Actually, Dad didn’t build the Viking Mars Lander himself. Nor did he build Viking Biology Instrument Package. But he did help design it. For twenty-five years, he’s been wagging his finger about, saying, “they did find signs of life on Mars.” He knew it, because he helped build it, and dammit he didn’t build it to break.
I’m Dad’s boy, so there’s no point in arguing with me, either.
However, even though I know this to be a fact, there are a number of people who dispute that life was discovered by Viking in 1975. Like, most of the scientific community.
Only one of the experiments among several reported what could easily be interpreted as positive indications of life. This was essentially ignored as a false positive, because it was not corroborated by the other experiments.
Now, coincidentally approaching the twenty-fifth anniversary of the landing, Space.com floats this article which revisiconspiracifies the issue. Or threatens to.
Or maybe my Dad’s been right all along.
I caught that link off of the guys at http://www.arstechnica.com , who are pretty hip dudes not easily suckered. The article isn’t all bad, either, although I have a reservation or two. Like I said at the start, there’s no point in arguing with me. I really can’t be objective about this, so I probably won’t have much to say. I just thought it would be a shame to not see what people think about the issue while there is revived speculation.
Geez, I hate to disagree with you again SK, but I don’t see this new wrinkle as any sort of proof. The point is that there appears to be some rhythym to the release of gases in the Viking package, which is equal in period to the Martian day. This is interesting, but hardly proof. I would be far more likely to suspect a temperature difference caused by thermal cycling due to sunrise and sunset.
I am no expert on this particular field, and I would need to read a scientific paper about it. But to claim this supports life on Mars is a bit of a reach, judging from what I have heard so far. It’s interesting (especially after so many years!), but they need to eliminate a lot of other possibilities first before claiming life.
I certainly hope life is currently present on Mars, but I have to reserve judgement until given incontrovertible evidence for this very reason.
Dr. Levin was the scientist behind the Labeled Release experiment performed by Viking, and he has championed the result as being consistent with life processes since that time. I found a few interesting facts on this topic at the same Space.com websiteSofa King referenced. Apparently, Dr. Levin’s experiment has not been duplicated using inorganic methods, which we should be able to do if the prevailing interpretation is correct. And at least one astrobiologist at the Johnson Space Center agrees with Levin’s view.
Also, according to this site the experiments which yielded negative results testing for the presence of organics may have not been sensitive enough. When tested in the Antartic, these same experiments again yielded negative results. Plus, the Mars Metorite ALH84001 shows that organic material does exist on Mars, even if we eventually decide it was created by inorganic means (and that question is certainly not resolved). Add to this the recent results Sofa King mentions about the circadian rhythms, and maybe we are starting to see a pattern emerge.
Finally, at least one scientific team thinks these images taken by the Mars Global Surveyor are consistent with vegetation changes on the Mars surface. Arthur C. Clarke agrees with them, but I’m not sure he lends any credibility to the idea. Kind of like Hoyle’s association with the recent space bugs in the news. But if indeed bacteria from Earth can find its way 40 km into space, why not all the way to Mars where it could flourish?
Overall, I have to say the evidence is leaning towards existing life on Mars. But unfortunately, I won’t be convinced until we find a “body”, and it probably will require a manned expedition to do so. I just wish I could go.
Careful with your terminology there: organic means containing carbon compounds. Organic compounds can be produced biologically (by living things) or abiologically (through chemical reactions, without the presence of life).
I look forward to sample return missions, which have unfortunately been delayed by the Faster Better Cheaper fiasco.
I don’t want to appear touchy Podkayne, but perhaps you are the one who should be careful with your terminology. Organic does not simply mean compounds that contain carbon – inorganic compounds can contain carbon also. A more precise definition of organic is a compound containing carbon bound to hydrogen as noted here. Plus, I already stated that the organic material on Mars may have been produced by inorganic (re:abiological) means.
You can find many other sources, including chemistry websites, that simply define organic as “of or relating to carbon compunds.” I did not bother with a more thorough definition because I was not trying to draw a distinction between organic compounds and inorganic compounds, but rather between “organic” and “biological”.
The “re:abiological” does not follow–that was my point. “Abiological” is not a synonym for “inorganic.” An organic chemical reaction is simply a reaction in which some of the reactants and/or products are organic compounds. Thus, organics are produced by abiologically in organic reactions, not in inorganic reactions.
I’m at a loss concerning your point. First, you urge me to be careful in my terminology, yet you get the definition of “organic” wrong. Then you try to draw a distinction between “inorganic means” and “abiological”, but the definition of inorganic is given at Merriam-Webster as “forming or belonging to the inanimate world” and “not arising from natural growth : ARTIFICIAL”, both of which fit what I said. So I think you are picking a nit which doesn’t exist.
I think we both agree that: 1) the Mars rock contains organic compounds. 2) these compounds may have been formed by processes not associated with life. If your entire point is that the phrase “inorganic means” doesn’t convey item 2, well… obviously I see it differently, but feel free to bring up many other such highly intriguing matters.
If the organic compounds on Mars were created by “inorganic” means, that would be pretty damn remarkable, if organic is defined as “compounds containing carbon” and inorganic is defined as “compounds not containing carbon.”
Before we get all into a semantic debate, can we all agree that many organic compounds such as hydrocarbons can be formed without the assistance of living organisms? I think that’s the basic point, regardless of the definition.
I think this hits the nail on the head. There are some interesting data from the Viking mission but, applying Occam’s Razor (or Sagan’s “extraordinary claims…”), there are more evidence hurdles to clear before reaching the conclusion of Martian life.
Yes, I believe that we are in agreement on the main point, that organic compounds on Mars (or anywhere else) are not necessarily formed by living things. However, I often see “organic/inorganic” vs. “biological/abiological” confused, so I thought it was useful to try to clarify the point.
I am not a chemist, and I gather you’re not either, hardcore, but I think we both appreciate that the distinction between organics and inorganic carbon compounds is a slippery one. Two laymen dueling with Webster’s dictionary defintions and webpage cites are unlikely to arrive upon a satisfactory solution. The same Merriam-Webster Dictionary you cite to back up your inorganic=artificial contention defines organic as:
Sense (1) is exactly the definition that I first put forth, and the one to which you so vociferously objected. Sauce for the goose isn’t sauce for the gander, eh? Sense (2) would have been better, of course, but also more wordy. As I said, if I’d wanted to contrast “organic” with “inorganic” I’d have had to use much more detailed definitions, but that wasn’t my goal.
However, there are most certainly organic compounds on Mars, by anyone’s definition of organic, and once we have agreed that we are dealing with organic compounds, I believe that is not correct to call a reaction involving those compounds an inorganic reaction.
For “inorganic”, you quote only M-W definitions 1 a (2) and 2, skipping around the clearly relevant defenition, 1 b: “of, relating to, or dealt with by a branch of chemistry concerned with substances not usually classed as organic.”
I believe that the defintions you quoted provide meanings of “inorganic” used in common parliance and never meant to be applied to questions of chemistry. For example, if you are told that an inorganic chemical reaction takes place between molecules floating in interstellar space, would you insist that the reaction was “man-made” because Webster’s says that “inorganic” means “artificial”? A word can mean many things, but a scientific definiton will usually have a very specific meaning. You can’t take the scientific term out of context and apply your favorite everyday definition to it.
All I can say to you is that in my experience, which is in astronomy, the term “organic chemical reaction” does not indicate biology, and the adjective “inorganic” cannot be applied to a chemical reaction involving organic compounds–whatever way you wish to define organic. I think it’s true that an inorganic reaction is necessarily abiological, but (AFAIK) it’s false that organics could be produced by an inorganic reaction. Again, IANAC, but this is the usage with which I am familiar.
I will happy admit that I am wrong if you have a good source saying that organic compounds can be formed by inorganic reactions, or defining inorganic reactions as reactions that can involve organic and inorganic compounds. I’m just telling you what I’ve been taught. Maybe we should start a GQ thread to try to pull in an actual chemist who will have a more informed answer.
Definition: A chemical compound which contains carbon. It may be based on carbon chains, rings, or both. It does not include binary carbon compounds such as carbon dioxide, ternary compounds such as sodium cyanide or carbonyl sulfide, nor metallic carbonates.
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This has always been my understanding as well (at least, anything with carbon except CO[sub]2[/sub]). This is very different than biological versus abiological.
Actually, I was a chemical engineer for 10 years before becoming a computer programmer, so I do have some experience in this area. I have tried to block that section of life from my mind, but apparently old habits die hard.
You will notice that I have provided 6 different chemistry websites supporting my definition, though I will freely admit even that one isn’t always correct. In truth, an organic compound and an inorganic compound are simply whatever the relevent scientists say they are. The dividing line is artificial and man-made, though the C-H bond definition works almost all the time. But anyone with any amount of knowledge realizes that some inorganic compounds contain carbon, so a strict definition based on carbon does NOT work.
Maybe this is where you jumped off track. Read what I said again. I didn’t say anything about an inorganic reaction. I said “created by inorganic means”. “Inorganic reaction” has a scientific connotation, so as such I wouldn’t use it unless I meant it. “Inorganic means” has NO direct correlation to a scientific term, and therefore the M-W definition for inorganic is entirely appropriate.
Again, you are reading things I didn’t say. I never said “organic chemical reaction” or “inorganic reaction”. I spoke of an “organic compound” (which has a scientific meaning) being “created by inorganic means”.
Now for further education, you should read about Wohler’s 1828 synthesis of urea (an organic compound) from silver cyanate (AgOCN) and ammonium chloride (NH4Cl), which are inorganic compounds. Notice that I have previously cited this here and here, so I can only guess that you haven’t bothered to check out my links except the one to the dictionary. Furthermore, there are plenty of other organic products that have been synthesized from inorganic starting materials.
I think where you and I miscommunicated was your interpretation of my statement “created by inorganic means”, which was intended to convey the production of the material without living organisms involved. You read this as “produced by an inorganic reaction”, which was NOT what I intended to say, because I haven’t studied the proposed alternate pathways enough to state whether the hypothesized reactions included organic precursors.
However, I completely agree that if we are to continue this discussion, it might be wise to start a separate thread and stop hijacking this one.
I have never quibbled with your definition of organic compounds. I have objected to your chacterization of the simpler definition as totally wrong instead of merely over-simplified. Nonentheless, it remains completely beside the point as far as distinguishing between biological and organic. I belabored the point because you were trying use defintions from the same tome that offers the same definition that I (and others) used which you rejected as inadequate. I wasn’t trying to stress that my definition was the best one, but rather that dictionary definitions are of limited use in this debate.
Indeed, you are quite right. I still think that “abiological” or “abiotic” would have been a much clearer choice, but I did indeed misconstrue what your intended use of the word.
Thanks, but I am familiar with abiotic synthesis of organic compounds. I have never contended that it is impossible to synthesize organics from inorganic compounds, simply that any reaction that did so would, because it has organic products, be considered and organic reaction, which is something quite distict from a biological process.
I did look at your other links, but since they were on what I consider a side issue (the definition of organic vs. inorganic compounds), and they don’t refer to synthesis of organic products from inorganic reactants an “inorganic” reaction, I didn’t find them very relevant. If such terminology is used in those links and I missed it, please point it out.
I still contend that a reaction with organic products is properly called an organic reaction or an organic process, whether or not it is abiotic, and you don’t appear to be in disagreement with this specific point, saying instead that you never meant to refer to an (in)organic chemical reaction or process in the formal sense.
I would go futher and say that the terms organic and inorganic should be used very carefully in this context to avoid confusion with biological and abiological or abiotic. Such confusion is particularly common among readers who have only a passing aquaintance with the subject, such as likely frequenters of the SDMB. If you think that the distinction is obvious and the error was entirely on my side, you are entitled to your opinion.
Podkayne, I have been out of town for a few days, but since you fired the first salvo in our little hijack, I think it only fair that I be afforded a final return volley before we move to another thread, if necessary.
Hopefully I have shown why the phrase “created by inorganic means” can lend itself to definitions from a dictionary. This is the only place I have referenced a dictionary. In other places where I have used the words “organic compound” and “inorganic compound”, I have stressed the use of scientific sources, and I believe rightly so, as these phrases have direct scientific meaning. Using a dictionary to try and establish the definition of an organic compound is what I rejected as inadequate.
You appear to be having this conversation solely with yourself. As you apparently have realized, I never classified the reaction as organic or inorganic. Good luck trying to do so, for these type of reactions fall in the hazy boundary between organic and inorganic chemistry, often called organometallic. Any attempt to label these types of reactions as one or the other is strictly for convenience and similar to efforts to pronounce all of our ancestors as either human or ape. To quote a previous link from the MadSci Network:
*Normally organic chemists study organic or organometallic compounds, and inorganic chemists study organometallic compounds or inorganic compounds. Organometallic chemistry is where the fields meet, and it’s neither “organic” nor “inorganic” any more than biochemistry is exclusively either “biology” or “chemistry.”
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This seems to be a very insubstantial point to merit such a lengthy hijack, particularly since my usage is consistent with the terminology utilized by the scientific community. For example, an examination of Recent Scientific Papers on ALH 84001 yields these phrases:
There are many more examples in the above cites where inorganic is used in a similar manner, but I feel I’ve made my point. Perhaps you see some significant differences between the usage by the above authors and my intended meaning, or maybe you think all these scientific sources should change their wording to avoid confusing you. But if you think my usage was somehow inconsistent with the current scientific norm, then I must continue to disagree and request some type of support for your view.
Okay, hardcore, I concede. You’ve produced what I asked for, and was unable to find on my own: good sources containing usage of “inorganic” in the same sense your original post.
It would appear that my instruction in this area was not consistent with general usage, but I will not make the same mistake again. I’m grateful to have this pointed out, as I might have mis-corrected a student’s work based on my own ignorance.
Continuing the hijack or not seems irrelevant, unfortuntaely, since we pounded this poor thread into the dirt days ago. Apologies, Sofa King.
