SkepticLance

Just reading the latest edition of Skeptic journal. Vol. 14 no. 2 from page 28. An article by Dr. Michael Shermer in which he refers to the basis for the Search for Extra Terrestrial Intelligence (SETI). Apparently the Drake Equation is very popular with SETI researchers. This was proposed by Dr. Frank Drake in 1961 and popularised by Dr. Carl Sagan. It refers to the number of intelligent, technological, and potentially contactable civilised species in our galaxy. The number of these is obtained by multiplying together the following. 1. The number of stars in the galaxy (E11) 2. The fraction of these stars with planets (usual guess 50%) 3. The number of Earth like planets per stellar system (usual guess 10% ??) 4. The fraction of these planets with life (usual guess 10% of item 3. ??) 5. The fraction of these planets with intelligent life (usual guess 10% of 4. ??) 6. The fraction of them with communicating technology(10% of 5. ??) 7. The average lifetime of communicating species Dr. Shermer spends a lot of time discussing the last of these. Apparently SETI researchers have more difficulty with this than the other factors. They are happy to slot in their best guess for the numbers of other factors, but have no idea of how long a civilised species might survive. Estimates of lifetime range up to 10 million years, and average 50,000. And the result of their best guess calculations range up to many millions of civilised, communicating alien species. Dr. Shermer comes up with his own version of the lifetime factor. He argues that we have a number of civilisations in our own past that give figures for the probably lifetime of our hypothetical species. He produces a list of 60 past Earth civilisations, from ancient Sumeria and Egypt to the British Empire, and an average lifetime of 420 years. Plugging this number into the Drake equation gives an estimate of just over 3 alien civilisations in our galaxy. My own view is that Dr. Shermer has introduced and artificial and unlikely number into the equation. I see all Earth civilisations as part of one single progression towards today's world. The ancient Hittites invented iron smelting. We still use that and it is a part of the current society. When the Hittite civilisation died, civilisation as a whole did not. In my view, this destroys Shermer's thesis. The true number for Earth is of the order of 3,000 years. Mind you, I seriously disagree with using 10% for factors 3 to 6 in the equation. That is a blatant guess, and probably utterly renders the whole thing meaningless. What do you think?

iNow Sorry mate. On this, you are wrong. Since the new information is only a couple of years old, the old myth about low self esteem is widely disseminated. You could find literally dozens of references on google showing the wrong message. As I said, recent empirical work shows the opposite. eg. http://behavioral-management.com/bullies-selfesteem/ I quote : "By James Burns • October 18, 2007 Psychologists used to believe that bullies have low self-esteem, and that they put down other people to feel better about themselves. But current research shows that most bullies actually have high self-esteem. Bullies usually have a sense of entitlement and a feeling of superiority over others, and lack compassion, impulse control and social skills. They enjoy being cruel to others and sometimes use bullying as an anger management tool, the way a normally angry person would punch a pillow. Research does support the fact that bullies have low empathy and don’t know how it feels to be in someone else’s shoes." Note the date. More recent information shows the new reality. You can quote outdated references and ideas all you like. That does not make them true. http://iidb.infidels.org/vbb/archive/index.php/t-92873.html I quote : "Here's a description of the recent study from UCLA (http://www.college.ucla.edu/juvonen.htm) which was published in Pediatrics at the end of last year. “Bullies are popular and respected: they are considered the ‘cool’ kids,��? said Jaana Juvonen, UCLA professor of psychology, and lead author of “Bullying Among Young Adolescents: The Strong, the Weak, and the Troubled,��? published in the December issue of the journal Pediatrics. “They don’t show signs of depression or social anxiety, and they don’t feel lonely. “We hope that these findings help us dispel the myth that bullies suffer from low self-esteem,��? Juvonen said. “Our data indicate that bullies do not need ego boosters. Unfortunately, this myth is still guiding many programs conducted in schools. Instead, we should be concerned about the popularity of bullies and how to change the peer culture that encourages bullying.��?" iNow We could enter into a reference war, quite easily. You could find dozens of outdated and outmoded references saying bullies have low self esteem, and I could reply with a bunch of references showing what the latest research indicates - that bullies have usually got high self esteem. I really think we have gone far enough. On this issue I am right, and you are clinging to obsolete ideas.

iNow You really do not have to argue with everything I say, you know. There is no law preventing you from simply accepting some of it. The new understanding of what motivates bullies is only a couple of years old. However, unlike the older view, this is based on real world tests, instead of psychologists 'political correctness.' Because it is so new, a lot of the old ideas are still being circulated. Reminds me of the discovery that ulcers were caused by a bacterium. Years after that was proved, and ulcers healed entirely with antibiotics, with all the results published in peer reviewed medical journals, many medical lecturers were still teaching that ulcers are a result of acidity. In this case, even though real world tests show bullying is caused mainly by an inappropriate sense of superiority, many psychologists refuse to believe it, and teach that it is caused by insecurity and poor self esteem, where the actual real world tests showed clearly that typical bullies have strong self esteem. This is a case where real data should be accepted, and mere "it seemed a good idea at the time" concepts should be dumped.

To iNow Re bullies I am afraid you are somewhat out of date. It is true that, for a long time, bullying was considered to be a result of low self esteem and insecurity. However, this idea was based on theory, not empirical studies. The sad thing is that this myth is still being promulgated in all sorts of literature. Only in the last few years have a few research psychologists decided to test the hypothesis. Much to their surprise, they found that the typical bully was actually someone with high self esteem. That does not stop them from being total scumbags who should have been strangled at birth, but their behaviour is not the result of low self esteem. I first read the modern version in a paper edition of New Scientist, reporting on the research. Sadly I have lost that reference. For what it is worth, here is their email version of that article, but you need to be a subscriber to read it all. http://www.newscientist.com/article.ns?id=mg18524891.400 Other articles like the one below report the same finding. http://www.byparents-forparents.com/causesbullies.html I quote : "Psychologists used to believe that bullies have low self-esteem, and put down other people to feel better about themselves. While many bullies are themselves bullied at home or at school, new research shows that most bullies actually have excellent self-esteem. Bullies usually have a sense of entitlement and superiority over others, and lack compassion, impulse control and social skills. They enjoy being cruel to others and sometimes use bullying as an anger management tool, the way a normally angry person would punch a pillow." And yes iNow, if you want to argue, you will be able to find lots of out of date references that claim bullies have low self esteem. There are even lots of so-called 'experts' who still make that claim. They are wrong. That was the old idea, now obsolete.

I am a moderately tall guy at 6 foot. However, I never exhibit 'tall man syndrome'. In fact, I am so easy going that nothing riles me. Interesting though, to see the recent studies of bullies. In spite of popular myth, bullies tend to be self confident people with high self esteem. They gain pleasure from tormenting those they see as inferior, but this has nothing to do with their own feelings of insecurity or any of those self effacing qualities. Basically, they are just arseholes!

To come up with a practical suggestion as how to control scale, we need to know what kind of scale, and in what situation. For example : calcium rich waters passing against a hot surface form lime scale on that hot surface, because the calcium salt is less soluble at higher temperature (reverse solubility). It can be cleaned off by acid wash. In industry, a corrosion inhibitor is added to the acid wash to prevent the acid attacking the metal surface. There are many kinds of scale. Silicate scale is much tougher. In industrial cooling water systems, various scale inhibiting chemicals are added to the water, such as polyacrylates. Pre-treatment of water, such as by softeners sometimes helps.

Just one small example of the practical application of evolution. Take micro-paleontology. This is utterly crucial to the oil industry. Micro-fossils are used to gain all sorts of information about rock strata, including age, and possible organic content of the rock. Without an understanding of evolution and the gradually changing nature of life, the practical interpretation of these fossils and their practical use in searching for oil would be much more difficult. Ditto for other fossils in geological studies. Knowing that life has evolved permits us to create a prehistoric 'tree of life' into which we tie specific fossils. These fossils in turn, give a lot of information about specific rock strata. In medicine there is a predictive value in understanding evolution. This permits us to predict probable development of resistance to drugs. In practical entomology, we have a better understanding of the changes that occur to pest insects with environmental change. This helps to design plans to control those insects. And so on.

The thing is that cosmic rays are particles travelling with tremendous energy. Just as it takes more armour to stop a cannonball than it does to stop a tennis ball, so it takes more shielding to stop cosmic rays compared to solar wind. I think you will find that, to simulate cosmic rays in the lab, you will need a powerful particle accelerator. You can buy one of these at your local lab supplies store. Cost about $ 10 billion.

To Astronautical Cosmic radiation is generally high energy ionised particles. Quite a range of particles. Solar radiation simply means any radiation from the sun, and includes particulate and electromagnetic radiation. EM is the main form, and covers most of the EM spectrum. EM, of course, is not ionised particles.

Ionising radiation in space is a real problem. Long term exposure leads to much increased cancer risk. It has been suggested that a round trip to Mars, taking 3 years, will increase your chances of dying young from cancer to 30%. A shield would be very necessary for long term exposure. As stated, water is good, but a lot is needed. Increasing the hydrogen level in your shield increases the protection. Some polymers and hydrocarbons are potentially good. However, the most feasible method, without unacceptable weight increase, is a magnetic shield. NASA researchers are working on that. Don't hold your breath!

scalbers I would be very happy if solar achieves grid parity by 2012. As I said, solar has many advantages, and would be a great addition. Maybe I am just a cynical old reprobate, but I do not automatically believe promises. We have been let down too many times in the past.

scalbers Your article states that solar power is 0.3% of world output. That sounds about correct to me. There is an optimistic suggestion that cost parity might be achieved by 2012. Perhaps. Solar panels would be a fantastic way of solving many of the world's energy problems, if and when the cost comes down enough. I am not holding my breath. In the mean time, there are lots of much cheaper ways of generating electricity.

My apologies. Got my A's and B's round the wrong way. Whoops!

To scalbers All is relative. A cliche, I know, but relevent. Solar energy is far too expensive relative to the alternatives. Current global electricity production by wind is less than 2% but growing. Nuclear is 12%. Most of the rest is coal, gas and hydro. Solar panel generation is way less than 1%. I call that less than significant. If and when solar panel electricity production becomes cost competitive, it too will grow rapidly. Right now it has a 250% cost disadvantage compared to wind, and wind is more expensive than coal or nuclear. I recognise that there are a bunch of solar wannabe's on this thread, but their wishes will not come true until the economics are right. Until then, it is indulging in fantasy.

Swansont Small scale experimental plants do not count. I am talking about normal power grid large scale generation. Even in Hawaii, there are much cheaper sources than solar cells. For example : there are available now small scale nuclear plants, wind generators, probably micro-hydro etc.

In teenagers a lot of hormones do fluctuate quite a bit. Based on your explanation, I would see no reason to assume anything abnormal. If you suffered from those label illnesses, you would be well aware of it. As you mature, you will probably grow out of it. In the mean time, enjoy those happy periods, and try to do something interesting during the sad bits to get your mind off it.

UV is not a single wavelength but a band. For medical pruposes, the band is often divided into two parts, called UVA and UVB. The UVA part of the UV spectrum causes sunburn, and will not pass through glass to any great extent. The UVB part does not cause sunburn but does cause melanoma, and should also be avoided. It has no problem at all passing through glass. For this reason, exposing unprotected skin to sunlight, even through glass, is not a good idea.

Most of this speculation assumes no rotation. However, we cannot assume that. The surface of the Earth travels at about 1000 kph at the equator in the direction of west to east. As you fell, the rotation speed gets less. That means you are going faster west to east than the part of the hole you are falling through, and you will smash into the eastern side of the hole. Thereafter you slide down that side of the hole. Assuming normal friction, you will abrade into hot powder well before you get very deep at all. The only way to avoid this would be drill a straight hole between the poles. You would start out very cold, and as you fell, you would get very hot very quickly! Of course, the pressure even a few kilometres down would be so great, the hole would collapse before it could be dug. If this was a fantasy forum, you could postulate a force field (magic) holding the hole open.

To swansont Sorry. Wrong! Solar panels as a source of electricity are simply more costly than other sources such as coal, gas, nuclear, hydro, or wind power. The big corporations will not use a more expensive alternative for mass generation. I am not aware of any situation where solar panels can generate mass power for the national grid at a cost competitive with the five mentioned above. Though there are situations where the cost does not matter - such as powering lighthouses or other isolated facilities. Solar panels are coming down in cost. But so are some of the alternatives, including nuclear and wind. The absolute cost of generation will not be the deciding factor. It is relative cost that will be the decider. The corporations will go for the cheapest method at the time. It is quite possible that one day that will be solar panels, but it is not likely to be any time soon. Re the use of solar power for electrolysis. Yes, I am aware of that development, which is excellent. However, it is an advance in electrolysis. It is NOT an advance in solar power. Even though the researchers used solar power, there is no reason why a commercial electrolysis plant has to use that compared to other sources of electricity. At current relative costs, it is seriously unlikely that a commercial operation would use solar. They would use the cheapest source of electricity.

My answer to both iNow and Mr Skeptic is pretty much the same. Solar panels are not currently suitable for mass generation of electricity. However, they have many other uses, where cost per kilowatt hour is not critical. The total market for solar panels is already substantial, even if it is still a tiny fraction of the market for mass generation. Even if solar panel cost drops dramatically, it will never be 100% or even close to 100% for electricity generation, for a range of reasons, including the fact that it is of value less than 12 hours in 24. Storing power, such as in batteries, at least doubles the cost of the electricity.

In the reference I originally quoted, solar electricity cost 25c per kwh. Wind 10c. In the graph Mr Skeptic shows, the absolute costs are lower, but the relative costs are pretty much the same. In both cases, solar energy costs 2.5 times as much as wind energy. As has already been pointed out, it is the relative cost that counts. Solar has to get down to the cost of wind energy or better, or else no energy corporation will use it for mass generation.

I am agnostic, so for me the question is akin to fantasy. Anyway, the best answer I read was : "Yes, he could, but he would choose not to." Think about it.

To iNow The original question on this thread relates to the possible impact of technology on human evolution. I doubt the questioner was referring to subtle changes that can be measured only by genomic studies. In that light, when I talk about strong changes, I mean those that can be seen and measured by ordinary people without scientific training or DNA analysis. For example ; the loss of body hair by Homo sapiens is a strong change.

iNow Sure. When solar panels get to 5 to 10 cents per kwHr I will support them. Hell, I'll go out and buy a whole heap and install them on my house. Let's get there first. Your reference was talking about a potential - not something we actually have. Please do not get touchy about the kilowatt hour explanation. Not everything I say on this forum is for your benefit. There are others also reading.

iNow I have told you this before. The 2005 figure is cost of generation of electricity in American cents per kilowatt hour - 25 cents for solar panels. Compare this to coal at 6c, Nuclear at 7.5c, Wind at 10c, or hydro at 5.7c. If solar panels could get the cost down to 10c, comparable to wind power, then we could begin large scale generation. I understand why the cost in Mr Skeptic's graph is dollars per watt, but this is not a good measure for comparing to other generating methods. A watt is a flow quantity. To measure cost per unit energy requires the time factor added in. Hence kilowatt hour.