Just a note to say that I have collected some of the cosmology blogs and put them in better order on the Cosmology page. This should help you keep track of what has been said.
Archive for June, 2010
According to Jaki, Einstein’s favorite personal saying was that “the most incomprehensible thing about the universe is that it is comprehensible.”
For this pithy word, Jaki gives him vast credit, because although he did not have the tools to consider the philosophic ramifications of his remark, he had the intuitive sense to love this great mystery: that we can know the universe.
What does that mean?
Is it accidental?
For the Darwinian who sees mankind as accidental, and for a man like Whitehead who sees the universe as going through all possible forms, this mystery can be only one accidental event among quintillions of quintillions – nothing worthy of note. This accidentalist approach to reality became increasingly pervasive through the 20th century, even working its way into the arts, though it was never totally triumphant.
Einstein challenges this world-view that keeps layering accident upon accident, in a campaign to bore the human heart out of its natural wonder. He correctly observes that of all the wonders we meet in this stunning universe, the possibility of man knowing the universe is the most stunning.
It is also one of the most instructive. Why is the universe knowable – and by one of its constituent parts? That is the key to one vast part of the question: Is there a Universe? It is a philosophic key, not a scientific one, but it is important: Yes, Linde, consciousness is part of the universe. Consider, Mr. Whitehead: not every possible form of physical universe would allow consciousness, and whatever form forbids it is not part of this universe.
Give that some thought. This universe is the physical totality that allows a self-reflective entity to develop within its boundaries and subject to its laws yet free to evaluate their meaning. That’s the kind of universe it is.
“An Old Insensitivity” is the title of chapter two of Jaki’s book, Is There a Universe? The insensitivity that he has in mind is the insensitivity to philosophy, which is so common in the scientific mind, and in particular an insensitivity to the philosophic dimension of the concept of the totality – the universe. The student of the natural sciences, disciplined to accept only measurement and numeration as proofs for his propositions, easily forgets that there are realms where measures cannot be taken, but nevertheless rational thought still flourishes.
In other words, he forgets that a conclusion may be rational even if its argument is not subject to measure. It may be Scientific in the larger sense, where Science is defined as reasoning from evidence to conclusions, even if it is not scientific in the sense of the natural sciences where the allowable evidence is restricted to things that can be measured.
In the case of the universe, these non-measurable aspects of the evidence crop up for two reasons, or perhaps I should say in two dimensions:
- Man himself is part of the totality of the universe, and the functioning of the mind of man takes place in relation to a physical brain that is subject to measure but which whose products, including judgments about love, beauty, and wonder are not.
- Even considering only the physical realm, there seems to be no definitive way to measure the strict totality of the starry realms. Boltzmann’s suggestion of universe segments at 7 x 10100th lights years distance of separation is a way of keeping excessive gravity and light out of the way, but who can prove whether such distant objects really exist? Hawking’s foam is a mathematical consequence of some ideas from quantum mechanics, but there is no orderly way to measure the existence or action of the multiverses he proposes. Worse, nobody is even proposing to lay out how some alien form of matter, which is presumed subject to the different physical laws of another universe and which could pop up right within our own universe, might interact with our matter.
- The most one can do for measure is say something about the measure of the universe that runs by our laws of physics, and this has been done. But any reason for accepting or rejecting the Hawking/Boltzmann multiverses must come from other lines of reasoning.
Facing up to these restrictions is hard for scientists, who, with a habit of insensitivity to philosophy, and usually with about zero training in it, simply ride roughshod over the issues and don’t even realize what they are doing.
Examples of insensitivity
Here is Andrei Linde trying to define the word universe: “Different people use the word differently. For anyone who tries to understand it, at least, the universe is everything which exists. However, this may not be the last word on the subject, since, first of all, the question arises whether we should include consciousness in the definition of everything which exists.”
Different people use practically every important word differently. The way to say something useful is to tease out the half-dozen or so most significant definitions, stake your own territory, and then say something that moves the conversation forward. Obviously Linde is troubled about the human dimension; this is wise in its way, but what next?
Here is Jaki’s description of Alfred North Whitehead’s cosmology: He says Whitehead rendered the universe “amorphous through the claim that it was bound to assume all possible forms through infinite ages.” A universe which assumes all forms cannot be said to be characterized by any form, can it? So what is to be said of it? Whitehead’s implicit response is found in the title his book Process and Reality. Like Darwin, he is ready to substitute a concept of history for a concept of reality.
To that extent, he would be saying, “No, there is no universe” – since none can be effectively defined.
Richard Bentley was a younger contemporary of Isaac Newton. After Newton had formulated his law of gravitation, he observed, in a letter to Richard Bentley, that if all the stars are drawn to each other by gravitation, they should collapse into a single point. One will be drawn to another; that star will grow and pull in still more and more. In time, everything must be drawn in.
How is the universe constructed so as to prevent this from happening?
It did not occur to Newton, or perhaps to anyone before the 20th century, that the universe is a changing space-scape. It has a history, at the start of which (in Big Bang theory) its matter was ejected apart; so far, it does not have the energy to re-gather everything in a universe-crushing event. Or maybe I should say that its momentum is still too great to be overcome by its gravity. Either way, it could face gravity collapse, but not yet.
Bentley’s Paradox (which maybe should be called Newton’s Paradox, since it is odd to name an insight after its first recipient, rather than its author) is similar to Olbers’ Paradox in that it does suggest a finite universe: an infinite universe would have infinite gravity and would certainly collapse.
Well, again, perhaps you’d have the Kelvin/Boltzmann suggestion of a universe with pieces far enough apart not to respond. But this suggestion only serves to indicate the distant (really distant!) possibility of a kind of multiverse. Unless it can be tested, it is not a scientific hypothesis, though it is an interesting thought experiment.
Simply put, Olbers’ thought was that if the universe were infinite with stars distributed equally throughout, then such stars would provide an infinite amount of light to shine upon any point in space. Even if dust inhibited some of the light, the sky would be brilliant at all times.
But the sky is dark.
How can that be? How can the universe have an infinite amount of light and yet offer its inhabitants a dark sky?
Ordinarily, the word paradox refers to a pair of statements that seem to contradict, but, upon closer examination, turn out to be unexpectedly compatible. In the case of Olbers’ Paradox, however, something different is going on. Some people are seeing a contradiction and concluding that the universe must not be infinite. Others are so committed to an infinite and eternal universe that they persist in calling it a paradox and trying to find a way that it can work.
History of Olber’s Paradox
Olbers’ paper on this subject dates only from 1823, but though he got his name on the idea, it seems to pre-date him by a good 200 years or more. Thomas Digges, who was the first to discuss Copernicus in English, and whose life falls between the death of Copernicus and the very early teaching career of Galileo, talked about the problem of so much light.
Shortly afterwards, in 1610, Kepler talked about it, and concluded that the universe must be finite.
The first detailed presentation was given by Lord Kelvin in 1901, and he proposed to resolve it by considering that the distance to some of the stars was so great that their light had not reached us. One wonders how such a state of affairs could arise, given that the light has an infinite amount of time for its travels, but of course the lives of individual stars are not infinite, so perhaps the universe proposed by Boltzmann was the right approach for maintaining the idea of a paradox.
A material totality
Still, this takes us back to the question of a genuine material totality.
- Material objects can be counted.
- An infinite universe with an even distribution of stars must have an infinite number of stars, which cannot, therefore, be counted.
- Therefore: there can be no such no such universe.
Boltzmann’s proposal, so far as I read it, did not necessarily present an infinite universe, just one so large that its parts did not interact. I wonder what he thought kept the parts apart?
But Kelvin was really going for infinity, and the reason for this was pantheistic at heart. Remember that if the universe is so segmented that its parts do not interact, then there is nothing scientific to say about any part except our own. Even the assertion that those other parts exist is not scientific. Why would you say it? Only because you find an infinite universe comfortable or because you are uncomfortable with the metaphysical implications of a finite universe. There’s less room for accident.
A matter of philosophy
Still, even if you have unworthy reasons for believing the material universe is infinite, unworthy reasons do not, by themselves, make a proposition wrong. False premises do not make a false conclusion; they make a conclusion with uncertain truth value.
So Jaki goes farther.
He states, as a point of philosophy, that countability is part of being material, and that there cannot be a collective material entity that does not have a countable totality. In other words, he is proposing a philosophical proof for the existence of a finite material totality.
At least this is how I understand his writing.
Note that since we are a part of the universe, it is not really like other scientific or astronomical objects. You can study all stars without taking human life into account – or all leaves or all bugs or all atoms. But the universe includes us, and its nature must be understood to include the fact of our presence.
At the beginning of the 20th century, the proposed infinity of the universe was merely a Euclidian extension of “empty” space – without Einstein’s definition of space. Even as late as 1917, the Milky Way was generally thought to be “the universe” as far as material objects were concerned; other galaxies visible in the sky were thought to be nebulae – bright little gas clouds – within its confines. Shortly after 1917, however, stars were resolved in the galaxies, doubts were raised, and 8 years of uncertainty followed concerning the placement of the galaxies. The debate finally yielded to Edwin Hubble’s identification of a Cepheid variable in Andromeda. A Cepheid variable is a star whose light varies over a period of time; its actual luminosity is exactly proportional to its period of variation. Knowing the “real” luminosity of a star makes it possible to judge its distance by its apparent brightness. By this means, the Andromeda Nebula was definitively located far outside our Milky Way galaxy.
So the galaxies were outside the Milky Way, but what was the status of the concept of total material creation?
In 1928, the famous scientist Sir James Jeans wrote about galaxies as “island universes,” something like Boltzman’s idea only the galaxies are much closer, genuine neighbors. But the phrase “island universes” shows that as late as 1928, the concept of a single universe containing all the galaxies was not fully clarified. It is true that (human) travel between galaxies is impossible since they are millions of light years apart; but no matter how far apart they may lie, galaxies exchange light (that’s how we see them) and they have gravitational interactions which are now obvious, although they were too subtle for the telescopes of the early 20th century. Thus they belong to a network of mutual interactions.
But the understanding of the universe as finite was still a work in progress; and without finity, as I have said, the universe is not really unified. In that case, no science of cosmology is possible.
I would like to initiate an extended discussion of Stanley Jaki’s book, Is There a Universe?. Jaki had a PhD in physics and also one in theology. His specialization was the history of science, and he wrote a number of illuminating books on the topic of the relationship between faith – a Catholic faith – and science. I remember telling my mother about him, and how she cried, saying if only my father had known him, he would not have felt so alone as a Catholic astronomer.
I have already touched on some of the themes of Jaki’s volume, but now I will take it one step at a time.
The New Science – cosmology
The idea of studying cosmology is new, relative to the history of philosophy, because in the world-view obtaining up to the time of Galileo, it was not clear that the stars or the planets or even the Moon were subject to the same physical laws as the earth. For that reason, the only relevant physics was earthly physics. As it gradually became clear that the planets and even the sun share our physics, and that other stars were suns like ours, there came a time to speak of the universe as a material whole or at least to consider whether it was a material whole. That’s what cosmology really is – the study of the universe as a material whole.
But it was a slow start, because the legacy of infinity as the home of the stars was not quickly shaken, and has been repeatedly resurgent even after it first gave way.
Isaac Newton thought the universe was finite. His dates are 1643 – 1727 and the year of his birth was the same year that Galileo died. The “infinite” mischief came primarily in the following generation.
In 1755, Immanuel Kant argued that the universe must be infinite because it is the work of an infinite God. This quick argument for cosmological infinity is worth addressing, since it has an undeniable intuitive appeal.
First, a word about the possible relationships between just a few objects: Suppose three objects interact. Each one may be aware of itself. Each may be aware of the relationship existing between itself and each of the other two. Each may be aware of the other two and their mutual relationship. Each may be aware of the relationship between the paired others and itself. Each may be aware, from a different perspective, of the relationship of the threesome. Each may be aware of the change in itself due to reflection on each and all of the relationships just listed. Each may participate in changed relationships with each other and with each twosome and with the threesome as a result of those reflections.
Do you see where this is going? A universe with as little as three objects can start pushing into an endlessly complex set of relationships just from that simple starting point and its interactions. In a universe with billions of material objects and also billions of personal beings, you can have a suitable expression of infinite creativity even without an infinite material universe. The relationships can generate an endless network, even if the relational objects are finite in number, and all the more so if God himself is in relationship with the persons in his universe.
That being so, it is arguable, against Kant’s assertion, that an infinite God could please himself in the creation of a finite universe. In saying this, I do not mean to ignore the fact of revelation, which takes precedence over our confused ramblings; but it serves the unity of the human mind to observe, whenever we can, that our theological opinions have also a basis in natural reason.
In 1761, John Heinrich Lambert turned back to finity, stating that the universe had to be finite because there could not be an actually realized, infinite collection of material beings. This did not deter Kant, who was still living, and neither did Olbers’ Paradox nor the similar gravitational paradox described by Bentley – which pointed out that an infinite universe would have intolerable quantities of gravity and light.
In the late 1890’s, Boltzmann stated that the Universe consisted of a whole series of universes, 7 x 10100th light years apart, each with its own physical laws. Since the universe as we now know it is only about 109th light years across, a number such as 7 x 10100th – however easily it slides across the mathematical tongue – is utterly beyond human imagination. I do not know where Boltzmann got his number. Presumably he was trying to have infinity but keep it at a distance where gravity and light would not overwhelm us. His idea is worthy of mention because he was an extremely intelligent and reputable physicist and it sounded so authoritative. The universe would generally – though not universally – be considered infinite from then until 1965.