”, says Peter.
“I have my doubts whether our universe is unique in its kind; I have also doubts whether our universe has originated from just one big bang. People tend to consider existence from their own perspective. Every person lives in his/her view within only one environment, in one society, in only one age, in only one world, in one planetary system, in one system of stars, in one universe wherefrom we now can see a part at the starry sky. This perspective is so overwhelming that an existence outside of our universe – let alone beyond the big bang and the end of our universe – is difficult to imagine.
Of course, I cannot show nor falsify my doubts regarding the uniqueness of our universe, it is metaphysics that is outside the scope of human perception”, says Carla.
“What possibilities do you have in mind for any existence outside our”, asks Man.
“There are possibilities sequentially and/or parallel within the space of our universe, and sequentially and/or parallel beyond the space of our universe.
Let’s start with sequential. If we abridge the 13.8 billion years of our universe to a few centimetres on a timeline, and imagine that our universe – as a harmonic system – cyclically expands to a certain maximum value that is determined by the total energy within our universe, and then shrinks back to almost one point, then re-expands with a huge explosion – a new big bang at the end of our shrunken contemporary universe – then arises again and again the same and new universe, that shrinks again to almost one point . This process can, in principle, continue infinitely when no energy is lost by damping or by energy escaping at the edges. Each consecutive universe looks from outside similar to the previous universe, but due to minor variations in the initial situation caused by quantum mechanical irregularities, differences will arise within each universe, allowing other forms of galaxies and other forms of life to origin and disappear. When this process continues into infinity, finite energy within our universe can cause precisely identical universes in the past and in the future. Infinity is so huge that our universe can try an infinite number of times to reproduce itself exactly. Think of the monkey that types on endlessly: at times of life, this monkey will once type the entire work of Shakespeare and much later again and again….
In addition, within the space of our universe there are sufficient possibilities for the presence of a second, a third and even an infinite number of similar universes. Within our world, four independent dimensions – length, width, height and time – have been expanded during the big bang. The standard model for the big bang is based on 8 to 11 dimensions that have expanded, because this number of dimensions mathematical sound results are feasible. This standard model is based on a mathematical model that is fairly cohesive, but it cannot be conclusively proven because there are still too many ambiguities.
Now imagine that from the origin of the big bang outside of our perception – so beyond the dimensions that are perceptible for us – twice as many dimensions have unfolded: this would have caused that at the same time from the same origin of our own universe, a second universe in parallel has unfolded.
In the same way, three times as many, four times as many, as infinite times so many dimensions can be unfolded, that have caused as many parallel universes. There is no mathematical rule that prohibits extending the unit matrix from four, to 8 or 11 dimensions, and then afterwards to a multiplicity – until infinity – of this number.
In addition, it is also possible that – next to the very tiny point that is the origin of our universe – at many other points in the undefined emptiness, there have unfolded (or will unfold) parallel universes; These parallel universes are – like our universe – expanded uniformly and evenly next to each other. This expansion can take place – almost identical to our universe – with small quantum mechanical fluctuations or with a different extent of expansions like balloons blown up next to each other in a more or less identical manner (or with a different size), whereby the void space will inflate identically in size, so the balloons will not hinder each other during the expansion. The quantum mechanical minor differences in origin cause noticeable differences during the expansion.
As far as I know, there is no mathematical way to prohibit that outside our own universe, an infinite number of other tiny point can exist, that may be origin for an infinite number of other big bangs similar.
When many universes can arise and disappear again – sequential and/or parallel within the origin of our universe or, sequentially and/or parallel from origins outside our universe –, there is selection possible of “trial and error” and thus of "Survival of the fittest" within the origin and disappearance of universe. Thus, evolution is possible within universe that corresponds to the evolutionary theory – rediscovered by Darwin  – or even surpasses this evolutionary theory, because there are infinite possibilities instead of finite possibilities in our finite universe”, says Carla.
“When there are infinite possibilities, I think everything will remain somewhere, sometimes, and then there will be no selection which would reduce less viable shapes of life”, says Man.
“You are absolutely right, on the condition that for all infinite universa that arise, there is enough space and there is infinite energy – and therewith matter – present. But as far as I can see now, there are at least two possibilities for selection caused by small quantum mechanical fluctuations at the origin – in this model during the separate big bangs – that will later have major and far fetching consequences for the expansion and survival of these universa.
First of all, there can be too little space for the amount of energy to be able to expand according to plan. This creates a different form and/or composition of matter than might be expected. The one form may be more sustainable or more viable for progeny of the following universe than the other form. There can also be too much space for the amount of energy, whereby the energy expands too fast and far, and this universe remains infinite as a lifeless balloon, and thus does not produce offspring and will fossilise into a lifeless cold. Even this lifeless source with a temperature at almost the absolute zero, still has many changes.
Due to quantum mechanical fluctuations, the distribution of energy across the universes can vary considerably over time, making one form more viable for offspring than another form.
In case there are infinite number of possibilities, infinitely many minor differences may arise: one form of infinity can develop much faster than the other form. In this way, the distribution of energy can be significantly more applied to preferred shapes than to other shapes, whereby the preferred shapes develop faster. The other shapes can grow in infinite steps to a finite value”, says Carla.
“Now that I have heard this explanation, I understand your hesitation regarding any kind of origin better. And suddenly a question arises: “Did you wish to graduate at TU Delft on this subject”? ”, asks Man to Carla.
“Partly: at that time I was definitely not so far. I have followed the developments on this subject. Later, a number of new insights were added, that I did not have before”, says Carla.
“How do you see the law of conservation of energy during the creation of our universe?”, asks Peter to Carla.
“As far as I am aware, there have never been any deviations from the law of conservation of energy. All deviations on paper have always been deduced to errors in calculation or to errors in observation. I think you ask where the enormous energy at the beginning of the big bang comes from?”, asks Carla to Peter.
“Yes, that is actually my question”, says Peter.
“A simple explanation for the energy that caused the big bang, is the merger of matter and antimatter after a shrinkage of a universe before to a minimum point by gravity. Or better: matter shrinks by gravity on one side along a positive timeline and antimatter shrinks by gravity on the other side along the negative timeline to reach a point smaller than the Planck space and then to annihilate in a fraction of a fraction of the smallest time unit; and then unfold and expand again via quantum fluctuations along the same dimensions, or perhaps unfolding other dimensions.
Another explanation is assembling all matter/energy within our own universe at a minimum point that is smaller than the Planck space. Matter/energy is compressed so densely by gravity whereby all matter, energy and radiation becomes homogeneous again. Until the aggregated internal energy of the entire universe will lose all the characteristics of mass and only energy remains: this total energy causes the unfolding and inflating of a new universe. The other possibility is that the internal energy will exceed the force of gravity, and the homogeneous point will disintegrated into a big bang and the universe is re-created anew.
The physicist John Archibald Wheeler has said according to a quote:
“No point is more central then this, that empty space is not empty.
It is the seat of the most violent physics” 
The origin of the first big bang is shrouded in nebulae and it asks for all the imagination that we have, or this event goes well beyond our imagination. I am reminded of the following description of Dante's Purgatory:
You, imagination, that prevented us
Many times to perceive the world,
Although around may sound a thousand cymbals.
What moved you, outside our sense?
A flash of light, created in heaven,
By itself, or by the will of God. 
Maybe we should come back to it another time because it's late. I think there is also a connection with your question about quantum mechanics”, says Carla.
“I will go to sleep, because I am tired. I wish you a good night”, says Man.
“Sleep well”, say Carla, Ferdinand, and Peter to Man.
They pour the last wine in their glasses.
“You are in your element tonight with your explanation of the origin of the universe”, says Peter to Carla.
“I have noticed that carry on too long, but when I'm explaining, I do not worry about Man. He is tired soon and I have the impression that he is still not used to the heat. I also feel the heat during day time, but in the evening I am recovered more or less”, says Carla.
“Man has consciously chosen for this trip, while he knows that his health is weak. When he needs extra rest during our trip, Man and I will interrupt the trek and seek a resting place”, says Ferdinand.
“Fortunately, you – as physician – will watch over his health”, says Peter.
“I am pleased with that. Now I will get ready for the night, because tomorrow we have to get up early. Sleep well”, says Carla.
“Good night”, say Ferdinand and Peter.
 Source: Zee, A, Einstein Gravity in a Nutshell. Princeton and Oxford: Princeton University Press, 2013, p. XIII
 Zie ook: https://en.wikipedia.org/wiki/Maasai_Mara
 Source image: https://nl.wikipedia.org/wiki/Masai_%28volk%29
 Source image: https://en.wikipedia.org/wiki/Maasai_people
 Source: Harrison, Edward, Cosmology – The Science of the Universe (2nd Edition). Cambridge: Cambridge University Press: 2013, p. 138. “All places are alike: this cosmological principle declares that apart from local irregularities the universe is the same everywhere.”
 Photo of the Crab Nebula, that originated from the explosion of a supernova. A supernova is a star that is many times heavier than the sun, and it has come to the end of its life. The supernova does not have enough energy to maintain its size and implode under the influence of gravity of its own mass. This implosion takes more than a month, whereby the supernova emits just as much energy and matter until a new stable cooled state is created again. The white spots around the Crab Nebula are stars.
 See also: https://en.wikipedia.org/wiki/Topology
 E.g.: the Planck Constant, or the Dirac Constant for the energy of a photon, see also: https://en.wikipedia.org/wiki/Planck_constant or the Dirac delta function, see also: https://en.wikipedia.org/wiki/Dirac_delta_function
 An example of a Calibi-Yau manifold. This type of manifolds are used in the string theory. Source image: https://de.wikipedia.org/wiki/Calabi-Yau-Mannigfaltigkeit
 See also: https://en.wikipedia.org/wiki/String_theory
 Source image: https://en.wikipedia.org/wiki/Bud
 See also: https://en.wikipedia.org/wiki/Entropy
 See also: Origo, Jan van, Who are you – A survey of our existence – part 2.3 – Emptiness. Amsterdam: Omnia – Amsterdam Publisher, 2015, p. 61 and 63
 Title of a popular scientific book about this subject: Greene", Brian, The Elegant Universe – Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory. New York: W.W. Norton & Company, 2003
[16a] See also: Booker, Christopher, The seven basic Plots – Why we tell stories. London: Continuum, 2010 and Lewis-Williams, David & Pearce, David, Inside the neolithic Mind – Conscious, Cosmos and the Realm of Gods. London: Thames & Hudson, 2009
 See also: https://en.wikipedia.org/wiki/Richard_Feynman
 Source: Taylor, Edwin F., Wheeler, John Archibald, Spacetime Physics – Introduction to special relativity; second edition. New York: W.F. Freeman and Company, 1992, p. 1
 Source image: https://nl.wikipedia.org/wiki/Astronomie
 Source: Weinberg, Steven. The First Three Minutes – A modern view of the Origin of the Universe. New York: Basic Books, 1993, p. 101 - 121
 Source: https://en.wikipedia.org/wiki/Feynman_diagram
 Source: Harrison, Edward, Cosmology – The Science of the Universe (2nd Edition). Cambridge: Cambridge University Press: 2013, p. 433
 The description of the first three seconds of our universe and the first 10 million years wherein the first living beings originated, is taken – in my own words – from: Weinberg, Steven. The First Three Minutes – A modern view of the Origin of the Universe. New York: Basic Books, 1993, p. 101 - 121
 Source image: https://en.wikipedia.org/wiki/Big_Bang
 See also: https://en.wikipedia.org/wiki/Conway's_Game_of_Life
 See also: Harrison, Edward, Cosmology – The Science of the Universe (2nd Edition). Cambridge: Cambridge University Press: 2013, Chapter 18
 See also: Harrison, Edward, Cosmology – The Science of the Universe (2nd Edition). Cambridge: Cambridge University Press: 2013, p. 370 figure 18.15
 See also 1963 woodcut Möbius II by M. C. Escher via: http://www.mcescher.com/gallery/recognition-success/mobius-strip-ii/
 Source image: https://en.wikipedia.org/wiki/M%C3%B6bius_strip
 Source image: http://en.wikipedia.org/wiki/File:Monkey-typing.jpg
 Image in dimensions: Example of 6 axes that unfold from one origin. Source image: https://simple.wikipedia.org/wiki/Calabi-Yau_manifold
 Source image: https://en.wikipedia.org/wiki/Identity_matrix
 See also: https://en.wikipedia.org/wiki/On_the_Origin_of_Species
 See also: Narayana, Narrator, Carla Drift – An Outlier, A Biography. Amsterdam: Omnia – Amsterdam Publisher, 2012, p. 43 - 50
 John Harrison, M. Space – A Haunting. London: Gollancz, 2012, p. 2
 Dante “Purgatorio” XVII.13-18; translation from: Dante Alighieri, De goddelijk komedie. Amsterdam: Atheneum – Polak & Van Gennep, 2008, p. 282