SkepticLance

"americans are nasty people." They say the cream rises to the top, except in the USA. There, all the decent people stay put, and the scum rises to the top, and calls itself politician.

"The solution to pollution is dilution." Obviously pollution in all forms is to be avoided. However, it is also good to prioritise and to know which forms of pollution are worst, so we can direct our efforts there. Pollution in the open ocean is least concern, due to the enormous diluting effect. If we were to manufacture one million tonnes of, say lead nitrate, which is very soluble and very neurotoxic, and dump it in the open ocean, the long term effects would be negligible. After complete mixing, the final concentration would be one part per trillion, which is way less than what is in the ocean already. The prime concern with pollution is local. Pollutants in smaller areas, like harbours, and river mouths, can cause a lot of harm.

I doubt that a comet would ever achieve a circular, planet-like orbit. The adjustment would be just too precise to happen by chance. However, there are comets that have their orbits changed drastically, even though they stay elliptical. For example : Halleys Comet orbits every 76 years. It must have been drastically altered by the gravity of some other object (probably Jupiter), since the 'natural' orbit of a comet is thousands of years. Incidentally, the asteroid belt was not a small planet. The total mass is way too small to even make up half of Earth's moon. Some astronomers think there should have been a planet in that orbit, but do not know what happened to it!

The biggest problem with woodland diets is simply to get enough calories to keep your body going. Large sources of complex carbohydrate are scarce. We need approx. 2000 kilocalories per day to maintain body weight, even with minimal exercise. Less and we begin the long, slow and painful process called starvation. If hunting is successful, fat can provide calories. One of the best sources of fat is brains! It is possible to survive entirely on a meat / fat diet. The biggest problem is, ironically, the same as with a totally vegetarian diet - getting enough of all kinds of nutrients. Vitamin C, for example, is found in the meat of predatory and carnivorous animals, though not in the meat of herbivores. A variety of meats, and the associated fat, plus a variety of offals etc., is needed to stay healthy on a totally carnivorous diet. Even there, it is debatable whether long term health can be fully maintained without plant material.

Evolution never stops. Just changes direction and speed. Humans are probably not changing very quickly at present due to the fact that selection pressure has dropped. However, some changes are inevitable. My favourite is the response to the fact that women now have control over their fertility. In many countries, replacement rates are now as low as 1.3 per couple. Many women are opting for no kids at all. However, there are some women who love kids and are opting for larger numbers. If the desire to have children is at all genetically based, the descendents of those women who want more kids will increase in number generation by generation, till eventually (in 1000 years??) the whole world will be descended from women who love lots of kids. What a population explosion we will see then!

Prime Evil. Don't forget that oil is biodegradable. There are lots of little bugs in the sea that thrive on it, and break it down completely, in a time ranging from a few days to a few years, depending mainly on temperature. If oil is spilled in the open ocean, it actually does little damage, and is lost fairly soon after. Indeed, there are places in the ocean where natural oil seeps,. releasing millions of tonnes over oil over a long time period, actually support flourishing ecosystems with enormous numbers of unique species not found anywhere else. Of course, if oil is spilled close to shore, and especially in an enclosed space such as a harbour or lagoon, it can do a lot of damage in the period before it is biodegraded. Fortunately, nature is able to recover. Most sites of oil spills after a decade or so appear to be right back to normal.

for ecoli. A source for simple summary of effects of St. Johns Wort is http://nccam.nih.gov/health/stjohnswort/ The key quote is : . "Are there any risks to taking St. John's wort for depression? Yes, there are risks in taking St. John's wort for depression. Many so-called "natural" substances can have harmful effects--especially if they are taken in too large a quantity or if they interact with something else the person is taking. Research from NIH has shown that St. John's wort interacts with some drugs--including certain drugs used to control HIV infection (such as indinavir). Other research shows that St. John's wort can interact with chemotherapeutic, or anticancer, drugs (such as irinotecan). The herb may also interact with drugs that help prevent the body from rejecting transplanted organs (such as cyclosporine). Using St. John's wort limits these drugs' effectiveness. Also, St. John's wort is not a proven therapy for depression. If depression is not adequately treated, it can become severe and, in some cases, may be associated with suicide. Consult a health care practitioner if you or someone you care about may be experiencing depression. People can experience side effects from taking St. John's wort. The most common side effects include dry mouth, dizziness, diarrhea, nausea, increased sensitivity to sunlight, and fatigue." The last sentence show increased sensitivity to sunlight. In extreme cases, if the eyes are unprotected, it can lead to cataract formation. (This can happen even without medication, to people who are exposed over long periods to strong sunlight, especially in the southern hemisphere, where UV is stronger).

Have to make an added comment. Our skins are quite resistant to damage, with a thick layer of dead cells for protection. However, other parts of our bodies are not so well protected, and will be damaged quickly and severely by said chemicals. Soft mucous membranes are more vulnerable, such as in our eyes, throats etc. The most vulnerable of all is lung tissue. If you spray a nasty product, and inhale the aerosol, it may even kill you. Rapid erosion of lung tissue leads to weeping in alveoli, and they fill up with liquid, which can lead to a form of drowning.

encipher. Not just acid burns, but chhemical burns in general tend to take a bit of time. If you dip your finger, or any part of your body, in strong acid, or alkali, or strong oxidising agent, and do nothing about it, you will get burnt. The stronger the chemical, the quicker, and more severe the burn. However, in my experience, if you wash off the affected part with water (soap and water is better) quite quickly, there will be no burn.

herpguy. Let me rephrase. In the long term the local effect would be negligible. Yes, inside enclosed spaces, there may be temporary problems. But over time, recovery is total. I have dived Truk lagoon. This is a small enclosed space, in which a big chunk of the Imperial Japanese fleet was caught by an American air attack, and large numbers of ships went down, with all the pollution that this entails. This is an extreme example, since it was a hell of a tonnage of shipping sunk, and in a very small enclosed space, and in a pristine tropical coral reef environment. Sure there would have been damage at the time. However, go there today, and you will be blown away by the sheer biodiversity and health of the marine environment.

Two comments. First, the concept of 'unnatural' is probably damaging. Replace it with the queries : Does it work, or does it not? Does it cause unacceptable side effects? Lots of 'natural' remedies are also in use, and can cause considerable harm. For example : St. John's Wart, which is prescribed by herbalists and naturopaths for depression, is only mildly effective, and is an ultra violet sensitiser. If you are on this herb, and fail to wear sunglasses, you may even go blind! Second : Drugs for psychiatric illnesses have a history of mis-use. They are still the best way of coping, speaking generally. However, they have frequently been over-used, used in the wrong place, or prescribed when they are totally ineffective. My advise is to be prepared to go for several opinions. Consult as many specialists as you can afford to, and see if they agree with each other.

Quantify the statement "the ocean is huge." In fact the oceans contain approximately one million, million, million tonnes of water. 10 to the power of 18. Any impact of pollutants would be negligible, even locally. On the other hand (and I am speaking as a mad keen scuba diver) those lovely wrecks that resulted would have produced magnificent artificial reefs that by now support enormous biodiversity and biological productivity. The damage from ocean battles is to human life. The environment reaps the reward.

Americans are not alone. It is a problem affecting the whole Western world, and rapidly affecting the rest, as they catch up to us in terms of prosperity. Americans simply get hit first. I believe it is primarily lack of exercise; secondarily diet (McDonalds, get thee behind me); and finally stress (way behind the other two in importance.). I am 57 years old, and weigh 95 kg. According to the tables, I should weigh 85 kg. I am, thus, well overweight. However, my cholesterol is way down; blood pressure that of a healthy 20 year old, and resting pulse to gratify a teenager. Why? I eat too much, and often the wrong kind of food. However, since age 19, I have always had 4 hours per week plus of exercise, sufficient to get me puffing fiercely. While I am not American, I have spent sufficient time in the USA to observe a few things. I believe Americans spend too much time in activities that do not burn calories. And that is the main reason for their ill health.

pretender. We all need to understand that a lot of what is understood about astronomy is not certain. Comets are interesting and we THINK we understand their origins????? According to latest theory, they originate from way out. Possibly the Kuiper Belt, which is beyond Pluto. A long, long way from the sun. They are lumps of frozen water, gases, and bits of rock and dirt, all mixed together, although their exact make-up may vary. They orbit in circular orbits, and there are millions of them. Normally they keep well away from the sun, or Earth, or any of the major planets. However, every now and then, something (Probably a large mass orbiting the sun at great distance. We now believe there are probably many planets at that great distance, even if we haven't seen them with our telescopes.) passes close to one of these lumps of frozen gas, water, and mud. Its gravity gives the mass a 'kick' and sends it spiralling down towards the sun. As it gets closer to the sun, the increasing temperature starts to evaporate the frozen gases. They are pushed away from the comet by the stream of particles coming from the sun. This forms the comets tail. A comet may pass round the sun just once, and be destroyed, or, like Halleys Comet, pass out and in many times.

Fellbeast. For every mutation leading to an increase in organisation in a living organism, there are a thousand leading to a decrease. The second law of thermodynamics is not the least bit threatened by evolution. The total entropy of the universe increases. I have just picked up this thread, and see 110 postings. Being too lazy to read all 110, I am going to present my answer to the original query, and hope no-one else has beaten me to it. Why are humans naked? In other words, functionally hairless (mostly). In a word; technology. Very primitive technology to be sure. Explanations I have seen include the aquatic life, the benefits of removing parasites, and the benefits of cooling the body. The first idea fails on the question : "why are there no marine pre-human fossils?" The sea is an ideal site for fossilisation, and if we had spent enough time fishing in the shallows, a number of our ancestors would have died there. Most pre-human fossils would be in marine sediments. It ain't so. The second and third ideas are good, but fail to address a more important issue. Fine for conferring benefits, but how do they overcome the major detriment? Humans are the only terrestrial mammal in our size range to be functionally hairless. Any benefit related to parasites or cooling surely would apply to other animals, which would also evolve hairlessness. They did not. The problem with becoming hairless, despite the advantages, is that it leaves the organism vulnerable to low temperatures. Even in equatorial areas, it sometimes gets so cold in the early morning, that death by hypothermia is almost inevitable, without a good coat of fur. To gain the benefits of lacking hair, first the organism must overcome the vulnerability to cold. For humans, the answer is technology, no matter how basic. It may have taken the form of nests of composting plants that our ancestors covered themselves with in cold mornings. or some form of basic clothing? Or fire? Once an alternate method of keeping warm is present, then evolution to hairlessness becomes an adaptive advantage.

The company that buys the secret off you will then need to begin safety and efficacy testing. From their viewpoint, they do not know if it will 'make the grade'. Pass the tests. It may turn out that your treatment causes long term shrinkage of genitals or something that would make it impossible to market or use. A full scale test program for this kind of product might cost US$ 100 million to US$ 1000 million. Quite a risk! The time factor is important also. We assume it was patented by you. Testing might take 10 years or more. The patent lasts 18 years. This does not leave a lot of time to make a bundle. On then other hand, if by some chance, it turns out to be everything you claim, the company selling it could make US$ 1 trillion before the patent ran out. If you were able to auction the secret, it is impossible to predict exactly how much it would fetch. That would depend on the perception of the companies bidding on the degree of risk. However, you could, I think, guarantee many millions. If perceived risk was low, my guess is US$ 100 million plus.

Actually, we could not survive either, unless, as Insane Alien suggests, we can cross to a hypothetical other universe, or find some other theoretical loophole we just do not know about today. On the Big Freeze. There was a Scientific American article on this subject a few years ago. The scientists who wrote it had worked out the details. Their verdict was that eventually the energy density would be too low to support any kind of life at all. This would, according to them, take about a trillion years. On the Big Crunch. According to Stephen Hawking "Brief History of Time", space itself is just a part of the universe. If the universe shrinks to a singularity, so will space. We cannot be 'outside' the shrunken universe, since there is no outside. Everything is within.

Odds of mutation is not a question for which there is a single, simple answer. Too many variables. Mutations in general are very common. It happens all the time inside our bodies. DNA is damaged. DNA is repaired. DNA is damaged and not repaired, and the cell dies. DNA is damaged and not repaired and the cell turns cancerous. The cancerous cell gets wiped out by our immune system, or turns into a tumour. Etc. The frequency of mutation also depends on the type of mutation. Some are relatively common; some rare. To be passed on to the next generation, the mutation must have happened in a germ cell, about to become a gamete, and this is not too common. However, over a few billion years of evolution, a hell of a lot of mutations build up in the population. So to your question. It depends.

The fact that global warming from 1999 to 2005 was essentially non existent probably does not mean too much. I have heard this statistic from other sources also, and it appears to be correct. I regard the cooling from 1940 to 1976 as being more meaningful, during a time of severe increase in greenhouse gases. However, you may be interested to know that, during this latest non warming period, carbon dioxide emissions actually doubled.

Ashennel. Fire has the ability to reproduce, but not to evolve.

Animal, I am going to give you two answers. 1. In science, there is an unwritten law that says : "If you can't measure it, it doesn't exist." By this, there is no reincarnation. 2. I have often thought that there might be a kind of equivalent, if not quite reincarnation itself. No magic. My line of reasoning goes a bit like this ... It is widely believed that each of us has a physical 'double'. someone who looks very like we do. Almost enough to fool your wife ..... If that is the case, what about a mental double. Perhaps over a 10,000 year period, in which a trillion people are born, live, and die, one of them is so close to you in a mental / personality sense, that it is equivalent to you living again. Obviously that persons memories will be different, but so are yours with each decade that passes.

Life on Earth has three qualities that can be incorporated into a definition. 1. Replication or reproduction. 2. Ability to evolve. 3. Based on a complex system of organic chemicals. Number 3 is needed to exclude certain computer programs. Now, there may be life off Earth which does not fit this definition. However, a definition does not have to include anything that is currently pure speculation.

Prime Evil. Your arguments are leaving a very nasty taste in my mouth. To suggest that, because others use mud slinging tactics, that justifies you doing it also, reflects very badly on you and no-one else. Sure, there is mud slinging on both sides. I read both sides of the global warming argument and have read both side's nastier tactics. Current paradigm supporters claim their opponents are in the pay of oil companies, when they are not. Skeptics claim that their opponents are nailing down cushy jobs by 'going with the flow' when they know they are on shaky ground. Prime Evil. Both arguments are dirty. I am not going to indulge, and I am asking you, please, clean up your act! Cthulhu. We still have not reached a meeting of the minds. However, your arguments are clean and polite. Thank you.

bjaminwood Your argument is a perfect example of the general principle, that if someone is a "True Believer", then they are immune to reason and logic. Any facts in conflict with their belief are simply ignored. As you have never seen one of these intermediate creatures alive you can not prove without doubt that what you see in the fossil records is not one of the creatures either side of an intermediate creature. E.g. dinosaur to bird. The fossil in my view is either likely to be one or the other and not an intermediate state. I would have more chance believing that a fossil was an intermediate creature if I had once seen a live version. As science is mainly based on things that can be tested in the here and now, I am happy to believe that birds existed years ago at the same time as other animals that exist today like monkeys and elephants. Can you please explain to me why we as humans do not evolve into something else and why don't monkeys evolve into humans today? No-one has seen these particular intermediate creatures alive for the simple reason they existed many millions of years ago. Yet their fossil skeletons, and fossil feathers are there, often in excruciatingly beautiful detail. Are you going to suggest that is someone's imagination? Your statement about 'either side of an intermediate creature' is hard to understand. You may have to repeat, using less ambiguous words. Are you suggesting that the fossils represent creatures not quite on the line of direct descent? In other words, side branches of the family tree? If so, it does not matter. These side branches could not exist without evolution. Modern day human and monkey evolution. Experiments with fruit flies suggest that at least 200 generations are needed to achieve a (very small) measurable evolutionary change. This, in human terms is 5000 years. Genetic studies have revealed a few genes that seem to have entered the human population within the last 10,000 years, so this is consistent. If we are to observe human and monkey evolution directly, we need to hang around for another 5,000 to 10,000 years. However, fast reproducing species that can go through 200 + generations within a few years can be experimented upon in the laboratory to see what evolutiony changes occur. This has been done with Drosophila among others, and the results are exactly what theory predicts.

Bascule. Do not put words in my mouth. I did NOT say models had no scientific value. Models have the same scientific value that scientific hypotheses have. This can be considerable. However, like hypotheses, models have to be tested against real world values to determine if they are valid.