SkepticLance

A definition of life cannot occur without it matching the expectations of the person doing the defining. Thus, a universla definition cannot exist. Currently, a definition of life will include organic life on Earth, and exclude such things as fires and computer programs. One definition I saw was : "Life is a complex organic chemical system capable of reproduction and evolution." The qualities often mentioned, like respiration, excretion, nutrition etc., cannot be used in a definition, since a forest fire exhibits all those. Reproduction and evolution are two vitally important qualities of life, but both these can be seen in certain computer programs. Thus the addition of a statement such as "complex organic chemical system". The definer in this case used the word 'complex' to exclude viruses. Personally, I think that is unjustified. I do not care that a virus cannot reproduce without the use of a host cell. It still displays the qualities of being organic, reproducing, and evolving. Lots of parasitic organisms cannot operate without a host to assist reproduction. eg. Mycoplasma bacteria.

In theory you can put wings onto a human but there is no way he can be given the ability to fly using those biological wings. They would be cosmetic only. If you want to fly without an aircraft, and without using biology, try a jet pack. http://archives.chicagotribune.com/2008/jul/30/nation/chi-jetpackjul30 The new gadget has been improved, and it is likely that it will become available commercially some time in the next few years. Unlike the James Bond style rocket pack, the jet pack will have substantial range, allowing it to take its pilot useful distances. A video showing it at an air show is available at : Looks unimpressive, but the reason it did not go above a metre off the ground was that the operators were denied permission to do so. It actually has the capability to fly to any height that a small airplane can reach.

All you aggressive types ..... If zombie attack is inevitable, I plan to use my legs, supplemented by a bicycle, car, train, plane, or anything that will get me the hell out of there!! Constructive cowardice = survival.

To DH Everything you say in your post is, of course, correct. However, the point I am making is that an astronaut in orbit still has weight, since there is gravity acting on him. In fact, it creates an acceleration which is measurable, and the concept of mass times accelerometer reading applies. When falling through a substantial gravity field, the concept of weightlessness is invalid.

To DH Weight as opposed to mass is the effect of gravity on an object. If gravity is less, weight is less, while mass will be constant. An astronaut in orbit appears to be weightless, but gravity is nevertheless acting on his body. The result is that the astronaut is falling. It is essentially no different (assuming no effect from air friction) to a person in free fall before he opens his parachute. In both cases they have weight since gravity is exerting an infuence (acceleration). In both cases, a devise for measuring weight will show zero weight, since the devise is also falling, and at the same rate. In both cases, if you were to exert a deceleration to balance the acceleration under gravity you would see the weight suddenly appear to return, and become measurable with simple scales. A good example is a base jumper. Standing on the jump site, he has weight. After jumping, and in free fall, he appears to be weightless, but the effect of gravity has not changed in quantity - just a qualitative effect, now exerting its effect as acceleration. If an astronaut is sufficiently far from the Earth, the effect of gravity is small, and he is said to be in a micro-gravity environment. Not a zero gravity environment.

Re weight of astronaut. The 'weightlessness' is an illusion based on the fact that the astronaut is falling. Imagine an astronaut in orbit 1000 kms above the Earth. He appears to be weightless, but this is only because he is moving. He is falling at the same rate as the apparatus used to measure his weight, which means the apparatus will give an incorrect reading of zero. Now imagine the same astronaut 1000 km above the Earth - but this time he is standing on something like a massively taller hypothetical version of the Eiffel Tower. The astronaut is not falling because he is standing on a firm surface. In this case, the astronaut has weight, and the apparatus will measure that weight as a high percentage of his weight at Earth sea level. What DH has been saying is correct, but sometimes unnecessarily difficult to understand. A circular orbit is understood simply by accepting that the object in orbit is falling, but the rate of fall is balanced by the fact that it moves out and away due to its orbital motion. In one minute, it may fall a kilometre, but in that minute it moves tangentially to the object it orbits, and thus moves out by one kilometre. The fall and the movement out balance. For an elliptical orbit, the distance fallen and distance moved out will not be the same, minute by minute, but average out equal over one whole orbit. Orbits change. If an object is made to slow, like low orbit Earth satellites that contact the outer atmosphere and are slowed by friction, it will spiral inwards to the object it orbits. If it is made to speed up, it will spiral out further from the object it orbits. A good example of the latter is Earth's moon. Earth's rotational energy is being slowly transferred to the moon by tidal interaction. The Earth's rotation is slowing, and the moon, in response, moves faster around the Earth. Over a period of millions of years, the moon moves further out from the Earth. The moon's orbit takes longer since it has to travel much further. Both the slowing of the Earth's rotation and the moon's longer orbit time can be, and have been, measured using highly accurate atomic clocks.

To add one to Charon's list. Anaerobic pyrolysis of organic waste, followed by reaction with hydrogen. Start with something like wood waste from the forest industries - sawdust and so on. Heat it in the absense of oxygen to drive off volatile organic compounds. Mix those volatiles with hydrogen gas and pass the mixture over a heated catalyst, and hydrocarbon fuel forms. Another by product is charcoal (carbon) which can be plowed into soils by the terra preta process to improve soil fertility and tilth. That carbon is thus sequestered and stored, potentially for thousands of years. This process provides biofuel, improves agriculture, and reduces CO2 in the atmosphere, storing it long term in the soil.

The two main 'bad for you' foods are those high in fat, high in salt, and those high in sugar. We have developed a taste for these, because all three are excellent in small quantities. Our hunter-gatherer ancestors could never get enough, and they evolved the desire to always eat more, which led to their improved health and reproductive success, as drives evolution. The problem is that modern civilisation, based on modern agriculture, can supply all the fatty, salty and sweet foods we might crave. Thus, we eat more of those foods, and our health suffers. Evolution gave us the desire for those foods, but did not need to evolve a maximum limit, since our primitive forebears rarely could get to that point, the foods being scarce. With no upper limit to our craving we eat too much of these foods, and our health suffers.

As long as a planet has good velocity, it will maintain its distance from the sun. If you could slow down Mercury in its orbit, it would spiral into the sun. However, how are you going to do that? Friction with particles in space will do it to a very minor extent, but this is a whole planet we are talking about, with utterly immense momentum. A little friction will not be enough to do it. We can expect Mercury to continue in something close to its current orbit until the sun goes red giant in about 5 billion years.

First : bizarre behaviour. General rule - if you can imagine someone doing it, then someone has done it. This includes weird forms of suicide and physical maiming to themselves. However, such weird behaviours are rare. It is just that, with 6.5 billion people on the planet, there are lots of examples of even the rareist behaviours. Second : Animals. The main reason why animals are seen as less weird is simply that we still have not studied animal behaviour in sufficient detail. As ethologists delve deeper and deeper, more and more aberrant behaviour arises. Chimps at war. Primates murdering each other. Animal homosexuality. Weird methods of animal masturbation. The more we learn, the weirder animal bahaviour gets.

scalbers I agree with your conclusions. Ocean fertilisation is just too uncertain to make use of to sequester carbon at this point in time. I am more of a fan of the terra preta system, myself. It ties in beautifully with the need to generate biofuel. http://en.wikipedia.org/wiki/Terra_preta Imagine that we start with, say wood waste from the forest industry. That waste is heated in the absense of oxygen, to drive off volatiles while leaving carbon behind. Hydrogen gas is generated on site - perhaps using nuclear power? Hydrogen gas is mixed with the volatile stream and the whole is passed over a heated catalyst, before distillation and catalytic cracking. Result - hydrocarbon fuel. The carbon is then mixed with fertiliser and plowed into fields. This makes a long term carbon storage - up to thousands of years - and improves soil tilth and fertility. It has been calculated that if the half of the Earth's land area that is arable were to gain 2 mm in thickness from this method over 50 years, it woud sequester all the CO2 released by humans over that time. It would also immeasurably improve soil structure and fertility, and make food production far more productive. http://www.worldchanging.com/archives/004815.html

scalbers Your logic is good, and your conclusion mostly correct. As I said before, only a small part of the carbon taken up by phytoplankton will go into long term carbon storage. This small part drifts to the ocean bottom and gets covered by sediment. From my reading, it appears that a hell of a lot of carbon is already stored beneath deep ocean sediment. As far as I am aware, no-one has determined how much of phytoplankton biomass ends up this way, and this casts a mass of uncertainty over the idea of deep ocean fertilisation.

scalbers Equilibrium relates more to movement into and out of solution. When organic matter falls to the ocean bottom, it enters a carbon sink long term (millions of years) and is not returned to the atmosphere for a very long time. In human time spans, this is not equilibrium. It is removal.

iNow When I asked bascule to repeat his question, that was a genuine request, hopefully worded courteously, since I was confused about what he wanted. in post 38, bascule said : "What a cop out. How about you point out what you think I've misinterpreted? As far as I can tell I haven't misinterpreted anything: you are a climate change denialist who seeks to spread fear, uncertainty, and doubt about climate science. And you apparently don't understand the basics of climate change. You're doing everyone on these forums a great disservice by even posting here."[/I] I cannot see anything here that amounts to a polite query!! If bascule is correct in saying that I am full of insults, then it is clear I am not the only one! If the question was, as you suggest, where bascule misrepresented me, it was in the distinction between safe water supply and overall global water shortage. As I said before, these are two quite distinctly different issues. I agree that there is a global water shortage. How much this may be related to global warming is somewhat moot, but I do not want to get involved in any argument on that point, because any cause and effect relationship is likely to be purely local, and overall generalisations, strongly suspect. However, I was not talking about global water shortage. I was talking about providing safe drinking water. There are very few places on Earth that cannot supply sufficient water for drinking. That is because we need very little water for drinking - just 1 to 3 litres per day per person. However, the question is whether that water is safe to drink. Often it is not. Making it safe is a question of applying appropriate water treatment technology. Sometimes that consists of simple filtering. Sometimes something related to higher technology. However, safe drinking water supply is not related to global warming. It is a health problem, and related to access to the technology to treat the water before drinking. I hope this answers the question. If not, please re-state.

To Sayonara Sorry to take so long to reply to you. I have been heavily involved in family Christmas celebrations and have not been on my computer. You asked the point of the thread. I am not really sure any more. I began it because I came across an interesting reference I wanted to share, and see what other people thought of the proposal. We got sidetracked and the degree of misinterpretation of what I was trying to say led down a merry garden path. Bascule. If you have a single question, please ask it again. There has been so much confusion in your recent posts that it needs clarification.

There is a bit of confusion here, I think. The ocean's ability to absorb CO2 is generally the ability to dissolve it. When iron or other fertiliser is added to the oceans, a different mechanism comes into play. Enhanced phytoplankton growth converts CO2 into organic compounds. A small part of this is supposed to sink and become part of the deep ocean carbon sink. As I said before, this is unproven, and the value of fertilisation is problematic. However, it is NOT the same as the ocean's ability to absorb CO2. If it works, it would have quite different limits. The fertilisation need not create anoxic spots. If the iron or other effective fertiliser is spread over wider parts of the deep oceans, instead of concentrations in shallower waters as currently happens in the Gulf of Mexico, which is just a matter of good management of the technique, then anoxic spots will not form, but fertilisation will occur. However, I am not convinced the technique has merit. Time and research are needed.

bascule I do not know what has got into you lately. I do not mind you disagreeing with me. However, it is simple courtesy to read what someone posts before you argue against something that is not even said. I said that global warming is a mixture of good and bad. Rather than 'singing the praises' I posted examples of both good things and bad things that global warming can bring. This was in direct response to your question about whether I thought it was good or bad. I answered you honestly, and in good faith, and your response was ... "You are singing the praises of global warming even though it's pretty clear at this point you don't know the first thing about it." All I am asking from you is basic human courtesy. That means reading my posts before you argue against them, and affording a little respect instead of accusing me of total ignorance. You have been posting to these threads long enough to know that I am quite conversant with these matters. Please, please, please read before responding.

iNow Most speculation I have seen on this topic is that fertilising the ocean will have the opposite effect. Phytoplankton growth is stimulated, and the increased biomass absorbs CO2. Some of this, presumably sinks to the bottom of the sea and adds to the carbon sink in the abyss. Of course, this is still unproven.

bascule It would help if you read my posts properly. I was NOT singing the praises of global warming. Read my post again, and try to understand.

iNow The divergence off topic began with this from bascules earlier post. "Originally Posted by SkepticLance If this is correct, I am glad it happened. I would much rather live in our current relatively balmy conditions than in a new deep freeze. " Do you think the millions of people who are about to lose access to safe drinking water feel the same way?[/ I responded with a statement that access to safe drinking water had nothing to do with global warming, which bascule totally misunderstood and misinterpreted, and we set off on our merry path to stupidity. Let's ignore that divergence and get back to the theme.

bascule I do not think I ever insisted that climate change was a good thing. My initial post asked the question of others. My private view is that climate change will be a mix of good and bad. Obviously, raising sea levels is bad. However, there will be good also. Greater warmth, especially in winter should be a boon in very cold countries. Nations such as Canada and Russia will gain the ability to produce more crops. Local changes should be varied. Some places will be drier. Some wetter. Some places will be better off. Some worse. If the reference I quoted initially turns out to be correct, and the global climate would have returned to a period of glaciations without human interferance, then overall anthropogenic global warming would be a good thing, though I think it is time to begin the process of halting it. Warming that is extreme would be bad.

iNow is correct again. I began trying to be courteous to bascule, but he insists on ignoring what I was saying and raising straw man arguments. Bascule, can you not understand the difference between shortage of fresh water, and lack of safe drinking water????? The shortage of water comes from the fact that vast amounts are needed. The average town dweller needs 200 litres per person per day for all domestic needs. The average farmer who needs to irrigate requires at least ten times that amount, and the need can be a thousand times greater. For drinking, we may need as little as one litre per day. Any person who cannot understand that needing 1 to 3 litres of safe drinking water per person per day is different from needing 200 to 2000 litres of general purpose water - well such a person is stupid indeed. So please drop your strawman. What I have said is quite correct, and your argument against it is irrelevent. If you persist in that argument, you are showing that my hypothetical idiot is you.

bascule Let me put it in very simple words, so you can understand. Most water use is for irrigation, not drinking. The amount of water needed for drinking is relatively very small. Apart from living in the Sahara or Gobi or other deserts, that small amount of water is pretty much always available. The problem is that it is not always safe. The problem then, is not how to get hold of water for drinking. The problem is how to make that water safe for drinking. Have I made that simple enough. Lack of water as a global problem is mostly related to lack of water for irrigation. Not lack of safe drinking water. This is a quite different problem. Try hard, and use your little grey cells. Maybe if you work at it, you can see the difference. iNow is correct that this is a side issue. However, if bascule suggests by implication that I do not know what I am talking about, when he simply confuses two quite separate issues, then I feel that I have to defend myself.

bascule It would help if you did not keep putting words in my mouth. I said safe drinking water has nothing to do with global warming, which is true. Total water supply may be a different story, but is not the same issue. As I pointed out to iNow, providing safe drinking water is simply a case of applying appropriate technology. It is not dependent on water quality. We now have the technology to produce safe drinking water from human sewage, or pretty much any other water source, including the sea. I did not downplay the water crisis. Instead you confused the issue of safe drinking water with total fresh water availability, which is a quite separate issue. Of all the water humans use, the amount we drink is a very small part. The vast bulk of the water crisis is a lack of water for irrigation and growing food - not for drinking. In this case, the ignorance you accuse me of is your own.

iNow There are literally hundreds of technologies related to providing safe drinking water. This is a different issue to simply providing water, of which most is needed for irrigation rather than drinking, and I suspect that this separate issue is what you are talking about. Some are low tech, such as filters using natural rocks and other cheap easily available materials. Some are high tech such as ultrafiltration. As long as water can be obtained, there are ways of making it safe for drinking. I have a home that is somewhat isolated, and not connected to municipal water. I collect rainwater into tanks and filter a small part of it via activated charcoal filters for drinking. I also have a home sewage treatment system that is supposed to purify our waste to the point where it is drinkable - though I am not prepared to try it! Global warming will have local effects on total water supply, with the main need being for irrigation. Some local effects mean more water. Some mean less. As an overall global average, there has been an increase in precipitation over the past few decades, which many ascribe to global warming.