APOD and General Astronomy Discussion Forum
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NON SEQUITURgeckzilla wrote:Non sequitur?FloridaMike wrote:
You may study the stars Chris, I study something much, much more complex. Humanity.
Many biological scientists (and in fact geologists as well) would disagree with your comment...."how unremarkable our planet appears to be". The abundance of water (where life arose and spent 85% of its existence), a stable atmosphere (yes no Oxygen for a couple of billion years but eventually), Plate Tectonics which provided much of the selective pressures resulting in the massive diversity of life and which is unique to earth at least in our solar system, and ...despite several mass extinction events....an incredibly sustainable and nurturing environment for living organisms for over 4 billion years. I would not call that unremarkable by any standards. Of course if you have an overzealous belief in extraterrestrial life then these facts don't matter. Also...I could be mistaken but from what I have seen the vast majority of astrobiologists are astronomers and physicists. These are not PhD "biologists" who have then decided to work in astrobiology.Chris Peterson wrote:I believe Rob is incorrect in his assessment. There are a number of biologists working in the area of exobiology. More than there are physicists, I think. Of course, modern biology really took off when physicists started becoming biologists. Biology is one of the last scientific disciplines to become rigorous, rather than just observation and classification, which is what it mainly was until about 50 years ago, or even less.BDanielMayfield wrote:I find Rob Gendler’s comments in this thread to be refreshingly candid. Spontaneous generation of life from non-living matter is an extraordinarily difficult thing. Many who doubt this must be unaware of the vast complexity of even the simplest single celled organisms. The evolutionary biologists Rob mentioned know this, which explains their reluctance to jump on the exobiology band wagon.
We have no grounds to make the claim that the initial creation of life is a difficult process. There is very good work being done in this area, and no reason to even think there is a well defined distinction between living and non-living. It is as likely that life is nearly inevitable under the right conditions as that it is rare. But given how quickly life formed on Earth, and how unremarkable our planet appears to be, I think the most reasonable view is that life is probably quite common in the Universe. Simple life. The history of life on Earth suggests that the step up to complex multicellular life may be more difficult than the initial development of life, and the evolution of technological intelligence even rarer yet.
Some might, but I don't know how many. We continue to discover systems similar to our own. A minority, for sure, but that we see them at all in such a small sample suggests that systems like ours, and planets like ours, aren't all that rare. Break down your criteria finely enough, and every system is unique, of course. But what is so uncommon here? Water is one of the most common compounds in the Universe. Plate tectonics appear the norm for terrestrial planets, existing (at one time) on Mars and Venus, as well as the Earth. Oxygen? Common, but actually bad stuff. Life did much better without it. Life has existed on Earth over a range of conditions well outside of what is usually defined as "habitable" by planetary scientists.Robgendler wrote:Many biological scientists (and in fact geologists as well) would disagree with your comment...."how unremarkable our planet appears to be".
Just thinking not saying. 
Ron-Astro Pharmacist wrote:
It would be great if we all had the knowledge of those at the top on their fields but most of us still only have access to limited to the things we might find interesting. Were left with speculating the unknown and speculating how things “might” be. I find it one of the more fascinating and fun parts of life. For instance I find the shape of DNA interestingly similar to the shape of the orbits of planets moving through the cosmos and the shape of our neurons curiously similar to the strands of dark matter but I would never expect them to really be related.
It would be really cool if the large and small of the universe were really related though!!
Interesting, but I think you are possibly presenting a logical fallacy. The idea here is to downplay the hypotheses of astrobiology by saying that biologists do not switch fields to astrobiology, so astrobiology must suffer from a dearth of knowledge in this area. But an intimate knowledge of biology is surely necessary for any astrobiologist. Ergo, any good astrobiologist should necessarily also be a good biologist. Conversely, any good biologist surely has valid ideas regarding astrobiology. The two are rather inseparable. Anyway, before we are able to find alien life, we have to come up with some sound hypotheses that will allow us to search the right places for it. Studying life based on something other than DNA is the ultimate pipe dream for just about any biologist.Robgendler wrote:Also...I could be mistaken but from what I have seen the vast majority of astrobiologists are astronomers and physicists. These are not PhD "biologists" who have then decided to work in astrobiology.
The average person is familiar with this speculation. Any news relating to astrobiology invariably results in inane headlines like this:Wikipedia wrote:Although speculation is entertained to give context, astrobiology concerns itself primarily with hypotheses that fit firmly into existing scientific theories.
The Register wrote:Galaxy is CRAMMED with EARTH-LIKE WORLDS – also ALIENS, probably
Nearest ones are probably getting our TV from 2001
Popular culture is completely full of references like this. They're stupid, but they get clicks. This is definitely wishful thinking. But present work in astrobiology is the only thing I can think of that could possibly be used for future interstellar missions should the searches in our local system prove fruitless. It could also be useful to prevent us from wasting our time on missions with low probability of success. We could send a robot to the nearest star and check it out, but what for? Surely this is important? Unfortunately, delusions about aliens aren't ever going to leave popular culture. Nothing we can do about that.Last week I talked to an astronomer (not a biologist and not an astrobiologist, admittedly) who claimed that the appearance of cyanobacteria, which release O2 as a waste product, was absolutely crucial for the appearance of complex animal life on Earth. Animals need so much energy that large amounts of O2 - which is a very potent source of energy - in the atmosphere and in the liquid water of the Earth was necessary for animals to keep their metabolisms going.Chris wrote:
Oxygen? Common, but actually bad stuff.
Being predatory meat eating members of large societies didn't hurt the evolution of complex brains either.Ann wrote:
Last week I talked to an astronomer (not a biologist and not an astrobiologist, admittedly) who claimed that the appearance of cyanobacteria, which release O2 as a waste product, was absolutely crucial for the appearance of complex animal life on Earth. Animals need so much energy that large amounts of O2 - which is a very potent source of energy - in the atmosphere and in the liquid water of the Earth was necessary for animals to keep their metabolisms going.
Oh yes, I agree that oxygen seems to be critical to any organic life with a high metabolic rate. But to be clear, I'm not making a case for how common animal life might be. Using the Earth as an example, we might reasonably expect the only common life to be very simple, and anaerobic forms may well be favored.Ann wrote:Last week I talked to an astronomer (not a biologist and not an astrobiologist, admittedly) who claimed that the appearance of cyanobacteria, which release O2 as a waste product, was absolutely crucial for the appearance of complex animal life on Earth. Animals need so much energy that large amounts of O2 - which is a very potent source of energy - in the atmosphere and in the liquid water of the Earth was necessary for animals to keep their metabolisms going.Chris wrote:
Oxygen? Common, but actually bad stuff.
This may be part of why Rob and I see things differently. There are very few people who actually call themselves astrobiologists, and it is true that many don't have a strong background in cellular biology (which I think is probably the important niche for this kind of work). But most of the important work in the area is being done by ordinary biologists. The important papers about biogenesis are coming almost exclusively from the biology community. This informs us much better about possibilities for extraterrestrial life than simply identifying candidate planets that have certain assumed characteristics.geckzilla wrote:But an intimate knowledge of biology is surely necessary for any astrobiologist. Ergo, any good astrobiologist should necessarily also be a good biologist. Conversely, any good biologist surely has valid ideas regarding astrobiology. The two are rather inseparable. Anyway, before we are able to find alien life, we have to come up with some sound hypotheses that will allow us to search the right places for it.
Yes, I made this point as well. I wouldn't use the word "improbable", but I would say that using the Earth as an example, complex life is rare. For most of the time that life has existed, it has been very simple. Indeed, many Earth-like planets probably don't stay that way for several billion years. There's no reason to think that life couldn't have formed on both Mars and Venus, but neither environment was stable long enough for it to evolve into something more complex.Robgendler wrote:We may be more in aggreement than we realize. In my original comment I said that simple life (prokaryotes) may well exist on a number of these worlds. The problem I have is with the assumption that complex life will automatically follow. This is an assumption that is quite naive. If you spend considerable time learning about the history of life on earth as we know it.....it was quite an improbable event to go from prokaryotes to eukaryotes and then again to multicellular life. It was so improbable that it took 3 billion years.
I don't think there is anything wrong with the approach being taken by most astronomers who are interested in seeking out life on other planets. I don't detect any zealous belief in complex life, only the very reasonable belief that life is common, and detectible instrumentally. This isn't really something that requires any complex biology, just some fairly basic biochemistry.This is that deterministic reasoning of the physical scientists which I don't agree with and which is not a valid approach when it comes to the biological sciences. True biologists realize this. Unfortunately since the astrobiologists of today become astrobiologists because they have an overzealous belief in this type of reasoning when applied to life...it is for this reason I just can't take them seriously. They are essentially astronomers at heart and in training. They may take the required biology courses but their approach is of a physical scientist.
Faith in science is just another way of saying "confidence in the skills one has developed" and/or "trust in the science already developed". To say that faith is always required in science (or by scientists) is not a controversial statement. Chris, I feel you are just wanting to avoid certain other connotations of the word "faith". Faith, confidence, trust and belief are synonyms in this rich language or ours. These words do not necessarily imply a lack of evidence.Chris Peterson wrote:I disagree. At least, you are defining "faith" very differently than I am. Faith is believing in something without evidence. My belief that science works as a method of finding answers is strongly evidence based. I will change my beliefs freely (and have done so many times) as the evidence changes.FloridaMike wrote:And Chris? Faith is ALWAYS required. If science did not have the faith it can find the answers, no one would be looking.
Faith has different meanings, some of which I would find offensive if applied to me. The bottom line is that defining simple belief as "faith" devalues and confuses both words. I am a proponent of precision in the use of language, and suggesting that "faith" is required by scientists seems to me both inaccurate and imprecise. So when such an assertion is made, I will argue against it.Nitpicker wrote:Faith in science is just another way of saying "confidence in the skills one has developed" and/or "trust in the science already developed". To say that faith is always required in science (or by scientists) is not a controversial statement. Chris, I feel you are just wanting to avoid certain other connotations of the word "faith". Faith, confidence, trust and belief are synonyms in this rich language or ours. These words do not necessarily imply a lack of evidence.
1. confidence or trust in a person or thing: faith in another's ability.
2. belief that is not based on proof: He had faith that the hypothesis would be substantiated by fact.
3. belief in God or in the doctrines or teachings of religion: the firm faith of the Pilgrims.
4. belief in anything, as a code of ethics, standards of merit, etc.: to be of the same faith with someone concerning honesty.
5. a system of religious belief: the Christian faith; the Jewish faith.
Faith, n. [OE. feith, fayth, fay, OF. feid, feit, fei, F. foi, fr. L. fides; akin to fidere to trust, Gr. to persuade.]Nitpicker wrote:
Faith in science is just another way of saying "confidence in the skills one has developed" and/or "trust in the science already developed". To say that faith is always required in science (or by scientists) is not a controversial statement. Chris, I feel you are just wanting to avoid certain other connotations of the word "faith". Faith, confidence, trust and belief are synonyms in this rich language or ours. These words do not necessarily imply a lack of evidence.
I agree 100% with those words Chris, when "as yet" is added.Chris Peterson wrote:... I have faith in absolutely nothing.
You have to admit astrobiology is a strange field.......the study of something in which we have absolutely no proof of its existence. I don't mean any disrespect....but to enter a field in which there is absolutely no proof of the existence of the subject matter would require an overzealous (and unrealistic) belief that it exists. Can you name another field of science which is similar? Also I'd love to see a few high ranking specialists in the field who have their "primary" training in the biological sciences. I doubt you can provide any. That says a lot since "biology" is part of the name they adopted. Again not a scientific field which I can regard in any serious manner.owlice wrote:Rob,
I didn't see Chris stating that he was speaking of complex life; where did he do so?
It seems to me you are very close to "true biologists = anyone working in biology (especially astrobiology) I disagree with." I certainly hope I'm wrong about that.
We are only into the Prediction stage of the Scientific methodrobgendler wrote:
You have to admit astrobiology is a strange field.......the study of something in which we have absolutely no proof of its existence. I don't mean any disrespect....but to enter a field in which there is absolutely no proof of the existence of the subject matter would require an overzealous (and unrealistic) belief that it exists. Can you name another field of science which is similar? Also I'd love to see a few high ranking specialists in the field who have their "primary" training in the biological sciences. I doubt you can provide any. That says a lot since "biology" is part of the name they adopted. Again not a scientific field which I can regard in any serious manner.
http://en.wikipedia.org/wiki/Atom#Atomism wrote:<<References to the concept of atoms date back to ancient Greece and India. In India, the Ājīvika, Jain, and Cārvāka schools of atomism may date back to the 6th century BCE. The Nyaya and Vaisheshika schools later developed theories on how atoms combined into more complex objects. In the West, the references to atoms emerged in the 5th century BCE with Leucippus, whose student, Democritus, systematized his views. In approximately 450 BCE, Democritus coined the term átomos (Greek: ἄτομος), which means "uncuttable" or "the smallest indivisible particle of matter". Although the Indian and Greek concepts of the atom were based purely on philosophy, modern science has retained the name coined by Democritus.Click to play embedded YouTube video.
Corpuscularianism is the postulate, expounded in the 13th-century by the alchemist Pseudo-Geber (Geber), sometimes identified with Paul of Taranto, that all physical bodies possess an inner and outer layer of minute particles or corpuscles. Corpuscularianism is similar to the theory of atomism, except that where atoms were supposed to be indivisible, corpuscles could in principle be divided. In this manner, for example, it was theorized that mercury could penetrate into metals and modify their inner structure. Corpuscularianism stayed a dominant theory over the next several hundred years.
In 1661, natural philosopher Robert Boyle published The Sceptical Chymist in which he argued that matter was composed of various combinations of different "corpuscules" or atoms, rather than the classical elements of air, earth, fire and water. During the 1670s corpuscularianism was used by Isaac Newton in his development of the corpuscular theory of light.>>
We have even more things to base the hypothesis on if we include our recent knowledge about the frequency of planetary systems.neufer wrote:We are only into the Prediction stage of the Scientific method
1) Formulation of a question: "Are we alone in the Universe?"
2) Hypothesis: "We are not alone in the Universe?"
based on the knowledge:3) Predictions: ....
- a) Life on Earth began right after its formation from ingredients common in the solar system.
b) After ~4 billion years we evolved by natural processes
c) There are ~ 7 x 1022 stars in the Universe
4) Testing: ....
Personally, I would not place much weight on the fact that a technological civilization evolved on Earth, only on the fact the life developed here. That said, however, and speaking as someone who is well educated in evolutionary biology, the way that life evolved on Earth can be wholly non-deterministic, and still produce a variety of predictable, largely inevitable outcomes. I would not say that evolution has followed a "random" path at all. Evolution is driven in part by small scale random effects, but that evolution itself is most certainly not random.robgendler wrote:This makes the big (actually huge) "deterministic" assumption that given simple life.....complex life (including lifeforms with consciousness) ultimately will evolve at some point. This is exactly what I'm talking about. Its an assumption often made by people who have only a superficial knowledge of the history of life and therefore aren't familiar with the extremely random, circuitous, capricious, arduous, and unpredictable path life has followed over 4 billion years. Its also a concept riddled with anthropocentric bias...the notion that we humans are the natural endpoint of evolution.
