Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: waytogo on 10/09/2012 01:04:13
-
Immagine that scenario with thousands and thousands of degrees...
So Big-Bang supporters, tell something please.
-
The early universe was indeed sterile, but it was not "static", instead it expanded.
As a result of its intrinsic expansion, it cooled down enough for electromagnetism to allow atoms and chemistry and then for gravity to clump stuff together.
The universe is so big that it was statistically possible to have somewhere the right conditions for more complex structure to form. Under the right conditions, the chances to form complex structures (amino-acids, glucides, proteins) are astronomically larger than what one may expect from random thermodynamic fluctuations.
Latter on, the complex chemistry resulted in complex bio-chemistry, then simple biology, and finally complex biology.
It was a mechanism, possible due to universe expansion (as I understand).
The universe expansion will however make impossible life in the future.
The amount of time in which our universe can support life is negligible and infinitely small compared to the amount of time in which our universe will not support life.
-
Well, I think that it's a 'bit' harder to believe at spontaneous generation.
-
what one may ask, assuming that you are correct flr, is why life can exist? How come 'complexity' leads to life? Or am I thinking wrong there?
-
Is life just chemistry?
The Belousov–Zhabotinsky reaction show that away from equilibrium even basic inorganic chemicals can have macroscopically observable evolution consisting in self-sustaining oscillations in chemical composition, as if the systems gets a "heartbeat" of its own.
Is life like a Belousov–Zhabotinsky http://en.wikipedia.org/wiki/Belousov%E2%80%93Zhabotinsky_reaction (in a sense that right chemistry/external constrains and far from equilibrium conditions is all that is needed) but astronomically more complex?
If yes, then the nature simply ran a very basic mathematical rule known as optimization via a genetic algorithm, and it did so just like it with other physical laws (like gravity). The universe is so big that it was statistically possible to happen somewhere, sometime.
-
Sterile by definition means there is no life present. The title can be slimmed down to: how did life begin? This belongs in the Life Sciences section.
The origin of life is an on-going area of study, and there is a lot of work going into answering that question. The main line of inquiry is trying to figure out how/where nucleic acids first appeared, and how they were able to start replicating. The entire basis of life is the transfer of genes to the next generation, so nucleic acids are essential. I understand there is also work going into figuring out how lipids fit into this - as membranes are also essential to life and may have provided an environment stable enough for nucleic acids (particularly RNA, which is pretty unstable) to play around.
As pointed out above, the general hypothesis is biochemistry having emerged from chemistry, and ultimately enabling life to appear. This is called the abiogenesis hypothesis. There is also the idea of panspermia, that life has started somewhere else and has migrated to Earth on space rock. Personally, I feel that's just kicking the can down the road - as you then have to answer how life got started elsewhere.
-
In view of the attitude of moderators to other threads, I would suggest that all that science at present has about the origins of life per se are several poorly developed and highly speculative theories, and that this thread therefore does not belong in "physics" -- at best it belongs in a biology discussion, but more probably in "new theories".
-
In view of the attitude of moderators to other threads, I would suggest that all that science at present has about the origins of life per se are several poorly developed and highly speculative theories, and that this thread therefore does not belong in "physics" -- at best it belongs in a biology discussion, but more probably in "new theories".
Mod note: Actually, I think it's OK to discuss these speculative theories so long as it's clear what is established vs. what is speculative and so long as the thread isn't being used to promote a particular speculative theory.
It's such a broad question: how do we go from the big bang to life, that it's hard to put it in any single forum. What science does have to say on this is going to pull from physics, chemistry and biology. Perhaps it would be best off in "general science?" Any objections to me moving it there?
-
I would have only a minor problem with the thread being moved to "General Science". I do have a problem with this sort of thing being seen as part of the domain of physics, and with far flung and inadequately justified speculations being considered part of the science of physics. (Physicists have a habit of laying claim to expertise in various areas of science, and of failing to recognise the specific expertise of other specialists who associate with the "lesser" sciences).
My secondary problem, which I would not really want to make an issue of, is that this sort of discussion which is not, and currently cannot be backed by any observational or experimental evidence, is so speculative that it is really philosophy rather than science, and should therefore be in the "new theories" forum. Alternatively the moderators need to rethink their attempts to relegate the SR discussion -- much more observationally based -- to the new theories forum and restore it to what might then become a rightful place in the physics forum.
-
I would have only a minor problem with the thread being moved to "General Science". I do have a problem with this sort of thing being seen as part of the domain of physics, and with far flung and inadequately justified speculations being considered part of the science of physics. (Physicists have a habit of laying claim to expertise in various areas of science, and of failing to recognise the specific expertise of other specialists who associate with the "lesser" sciences).
As a physicist, I resemble that remark! But seriously, there definitely is a lot of cross-over between disciplines on a question like this. Even a simpler question like hunting for extraterrestrial life involves many branches of science working together. In some sense, we physicists like to think that everything is physics, because in our minds you should be able to build everything else up from basic physics theories (quantum theory + relativity). In reality, it would be absurd and fruitless to try to base most of what is studied in biology on quantum mechanics.
My secondary problem, which I would not really want to make an issue of, is that this sort of discussion which is not, and currently cannot be backed by any observational or experimental evidence, is so speculative that it is really philosophy rather than science, and should therefore be in the "new theories" forum. Alternatively the moderators need to rethink their attempts to relegate the SR discussion -- much more observationally based -- to the physics forum.
I disagree. There are definitely some rough connections you can draw from the big bang to the formation of the elements for example, and from the formation of the elements to inorganic chemistry, then from inorganic chemistry to the formation of amino acids (I'm thinking of the Urey/Miller experiment here, but I know there's been other work on it), which would likely be a path to organic chemistry. I know people are investigating how you could go from basic organic compounds to life, but I don't know much more than that. There is plenty here that is based on experimental observations.
None of this proves at all how life formed, of course, and there are huge gaps in the understanding, but that doesn't mean we can't discuss the science that does exist in between those gaps.
----------------------------
This isn't the place to go into details on reasons for moderation of particular threads, but we generally only step in to moderate a thread when we believe it is in violation of forum rules. One of those rules is that it is being used to intentionally promote non-mainstream science. I don't see that this thread is being used to promote non-mainstream science at this point. This can be a tricky decision to make, and if you have particular concerns I'm more than happy discuss them via PM and take them to the other moderators for discussion.
-
None of this proves at all how life formed, of course, and there are huge gaps in the understanding, but that doesn't mean we can't discuss the science that does exist in between those gaps.
I fully agree, but can you point to any part of any post in this thread that really does discuss "the science that does exist"?
-
I think in order to answer this question, "life" first has to be defined. Good luck with that! I see no separation between how matter came from the big bang and how life emerged.
The term "sterile" can also seem a bit subjective, for instance, is an electron "sterile"? Is a photon "sterile"? Is an atom "sterile"? Is electro-magnetic radiation "sterile"?
We are all made of atoms, at what scale do we stop being sterile and become life?
-
We are all made of atoms, at what scale do we stop being sterile and become life?
Higher order hierarchy: biochemistry to biology.
-
Spontaneous generation of life is still somewhat of a mystery to scientists.
But I think its easy for everyone to believe in spontaneous generation of entropy.
According to thermodynamics, entropy is bound to increase over time in macroscopic systems of sufficient size (ie well above the nuclear/atomic scale). http://en.wikipedia.org/wiki/Second_law_of_thermodynamics
One characteristic of life is that overall, entropy increases more rapidly in its presence than if the same materials were present, but without life.
Life achieves this by a smaller, more local decrease in entropy, on the scale of the organism.
Thermodynamics permits this apparent anomaly as long as the energy expended in decreasing the local entropy is exceeded by the global increase in entropy. Thus life requires a readily-available source of energy, in a form that is not too disruptive to the organism's structure & integrity.
Perhaps Life is Nature's way of accelerating the ultimate heat death of the universe
http://en.wikipedia.org/wiki/Heat_death_of_the_universe (or God's way, if you prefer...).
-
We are all made of atoms, at what scale do we stop being sterile and become life?
Higher order hierarchy: biochemistry to biology.
(red text) Sorry, but it's too easy your point and it does not explain nothing...
-
I disagree. There are definitely some rough connections you can draw from the big bang to the formation of the elements for example, and from the formation of the elements to inorganic chemistry,
Hi, can you provide some examples?
-
I suspect JP may have intended to type organic chemistry rather than inorganic - otherwise the sentence is not really relevant. I'll answer on that basis. As you may be aware only hydrogen, helium and a smidgeon of lithium (?) emerged from the big bang. It took nucleosynthesis in stars to generate more complex elements and supernovae to produce the full range of these and to distribute them in the interstellar medium.
Carbon, hydrogen, oxygen and nitrogen are the key elements for terrestrial biology. Of course hydrogen is the most common element in the universe. Oxygen is the third most common, carbon the fourth, nitrogen the seventh. These combine in interstellar place to form a wide variety of organic molecules - over one hundred have been identified.
Some of these compounds and additional ones, including amino acids, are found in meteorites. The reflectance readings from some asteroids matches organic compounds. Other organic molecules have been identified in comets. On the basis of this it is generally thought that the early Earth was seeded with a wide range of organic materials which would have kick-started a wealth of prebiotic chemistry.
-
@Ophiolite
I've reply to JP, however now I'm going to use your method, so: 'The responsibility to demonstrate that lies with you.' (from here: http://www.thenakedscientists.com/forum/index.php?action=post;quote=397870;topic=37162.0;last_msg=397873).
You shuold demonstrate with some facts, don't you?
-
waytogo,
you asked a question. I have given you a concise answer that accurately reflects current understanding of this fascinating area. I am not making weird assertions, but recounting information that is well understood by those with an interest in these matters. It is when novel claims are made that the responsibility rests with the proposer. Such is not the case here.
If you have a specific question on this I shall be happy to try to answer it. Otherwise, if you don't wish to take advantage of my knowledge in the area, built up over several years and based more on original research papers than textbooks, or popular science works, then just ignore what I've said. I've tried to help you, I find your response rather offensive.
-
Woops :)
We have some knowledgeable guys here, and then we have us other :) It's a interesting field and from what I understand most expect it to have some sort of self organizable principle to it? Or am i thinking wrong there? Can you assume that something can 'evolve' as this universe and Earth seems to have done without something enabling certain combinations as more probable than others? In a way it becomes a merry go round as arguing this somehow seems to invoke some initial setting that creates it? But no matter what one call it, entropy, or ? in a general way, how would you create a living universe without needing to set rules?
-
You ask some excellent questions and make some good points. . I'll start at the end.
The universe does have a set of rules and these have led directly to life. The four fundamental forces, the family of elementary particles and a small group of constants (read Martin Rees's Just Six Numbers) are what has made it possible for life to emerge from a sea of energy via some complex, but apparently inevitable processes. (If one wished to make an argument for a creator the best evidence lies in the fortuitous combination of forces, particles and constants.)
Why did these combinations give rise to a universe of stars, galaxies and planets, and to a chemistry that allowed, in at least one instance, life to develop? It has been suggested that it was chance and that if the universe were not suitable for life then clearly we would not have been here to observe it: The Weak Anthropic Principle.
Self organisation plays some role in the process. The elements of life are common. There are many environments that would be conducive to life. There seems ot be a trend towards complexity, it is just that we have not yet nailed down excatly the pathways that were followed, or determined if this is the only possible route.
I mentioned the amino acids in space. Researchers put amino acids into ice and fired a lump at hypersonice speeds into a target. They wanted to see if the amino acids could survive an impact with the Earth at the speed of an incoming comet. Not only did they do so, but they linked up to form polypeptides. Proteins are polypeptides, just more complex.
Everywhere we look we see small reactions that tend to mimic or duplicate processes we see in life. Lipids will form small vesicles in which other chemicals might concentrate, bearing a resmblance to cell walls. And so on.
We have a considerable distance to go in our understanding, but there is a great deal of research ongoing - a fascinating field.
-
... Everywhere we look we see small reactions that tend to mimic or duplicate processes we see in life.
e.g. https://en.wikipedia.org/wiki/Rule_30
(https://upload.wikimedia.org/wikipedia/commons/9/9d/CA_rule30s.png)(https://upload.wikimedia.org/wikipedia/commons/thumb/7/7d/Textile_cone.JPG/220px-Textile_cone.JPG)
e.g crystallization like plant roots ...
[ Although I'd say the living thing includes these processes rather than the processes mimicking life ]
-
Good examples RD. There seems to be, in the universe, and inherent tendency to build complexity out of simplicity.
It is not a popular view and it is at odds with the current methodological naturalism of the scientific method, but I see teleological implications for these trends. This does not imply a creator, but rather a, perhaps inevitable, end goal. Of course saying such things out loud usually constitutes an own goal.
-
The universe does have a set of rules and these have led directly to life. The four fundamental forces, the family of elementary particles and a small group of constants (read Martin Rees's Just Six Numbers) are what has made it possible for life to emerge from a sea of energy via some complex, but apparently inevitable processes. (If one wished to make an argument for a creator the best evidence lies in the fortuitous combination of forces, particles and constants.)
I don't know about that, I was under the impression that the argument of the fortuitous combination of forces, particles and constants, as you say, had never held much sway with respect to the scientific method. Isn't that what you mean when you say "There seems to be, in the universe, and inherent tendency to build complexity out of simplicity....It is not a popular view and it is at odds with the current methodological naturalism of the scientific method..."?
-
The universe does have a set of rules and these have led directly to life. The four fundamental forces, the family of elementary particles and a small group of constants (read Martin Rees's Just Six Numbers) are what has made it possible for life to emerge from a sea of energy via some complex, but apparently inevitable processes. (If one wished to make an argument for a creator the best evidence lies in the fortuitous combination of forces, particles and constants.)
I don't know about that, I was under the impression that the argument of the fortuitous combination of forces, particles and constants, as you say, had never held much sway with respect to the scientific method. Isn't that what you mean when you say "There seems to be, in the universe, and inherent tendency to build complexity out of simplicity....It is not a popular view and it is at odds with the current methodological naturalism of the scientific method..."?
Naaman the neatly parcelled versions of "the scientific method" that are discussed in throwaway sections of chapter 1 of scientific textbooks and presented as dogma in high school syllabus have almost nothing to do with either the way that scientists actually operate or the scientific method as it is seen in current philosophical debate. Two really good books if you want a deeper understanding of the notion of "scientific method" -- Alan Chalmers "What is This Thing Called Science?" and H H Bauer "Scientific Literacy and the Myth of the Scientific Method".
Far from "never held much sway" there is a successful account of how a set of random factors operating under a regime of strictly increasing disorder in the universe (second law of thermodynamics) can and does produce a lot of local order and self-organization. It earnt Prigogine a Nobel prize, is greatly respected to this day, and has opened up a vast and productive new field of non-equilibrium thermodynamics. It is rather dry, esoteric, and difficult to work with, and does not deal with things like SETI and terraforming and big bangs and the like that can capture the public's imagination, but it does provide a framework for understanding how life could have arisen in a naturalistic and dissipative and non-teleological universe.
Science is geared up to provide essentially mechanistic rather than teleological explanation, and it has done a much more productive job of it since Aristotle's approach was abandoned. Yes, Aristotle had a teleological view of the world even though he was quite non-religious. His "five causes" are a particularly insightful and interesting way of approaching causality -- they include a "material cause" which pretty much refers to chemical composition, an "efficient cause" which refers to mechanism, and a "final cause" which refers to purpose. There are indeed many ways of answering the question "why...?"
So when we ask "why does life exist?" we might be asking "how did it start?" or "what are the special properties of the materials that living things are made from?" or "how do living things work to perpetuate their existence?" or "what is the purpose of life in the universe?"
There is plenty of room for answers to all four of these questions in a world view, but a scientific approach can only potentially provide answers to the first three, and is quite able to even deny that the last is a valid question. So far science has not provided a satisfactory answer to the first of these particular questions either, but I think it is a question that science can validly deal with, and that it is more probable than not that it will be answered at some future date as the result of scientific investigations.
Why do I think that? Because the sorts of things that scientists do, and the sorts of approaches that they take to finding new knowledge, are capable of obtaining evidence that will contribute to an answer to a question like this. I would not say the same thing about the fourth question.
-
Thanks, I put those on my to-read list. I am realizing that my impression of scientific methodology is wrong and not fair in some ways, as JP and others have pointed out. I've been trudging away at my own models and hypothesis that have come out of my interest in neural networks and emergent properties, and I guess I've been getting the wrong impression from visiting forums and the like that such ideas will ultimately not be given the light of day by their very nature.
I guess what irks me sometimes is when science seems to overstep its own calls for evidence-based statements of belief, and when claims or interpretations of experimental results are given authoritatively when they have no basis in evidence. It's not unlike some of the recent discussions on this forum about interpretations of SR as being many-words, or wave-function collapse, or pilot-waves. JP noted that the math behind SR does not imply any particular interpretation. But I won't argue that this was done with any particular intention in mind, as I see where poor reporting of science can play a role here.
If I remember right, you said you were Christian, so you might sympathize why such claims can be a hot-button issue for believers. At least for me, it is anything but in defense of some vague spirituality or psychological need for belonging. The teleological argument for me lies at the height of pragmatic importance as it affects the public conception of the very nature of reality.
-
I can indeed see why teleological explanation is problematic and largely discredited in life sciences. I can also see the biologists who would be most opposed to teleology as strict adherents of scientism, occasionally getting carried away with their own type of teleological explanation. In a popular Science type TV programme that I watched the first ten minutes of recently, the zoologist commentator was carrying on with a story about a dinosaur (for which he really only had hard evidence about its morphology and evolutionary relationships) being driven by the urge to have lots of offspring, adopting particular strategies to avoid predators, etc., etc.
We cannot have a world view that disposes of teleology altogether. If I dig a vegetable patch and plant some beans, then those beans have a purpose -- it is not a purpose of their own, but a me-given purpose and destiny: they are to be harvested and incorporated into a meal at a later date. Why are those bean plants there? because I want to harvest them
and cook the beans when they are ready. That is a soft sort of teleology that answers a question "why ...", but is otherwise fairly uncontroversial.
On the other hand, it is very much harder for scientific investigation to produce evidence that relates to the purpose of an object, as opposed to its origin, or its composition, or its mechanism. It might not even be possible at all.
That, in my view, leaves us with just three choices for arriving at a consistent and complete world view:
1) Accept teleological explanation into the body of scientific explanation. This is fraught with many dangers, as biologists (mainly) have found.
2) Totally deny the validity of any teleological explanation without human agency.
3) Accept that ultimate cause -- purpose -- is indeed a valid aspect of the world, but that it is a dimension in which science is quite impotent. It can then be seen as part of a body of knowledge and belief that stands apart from scientific knowledge and belief. Such a body of knowledge and belief might include such things as ethics, aesthetics, culture.
Obviously I am going to choose the third path, and I expect to be opposed and probably engaged in debate by those who adhere to scientism -- the belief that scientific knowledge and investigation is capable of forming the basis for a total world view -- a belief system that I would designate as scientism.
I am a scientist, not in the sense of an adherent of scientism, but in the sense that pursuit of a mechanistic understanding of the way that nature works has for me been a vocation and a lifelong passion. I believe that there are other valid areas of knowledge outside scientific knowledge, and that science cannot provide a basis for all aspects of life.
I also believe that intrusion of teleology, in the form of "intelligent design" and the like, into scientific debate and endeavour can only lead to confused and lazy science, and would hinder our understanding of the way that nature works. And that is, perhaps surprisingly, not at all inconsistent with my personal belief in an intelligent designer!
And all of this is philosophical debate rather than scientific, and probably should be consigned to a different area of the forums. (But I note that the Physics forum here, in particular, often diverts into speculative and philosophical debate well removed from any real science content).
-
On the note of "intelligent design" leading to lazy science, I would say, it depends. If you allow the argument into a scientific discussion that something has particular properties because it was designed to have those properties, and simply leave it at that, then of course this would be a step backwards. On the other hand, we might ask that if something has particular properties because it was designed to have them, then is there such a thing as a blue-print to those designs? If so, where would the blue-prints exist? In what form?
And all of this is philosophical debate rather than scientific, and probably should be consigned to a different area of the forums. (But I note that the Physics forum here, in particular, often diverts into speculative and philosophical debate well removed from any real science content).
I would add, that physics forums in general probably attract people like me :P It shouldn't be surprising though, since it is from physics that the grandest of claims about the nature of reality come from.
-
Sorry Ophiolite, I've read you but I've also been away for some time. It's interesting indeed, and somewhere I think the question can be put as 'is there a purpose to life'? If there is, and btw, I totally agree Damocles, we become indeed a quite philosophical 'forum species' at times, but that is not a altogether bad thing I think?
If one think there is a purpose, the next question must be, does that purpose consider me? There is the possibility that there can be a purpose for which we, even though a necessary, as in 'unavoidable', part of 'it all' not necessarily are the answer to the universe. As I feel we're more of a living part of the universe but not any answer to it, that's also the way a lot of nature people seemed to have felt. As we all was as necessary, animals flora fauna and earth fire water yin and yang in china and the tao.
But we differ from what we see around us in one important aspect. We can observe and draw conclusions from those observations. Maybe that is our purpose, to describe ourselves, as we in my view are 'the universe' existing 'undifferentiated' from anything else by some cosmic perspective ignoring 'the arrow'.
-
Without addressing specific points I want to comment on aspects of the posts of Damocles and yor_on, or thoughts that were prompted by these posts.
First we absolutely must distinguish teleology from any hint of ID. ID is a contrived attempt to undertake distorted science to prove an agenda.
Secondly, I don't even feel comfortable restricting teleology to biology, or to giving biology pre-eminent place.
Life is an emergent property, just as there are other properties of the universe (e.g. star formation) that preceeded it. SOme have made the case that intelligence is an emergent property. For the first time - apparently - the universe can contemplate itself. Why would we think this is the last of the emergent properties? Things may be heading somewhere even more interesting.
There is a fourth alternative for Damocles' options. Neither accept nor reject teleology from science, simply consider the possibility it may be active and, from time to time, look for evidence. If we don't look we will assuredly not find and there is more evidence for it than there is for green unicorns. (And I say two of them only yesterday.)
-
from Ophiolite:
There is a fourth alternative for Damocles' options. Neither accept nor reject teleology from science, simply consider the possibility it may be active and, from time to time, look for evidence. If we don't look we will assuredly not find and there is more evidence for it than there is for green unicorns. (And I say two of them only yesterday.)
I would see admitting the possibility of teleological explanation in any hard sense (i.e. other than "my bean patch" type examples) as equivalent to including it, my option (1).
I also find it hard to imagine what type of result could be uncovered in scientific research that could unambiguously be taken as evidence of "ultimate cause" as opposed to "efficient cause".
I know of several examples where an explanation in terms of "ultimate cause" seemed appropriate and convenient at the time, but where its acceptance would have stifled further enquiries that uncovered several layers of explanation (and opened productive technologies) in terms of "efficient cause", with consequent advances in science. One such was the discovery and eventual mechanistic explanation of oscillating chemical reactions.
And I was never meaning to confine my remarks to biology -- indeed I am totally without specialist knowledge in biological areas. But it is only in the philosophy of biology that teleological explanation has been extensively discussed. Physics generally raises quite different philosophical issues, and chemistry raises several quite unique and little explored ones.
-
I find it enjoyable that more than me share that thought Ophiolite :) that we might be the universe, observing itself. For that I think it need a arrow, as it is only then you may find this specific linear causality we observe macroscopically. And if one like then one also are free to interpret it as we all could be seen as a part of something more. The arrow, or rather 'time', is a mysterious thing to me, in Einsteins description a indivisible part of the 'room' we live in, but it surely exist for us all. And that was a interesting comment Damocles, "Physics generally raises quite different philosophical issues, and chemistry raises several quite unique and little explored ones." Not physics but what you said about chemistry? Could you give us a example of what you think of?
-
...(snip)...
And that was a interesting comment Damocles, "Physics generally raises quite different philosophical issues, and chemistry raises several quite unique and little explored ones." Not physics but what you said about chemistry? Could you give us a example of what you think of?
I will give you not just one, but three, in the course of one of my long raves.
Firstly, an historical case: Physics makes a lot of its clash with organized religion in an examination of the Geocentric vs Heliocentric planetary system in the early renaissance. Biology looks to the clash between creationism and Darwinian evolution. There is a similar, but much darker and more carefully hidden clash in the history of chemistry: the clash between mediaeval alchemists, who managed to create a lot of new materials, quite unlike anything that had previously been seen, and the religious doctrine that God's work of creation of everything on the Earth was a finished work, as described in the Genesis legends. And the religious authorities were in an extremely difficult position, because uncreated materials that had been discovered centuries earlier -- iron, steel, and glass, were an essential part of the economy and culture, and vitally important for an ongoing existence, and they did not want the parallels there to be exposed until and unless their own scholars had gone a long way towards sorting out the issues.
Secondly, a very current and practical issue: emergent properties arise in all disciplines, but nowhere are they as important and as widespread as in chemistry. And they have some very practical implications.
How should we look at the properties of a substance? It is commonly said that gold is a yellow metal that is soft and plastic (i.e. malleable and ductile), a very good conductor of heat and electricity, and chemically unreactive.
But most of these properties are emergent properties: gold is not yellow unless you have a particle at least about 5 µm in diameter; it is not plastic in any measurable sense unless you have a sample that is slightly larger even than this. And thermal and electrical conductivity works quite differently for samples of just a few atoms of material than for the bulk material.
A pure substance is usually defined by chemists as a bulk substance consisting of identical molecules or of a lattice of ions or atoms in a regular network structure. But such a definition takes us back to a Platonic ideal. It is unrealisable in practical situations. It is (almost? completely?) impossible to prepare a sample of pure water with sodium ion content less than 1 fM (10–15 M). And even if it were possible, that water would still contain 10–7 M each of hydronium cations and hydroxyl anions along with its H2O molecules. Perfectly pure water belongs in Plato's paradise, along with a perfect triangle and the number 575.
This particular issue has recently developed a really practical concern with the rise of nanotechnology. Colloidal material structures often display physical and chemical properties quite different to those of bulk materials, and that even show differences for different colloidal morphologies. Bulk gold is yellow, but nanoscale gold may be orange, crimson, or deep purple. A huge practical problem is the following: when should a nanoscale preparation be required to undergo a complete battery of safety tests before it can be commercially deployed? and how should MSDS for colloidal mixtures be prepared? (So far it has usually been addressed by a combination of MSDS for the several substances involved in the mixture, which is fine for larger particle-size dispersions, but might be dangerously inappropriate for colloids.)
The nineteenth century chemist worked largely at preparing and characterizing a huge number of new materials. The twentieth century chemist worked largely at trying to understand how differences in behaviour at the molecular level were related to differences in bulk properties. The twenty-first century chemist will need to develop an understanding of how chemical and physical properties of substances change through the colloidal scale with both size and morphology.
Third problem? Pluralism in chemical "explanation". Most chemical theory deals with systems that are only solvable as numerical approximations in strict quantum mechanics. Detailed theoretical structures of molecules can be obtained at various levels of approximation using the "Gaussian" program. But for treating reactions there is no methodology that should really count as an "approximation", and chemistry is a dynamic subject, not a static one -- it is about transformations as well as structures (and trying to incorporate chemical dynamics into a structural property called "reactivity" is really cheating!) So in practice, what a chemist usually works with is a simplistic model, a caricature, rather than an approximation to reality. This is what leads to the pluralism that underlies chemical theory: ligand field theory and VSEPR theory are both simplistic theories that address aspects of inorganic structures. And chemists mix and match them according to the particular problem they are looking at. No chemist would claim that VSEPR theory is 'right' or 'wrong', but they would claim that it provides a better or poorer model for some sorts of problems.
Now this sort of thing happens a little with physics models as well, but in chemistry it pervades and underpins the whole subject.
There is another problem. When you use Gaussian at a low level of approximation, you can see all of the familiar concepts that chemists like to incorporate in their explanatory frameworks -- p-orbitals, bonds, lone pairs, electron withdrawing groups, and so on. When you go beyond a certain level of sophistication to a high level of approximation in the method you use, you tend to lose all of the explanatory framework. You can see the input and the output from the program, and all you can really say is "oh yes, Gaussian got the value of that property pretty right". You cannot trace a causal chain of mechanistic explanation in the way that chemists are accustomed to.
It is my belief that these sorts of issues, when you scratch the surface, lead to quite deep philosophical problems that are distinctive to chemistry. I recommend a volume: "Of Minds and Molecules" Eds. Rosenfeld and Bhushan, Oxford UP, 2000. (I should declare an interest as co-author of one of the chapters; not a monetary interest I might add)
-
Monetary interests when it comes to as specialized books as this are probably quite small :) if you can't get it to be a school book that is (as a guess). Very interesting Damocles, and it's about 'Quantum chemistry' you talk there right? It seems as everything become fuzzy when you go down in scale? But what you're discussing seems also to be to find the borders that differ 'particles' from 'matter', am I right there? And mass is really interesting, what makes something to become 'matter', where goes the border between what we can measure as the macroscopic properties of a material relative the properties you find at a small scale, and why/how do they transform?
=
And there is one very important thing more, to me that is :) what differs 'dead matter' from living?
-
The book sounds cool btw. A very impressive assortment from various field of science contributors, if I may say so? You can take a peek in it at Of Minds and Molecules: New Philosophical Perspectives on Chemistry (http://books.google.se/books?id=eKhy2SCmGNAC&pg=PA3&lpg=PP1)
-
What a fasinating subject we have here....
To take the nuts and bolts of this topic that particles can be arranged in such a way so as to be able to attempt to understand themselves is brilliant, i.e humans.
I find the idea of how we are, where we are in evolution at this point extremely hard to believe. I mean in such a miniscule amount of time we have become the machines we are. Not just a form of life or an arrangement of particles but a machine that has a conscious, but not just that, a machine that interacts with itself on a biological level of phenominal complication as any good medical physiology book will emphasise.
Assuming that evolution is not near its end the future of life and this universe and its connection are something to behold .....
Ace
-
Do you consider 3,500,000,000 years plus a miniscule amount of time. If we consider the first eukaryotes came in around 2 billion years ago and the average generation time for a prokaryote is one hour, then that's 1.3 * 10^13 generations to develop all the interesting stuff.
-
What a fasinating subject we have here....
To take the nuts and bolts of this topic that particles can be arranged in such a way so as to be able to attempt to understand themselves is brilliant, i.e humans.
I find the idea of how we are, where we are in evolution at this point extremely hard to believe. I mean in such a miniscule amount of time we have become the machines we are. Not just a form of life or an arrangement of particles but a machine that has a conscious, but not just that, a machine that interacts with itself on a biological level of phenominal complication as any good medical physiology book will emphasise.
Assuming that evolution is not near its end the future of life and this universe and its connection are something to behold .....
Ace
I agree, and science does not have any possible answer of that.
However ...still waiting for a credible clue about this Question thread since years.
-
Do you consider 3,500,000,000 years plus a miniscule amount of time. If we consider the first eukaryotes came in around 2 billion years ago and the average generation time for a prokaryote is one hour, then that's 1.3 * 10^13 generations to develop all the interesting stuff.
To even get to any complexity at all i find amazing in any given amount of time. On some level where life started the very fact that it knew it needed to evolve at all is odd. None of the elements evolve chemical molecules dont evolve as im aware water has never evolved since it was first created. Stars dont evolve. All these things have a cycle but they dont slowly change into other things so no 2 billion years isnt that long.
-
Your choice of words is odd. Life did not 'know' it needed to evolve. Evolution is a natural consequence of the 'laws' which govern the universe.
In one sense water has evolved, by reacting with other chemicals to intitiate, then evolve life. In this particular sentence, that may exist as a distinct, unique sentence for the first time ever in the entire universe, the letter 'e' is unchanged from the 'e' I was using as a child half a century ago. The letter 'e' has not evolved, but the sentence it is in and the meaning that sentence conveys, has changed.
Stars changed into us.
-
So are you saying water is alive then or partly alive?
I think lifes a little like a painting you can have as many paints as you like but you dont have a picture the euivalence of the the painting is the inteligence part or life.
The letter 'e' is just a letter but a story is something else dont you think?
As for stars once again are they alive? i dont think so like the explanation i gave above they are merely the paint and not the picture.
-
simply trying to say life can't form out of an environment that's "too hot" for life to have originated from doesn't disproof a known fact if you ask me.
note that by known fact i mean not the big bang but the observation made that leads to the theory. the observation is always right no matter what, theories aren't. i think the big bang doesn't cover nearly enough to be sattisfying but it's all you can say on the subject without going into massive speculation.
-
So are you saying water is alive then or partly alive?
I'm not sure how you formed that impression from what I wrote. Water is an essential constituent of life as we know it. Prior to such life exisiting then, obviously, water was not part of life. Therefore, in that sense, water has evolved inasmuch as it is a component of an emergent property, life. Water is no more alive in these circumstances than a molecule of thymine.
As for stars once again are they alive? i dont think so like the explanation i gave above they are merely the paint and not the picture.
I didn't disagree. You asserted, I think, that stars do not evolve. I pointed out that we are composed of the ashes of dead stars. That, in a non-biological sense, is evolution.
-
I see where your coming from ophiolite, stars do evolve in a sense but to compare that evolution to life concerns me.
A star will go through several defined periods of its existence but id say life has some very fundamental properties which nothing "unliving" can have. Using stars as an example, they do the same now as they allways have in the foreseable past.
Compared to a living being they are born and go through all their different stages to death, but if you see my point they are not changing from one generation to the next becoming more complex ie as we have gone from being monkeys who walked on all fours to people who can communicate.
Moving on id say the point of life starts when conciousness is first available. Without this i dont believe a soup of chemicals can know to evolve. Reactions can take place between elements and molecules through the laws of physics and chemistry but for a structure to know it must evolve is something more.
-
I think asking the question "when did life start?" is like asking "when did humans start?". There is no point in history when an ape gave birth to a human. Each generation looked pretty much the same as the several hundred either side of it.
I think matter just combines in more and more exotic forms and the forms that continue are the ones that can re-produce themselves. We label these forms as "life" but to me it's a fairly arbitrary term.
-
I think asking the question "when did life start?" is like asking "when did humans start?". There is no point in history when an ape gave birth to a human. Each generation looked pretty much the same as the several hundred either side of it.
I think matter just combines in more and more exotic forms and the forms that continue are the ones that can re-produce themselves. We label these forms as "life" but to me it's a fairly arbitrary term.
There is a real problem with this type of argument. It is the "missing link" argument. If "life" is as probable and/or inevitable as most would like to think, then what is the factor that limits its generation to 3 Gyr ago in the Earth's history? With the huge variety of environments accessible in the natural world, augmented by those which can be prepared by the machinations of scientific investigators, it seems enormously surprising that we are have not found any systems that are "nearly alive, but not quite"! There is, after all, evidence of a huge variety of living forms, from the very simplest archaea to the most complex vertebrates.
I think that that is pretty strong evidence against the notion that whenever we find a planet in the "Goldilocks zone" of a star similar to our sun, we are likely to find some form of life. Very strong evidence, at least with the present state of knowledge about such matters.
To my mind, that leaves just two possibilities. The first is that a Creator "waved His magic wand" to get life started on Earth. Although I am unashamedly a religious person, I would dismiss that one, out-of-hand. The other is that life as such has a natural origin, but its emergence is an enormous fluke that has only happened a small number of times, and possibly only once, in the history of the cosmos. Because of the soft form of the cosmic anthropic principle, there is really no evidence against this latter view.
-
Your logic is flawed Damocles. Since life now exists in great variety, any "almost alive" collections of pre-biotic components would be snapped up by one or other of those varied life forms before the "almost alive" could become alive.
I think matter just combines in more and more exotic forms and the forms that continue are the ones that can re-produce themselves. We label these forms as "life" but to me it's a fairly arbitrary term.
Totally agree. A few years back at a biology conference delegates offered up around one hundred definitions of life. That reflects the difficulty of imposing absolute yes/no decisions on something that is a continuous spectrum.
I see where your coming from ophiolite, stars do evolve in a sense but to compare that evolution to life concerns me.
I think you will see that I was comparing and contrasting. I repeat: you said stars do not change; I pointed out that they changed into us. It's not deeply philosophical, it's just a statement of fact.
Compared to a living being they are born and go through all their different stages to death, but if you see my point they are not changing from one generation to the next becoming more complex ie as we have gone from being monkeys who walked on all fours to people who can communicate.
Well, stars do in fact change from generation to generation. The metal content (to an astronomer any element other than hydrogen or helium) rises from generation to generation, hence we have Population III, Population II and Population I stars.
Also, you imply that you see evolution as being a matter of becoming more complex. While a small number of evolutionary steps lead to greater complexity, this is only a very small part of the evolutionary process.
Moving on id say the point of life starts when conciousness is first available. Without this i dont believe a soup of chemicals can know to evolve. Reactions can take place between elements and molecules through the laws of physics and chemistry but for a structure to know it must evolve is something more.
This is seriously wrong. I have already pointed out to you that there is no 'need' to evolve and certainly no conscious intent to evolve. That is the entire point of Darwinian theory and all the offshoots and developments of it. What you are proposing is not science.
You say "i dont believe a soup of chemicals can know to evolve." Correct, but neither do they require consciousness to do it.
-
Hi folks,
so after all, can science prove it or not? Obviously I mean life from a sterile condition.
-
Science doesn't generally prove things, especially something as complex as the origin of life. Science gathers observations, constructs hypotheses, tests these hypotheses, rejects some and strengthens others, until it arrives at the best available explanation based on the available data.
What Science has done is to demonstrate a variety of ways in which the building blocks of life could be readily produced and to construct several plausible scenarios by which these could combine to become life. To think of the primeval world, rich in prebiotic chemicals, as sterile, is to misuse the term.
Details will emerge from further research.
-
I think the most important thing discussed here is :)
"3) Accept that ultimate cause -- purpose -- is indeed a valid aspect of the world, but that it is a dimension in which science is quite impotent. It can then be seen as part of a body of knowledge and belief that stands apart from scientific knowledge and belief. Such a body of knowledge and belief might include such things as ethics, aesthetics, culture."
We live by ethics, and evolve them, and us, together. Like the idea of democracy. They are what makes life worth living although they from a strictly narrow minded behavioristic point of view may be seen as unnecessary to life. So, I think the idea 'from simplicity to complexity' holds there too. Although I have a nagging feeling that totally ethic beings wouldn't agree on their view being complex, instead point out that it would be mine that is fragmented?