More from the book I mentioned last week.
Some species have "evolutionary potential" and others don't. Some have come to an evolutionary dead end. That distinction has some support from Ohno.
Among those species with EP, the potential becomes actual when there is a shock from without, a benevolent infection.
"It is interesting that among birds those in which influenza virus has been found -- chicken, duck, turkey, quail, shearwater -- tend to be long-lived species. We remarked above that program changes which are not improvements show up as disease, from which it follows that species susceptible to program changes -- i.e. those stil with evolutionary potentisal -- must exhibit a greater tendency to disease than static spcies without evolutionary potential."
Showing posts with label Fred Hoyle. Show all posts
Showing posts with label Fred Hoyle. Show all posts
03 June 2011
22 May 2011
Evolution From Space
I'm finally in possession of a copy of a book I've only heard about and read second-hand reports of until now. It is EVOLUTION FROM SPACE by Fred Hoyle and N.C. Wickramasinghe, published in 1981.
The late Fred Hoyle was of course a very prominent astronomer and astrophysicist, once the leading proponent of the steady-state theory of the cosmos, and renowned for his work on the evolution of stars.
Wickramasinghe is professor of applied mathematics and astronomy at Cardiff University.
Today, they spin out their theory of panspermia. It is a theory not only of the origins of life on earth, but in their hands (as the book's title implies) a theory of how life has developed since. For the arrival of new genetic material from the stars was not, for them, as it was for other advocates of panspermia, a one time event.
Let's take fairly recent history -- in terms of geological or biological time. Let us consider especially the span of time between the emergence of the first hominids and our own selves. Hoyle and Wickramasinghe quote a Japanese biologist, Susumu Ohno, thus:
"Did the genome of our cave-dwelling predecessor contain a set or sets of genes which enable modern man to compose music of infinite complexity and write novels with profound meaning? One is compelled to give an affirmative answer....It looks as though the early Homo was already provided with the intellectual potential which was in great excess of what was needed to cope with the environment of his time."
This seems to Hoyle et ux to mean that Ohno has given up on Darwinism. If the cave dwellers already had the capacity to compose like Bach, without an environment that would get them any natural advantage out of composing like Bach, or having that capacity, then ... something other than natural selection was clearly at work.
If new genetic material repeatedly rains down on the earth from space, and if it must be absorbed somehow, then it is easier (these authors think) to see how human develpment could get ahead of the environment to this degree.
At least ... I think that is what they are saying. I have only just dipped into the book.
The late Fred Hoyle was of course a very prominent astronomer and astrophysicist, once the leading proponent of the steady-state theory of the cosmos, and renowned for his work on the evolution of stars.
Wickramasinghe is professor of applied mathematics and astronomy at Cardiff University.
Today, they spin out their theory of panspermia. It is a theory not only of the origins of life on earth, but in their hands (as the book's title implies) a theory of how life has developed since. For the arrival of new genetic material from the stars was not, for them, as it was for other advocates of panspermia, a one time event.
Let's take fairly recent history -- in terms of geological or biological time. Let us consider especially the span of time between the emergence of the first hominids and our own selves. Hoyle and Wickramasinghe quote a Japanese biologist, Susumu Ohno, thus:
"Did the genome of our cave-dwelling predecessor contain a set or sets of genes which enable modern man to compose music of infinite complexity and write novels with profound meaning? One is compelled to give an affirmative answer....It looks as though the early Homo was already provided with the intellectual potential which was in great excess of what was needed to cope with the environment of his time."
This seems to Hoyle et ux to mean that Ohno has given up on Darwinism. If the cave dwellers already had the capacity to compose like Bach, without an environment that would get them any natural advantage out of composing like Bach, or having that capacity, then ... something other than natural selection was clearly at work.
If new genetic material repeatedly rains down on the earth from space, and if it must be absorbed somehow, then it is easier (these authors think) to see how human develpment could get ahead of the environment to this degree.
At least ... I think that is what they are saying. I have only just dipped into the book.
28 February 2010
Maxwell's demon: Hoyle's steady state
The second law of thermodynamics says that we can't win. The amount of useful energy available in the cosmos, and in any "closed system" within the cosmos, is lessening. Why? Well ... because useful energy is created by differences. For example, the water above a cliff has a different altitude than the water at the bottom of the cliff. Hence, the resulting waterfall can be employed to generate electricity. Over time, though, differences within any closed system are worn away (cliffs are worn down to level plains, entropy increases), which means that there are fewer and fewer opportunities for the generation of energy, i.e. the doing of work.
As an inevitable extension of this law, cosmologists speak of the "heat death" of the cosmos, in which what is left of the world is mostly nothingness, punctuated perhaps by whatever irreducible particles may remain, which simply drift further and further away from one another, without interaction, without heat, and of course without life.
If the world has that as an end, then presumably the world also had a beginning. The law of entropy naturally suggests the cosmogony of the Big Bang -- though as a matter of the history of science there was a period of contention as that implication worked itself out. Most notably, Fred Hoyle, Thomas Gold, and Hermann Bondi developed an elaborate steady-state theory in the 1940s, that would accomodate the expanding universe by having new matter pop into existence, so that the density of the universe remains constant over time. According to this theory as they and others developed it through the 1950s and 1960s, the new matter would be mostly hydrogen, and would be in such small amounts that it would not be directly detectable: roughly one hydrogen atom per cubic meter per billion years, with roughly five times as much dark matter.
Such a creation rate, however, could allow for the fact that all human-scale observations support the second law, while it allows for a subtle re-setting of the clock of time on the Big Scale involved, re-creating the differences, the disequilibria, that the unchecked operation of the 2d law of thermodynamics would destroy.
How did matter pop into existence, on that scale or any other? From a philosophical point of view, Hoyle etc. replied that this question is not more or less difficult than "how did the Big Bang happen"? One begs the universe all at once, or one begs it in pieces over the everlasting run of time. We are beggers in the matter of Being in either case. It is simply the old "why is there anything rather than nothing?"!
Yet this atoms-popping-into-existence stuff makes for an unattractive theory without more. That (perhaps even more than the background cosmic radiation, which has been called the echo of the Big Bang but could well have other explanations) has been the real drawback. If the popping is supposed to take place within the observable universe, it should be ... well ... observable.
Consider a thought experiment that goes back to one of the greatest physicists in history. James Clerk Maxwell spoke of a hyptothetical "demon" who could defeat the 2d law:
"If we conceive of a being whose faculties are so sharpened that he can follow every molecule in its course, such a being, whose attributes are as essentially finite as our own, would be able to do what is impossible to us. For we have seen that molecules in a vessel full of air at uniform temperature are moving with velocities by no means uniform, though the mean velocity of any great number of them, arbitrarily selected, is almost exactly uniform. Now let us suppose that such a vessel is divided into two portions, A and B, by a division in which there is a small hole, and that a being, who can see the individual molecules, opens and closes this hole, so as to allow only the swifter molecules to pass from A to B, and only the slower molecules to pass from B to A. He will thus, without expenditure of work, raise the temperature of B and lower that of A, in contradiction to the second law of thermodynamics...."
Notice that Maxwell is not bringing God into the picture here -- he is thinking as a secular scientist, and is specifying that the demon is as "essentially finite" as we are. But the demon works at a different level, a micro-level.
Notice also that while Hoyle et al sought to limit the Second Law to the human scale by escaping toward a much Bigger Picture, where humanly undetectable violations thereof can become important ... Maxwell follows the opposite strategy. He seeks to limit the Second Law to the human scale by escaping toward a much Smaller Picture, where an intelligent being can work molecule by molecule.
And now we bring in nanotechology, the development of a molecule-by-molecule, indeed atom-by-atom, variety of engineering accoring to which humans may yet create robots that can in term act as does Maxwell's hypothetical demon.
Ah, am I suggesting, by making this connection, that humans have a cosmic role to play by inventing Maxwellian demons that will enable the cosmos to avert heat death? No ... not exactly. That would have an unnecessarily arrogant sound to it. There is no reason to believe that life exists only on this planet, or that the intelligent beings here have a unique role.
Perhaps through the everlastingness of time, intelligent creatures have developed on myriad planets, and that in many of these cases they reach a point at which they develop a nanotechnology capable of beating the 2d law in their localities. And perhaps, the collective effect of all these independent nanotechnological/civilized planets is to keep re-setting the clock. Perhaps intelligent life on sporadically located planets has the same effect that Hoyle sought to model through this random popping into existence of hydrogen atoms he hypothesized.
The alliance of Hoyle and Maxwell moves in both directions at the same time, for the tiniest of scales may give us a crucial clue to what is happening on the largest.
As an inevitable extension of this law, cosmologists speak of the "heat death" of the cosmos, in which what is left of the world is mostly nothingness, punctuated perhaps by whatever irreducible particles may remain, which simply drift further and further away from one another, without interaction, without heat, and of course without life.
If the world has that as an end, then presumably the world also had a beginning. The law of entropy naturally suggests the cosmogony of the Big Bang -- though as a matter of the history of science there was a period of contention as that implication worked itself out. Most notably, Fred Hoyle, Thomas Gold, and Hermann Bondi developed an elaborate steady-state theory in the 1940s, that would accomodate the expanding universe by having new matter pop into existence, so that the density of the universe remains constant over time. According to this theory as they and others developed it through the 1950s and 1960s, the new matter would be mostly hydrogen, and would be in such small amounts that it would not be directly detectable: roughly one hydrogen atom per cubic meter per billion years, with roughly five times as much dark matter.
Such a creation rate, however, could allow for the fact that all human-scale observations support the second law, while it allows for a subtle re-setting of the clock of time on the Big Scale involved, re-creating the differences, the disequilibria, that the unchecked operation of the 2d law of thermodynamics would destroy.
How did matter pop into existence, on that scale or any other? From a philosophical point of view, Hoyle etc. replied that this question is not more or less difficult than "how did the Big Bang happen"? One begs the universe all at once, or one begs it in pieces over the everlasting run of time. We are beggers in the matter of Being in either case. It is simply the old "why is there anything rather than nothing?"!
Yet this atoms-popping-into-existence stuff makes for an unattractive theory without more. That (perhaps even more than the background cosmic radiation, which has been called the echo of the Big Bang but could well have other explanations) has been the real drawback. If the popping is supposed to take place within the observable universe, it should be ... well ... observable.
Consider a thought experiment that goes back to one of the greatest physicists in history. James Clerk Maxwell spoke of a hyptothetical "demon" who could defeat the 2d law:
"If we conceive of a being whose faculties are so sharpened that he can follow every molecule in its course, such a being, whose attributes are as essentially finite as our own, would be able to do what is impossible to us. For we have seen that molecules in a vessel full of air at uniform temperature are moving with velocities by no means uniform, though the mean velocity of any great number of them, arbitrarily selected, is almost exactly uniform. Now let us suppose that such a vessel is divided into two portions, A and B, by a division in which there is a small hole, and that a being, who can see the individual molecules, opens and closes this hole, so as to allow only the swifter molecules to pass from A to B, and only the slower molecules to pass from B to A. He will thus, without expenditure of work, raise the temperature of B and lower that of A, in contradiction to the second law of thermodynamics...."
Notice that Maxwell is not bringing God into the picture here -- he is thinking as a secular scientist, and is specifying that the demon is as "essentially finite" as we are. But the demon works at a different level, a micro-level.
Notice also that while Hoyle et al sought to limit the Second Law to the human scale by escaping toward a much Bigger Picture, where humanly undetectable violations thereof can become important ... Maxwell follows the opposite strategy. He seeks to limit the Second Law to the human scale by escaping toward a much Smaller Picture, where an intelligent being can work molecule by molecule.
And now we bring in nanotechology, the development of a molecule-by-molecule, indeed atom-by-atom, variety of engineering accoring to which humans may yet create robots that can in term act as does Maxwell's hypothetical demon.
Ah, am I suggesting, by making this connection, that humans have a cosmic role to play by inventing Maxwellian demons that will enable the cosmos to avert heat death? No ... not exactly. That would have an unnecessarily arrogant sound to it. There is no reason to believe that life exists only on this planet, or that the intelligent beings here have a unique role.
Perhaps through the everlastingness of time, intelligent creatures have developed on myriad planets, and that in many of these cases they reach a point at which they develop a nanotechnology capable of beating the 2d law in their localities. And perhaps, the collective effect of all these independent nanotechnological/civilized planets is to keep re-setting the clock. Perhaps intelligent life on sporadically located planets has the same effect that Hoyle sought to model through this random popping into existence of hydrogen atoms he hypothesized.
The alliance of Hoyle and Maxwell moves in both directions at the same time, for the tiniest of scales may give us a crucial clue to what is happening on the largest.
Subscribe to:
Posts (Atom)
